Author Topic: From no parts to decent stockpile, best approach?  (Read 79556 times)

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Offline alexanderbrevig

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From no parts to decent stockpile, best approach?
« on: August 19, 2015, 08:13:00 am »
Hi again guys, and welcome to the next installment of beginners (played by me) asking the wise and omniscient professionals (that's you) stupid questions.

I'm a software developer trying to get into EE and circumventing 10 years of gathering parts and test equipment.
The first thing I did was build a workbench, and acquire the . Now onto the tedious part; components!

What is the easiest way to get a decent stockpile of components?

My main goal is to be able to prototype most ideas.

Is there something like the (now discontinued) Seeedstudio Open Parts Library but for everything?

I need resistors, caps, inductors, chokes, ferrites, crystals, TVSs, fuses, diodes/zeners/bridge rectifs, transistors, leds, triacs, voltregs, op amps, audio amps, logic ics, optoelectronics, some sensors, wire and connectors.

I'm tempted to make a 'reel to plastic bag' robot and make these kits myself if they don't exist.

Any ideas and pointers are much appreciated!
 
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Offline fivefish

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Re: From no parts to decent stockpile, best approach?
« Reply #1 on: August 19, 2015, 09:13:48 am »
When buying components, (resistors, caps, etc), buy 100pcs of the part. Usually, it's much cheaper per piece than buying 1-2 pcs. only.
Also check out eBay for "set kits"... resistor kit, ceramic caps kit, diode kit, zener kit... you get lots of values (the whole range) with 10-20 pcs for each value.
Electrolytic kits are more expensive, it's better to just order a few extras when you order parts for a specific project. Over time, you'll build a good stock.
If you can afford to wait, you can buy specific parts for a project from eBay (China). Slow shipping though so plan ahead.
If you don't mind re-using parts, salvage parts from broken equipment.
Build a small decade resistor box (using the up/down switch and some smd resistors). Usually in a project, a few parts will be critical in value and if you don't have the right value, a decade resistor box will help in a pinch.
Organize organize organize -- nothing is worse than knowing you have the part, but can't find it in your stockpile.
 
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Offline xrunner

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Re: From no parts to decent stockpile, best approach?
« Reply #2 on: August 19, 2015, 09:28:25 am »
Just wanted to comment - hell of a nice workbench there!  :-+
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Offline michaeliv

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Re: From no parts to decent stockpile, best approach?
« Reply #3 on: August 19, 2015, 11:18:13 am »
Also check out eBay for "set kits"... resistor kit, ceramic caps kit, diode kit, zener kit...
I would recommend AliExpress instead of eBay if you are looking for the lowest price and can wait a bit more ( In my experience electronic components are cheaper ~20-50% on AliExpress than eBay, there's a bigger variety, but AliExpress sellers do take time to ship out items, some ship immediately, some after 1-2 weeks).
 

Offline tooki

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Re: From no parts to decent stockpile, best approach?
« Reply #4 on: August 19, 2015, 11:32:34 am »
I wouldn't recommend trying. You will either have too many of things you will never use or not enough for the next project. They will take up space and time in organising them or even more time if you don't organise them.
Get a resistor and capacitor kit for breadboarding. Buy a few extra parts of stuff you are using. Either they will suit as spares or they fit the circuits you are interested in.

Have a couple of projects in mind and you can order parts for the next one whilst working on the current one.

The real problem is not having enough parts, it is having too many. How much is too much? If you can't carry it to the rubbish bin in one trip you have too much.

Quoted for truth. The only things I stockpile are LEDs, resistors, a basic set of caps, a few basic transistors and diodes, and a bunch of headers and matching connectors. Other than that, I buy as needed. I just haven't found it useful to stockpile components I may or may not need. (It helps that the main components company in Switzerland, Distrelec, delivers next-day, so if I'm really in a pinch I can get it the next day -- or order online and pick up in person.)
 
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Offline rdl

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Re: From no parts to decent stockpile, best approach?
« Reply #5 on: August 19, 2015, 12:38:28 pm »
Yeah, don't think you have to buy a bunch of parts right off just to have inventory. Maybe a resistor kit and a kit of film caps, maybe 5-10 each of common values of electrolytic less than 500uf (you won't need many different values of electros). But anytime you have to order parts, buy a bunch. For cheap parts buy a hundred, more expensive such as logic, micros, regulators etc, try to at least go up to the first price break (usually 10 but sometimes 25).
 

Offline matseng

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Re: From no parts to decent stockpile, best approach?
« Reply #6 on: August 19, 2015, 01:21:59 pm »
Every now and then I pick up some cheap resistors and caps kits just to stock up on some uncommon values I've depleted.  Then I get full reels (for smd) or ammo boxes (for thruhole resistors) of the more commonly used parts.

And I always purchase *a lot* more of the a bit more specialized parts (ICs, power fets) than I actually need, because If I need them today I most likely will use them again in the future.

I also tend to purchase bulk from Taobao for stuffs like header pins, tactile push buttons, plain jellybean indicator LEDs and such.  Like instead of getting 10 pcs of a pushbutton from Element14/Farnell I can get a bag of 1000 of them from Taobao.  Same thing with diffused 3mm LEDs - I can get a bag of 1000 for a few dollars - and they will last a few years - actually the leads on them will be corroded and ugly before they are used up for prototyping and general mucking around.
 

Offline pickle9000

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Re: From no parts to decent stockpile, best approach?
« Reply #7 on: August 19, 2015, 01:31:28 pm »
Order 100 bucks worth every time you order to make the shipping worthwhile. When hitting digikey, farnell / whomever the trick is to keep it down to 100 bucks. 
 

Offline fivefish

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Re: From no parts to decent stockpile, best approach?
« Reply #8 on: August 19, 2015, 03:54:12 pm »
Sometimes you just need jelly bean parts in your lab... 2n3904/2n3906, some 2n3055/mj2955 or equivalents... some n- and p-channel mosfets, some SCRs, to use for prototyping.

Then you can check out performance of your project and make a determination (ooops, need larger power dissipation, or higher hfe, or higher voltage rating) and you go buy that part specifically. (and make sure to order several extras, in case your part becomes damage during experimentation, or for future use).

But at least you've already tried your prototype and know it works.
 

Offline tooki

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Re: From no parts to decent stockpile, best approach?
« Reply #9 on: August 19, 2015, 07:29:27 pm »
And I always purchase *a lot* more of the a bit more specialized parts (ICs, power fets) than I actually need, because If I need them today I most likely will use them again in the future.
Translation: Have extras on hand to replace the ones you fry during experimentation.  ;D :-/O

P.S. I think someone needs to create a "magic smoke" smiley.
 

Offline alexanderbrevig

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Re: From no parts to decent stockpile, best approach?
« Reply #10 on: August 19, 2015, 07:56:20 pm »
Thanks guys :) I know the convention is to buy for each project and then buy a bit more than needed.

Basically you give me two advices; do not buy so you end up with too much, but buy more than you need. I understand the argument that when you buy because you need then you are likely to need that part again.

I will probably end up bying kits for resistors, caps, transistors and diodes, and then make a order with some specific parts as well.

My main goal is to not be hindered when I want to test something, as in - I want to have most "jelly bean" parts on hand.


I will continue to look around for good kits...
Do you think it would be a market for a "no parts to prototype stockpile" kit?

Offline matseng

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Re: From no parts to decent stockpile, best approach?
« Reply #11 on: August 19, 2015, 08:32:56 pm »
And I always purchase *a lot* more of the a bit more specialized parts (ICs, power fets) than I actually need, because If I need them today I most likely will use them again in the future.
Translation: Have extras on hand to replace the ones you fry during experimentation.  ;D :-/O

P.S. I think someone needs to create a "magic smoke" smiley.
And I tend to not use sockets for DIP parts so I can't really re-use them for the next project. And the same goes for SMD parts of course....

And since resistors and jellybean caps and transistors like the BC547 and 2N2222's costs next to nothing I usually just rip them out of my solderless breadboards and shove them into a mixed junkbox that I give away every now and then to school kids with a limited budget for parts.  For me it's too tedious to straighten out and sort the parts into their proper places agin. ^_^
« Last Edit: August 19, 2015, 08:50:53 pm by matseng »
 

Offline JoeN

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Re: From no parts to decent stockpile, best approach?
« Reply #12 on: August 19, 2015, 08:41:10 pm »
Sample early, sample often.   :box:

Didn't your mom tell you to always cut away from yourself?   Please post the video where you slice your other hand open someday. :rant:
« Last Edit: August 19, 2015, 08:43:21 pm by JoeN »
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Offline Deathwish

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Re: From no parts to decent stockpile, best approach?
« Reply #13 on: August 19, 2015, 08:51:52 pm »
An idea for you, put a set of long thin drawers under the shelf you put your rigol kit on and maybe put your scope tips and spare probes in them , manuals , etc.
Electrons are typically male, always looking for any hole to get into.
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Offline JoeN

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Re: From no parts to decent stockpile, best approach?
« Reply #14 on: August 19, 2015, 09:08:43 pm »
My main goal is to not be hindered when I want to test something, as in - I want to have most "jelly bean" parts on hand.


I will continue to look around for good kits...
Do you think it would be a market for a "no parts to prototype stockpile" kit?

This idea of having a large stock of parts was borne out of the era when getting parts was way harder than a next day delivery via an online distributor.  It really just isn't necessary anymore. By all means accumulate part s as you find them but building up a parts inventory is so last century. Every parts collection is 99% destined to never get used.

You'll start out excited that you have all this stuff to do things with and then years down the track you will dispair at the things you don't have time to do. You can't win.

I sort of agree and sort of don't.  Having kits of resistors and capacitors is just a must.  You don't want to have to stop prototyping and wait even 24 hours for a part, especially when it will cost you $25 to overnight a 50 cent crystal or some caps.  That would make me unhappy, so I make sure it doesn't.

Kits to have:

1/4 watt through hole resistor kit.
0805 or 0603 resistor kit.
Through-hole ceramic caps kit  A few hundred of .01uF, .1uF and 1uF are not bad to have because your will use those everywhere and those are very cheap.
Through hole smaller value electrolytic caps kit.
0805 or 0603 SMT capacitor kit.
At least a few hundred 5mm LEDs, a few different colors, red, green, white are probably the best.
At least a few dozen 16Mhz and 20Mhz crystals and a kit of a few each of different values doesn't hurt.
At least a few dozen adjustable and 5V regulators.  Again, a small kit of different values doesn't hurt.
Transistors:  100 each of 2N3904, 2N3906, 2N7000.  Jellybean parts.

You will know what other parts you end up using a lot.  For me it is ATMega328P-PU, ATTiny88, 74HC595, MAX7219 (cheap clone from eBay), certain connectors, hardware and project boards.

But samples are the best.  If you can, get some op amps, comparators, instrumentation amplifiers, 16/24 bit ADCs, 16 bit DACs, digipots, LED drivers, clocks, microcontrollers, etc.  Those are nice to have in the bin.

I think kits like these are just good deals:

http://www.ebay.com/itm/2000-pcs-Assorted-1-4W-0-25W-5-Through-Hole-Carbon-Film-Resistor-Kit-0-10Mohm-/111275963196
http://www.ebay.com/itm/1000pcs-50-Values-50V-Ceramic-Capacitor-Assorted-kit-Assortment-Set-Hot-Sale-/151128848522
http://www.ebay.com/itm/2300pcs-SMD-0805-0-10M-50value-Resistor-2-2pf-1uf-40value-Capacitor-Kit-Set-/110941312626 
http://www.ebay.com/itm/1000Pcs-5MM-LED-Red-Yellow-Green-Blue-White-Round-led-diode-Mixed-Color-kit-/291197363177
« Last Edit: August 19, 2015, 09:14:20 pm by JoeN »
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Offline matseng

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Re: From no parts to decent stockpile, best approach?
« Reply #15 on: August 19, 2015, 09:11:57 pm »
This idea of having a large stock of parts was borne out of the era when getting parts was way harder than a next day delivery via an online distributor.  It really just isn't necessary anymore. By all means accumulate part s as you find them but building up a parts inventory is so last century. Every parts collection is 99% destined to never get used.
That has some truth to it.  But even if I have free overnight courier shipping from Element14 Singapore to my doorstep in Malaysia I still prefer to just swivel my chair around and pick out the parts I need from the shelves behind me.  It's extremely irritating to discover that I have to stop tinkering for a day just because my box of bat54 Schottkys just ran out.  Or just being able to test 5 different stem heights of tactile switches to discover which height that fits best in the 3d printed enclosure.

When I'm in my second living place - Bangkok - I don't have access to overnighters. Stuff usually takes 3-4 days to arrive, then it starts to be really annoying. And unfortunately I just have a really small desk there - my main lab is in Malaysia where I have overflowed into a second room to the wife's dismay . :-)
 

Offline Deathwish

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Re: From no parts to decent stockpile, best approach?
« Reply #16 on: August 19, 2015, 09:12:54 pm »
I have a number of different diodes, resistors , some caps, bridge rectifiers, voltage regs +5/9/12 -12v and lm317T / 337T as a must have set. Always bet a psu will play up somewhere
Electrons are typically male, always looking for any hole to get into.
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Offline Chris C

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Re: From no parts to decent stockpile, best approach?
« Reply #17 on: August 20, 2015, 04:22:02 am »
Organize organize organize -- nothing is worse than knowing you have the part, but can't find it in your stockpile.

I really want to stress this.  The more parts you have, the more critical it becomes.  Give some serious thought to your organizational system.  It may undergo many revisions, with each successive migration taking more time:

1) I started out with those common part organizers, the ones with lots of pull-out drawers, that can be partitioned in half.  They're ok for rapid access to a few parts, but each separate area tends to waste a lot of space.  And they don't travel well!  I took them in the car once, and they got tipped over.  What a mess.  Some drawers opened and parts flew out.  Some drawers got jammed by parts so badly I had to destroy the drawers to remove them.  Parts traveled surprisingly easily between drawers and partitions, getting mixed together.

2) Next system - Plano Stowaway #3600 series boxes.  The specific variety that can be partitioned in up to 24 areas per box.  Apparently not sold separately anymore, included only with a larger organizer that holds 4x boxes, which I also use; if interested, I can look up the model #.  These served me well, and still do.  They travel without issue.  Though each partitioned area may still waste a lot of space.  At some point I got a few hundred smaller hinged-top plastic boxes, cheap via surplus outlet, that fit well and further subdivided the space.  But eventually I ran out, and though I searched extensively, I couldn't find the same item.  All similar replacements didn't fit as well, and were much more expensive.  Also, when my parts collection grew, moving around partitions, boxes, and parts to keep similar items together became quite a chore.

3) I'm gradually migrating to use of a lot of Ziploc-style bags, of many different sizes, some quite small.  These waste virtually no space, if you press the air out before sealing.  Sometimes I don't get all the air out, so I typically poke a little hole in the bags to let the air escape, pressed out by the weight of other bags.  And I have a Brother label printer to make nice self-adhesive labels.
3a) For frequently-used parts, I still use the Plano 3600's.  For example, I have a 3600 for most resistors.  For 1/4W leaded, each partition holds a decade (0-9.9ohm, 10-99ohm, 100-999ohm, etc).  The individual values are kept in bags within the appropriate partition.  I have fewer 1/2W leaded, those get just a couple of partitions with bags.  Another partition for current measurement shunts.  A few partitions for trimmers.  And so on.
3b) For lesser-used or bulky parts, I use a nested bag system.  For example, I have a medium bag for diodes, containing smaller bags for switching, rectifier, fast recovery, varactor, and Schottky; and each of those containing tiny bags for each part # and value.  The medium "diode" bag goes into a Rubbermaid bin for "semiconductors", along with transistors and such (not including IC's, I have enough of those they get their own bin).  Power resistors and large potentiometers would take up too much room in the 3600's, so they all get bagged and binned.

It takes a while to collect many different parts for a project, but at least I always know exactly where those parts are.  The alternative is chaos and a lot more wasted time.

I will also warn against buying random part assortments where the parts are not already sorted/separated and clearly labelled.  No matter how incredibly cheap they may be.  You will put off sorting them.  When (if) you finally do, you will typically find lots of oddball parts and values, that you'll then feel obliged to spend time organizing when it will probably never benefit you.

I bought some SMD ceramic cap and resistor assortments from an Ebay seller.  Each value is on tape, and the value hand-written on the tape.  But not particularly legibly!  I don't regret it, but I had to spend some time relabeling them all, including testing those for which I was unsure.  If I had to do it again, I'd try to buy from a listing that includes a picture showing the seller's handwriting. ;)

For orders from traditional large distributors, I prefer Newark over Digikey/Mouser.  Not just because they're cheaper in general, but because they print part specs in a small square on the invoice, that can be cut out and taped onto something as a useful label.  Big time saver.  They used to include a separate sheet with the same info printed on actual peel-and-stick labels, but I haven't got that with my last few orders; either they stopped doing that, or they do it only for orders exceeding a certain size (my last few orders have been smaller).

Buy some panels of anti-static foam that you can cut down to size as needed.  And some anti-static Ziploc-style bags of various sizes.  You'll need them to repackage ICs and static sensitive discretes that you receive packaged in ways incompatible with your storage system.  Schottky diodes are static sensitive, unless they have an integrated guard ring, so when possible I get the latter to reduce special packaging and handling requirements.

Some useful "jellybean" ICs that I think everyone should have, whether you want them in DIP or SMD (or both) is up to you:
* LM393 (dual) and LM339 (quad) comparators (same specs per each comparator)
* LM358 (dual) and LM324 (quad) op-amps (same specs per each op-amp)
* TL084 quad JFET op-amp
* TL431 shunt regulator

Supplement with special case op-amps as needed.  I like to have a few rail-to-rail varieties on hand, MCP6002 is good for relatively slow signals, MCP6294 is faster; but they are by no means the only options or even clearly superior, they're just what I quickly picked to fill a possible need.  And in fact I've never actually needed them. ;)

For digital work, a variety of 74* series logic ICs may be handy.  In particular, the 74HC family, which seems most useful for interfacing to any other logic family, and isn't too expensive.  But there's still a lot of parts in that family, you'll have narrow it down to what you think you'll use.  If you get into MCUs, and use those with sufficient number of pins that you don't need to multiplex input/output signals, you may never need any of the 74*.

The KIS-3R33S is a tiny 3.3V 3A switching regulator module, available dirt cheap on Ebay and such.  Can be modified for other output voltages via external feedback resistor or modification.  I bought a few dozen of them for something like $0.20 each, love them, and use frequently whenever a switcher shows clear benefit over a linear reg.  Always put at least a 10uF ceramic or low-ESR electrolytic on the output to ensure stability; or if you want low switching noise, use a Pi filter (cap-inductor-cap).

I could go on and on.  You will always find yourself in need of something.  And in trying to prevent that, you will always buy a lot of stuff you will never end up using.  Plus your needs will change as time goes on.  Whenever you think of something you'd like to have, but don't need immediately, put it on a list.  Whenever you need something immediately, evaluate your list, and also order the items on the list you want most; feeling free to leave low-priority stuff on the list.  You may find some things stay on your list a long time, until you decide you really didn't want or need them after all.
« Last Edit: August 20, 2015, 04:27:49 am by Chris C »
 
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Offline Kintekobo

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Re: From no parts to decent stockpile, best approach?
« Reply #18 on: August 20, 2015, 04:47:32 am »
One of the best component buys I made was the RS Components resistor set. Not sure if they still sell them but it is incredibly useful especially when designing and you need to try lots of different values. I just wish that they had made a similar one for caps.
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Offline alexanderbrevig

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Re: From no parts to decent stockpile, best approach?
« Reply #19 on: August 20, 2015, 05:07:19 am »
An idea for you, put a set of long thin drawers under the shelf you put your rigol kit on and maybe put your scope tips and spare probes in them , manuals , etc.

That is an excellent idea!
I'm currently printing some holders for wires and probes but a shelf there for various tidbits would be awesome. Thanks :)

Offline john_p_wi

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Re: From no parts to decent stockpile, best approach?
« Reply #20 on: August 20, 2015, 05:17:15 am »
Chris above has a lot of valid points.  I have been involved with electronics for something like 30 years and work on everything from 100 watt vacuum tube amps using high wattage leaded components to SDR radios using SMD components and micro processors.  Whenever I order anything I try to order a few extra pieces to meet the first price break, that being said, the true challenge will be organizing the components and remembering what you have.  My method seems to be similar to Chris's and I tend to group like components in small envelopes / storage containers then box the groups and shelve.  Additionally IF you order from places like mouser you can export a spread sheet of your order allowing you to build a simple inventory spread sheet so you don't continue to order, order, order.
 

Offline alexanderbrevig

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Re: From no parts to decent stockpile, best approach?
« Reply #21 on: August 20, 2015, 05:26:25 am »
Awesome posts guys!

RE: stocking up, I live in Norway and because of all the taxation (and my extreme impatience when excited by a new idea) I want at least some stock on hand. I won't go crazy with it, but I want to be able to build some simple stuff and fix typical things when I want to :)

In terms of organization I use the drawers at work for proto and I've grown the habit of pulling them out entirely and place them on my desk. It's a ritual when I ponder and plan while I get the parts. Not the best way, but it's how I do it now. I label each drawer ex "47 R" which contains 4.7 47 470 4.7k in that drawer.

SMT parts I'll store in those 'ice cube trays' with lids, and some in air tight zip lock bags for MSD stuff. Most projects will buy MSD in 'exact' quantities so I don't get popcorn when reflowing...

Thank you @JoeN for concrete suggestions! They are added to my excel sheet (I'm not usually this ... pedantic but I'm having fun with this. Might as well as my hopes for a complete stockpile kit seems hopeless (need to keep my spirits up).

@john_p_wi Keeping inventory seems like a really nice idea! Do you know if there is a tool (there's an app...) for that? The software developer in me awoke ;)

Offline Chris C

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Re: From no parts to decent stockpile, best approach?
« Reply #22 on: August 20, 2015, 05:31:24 am »
One of the best component buys I made was the RS Components resistor set. Not sure if they still sell them but it is incredibly useful especially when designing and you need to try lots of different values. I just wish that they had made a similar one for caps.

Sets like those seem nice at first glance.  But I've always avoided them for two reasons:

1) They're pricey, mostly due to including their own custom organizer.
2) What happens when you also want to stock a value not included in the original set?  No place to add it in an organizer like that.  So you're stuck with keeping two organizers - theirs and one of your own.  And every time you check their organizer, then find you have to check the other, you will wish you had all the resistors together.  Eventually the series of small frustrations may add up enough that you decide to consolidate, and then their organizer (and the extra money paid for it) is wasted.

It looks like RS' current offering is different, being based on pages that fit in a three-ring binder, each containing 24x pockets.  That might be expandable.  Still rather expensive.  I've spoken to a lot of people who use cheaper DIY versions, using trading card holder pages if I remember correctly.  Though I've never used that system either.  The first and natural tendency is to keep resistors in ascending order without gaps, but then when you go to insert a new value, I'd imagine shifting EVERY component and label following it is time consuming!  Worse if you permanently affixed labels, or wrote them on with a Sharpie.  It's better if you leave gaps to minimize how many components need to be moved.  But leave too few, and you'll still sometimes have to shift a lot of stuff.  Leave too many and it's inefficient, and those binder pages aren't exactly cheap either.  I considered this system, but found myself indecisive how best to set it up, until I abandoned the idea for my current system instead which never requires shifting.  Others might be perfectly happy with it though, there's no one-size-fits-all solution.
 

Offline Chris C

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Re: From no parts to decent stockpile, best approach?
« Reply #23 on: August 20, 2015, 05:50:55 am »
Keeping inventory seems like a really nice idea!

It is.  I don't keep an exact count of how many of each component I have on hand.  But being able to pull up what components I have is really nice.

For example, I'm designing a final PCB, for something I earlier prototyped using through-hole components.  But on the PCB, I'm using SMD components.  I'm adding a cap to the layout.  I *know* I have the cap in stock, as it's a common value.  But are the SMD 10uF ceramic caps I have 0604 or 0805 footprint at the required voltage?  Darn, I can't remember, and the prototype next to me is through-hole; so I'll have to go look through my SMD parts.  Repeat many, many times, unless you have a database. ;)

When I go to build the PCB, then I pull the actual part.  And if I notice I'm running low on that cap, I add it to the list for my next order.

For the inventory, I just use a general-purpose database.  Microsoft Access, it's a familiar program, as I used to do development in it.  Not sure what's out there in terms of programs dedicated to this task.
« Last Edit: August 20, 2015, 05:52:48 am by Chris C »
 

Online rx8pilot

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Re: From no parts to decent stockpile, best approach?
« Reply #24 on: August 20, 2015, 05:53:09 am »
My approach, starting about 2 years ago was to get only resistors and capacitors in 0805 SMT kits. They were from DigiKey and I got about 250 of nearly all the 1% values and a much smaller selection of caps since they have so many more specs to consider. I went mainly with 50v for the small ones and 25v as they got higher. Tried to stick with X7R when possible. The reason for the 1% and X7R was that I did not want a poor performing cap  in-between resistor to slow me down. They are so cheap that it was not so bad and I have been very happy having a big variety.

For other components, I could not make any sense out of random buys. When I did a new project, I always buy alternates and extras that get added to the collection in the end. After two years, I have a solid stash of useful parts that I am already familiar with and have probably used before. I have examples of a few hundred types of parts to get me through my late night ideas.

How challenging is it for you to have access to parts?
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Offline alexanderbrevig

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Re: From no parts to decent stockpile, best approach?
« Reply #25 on: August 20, 2015, 06:39:35 am »
Let me show you what I've got so far (and you also get to see how the prices per order skyrocket):



So, an order of $275 becomes $434 for me. This is fairly typical and as I tax on shipping I save money if I can keep the number of shipments down. I am probably going to add a bit more bags of ICs, just some 'jellybean' stuff.

I'd probably save a lot by taking the time to manually order each part but I'm not sure I want to spend the time...

@Chris C, at work we use a fab house that provided us with a set of symbols which linked into their registry for parts. Maybe I could do something like that... Then I could have CAD (not sure CircuitMaker allows plugins) help me manage count.

EDIT: I just found this; http://demo.partkeepr.org/ and it's open source :)

BTW: I'm still very much learning. I have some grasp on the theory now but I'm looking to experiment and build up my intuition. That's why I want breadboardable components at hand. I mean, I've never even built an astable 555 timer circuit, though I know the math. I'm weird like that.

STM stuff I'll order per project and try to do inventory in some way.
« Last Edit: August 20, 2015, 07:09:26 am by alexanderbrevig »
 

Online rx8pilot

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Re: From no parts to decent stockpile, best approach?
« Reply #26 on: August 20, 2015, 07:21:52 am »
I would say that before you pull the trigger - consider 3-4 simple projects that you would like to get through and see if you have enough stuff to do it.

A small audio amplifier, a power supply, LED dimmer, LED chaser, etc. They only take a handful of parts but I don't think you could finish much with what is on your order. For me, there is nothing more satisfying and motivating than finishing a project.
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Offline tooki

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Re: From no parts to decent stockpile, best approach?
« Reply #27 on: August 20, 2015, 08:37:42 am »
Alexander, for many of those things, unless you're in a hurry, I'd suggest buying them from China via FleaBay, just due to price. (But get the PanaVise and some solder and solder wick from amazon. Look at the MG Chemicals and Kester products.)
 

Offline JoeN

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Re: From no parts to decent stockpile, best approach?
« Reply #28 on: August 20, 2015, 08:39:21 am »
Organize organize organize -- nothing is worse than knowing you have the part, but can't find it in your stockpile.

I agree on this.  I keep an enormous inventory list in a spreadsheet.  It may seem like overkill but it helps in finding parts since I not only put in the part number but also the Digikey description (or alternate description if Digikey does not carry it) 2180 lines total.  This is not even including the separate spreadsheet of samples.

The quantities are almost never correct.  Just a rough idea and I update it if I have to buy more but rarely decrement it correctly.



« Last Edit: August 20, 2015, 09:04:17 am by JoeN »
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Offline ez24

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Re: From no parts to decent stockpile, best approach?
« Reply #29 on: August 20, 2015, 09:16:48 am »
Organize organize organize -- nothing is worse than knowing you have the part, but can't find it in your stockpile.


I could go on and on...........

I wish you would - there is so much wisdom there that I think your message should be a sticky.

I use the baggie method thinking someday I would get a more advance system.  I think I will stay with the baggie system.  I use Costco part boxes to put them in.

I also use a label maker but until I make labels I use Post-It tape, I like yellow.

http://www.amazon.com/Post--Labeling-Cover-Up-Inches-658/dp/B00006IF84/ref=sr_1_1?&ie=UTF8&qid=1440025640&sr=8-1&keywords=post-it+tape

I totally agree with using Aliexpress for parts kits and those that are sorted and labeled.  I started with the cheapest un-sorted kits and regret it now.  I pay more for labeled kits now.

Now to re-read Chris C's response - thanks Chris
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Offline ez24

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Re: From no parts to decent stockpile, best approach?
« Reply #30 on: August 20, 2015, 09:38:42 am »
Quote
EDIT: I just found this; http://demo.partkeepr.org/ and it's open source :)

Looks interesting but the horsepower needed is a little too much for me

https://www.partkeepr.org/download/

Quote
You need a web server like Apache2 with PHP5.3 or higher and a MySQL database.

But looks like a good Apache, PHP, MySQL project.
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Offline JoeN

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Re: From no parts to decent stockpile, best approach?
« Reply #31 on: August 20, 2015, 09:42:47 am »
That database system is just way the F overkill unless you are running some sort of company and need a multi-user system.  And what the hell ever happened to a nice client-server desktop app?  All the server dependencies go away if you keep it simple.  But for me just putting it in Excel works out the best.
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Offline fivefish

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Re: From no parts to decent stockpile, best approach?
« Reply #32 on: August 20, 2015, 10:01:34 am »
For SMD, little SMD containers in groups, then stored in it's own drawer.
For TH, zip bags inside zip bags inside zip bags (a'la Inception)











« Last Edit: August 20, 2015, 10:03:23 am by fivefish »
 

Offline sleemanj

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Re: From no parts to decent stockpile, best approach?
« Reply #33 on: August 20, 2015, 11:23:53 am »
Don't fall into the trap of buying packs of assorted resistors or (especially) transistors from china IMHO, you always end up with most of it sitting in the drawer and probably being thrown out when you die, or items that are so similar you sit there for ages figuring out which would be "best" to use, when frankly any random one would have done the job.  Keep it simple, give yourself fewer choices not more.

For example, I don't keep a full selection of resistors, I don't need them, but the values I do keep are sufficient to do the job...

  Through hole 1R, 10R, 100R, 1k, 10k, 100k and a couple of other "typically good for led [and zener] limiting" values 240R, 330R, and some 0R for diy pcb purposes.  I don't use through hole much, so this rather course selection is fine.

  Surface mount, 6 decades of each these 1, 1.5, 2.2, 2.7, 3.3, 3.9, 4.7 and 5.1 (ie, 1R, 1.5R, 2.2R .... 10R, 15R, 22R .... 100R, 150R, 220R .... up to 100k, 150k, 220k...), also 1M, 0R and some useful led-limiting-values  20R, 180R, 240R, 300R, 360R, 430R.  I store these in pill organisers and use 1206 size.  If I need other values I use the resistor paralleler to get the ones I need

  Add a few trimpots also, multi turn (3296 style) and single turn.  The values aren't that important, 100R, 500R, 1k, 10k, 100k.  Something like that.  I use smd single turn.

  Capacitors: 100nF, 22pF, 10uF, 100uF, 1000uF, and that's about it for general digital purposes where you are looking to decouple, or filter power supply rails mainly - but I don't do analog stuff, if you did, a bigger selection is warranted.

  BJT: 2222, 2907, 3904, 3906 (all in SMD variants) and that's it.  Add some ULN2003 darlington drivers, they come in handy occasionally.
 
  MOSFET: One N channel and one P channel which have logic-level-suitable gate drive requirements and a reasonable current capacity (low RDSon).  Personally I use Si2302SD, AP2305, and for less demanding situations the good old 2N7002

  Diodes: 1n4007 (or 4004, whichever is cheaper at the time), 1N5819.  That's about it, anything more "exotic" buy as needed.

  Zener Diodes:  5v1, 3v3 for obvious slap-dash regulation reasons.  5v6, 3v6, 6v8, 15v for protecting against over voltage on various things (IC pins, mosfet gates).

  LEDs: 5mm assortment, 3mm assortment, smd assortment (I use 1206 size).

  Regulators: 5v, 3v3, 12v, and adjustable, in both through hole (LM78xx, LM317) and smd (various, I use 1117 series).  Also, a few cheap DC-DC converter modules from China in your drawer can save the day.
s
  As for IC's, apart from the ULN2003 already mentioned, 74HC595 and 74HC166 shift registers, 74HC4051 analog switch, *324 op-amp or other fairly generic quad op-amp, optoisolator (EL817/PC817/LTV817 are common for through hole, EL357 for SMD), maybe  some 4049/4050 hex buffers (useful for level shifting).  And of course most important of all in the modern world, microcontrollers - whatever one floats your boat.  I wouldn't bother with many other IC's than those for general on-hand supply.

  Various hardware also I like handy:
  5.5/2.1mm DC barrel plugs and sockets (panel and pcb mount, get round panel mount ones, easier to fit!). 
  Rocker switches for panels (power mainly), double throw best to maximise your options.
  Toggle switches for PCB and panel, dpdt ones to maximise your options.
  Standard 6mm tact switches, through hole and/or smd depending on preference.  Some 12mm ones too can be nice. 
  A few panel mount pots and encoders if you come across them cheap, or just buy as you need.  Again, with the pots, KISS, one value, maybe 2.  Don't forget to have some cheap plastic knobs to fit them.
  Insulated crimp terminals, bullets or spades as long as they are fully insulated.  Ring terminals too (eg for ground connections).
  Wire, get a good length of rainbow ribbon cable (comes in various widths from china in 10 way repeating colour sequence), a couple spools of general hookup wire in the AWG26-30 range, and some thicker stuff around say AWG20.  Some twin core (figure-8) red+black would be nice too.
  Misc small self tapping / wood screws, nuts, bolts in small metric sizes.
  And of course loose alligator clips, test hooks, and banana plugs make it easy to make an extra test lead when you need it.
  A generic relay rated for your mains voltage also handy.
« Last Edit: August 20, 2015, 11:31:55 am by sleemanj »
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Offline ez24

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Re: From no parts to decent stockpile, best approach?
« Reply #34 on: August 20, 2015, 11:27:21 am »
Were test leads mentioned? 

The first "thing" that stopped me experimenting was the lack of leads,  alligator to alligator and alligator to banana.

Made up test leads from China are really really really crap and not worth any penny paid. They are 66 ga wire pressed to the metal clip that have a 1 ma load capacity.  Better to use your fingers.
So far these have been my only total Chinese failure.

I bought clips on ebay (and it was hard to find good ones) and made up my own leads with different size wire (12ga to 18 ga).  I had to get banana ends from china but I soldered them to the wires.

So another thing maybe not mentioned is --->  wire

FYI since I am in the US I was able to find Radio Shack alligator clips.

Also with some of the cheap ass china leads, I could not even squeeze the clip because the metal clip would slide around in the plastic.

Since you have a good GF go for the Pomona leads.

Anyway a good practice to use your new solder station is by making test leads.  ie soldering the wires

Enjoying this topic, thanks for starting it  :)
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Offline Chris C

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Re: From no parts to decent stockpile, best approach?
« Reply #35 on: August 20, 2015, 02:44:05 pm »
So many good suggestions, yet a few things still virtually untouched upon:

HEADERS

I stock plenty of 0.1" straight single-row 40-pin snappable male headers, and fewer dual-row, both in common black.  They let you build up any male header of any size you want on a PCB.  Before soldering header segments which are adjacent but disconnected, attach female headers to them, as that holds them straight in relation to each other.  And keeps you from burning fingers on exposed male pins.

More recently, I started stocking a few single-row in white too.  I've found them handy to visually mark certain pins.  Supposedly the plastic part of the header is nylon, and easily dyed from white to any color one might need on a whim; but I haven't gotten around to trying it.

"Snappable" female headers really aren't.  They don't snap cleanly, and they're even a pain to cut cleanly.  More recently I've started getting small ones (like 1x2, 2x2, 1x3, and 2x3) so I can build up what I need without ever having to cut.  Plus 2x4, but only because I actually use that frequently.  Again, when combining multiple female headers together, I put male headers into them before soldering, to ensure perfect alignment.

You can buy the crimp tool, male/female pins, wire/ribbon cable, and empty plastic shells to make single or multipin jumpers yourself.  And I have all these.  But I found it's time consuming, requires some practice, and doesn't always look that great.  More frequently I just end up using these:



In M-F, M-M, and F-F, each in both a short length for intra-board connections, and a long length for intra-board connections.  You can tear them apart as needed, or not.  Only complaint is that if you leave multiple wires connected for a tidy multi-pin jumper, it looks like Rainbow Brite puked all over your project, clashing with any single pin wires/jumpers you deliberately color-coded.  I've contacted several manufacturers begging for these in some neutral color like gray or black, but so far no one has done it.

SCREW TERMINALS

These things:



Get a stack of the two and three pin varieties.  They snap together securely, so you can build up any size terminal block you want, and not bother larger ones.

SPECIALTY CONNECTORS

If you want one or two of a large variety of connectors on hand "just in case", try 4UCON, at www.4uconnector.com.  They're a manufacturer, with a huge variety.  Sign up and you'll be able to order samples of many of them, from one up to a limit which differs with each part.  I went a little crazy.  Fair warning, shipping cost goes is inflated and goes up with every part, and it took 6 weeks for them to even ship.  But even including shipping it came out cheaper, per connector, than if I'd bought all those connectors anywhere else.  This is where Sparkfun gets many of their connectors, adding a 500-800% markup (based on sample prices, they probably pay less by buying in quantity).

WIRE

Yep, humble wire.  Solid, stranded, a few different gauges.  But I also like to color-code my wires, and also keeping a decent selection of wire colors would make the number of wire types needed go sky high.  Except I realized that I typically only need each end of the wire color coded.  A $10 heat shrink tubing kit, with a variety of colors and diameters, allows me to easily do that.
 

Offline Neganur

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Re: From no parts to decent stockpile, best approach?
« Reply #36 on: August 20, 2015, 03:22:44 pm »
I would heartily recommend only to buy what you need for your current project. The rest just sits around and collects dust.

Also avoid spending so much time on planning component storage/sorting stuff. Spend it on the project :) collect stamps or coins if you feel the need to catalogue stuff, it quickly escalated into "must have all the EXX values" without any real need.
 

Offline ez24

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Re: From no parts to decent stockpile, best approach?
« Reply #37 on: August 20, 2015, 03:24:13 pm »
Quote
HEADERS

+1

If I remember right the OP mentioned that his GF is letting him buy this stuff  so.....

my suggestion to the OP is buy everything mentioned hear while you can get it and mention to your GF that everyone "told" to you that you HAD to get all of this stuff.  You may not be able to get it later.

Also mention this will allow you to make more money in the future.

Everyone here is talking like they are masters of their own domains (lucky them).
« Last Edit: August 20, 2015, 03:42:09 pm by ez24 »
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Offline sleemanj

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Re: From no parts to decent stockpile, best approach?
« Reply #38 on: August 20, 2015, 04:46:45 pm »
So many good suggestions, yet a few things still virtually untouched upon:

HEADERS

I stock plenty of 0.1" straight single-row 40-pin snappable male headers, and fewer dual-row, both in common black.


Oh yes, how did I forget headers! 

I keep plenty of straight single row male and female 2.54mm (0.1"), if i need a dual row I just use two singles. 

Also have low profile and normal profile single male right angle (aka long-block and short-block), single row female right angle, double row right angle male. 

Rolled pin/machine pin headers in female, and also male, the female ones work for IC pins if necessary, and the pair work as a lower-profile and more easily top-solderable interconnect.

And a few different colours of male single straight.

Also shorting links (jumpers), in different colours.

Quote

"Snappable" female headers really aren't.


Normal female headers are easy to cut to length, yuou lose one pin, just score along the Nth+1 pin, snap, and then clean the cut end by whittlin' like you're Jed Clampett sitting on your porch.

Quote
More frequently I just end up using these:




If you get some dupont wires like these, get a selection of dupont shells also, I keep 1x2, 1x3, 1x4, 1x5, 1x6, 1x8, 1x10 and 1x20, if I need a 2x, I'll just superglue two 1x togethor.  The 1x1 aleady on the dupont wires is easily slipped off, just use a pin or your thumbnail to lift the tab.
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Offline alexanderbrevig

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Re: From no parts to decent stockpile, best approach?
« Reply #39 on: August 21, 2015, 06:51:22 am »
Thank you all so much!

I realized that if I placed orders that amount to $40 then I would not need to pay tax on it. Rules are weird...

So, I ended up ordering kits and assortments from ebay, in individual purchases. It took some time, but I think I should be able to make most of the really simple beginner circuits when the parts arrive.

I'm excited! Also, very grateful for the awesome ideas and responses from you  guys. Thanks :)

Offline JoeN

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Re: From no parts to decent stockpile, best approach?
« Reply #40 on: August 24, 2015, 02:07:55 pm »
Thank you all so much!

I realized that if I placed orders that amount to $40 then I would not need to pay tax on it. Rules are weird...

So, I ended up ordering kits and assortments from ebay, in individual purchases. It took some time, but I think I should be able to make most of the really simple beginner circuits when the parts arrive.

I'm excited! Also, very grateful for the awesome ideas and responses from you  guys. Thanks :)

That's great.  When I order kits from eBay sellers, so many throw in the shipping and it is very cheap.  Like the stuff I linked earlier, that is how I acquired most of my small passive parts, hardware, headers, etc. - $2 to $20 a time from a large number of sellers.  I have no loyalty, I find when I need and buy it from the cheapest guy - most of the sellers are selling the exact same items out of Chinese mega markets.
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Offline Stonent

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Re: From no parts to decent stockpile, best approach?
« Reply #41 on: September 21, 2015, 09:15:44 am »
Sample early, sample often.   :box:

Didn't your mom tell you to always cut away from yourself?   Please post the video where you slice your other hand open someday. :rant:

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Offline tooki

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Re: From no parts to decent stockpile, best approach?
« Reply #42 on: September 22, 2015, 05:32:23 pm »
I realized that if I placed orders that amount to $40 then I would not need to pay tax on it. Rules are weird...
You'll also find that the Chinese vendors invariably write very low customs values, like $3. :)
 

Offline JoeN

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Re: From no parts to decent stockpile, best approach?
« Reply #43 on: September 23, 2015, 06:13:46 am »
I realized that if I placed orders that amount to $40 then I would not need to pay tax on it. Rules are weird...
You'll also find that the Chinese vendors invariably write very low customs values, like $3. :)

Sometimes it's totally justified.   O0

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Offline KL27x

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Re: From no parts to decent stockpile, best approach?
« Reply #44 on: September 23, 2015, 10:43:08 am »
This problem is why Mouser is my first stop for components.

Save projects, BOMs, and any part you have interest in to your account. Give parts any name or custom ID# you wish. Name your interesting purchases by giving them a unique P.O. (Project X) so you can find them easily in your purchase history. Share your projects or BOMS with partners, manufacturers, etc with an email link.

Any project that requires volume is straight to mouser/Newark/digikey and then sort by price, anyhow.

Self restraint goes a long way. I have binned a lot of my early "stockpiles," and if I had any common sense I have a bunch more that would be headed to a landfill.

I keep an assortment of SMD resistors caps and SMD LEDs in a test tube rack. I keep one SOT 23 logic PFET, one SOT23 logic NFET, some SOT23 pnp and npns. 1 type of Schottky on hand, some boost converter ICs and inductors, some piezos. USB connectors (for power, more than for actual USB). Pin headers, tac switches. Basically just the stuff to build the brains of a circuit. For any major power handling, I scrounge/salvage/order. Don't get me wrong, I got a lot more stuff, but it's not that I would have to go out of my way to collect it.

 

« Last Edit: September 23, 2015, 11:05:08 am by KL27x »
 

Offline nbritton

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Re: From no parts to decent stockpile, best approach?
« Reply #45 on: September 24, 2015, 07:41:00 pm »
During the through hole years as a teanager the only thing I stocked were the parts I pull out of dead equipment. I had a large bin of dead equipment that people would give me for free and a disordering iron.
 

Offline nzo

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Re: From no parts to decent stockpile, best approach?
« Reply #46 on: September 28, 2015, 08:31:08 pm »
I wouldn't lose any sleep over "what will happen to my unused parts when I die?".

Just buy a little stock from Ebay or AliBaba. So what if you don't use it! Leave a note in your will and GIVE all your  parts etc to local school electronics enthusiast(s).

I don't understand experimenters who line the pockets of overpricing suppliers like RSComponents, Mouser, Digikey etc. Why spend $200 or $400 when you only need to spend $20 or $40? Guess where they get their components from! Of course if you're wealthy you probably don't give a damn.
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Offline matseng

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Re: From no parts to decent stockpile, best approach?
« Reply #47 on: September 28, 2015, 09:22:37 pm »
I don't understand experimenters who line the pockets of overpricing suppliers like RSComponents, Mouser, Digikey etc. Why spend $200 or $400 when you only need to spend $20 or $40? Guess where they get their components from! Of course if you're wealthy you probably don't give a damn.
Are you seriously suggesting that the three companies you mentioned gets their parts from the Huaqiangbei market in Shenzhen or similar places and not directly from the manufacturers?
 

Offline wagon

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Re: From no parts to decent stockpile, best approach?
« Reply #48 on: September 28, 2015, 10:33:57 pm »
I've got lots of parts in drawers, many in compartment boxes, some in open boxes.  Chinese food containers are useful too.

An assortment of nuts & bolts is a must if building stuff, and various headers, etc.  I've gotten lots of good stuff out of 'grab-bags', junk-boxes, etc. over the years.  I sit on the floor at home and sort them, them stuff them back into the car and take them back to my workshop.
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Offline madires

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Re: From no parts to decent stockpile, best approach?
« Reply #49 on: September 28, 2015, 11:03:31 pm »
As a teenager I bought "surprise bags", i.e. overstocked parts from production lines and such stuff. Those bags were quite inexpensive and comprised a lot of common parts used back then and some special components. IIRC, mostly Philips. BTW, good training for learning color codes ;)
 

Offline wagon

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Re: From no parts to decent stockpile, best approach?
« Reply #50 on: September 28, 2015, 11:43:48 pm »
As a teenager I bought "surprise bags", i.e. overstocked parts from production lines and such stuff. Those bags were quite inexpensive and comprised a lot of common parts used back then and some special components. IIRC, mostly Philips. BTW, good training for learning color codes ;)
Sometimes goodies found in  those bags of stuff give you inspiration to build stuff, too.
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Offline ez24

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Offline obiwanjacobi

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Re: From no parts to decent stockpile, best approach?
« Reply #52 on: October 01, 2015, 02:34:22 am »
Stock-piling is so last century. Just order what you need for a project...
I order my stuff on ebay - cheap but long wait - or at Farnel - not so cheap but only a couple of days away (no shipping cost).

[2c]

Offline stevenhoneyman

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Re: From no parts to decent stockpile, best approach?
« Reply #53 on: October 01, 2015, 04:56:39 am »
Stock-piling is so last century. Just order what you need for a project...
I order my stuff on ebay - cheap but long wait - or at Farnel - not so cheap but only a couple of days away (no shipping cost).

[2c]

Avoiding stock-piling isn't possible really... I mean, unless you intend to try and buy individual resistors etc then you'll probably have 198 of them left over from a $1/£1 piece of cut tape from ebay.

I'm not saying that's a bad thing, it's what I do!
 

Offline alexanderbrevig

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Re: From no parts to decent stockpile, best approach?
« Reply #54 on: October 01, 2015, 09:46:06 am »
Stock-piling is so last century. Just order what you need for a project...

Then please make a list for what to order when the project is "learn electronics (and make stuff along the way)" ;)

Offline obiwanjacobi

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Re: From no parts to decent stockpile, best approach?
« Reply #55 on: October 01, 2015, 02:59:20 pm »
You don't learn electronics by having a bunch of parts in your home. You learn it by doing simple projects (at first) to see/understand how they work and build from there. You really start with a battery, switch and light-bulb (ok LED and resistor).

And I am not saying you should not have a small assortment of resistors and caps (and some small diodes) at hand - of course that makes sense. But that is like 20 or 30 different parts (say 5-10 each) and doesn't cost a lot of money. The rest you buy when needed. My parts cabinet is a "cookie-jar" (it is not really - it is a small box). And of the 3 E12 decades of resistors I bought I mainly use the 220, 1k, 4k7 and 10k.

Also when you're starting - its no use to buy SMD components. Buy a bread-board and through-hole stuff. When you start doing your own PCBs (or start repairing stuff) then is the time to think about SMD.

I know it is the "norm" to have a huge stockpile of stuff - but most of it you will never use (saw it in Dave's latest clock video - he had old 70's and 80's logic ICs that he never touched). That "money" is just sitting there doing nothing. Bad investment if you ask me.

In the end you decide. Do what you think will work for you. Change it if it doesn't. But start small and build up from there.

[2c]

Online rx8pilot

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Re: From no parts to decent stockpile, best approach?
« Reply #56 on: October 03, 2015, 12:12:51 pm »
You don't learn electronics by having a bunch of parts in your home. You learn it by doing simple projects (at first) to see/understand how they work and build from there. You really start with a battery, switch and light-bulb (ok LED and resistor).

I agree. My efforts were focused on creating a project or project series and gathering the parts most likely to be needed for that AFTER I had gone through some design efforts.

It only takes a handful of small projects to get a feel for what you should have on hand. You will always want passives a few values up/down from the usuals.
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Offline wagon

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Re: From no parts to decent stockpile, best approach?
« Reply #57 on: October 04, 2015, 01:29:24 am »
You can also rat old machinery and stuff for good bits.  For example, I ratted a huge photocopier today.  I scored a 5V 20A power supply, a 24V 31A power supply (has M6 bolts for output terminals!),  various beautiful DC motors with shaft encoders and a great big pile of driver boards.  No doubt there's good bits in all that crap.  I might start a thread about it.
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Online rx8pilot

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Re: From no parts to decent stockpile, best approach?
« Reply #58 on: October 04, 2015, 04:13:46 am »
  I scored a 5V 20A power supply, a 24V 31A power supply (has M6 bolts for output terminals!),  various beautiful DC motors with shaft encoders and a great big pile of driver boards.  No doubt there's good bits in all that crap.  I might start a thread about it.

24v @ 31A is no joke! You can make a little welder with it.
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Offline karoru

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Re: From no parts to decent stockpile, best approach?
« Reply #59 on: October 04, 2015, 11:21:35 am »
24v @ 31A is no joke! You can make a little welder with it.
He just should make sure that contacts are good before testing overload protection, unless that screw connection is going to be permanent;) It reminds me when my father wanted to check how does the voltage from new shiny IGBT arc welder works. He used my old Philips scope and el cheapo 60 MHz chinese Uni-T probe but didn't notice that this thing has that ground ring on it. After a bit of meddling with the uncovered probe tip around the big red hole with ground alligator clip in the black one, it made beautiful sparks. Funny thing is that this probe after getting 180A current through it still works a treat... Plastic and a fragment of ring melted but besides that no problem whatsoever.
 

Offline wagon

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Re: From no parts to decent stockpile, best approach?
« Reply #60 on: October 04, 2015, 11:47:01 am »
I was thinking more along the lines of trimming the output voltage to 28.8V and making into a big battery charger.  Should pump up a mobility scooter battery from dead in no time.
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Offline bumba000

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Re: From no parts to decent stockpile, best approach?
« Reply #61 on: October 15, 2015, 05:27:10 pm »
I've been tearing into everything. Old computer power supplies, 120 to 12v converters, LCD monitors, video cards, sounds cards and a cable TV remote control. Also spent $80 at radio shack last week for a bunch of resistors, diodes, pots, bread boards and some conductive glue stuff. Not sure what I'll do with the conductive glue but I thought it was pretty cool and it was on clearance so I bought both on the peg. I'm a sucker.
 

Online blueskull

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Re: From no parts to decent stockpile, best approach?
« Reply #62 on: October 19, 2015, 02:09:33 pm »
I don't stock parts at all, with a few exceptions:

a. 0.1uF, 1uF, 2.2uF, 10uF, 33uF MLCC capacitors for obvious reason -- I will use them in almost all projects.
b. Reference grade parts such as rubidium clocks, OCXOs, I stock them as lab or equipment references.
c. Excessive parts from previous projects.
d. Big boys such as ultracapacitors, batteries, display modules and etc.
e. Boards and kits used from previous projects.

Besides, I stock no parts. The reason behind this is simple - I do SMT designs all the time, so anyway I need to wait OSHPark to deliver my PCB, and in the meantime, I have more than enough time to order things from DigiKey.
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Offline David Spicer

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Re: From no parts to decent stockpile, best approach?
« Reply #63 on: October 31, 2015, 02:22:01 pm »
You wrote a msg to me last month but I was OS and couldn't reply. Sorry. Drop me an email David.spicer@icloud.com re Xilinx dev kits. My post attracted no interest at all so if you want one it's yours. You do know what you are buying I hope. Flags have a steep learning curve though the end result is worth it! Ds
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Offline eugenenine

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Re: From no parts to decent stockpile, best approach?
« Reply #64 on: November 01, 2015, 09:03:20 am »
Places like DigiKey, etc sell assortments.
http://www.digikey.com/product-search/en/kits/resistor-kits/2490615

Years ago I bought small boxes from Radio Shack and the first couple assortments I ordered from DigiKey came in the same size as well.
I started with a resistor and capacitor kit, then when I'd run out of one size I'd replace it with a 100pack.  For example the kit might come with 10 .1uF caps so I'd order 100.

I'm in the process of re starting the hobby again now that my kids are old enough to be interested.  So I'm using some of my old stock and then adding to it.

In the picture you can see the little boxes (opened here holding resistors), there are several inside the toolbox I've had since I was a kid, then I added the (fishing) bag to the right with mechanical parts.

I also saved up and bought one nice big protoboard and seem to have lost it somewhere over the years.  I've now bought a few smaller ones so I can put a project I'm working on away until I get the rest of the parts it needs.

I'd start with a resistor and capacitor assortment, a few regulators, a couple smaller protoboards and wire kits.  Then decide what you want to make and buy stuff specific to that.  For example I'm re-learning PIC's after selling my programmer after college so I bought the Pickit3 and 44 pin demo board and a few other pics and they are in the microchip cardboard box.
« Last Edit: November 01, 2015, 09:22:39 am by eugenenine »
 

Offline SharpEars

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Re: From no parts to decent stockpile, best approach?
« Reply #65 on: December 12, 2015, 02:24:50 am »
Places like DigiKey, etc sell assortments.
http://www.digikey.com/product-search/en/kits/resistor-kits/2490615

Years ago I bought small boxes from Radio Shack and the first couple assortments I ordered from DigiKey came in the same size as well.
I started with a resistor and capacitor kit, then when I'd run out of one size I'd replace it with a 100pack.  For example the kit might come with 10 .1uF caps so I'd order 100.

I'm in the process of re starting the hobby again now that my kids are old enough to be interested.  So I'm using some of my old stock and then adding to it.

In the picture you can see the little boxes (opened here holding resistors), there are several inside the toolbox I've had since I was a kid, then I added the (fishing) bag to the right with mechanical parts.

I also saved up and bought one nice big protoboard and seem to have lost it somewhere over the years.  I've now bought a few smaller ones so I can put a project I'm working on away until I get the rest of the parts it needs.

I'd start with a resistor and capacitor assortment, a few regulators, a couple smaller protoboards and wire kits.  Then decide what you want to make and buy stuff specific to that.  For example I'm re-learning PIC's after selling my programmer after college so I bought the Pickit3 and 44 pin demo board and a few other pics and they are in the microchip cardboard box.

I'm in the same boat. I restarted when the kids got old enough to care. Unfortunately, I have become a packrat and a voltnut in the process. If you knew how many high quality digital power supplies and 6 1/2 digit meters I have, you would feel truly sorry for me.

I mean seriously, here are power supplies I own that even I would consider extreme:

http://www.eevblog.com/forum/testgear/hpagilent-6675a-the-120-v-18-a-2000w-monster-power-supply/msg565113/#msg565113
http://www.eevblog.com/forum/testgear/what-to-do-with-a-4-000-v-power-supply-(plus-mini-tear-down)/
http://www.eevblog.com/forum/testgear/looking-for-goodinexpensive-bench-power-supply/msg546127/#msg546127
http://www.keysight.com/en/pd-836789-pn-6626A/precision-system-power-supply-25w-or-50w-4-outputs?cc=US&lc=eng - Mini teardown coming this weekend...

Don't become a VoltNut, it's a slippery slope and very easy to fall into and it becomes more about the parts and tools you have than the projects you can build. It's very easy to get into a: I need every value available, every tolerance available, every kind available, very low ppm, very low tolerance, etc..., rot.

Coming up with interesting projects to do that is the hard part in making electronics your hobby...
« Last Edit: December 12, 2015, 03:06:11 am by SharpEars »
 

Online blueskull

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Re: From no parts to decent stockpile, best approach?
« Reply #66 on: December 12, 2015, 02:32:09 am »
Will one become a voltnut even after having a 8.5 digit dmm? I mean, there is the ultimate, and you have reached it.
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Offline SharpEars

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Re: From no parts to decent stockpile, best approach?
« Reply #67 on: December 12, 2015, 03:07:07 am »
Will one become a voltnut even after having a 8.5 digit dmm? I mean, there is the ultimate, and you have reached it.

One 8.5 digit dmm may be on the fringe of what is "reasonable." One 7.5 digit, six 6.5 digits and several 5.5 digits (i.e., where I am hailing from) combined with (I've lost count of how) many high end power supplies is definitely VoltNut territory. I've given up on even trying to answer the question, "Why do you need another one?" These things have become like Pokemon cards - you've got to catch them all.

« Last Edit: December 12, 2015, 03:11:24 am by SharpEars »
 

Online blueskull

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Re: From no parts to decent stockpile, best approach?
« Reply #68 on: December 12, 2015, 03:11:00 am »
I will just stop here with a k2002. The intention of buying a k2002 is because it reaches the top, and that means I don't have to buy any better. I don't want to fall in to the pit of voltnuts. 3458 is a different beast, but I don't have big enough bench space for it.
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Offline bapou

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Re: From no parts to decent stockpile, best approach?
« Reply #69 on: December 12, 2015, 04:29:42 am »
Use an inventory managment system:
Since we use partkeepr (open source and free, I'm not related, just a happy user)
https://partkeepr.org/
which keeps track of the parts, the projects, the vendors of the parts etc., live got much easier and
we now have a large accessible stockpile
 

Offline halloween360

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Re: From no parts to decent stockpile, best approach?
« Reply #70 on: December 12, 2015, 04:57:39 am »
When you say that partkeepr keeps track of projects, does this mean it would allow you to update inventory by project?

Example:

Lets say project xyz uses the following:
qty    part
1        a
2        b
3        c

If you were to build project xyz, would it deduct the parts used from your inventory?

 

Offline bapou

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Re: From no parts to decent stockpile, best approach?
« Reply #71 on: December 12, 2015, 08:00:47 am »
yes, it does;
you can choose project report: This reports you what you need for the project and what you have to buy (and shows the supplier + nr's if you want)... and if you click "remove part from stocks" it removes them.

I have it coupled to a label printer (running on a raspberry pi as a printerserver) and this allows to directly to print labels for the parts, but
also for the boxes containing the parts.
 

Offline halloween360

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Re: From no parts to decent stockpile, best approach?
« Reply #72 on: December 12, 2015, 09:24:46 am »
Might have to download and play with this! Thanks for the info!
 

Offline matt.zepess@gmail.com

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Re: From no parts to decent stockpile, best approach?
« Reply #73 on: December 16, 2015, 02:56:54 pm »
Two ways... Buy a hundred pack of every component you think youll need. Or Take some time and hunt for old printers and electronics that you can find for cheap at thrift stores or yard sales and then desolder the parts you want.
 

Offline wonderfulpcb_sales

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Re: From no parts to decent stockpile, best approach?
« Reply #74 on: December 18, 2015, 02:48:13 pm »
I think you need to design a circuit, and then use the electronic component mounting to the circuit board.you can do it! :-+
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Offline VEGETA

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Re: From no parts to decent stockpile, best approach?
« Reply #75 on: February 11, 2016, 07:14:30 am »
where to buy all of these assorted kits and basic essential parts all together from one place? that is the problem I am facing where I am forced to wait a lot to get some resistors and wait another time to get some caps.

Offline rob77

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Re: From no parts to decent stockpile, best approach?
« Reply #76 on: February 11, 2016, 10:04:40 am »
if you want to have a good and useful stock of parts then be prepared for a investment comparable to the price of the gear on your bench. and actually you'll need 2 "sets" of parts - through hole for quick proof of concept circuits on breadboards or stripboards and then SMDs for the final build - PCB area is expensive for one offs if you're not making your own PCBs.

a good practice is every time you order some parts for a project - order more than you need - especially from the common parts you'll use in another projects. and always watch for sale items... it really pays off (e.g. last month i scored IR half bridge drivers for 25 cents a pop - they're going for approx 1 eur in 100 quantities, this month i scored  some nice power mosfets in DPAK for 7 cents a pop)
 

Offline VEGETA

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Re: From no parts to decent stockpile, best approach?
« Reply #77 on: February 11, 2016, 04:32:41 pm »
if you want to have a good and useful stock of parts then be prepared for a investment comparable to the price of the gear on your bench. and actually you'll need 2 "sets" of parts - through hole for quick proof of concept circuits on breadboards or stripboards and then SMDs for the final build - PCB area is expensive for one offs if you're not making your own PCBs.

a good practice is every time you order some parts for a project - order more than you need - especially from the common parts you'll use in another projects. and always watch for sale items... it really pays off (e.g. last month i scored IR half bridge drivers for 25 cents a pop - they're going for approx 1 eur in 100 quantities, this month i scored  some nice power mosfets in DPAK for 7 cents a pop)

where do you buy these? aliexpress? but shipping from china takes a lot, and during this time you may change your mind or your project.

collecting them separately is very hard... I wish there is one way we can use to get all general purpose parts at once.

________

Another topic which is strongly related: CUSTOMS!!!!!!!!!!!!!!!!!!

please tell me how exactly is it in your country? like when you get an oscilloscope or some little parts.

thanks!

Offline JoeN

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Re: From no parts to decent stockpile, best approach?
« Reply #78 on: February 11, 2016, 06:14:11 pm »
In the US I have never had any issue with customs for small parts.  I buy all the time.  No fees at all.  I bought all my equipment in the country, through.

Just a few items I have bought recently from China that came through without problems, usually in about 2 weeks:

http://www.ebay.com/itm/171505067685
http://www.ebay.com/itm/200911914297
http://www.ebay.com/itm/371089057890
http://www.ebay.com/itm/351493804042
http://www.ebay.com/itm/371278122006
http://www.ebay.com/itm/181847022613

Most of these have come in small padded envelopes.  A couple of times I bought a large number of LED displays at a time that came in a big box and no customs that time either.  I don't think anything has ever been opened.  I hope they xrayed a few of them though.  Bought the displays from these guys:

http://www.futurlec.com

A couple dozen of these made for a large box:

http://www.futurlec.com/LED/LEDMVL58R.shtml
« Last Edit: February 11, 2016, 06:19:36 pm by JoeN »
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Offline rob77

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Re: From no parts to decent stockpile, best approach?
« Reply #79 on: February 11, 2016, 08:16:15 pm »
if you want to have a good and useful stock of parts then be prepared for a investment comparable to the price of the gear on your bench. and actually you'll need 2 "sets" of parts - through hole for quick proof of concept circuits on breadboards or stripboards and then SMDs for the final build - PCB area is expensive for one offs if you're not making your own PCBs.

a good practice is every time you order some parts for a project - order more than you need - especially from the common parts you'll use in another projects. and always watch for sale items... it really pays off (e.g. last month i scored IR half bridge drivers for 25 cents a pop - they're going for approx 1 eur in 100 quantities, this month i scored  some nice power mosfets in DPAK for 7 cents a pop)

where do you buy these? aliexpress? but shipping from china takes a lot, and during this time you may change your mind or your project.

collecting them separately is very hard... I wish there is one way we can use to get all general purpose parts at once.

________

Another topic which is strongly related: CUSTOMS!!!!!!!!!!!!!!!!!!

please tell me how exactly is it in your country? like when you get an oscilloscope or some little parts.

thanks!

i'm buying parts from TME http://www.tme.eu/ - no customs as it's within EU  - it's next day shipping.  raw materials for PCBs from http://pcb-diy.com/ (copper clad, riston, dynamask) - it's a local company - so it's again EU and no customs

i'm buying only some extremely jelly bean parts from china -  with those it's unlikely they'll be fake , and some raw materials from china (UV curable solder mask, solder paste) and here and there some modules (relay modules or DC-DC convereters...etc...)
 

Offline Grzegorz2121

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Re: From no parts to decent stockpile, best approach?
« Reply #80 on: February 11, 2016, 10:27:05 pm »
If you want to get few components to start with i recommend to start collecting electro-trash.
These stuff can give you a lot of good components:
-electrolytic capacitors
-power transistors
-huge amount of IC. (regulators, drivers, microcontrolers, logic, opamps)

Now I have good amount of these components from unsoldering!
 

Offline VEGETA

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Re: From no parts to decent stockpile, best approach?
« Reply #81 on: February 11, 2016, 11:25:37 pm »
So there is not way we can get them all together, we have to collect them. However, can anyone lists ALL of these general purpose components so one can revert to his list rather than forgetting half of it xD?

* I bought these:

- PICKit 3.
- PIC16F877A.
- big breadboard.
- resistor set (1280 one).
- cap set (ceramic).
- cap set (elec..).
- 4001-4007 diodes.
- zener diodes.
- PNP and NPN transistors.
- LM358 op-amps.
- 2x16 LCDs (locally).
- breadboard potentiometer set.
- breadboard encoders set.
- jumper wires of all sizes.
- multimeter (cheap uni-t).
- 500 LEDs (5 colors).
- some screw drivers.
- LM317 regulators.
- Shameful retarded soldering iron + solder.


* What I miss and I think it is necessary:

- analog oscilloscope (this is my biggest problem because shipping is a hell = read: donations are welcome xD).
- inductors set.
- MOSFET set (or IGBT).
- TRIACs...
- opto-isolators (don't know what kind).
- power resistors (really useful?).
- thyristors (necessary?).
- some LCDs of different sizes than 2x16.
- What about SMD stuff?! by this, I must get all above parts but as SMD... not to mention its tools!
- transformers!! what kinds and what sizes?!
- Power supply, as I use a phone charger+7805 for now. I got a DP30V2A module which I think it is great but it needs DC input (transformer+rectifier).
- different types of linear regulators like LT3080 and others.
- shotky diodes, still thinking if they are necessary or not.
- switches...
- push buttons...


* What I miss and I don't think it is a must _NOW_:

- STM32 discovery kit.
- PSoC kit.
- TFT LCDs and their driver chips.
- switching supply ICs like those of LTC and TI for building SMPS.
- good and cheap JTAG programmer.


* What I miss and don't think they are necessary:

- digital ICs like flip-flops or such stuff.


please tell me in details what do you think of my list (which I don't think I mentioned all of it). If you have any recommendations please give it to me... Also, is this set can get me to design and prototype practically anything I want (nearly)?


« Last Edit: February 11, 2016, 11:28:35 pm by VEGETA »
 

Offline JoeN

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Re: From no parts to decent stockpile, best approach?
« Reply #82 on: February 12, 2016, 02:35:28 pm »
Some small programmable logic.  Then you can make your own "digital ICs", whatever you want, whenever you want.  These are very cheap for that purpose and you can teach yourself an interesting and useful skill.

http://www.ebay.com/itm/10PCS-IC-EPM240T100C5N-TQFP100-ALTERA-NEW-/171529814418
http://www.ebay.com/itm/altera-Mini-Usb-Blaster-Cable-For-CPLD-FPGA-NIOS-JTAG-Altera-Programmer-/200943750380 

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Offline eugenenine

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Re: From no parts to decent stockpile, best approach?
« Reply #83 on: February 13, 2016, 03:49:58 am »

- analog oscilloscope (this is my biggest problem because shipping is a hell = read: donations are welcome xD).


- inductors set.
- MOSFET set (or IGBT).
- TRIACs...
- opto-isolators (don't know what kind).
- power resistors (really useful?).
- thyristors (necessary?).
- some LCDs of different sizes than 2x16.
- What about SMD stuff?! by this, I must get all above parts but as SMD... not to mention its tools!
- transformers!! what kinds and what sizes?!
- Power supply, as I use a phone charger+7805 for now. I got a DP30V2A module which I think it is great but it needs DC input (transformer+rectifier).
- different types of linear regulators like LT3080 and others.
- shotky diodes, still thinking if they are necessary or not.
- switches...
- push buttons...
 

Offline eugenenine

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Re: From no parts to decent stockpile, best approach?
« Reply #84 on: February 13, 2016, 03:55:51 am »

- analog oscilloscope (this is my biggest problem because shipping is a hell = read: donations are welcome xD).
See if you can find a used one local, you don't need anything fancy to get started.

- inductors set.
I can't recall the last time I used an inductor.  Maybe if you want to build switching power supplies.

- MOSFET set (or IGBT).
- TRIACs...
What are your longer term plans? controlling motors or other big loads? wait until you need them.

- opto-isolators (don't know what kind).
- power resistors (really useful?).
- thyristors (necessary?).
- some LCDs of different sizes than 2x16.
Again what do you want to do, wait until you have a need or want.

- What about SMD stuff?! by this, I must get all above parts but as SMD... not to mention its tools!
Learn to protoboard first then start looking at these when you want to start soldering up something more permanent.

- transformers!! what kinds and what sizes?!
maybe one or two if you want to build a power supply otherwise I never use them.


- Power supply, as I use a phone charger+7805 for now. I got a DP30V2A module which I think it is great but it needs DC input (transformer+rectifier).
If you want to learn to build power supplies or build a nice bench supply otherwise just get a wall wart for the dc input.

- different types of linear regulators like LT3080 and others.

If your getting started maybe a few 78xx or LM317xx but not too many as there are a lot of newer better ones.  I bought a couple of microchips.
- shotky diodes, still thinking if they are necessary or not.
- switches...
- push buttons...

maybe a handful of pushbottons that can fit the protoboard to srart
 

Online boffin

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Re: From no parts to decent stockpile, best approach?
« Reply #85 on: February 13, 2016, 05:26:22 am »
I'm going through this right now.  I agreed to teach a basic electronics course to a bunch of co-workers (all programmers, so heavy on the MCU side), and got them to commit to $10/week for parts for 8 weeks

I then placed thirty-six different orders on Aliexpress for various things (breadboards, ICs, LEDs, resistors, Arduinos, displays etc).

I find that most assortments contain a bunch of stuff I don't need, and not enough of what I do need.   For example, do I need every ten of E12 resistor value?  Probably not, it's more useful to have 30x of every E3 value; can't say I've often gone "damn I don't have a 910k resistor" when I know I have 1Ms in the drawer

But I do echo the sentiment that it would be cool for someone (Franky? Dave?) to sell a beginner component kit that included what you really need.

R:  30ea: 10 Ohm -> 1M Ohm  (E3 series - probably don't even need 30 of 100k+)
C(ceramic):  10ea: 47pF -> 0.047uF (E3 series) + 30* 0.1uF
C(electrolytic): 10ea 1uF -> 100uF , 5ea 220uF -> 2200uF (E3 again)
Semiconductor assortment:  10* of the common stuff 1N4148, 1N4004, 2N7000, 2N4401 (my go-to 3904/2222 replacement),  5* of slightly less used 2N4403, IRLB8721, 7805
...

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Offline VEGETA

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Re: From no parts to decent stockpile, best approach?
« Reply #86 on: February 13, 2016, 11:04:46 am »

- analog oscilloscope (this is my biggest problem because shipping is a hell = read: donations are welcome xD).
See if you can find a used one local, you don't need anything fancy to get started.


I could not get anyone locally, I tried but no one is interested in this. Even my previous university refused to sell me one.

Quote
- transformers!! what kinds and what sizes?!
maybe one or two if you want to build a power supply otherwise I never use them.


- Power supply, as I use a phone charger+7805 for now. I got a DP30V2A module which I think it is great but it needs DC input (transformer+rectifier).
If you want to learn to build power supplies or build a nice bench supply otherwise just get a wall wart for the dc input.

my plan is to use a transformer + rectifier and connect them to the DP30V2A module to get a basic and good power supply. Actually, the price of this module is great for the features that it has. I will do a review of it once I get it. As you said, no need to get pricey stuff from the start.


Quote
- different types of linear regulators like LT3080 and others.

If your getting started maybe a few 78xx or LM317xx but not too many as there are a lot of newer better ones.  I bought a couple of microchips.
- shotky diodes, still thinking if they are necessary or not.
- switches...
- push buttons...

maybe a handful of pushbottons that can fit the protoboard to srart

I got about 20 of LM317 (i think it is the 1.5A version). I really like these good ICs of TI and LTC in the switching and linear power supply field. These custom ICs are more professional and efficient than the traditional LM317 I guess... and I plan to use them to design a power supply in the future. But for now I will stick with LM317.

About buttons, I want a package (ONE PACKAGE) to contain all types of buttons and knobs in it, cuz then I won't be forced to pick each type alone. Do you know one?



now, what is your parts list? how do you get an idea of a project?
____



Side note: I am about to join a local company that is specialized in fixing industrial electronics like Inverters and PLC cards and stuff like that. Do you think it is a good idea?

what 

Offline egeorgiadis

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Re: From no parts to decent stockpile, best approach?
« Reply #87 on: March 04, 2016, 07:58:26 pm »
I just wanted to say how jealus I am :) nice Equipments and nice place...  :-+
 

Offline alexanderbrevig

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Re: From no parts to decent stockpile, best approach?
« Reply #88 on: March 04, 2016, 11:12:54 pm »
I've just stumbled upon something that's a nice addition to the 'stockpile' and that is learning a SPICE.

I've now learned LTSpice and it is so nice being able to test things out before deciding what's needed for your particular design. It makes it possible to experiment without having an 'infinite' stockpile. :)

Offline BobbyK

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Re: From no parts to decent stockpile, best approach?
« Reply #89 on: March 07, 2016, 05:17:41 am »
How to stock up on Electronic parts and not waste (too much) money and your girlfriend's goodwill:

1. Buy a resistor kit from eBay. Buy additional 100x of 100Ohm, 1KOhm and 10KOhm resistors. If you ever need more resistors, say 2 for a project, buy 10, unless the value is in the E12 resistor series, then buy 100.
2. Buy a Capacitor Kit from eBay. The electrolytics in these sets should not be used in anything you want to last long. Buy additional 2200uF 50V and 4700 50V caps from Mouser for your power supply needs.
3. Buy a 1W Zener Kit from eBay (about 10 pieces per value)
4. Diodes: get 1N914 and 1N4007 (100 each). Additionally get some 35Amp hard core bridges (5 e.g.) for power stuff. Everything else should be bought from DigiKey or mouser in 10 quantities)
5. LEDs (buy 100-200 packs from eBay. They are dirt cheap.)
6. Buy TO-220 Regulators. 3.3, 5, 9 Volts. Buy 10 of each from a reputable source. Also buy a bunch 10 of LM317 and 337s. Also get a few  low droputs like LD1117V33 (goes from 5V to 3.3 nicely).
7. For transistors buy a transistor kit from ebay (you will mainly need 3904, 3906 and 2222s. Any other transistor you will need, buy in 10 packages from mouser. I always buy 100, and I always end up with lots of leftovers - and leftovers take up space. Remember, Space is what you will run out of long before you run out of money.
8. Pots - you will need Lots, from good manufacturers. You will either reuse pots all the time in different projects, in which case you want them to last, or you will build them into a device you will use for a long time, again, they need to last. 10 turns are expensive but worth-while. Lots of 3/4 turns one (larger ones). same with trimmers, buy good quality from Mouser or Digikey.
9. Buy a bunch of dev boards, and LCD displays that fit the dev board. I bought about 10 MEGA2560 boards that get swapped around for different projects, but MSP432 will do just as well. eBay has them for cheap.
10. Battery holders for 2, 4 and 6 batteries. + 9V battery leads (or make them from old 9V Batteries)
11. Pin headers. I got about half a kilo of these at a surplus sale two years ago, and I have used up about half of that already. Buy different styles, though straight are best, and can be bent if they are long enough.
12. Solder - buy thin 60-40 in a half kilo roll. More than that, and it will get old before you are done.
13. Lots of stripboard, veroboard, prototyping board, thin pcb, single and double sided. PCB is to an EE as paper is to a painter. You need different types and lots of each.
14. Buy a good side cutter. I got a Knipex, and it has served me well.
15. If you don't already have one, buy a good drill and some carbide bits for different screw sizes!
16. A USB isolator is great. Adafruit has a 20$ one.
17. pushbutton switches. Something with nice long pins that is big enough for a "manly" finger!
18. ICs - only get them from reputable distributers:
4N35 optoisolators x 10
TL072 x 25
TL431 voltage reference x 5
LM386N (for those times you need to "hear" a signal!) x 5
Low voltage (3~5 volt) Rail to Rail OpAmps (anything you can get for cheap) x 10
Get a few microcontrollers that are through hole. ATMega328Ps are fine x 5.
Crystals: 4, 8, 10, 16 MHz crystals. 5 of each from eBay - or a few bags of crystal kits from eBay.

19. Cool Parts that you should have at least one of:
high power IR LEDs.
high Power RGB LEDs.
High Speed or High Resolution ADCs and DACs.
wide frequency range VCO e.g. MAX260X series
ARM microcontroller dev board
Precision opamp
Precision Voltage source
Digital Switch
Digital Pot
Encoder Switch


20. Anything else is really not worth while stockpiling. I have a ton of "Jellybean" parts that I will probably never use, simply because they are the lowest common denominator. Just buy a few extra whenever you need them for a specific reason. And don't forget, you should probably simulate a circuits, and reading all the datasheets and looking at similar circuits (what part have others used in this role or setting) before e.g. buying 5 different parts to test out for yourself.
Remember when making orders from Mouser, DigiKey, Farnell, etc. Don't pad out your purchase (e.g. for free shipping) with "more of the same" resistors, transistors, etc. Instead, buy a cool part that you have never used before (e.g. Hall Effect sensors, MEMS Gyros, etc. etc.) There is a lot of learning value and fun to be had in playing with more those parts.

« Last Edit: March 07, 2016, 05:27:17 am by BobbyK »
 

Offline eugenenine

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Re: From no parts to decent stockpile, best approach?
« Reply #90 on: March 07, 2016, 11:06:45 pm »
I can never understand why so many people on the forum buy small parts from ebay.  I gave up on them a long time ago when it got to be more time and effort sorting out the one non scammer from the 25 scammers for each product.  If your buying parts from digikey and mouser anyway just buy some assortment kits from them at the same time as well.
 

Offline BobbyK

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Re: From no parts to decent stockpile, best approach?
« Reply #91 on: March 08, 2016, 03:15:02 am »
I went back and looked at my eBay purchases. I have purchased about 200 items in the past year. Out of all of those, there were two items that had issues.

1. item never arrived from china. Seller kept delaying tactics. Eventually gave me a refund. Item was about 12 bucks.
2. item was supposed to be used, but was dead on arrival. Checked inside, and all caps had been blown. Basically, I had paid 10 Euros for a CD player/Radio, and I only got two (albeit good Panasonic) speakers out of the deal, so no big loss.

Overall that gives me a 1% failure rate when shopping on eBay. Just make sure you never buy very specialized items at too-good-to-be-true prices. I recently saw a listing for 40 Euros, for a Virtex-5 FPGA dev board, where the item picture was taken from the internet  :palm:. Did I buy it? You bet I didn't!

To OP: make sure you don't start mixing items you use for prototyping (generic, ebay, etc.) with items you want to use in a product that you plan to keep (e.g. an Amplifier, Power supply, etc.) or sell. After getting something to work using cheap throwaway stuff, calculate/simulate temperature ratings, and buy the appropriate parts from a proper vendor, if you want your stuff to last.

BTW. One thing I would not cheap out on either is Leads and Breadboards. Proper alligator leads, etc. of good quality will last you many years, and not being able to trust your testing equipment/leads/Breadboards basically makes those things useless.



 

Offline inteljoe

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Re: From no parts to decent stockpile, best approach?
« Reply #92 on: March 15, 2016, 05:09:53 am »
While I agree and disagree with various statements made in this thread, for whatever my opinion is worth, I will say that few things are more frustrating then having to order a part and waiting days or weeks for it to show up. Especially when I only need something that costs a few cents, for example a single resistor, capacitor, diode, etc.

I am guilty of buying components and equipment I will likely never use, and simply buying too many of any given component, or at least that is what my girl gives me guilt trips over. I will post a picture or two of my component drawers sometime... But that aside, I like being prepared, I like having options when designing and building a project. I like to experiment and learn how components work and they interact with each other. Theory only takes me so far, I'm more of a physical hands-on guy.

So, if that requires a stock pile or "going overboard" (aka overkill), so be it. But to each their own.

I would also like to note that I have no realistic options locally for sourcing components or equipment (aside from the lack of overpriced selection at my local Fry's & Radio Shack), I can't run out to my local electronics shop and buy something anytime I need it. Aside from the occasional Craigslist deal, everything I buy is online, it takes time to ship and I have to account for the cost of shipping. It's better to buy in bulk then waste money shipping a few dollars worth of components.
 

Offline BobsURuncle

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Re: From no parts to decent stockpile, best approach?
« Reply #93 on: March 27, 2016, 07:53:12 am »
After getting your basic passive components and some EBay grab bags you might consider the parts list inside the book Learning The Art of Electronics, by Thomas C. Hayes and Paul Horowitz.  This lab focused book covers a wide range of analog and digital electronics exercises that require well over a hundred different components which could be a good way to stock a general electronics lab.  The link below has spreadsheets with all the parts.

http://www.eevblog.com/forum/beginners/learning-the-art-of-electronics-parts-bom/msg904674/#msg904674
 

Offline zal42

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Re: From no parts to decent stockpile, best approach?
« Reply #94 on: March 27, 2016, 09:21:17 am »
I don't really stockpile as such, but when I need to buy parts, I always buy a few more than I need. If I can afford enough more to get a price break, I buy that much, otherwise I usually just go with 5 extra. Originally, it was to allow for part-destroying mistakes, but really what it means is that I always have a small supply of the parts I'm most likely to use, and I don't have boxes full of things "I might need someday" but never seem to.
 

Offline TheAmmoniacal

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Re: From no parts to decent stockpile, best approach?
« Reply #95 on: March 27, 2016, 09:32:07 am »
I've been stocking up on generic parts (mostly SMT) by buying assortment kits like these:

http://www.aliexpress.com/store/group/Electronic-component-kit/506373_500791312.html
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Offline epiflow

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Re: From no parts to decent stockpile, best approach?
« Reply #96 on: March 30, 2016, 11:00:11 am »
I wouldn't recommend trying. You will either have too many of things you will never use or not enough for the next project. They will take up space and time in organising them or even more time if you don't organise them.
Get a resistor and capacitor kit for breadboarding. Buy a few extra parts of stuff you are using. Either they will suit as spares or they fit the circuits you are interested in.

Have a couple of projects in mind and you can order parts for the next one whilst working on the current one.

The real problem is not having enough parts, it is having too many. How much is too much? If you can't carry it to the rubbish bin in one trip you have too much.

THIS
 

Offline FrankE

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Re: From no parts to decent stockpile, best approach?
« Reply #97 on: April 07, 2016, 09:31:37 pm »
I don't want to live somewhere resembling a digikey warehouse and I have enough with tools kicking about.

Next day isn't long. I stack whatever it is that needs the part, write up the notes and get on with the many other things that I need to do.
I'll get a 5 or 10 pack if it's good value and I'll use it within a year but to heck with tying my money up in speculative stock.
 

Offline neslekkim

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Re: From no parts to decent stockpile, best approach?
« Reply #98 on: May 01, 2016, 07:38:03 am »
Stock-piling is so last century. Just order what you need for a project...
I order my stuff on ebay - cheap but long wait - or at Farnel - not so cheap but only a couple of days away (no shipping cost).

In Norway you need to be an company to order from Farnell..
 

Offline JoeN

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Re: From no parts to decent stockpile, best approach?
« Reply #99 on: May 01, 2016, 03:47:53 pm »
Stock-piling is so last century. Just order what you need for a project...
I order my stuff on ebay - cheap but long wait - or at Farnel - not so cheap but only a couple of days away (no shipping cost).

In Norway you need to be an company to order from Farnell..

Why?  Stupid law of some sort?
Have You Been Triggered Today?
 

Offline rqsall

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Re: From no parts to decent stockpile, best approach?
« Reply #100 on: May 01, 2016, 04:05:42 pm »
Stock-piling is so last century. Just order what you need for a project...
I order my stuff on ebay - cheap but long wait - or at Farnel - not so cheap but only a couple of days away (no shipping cost).

In Norway you need to be an company to order from Farnell..

Why?  Stupid law of some sort?

No, Farnell doesn't want to deal with small orders. They have a fixed price contract with their shipping company and offer free shipping on any order, also small ones. Companies however usually order larger amounts so it works out for the shipping company and farnell.

In The Netherlands, farnell will sell to private people but only for orders of 50 euro or more and then you get free shipping.
 

Offline neslekkim

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Re: From no parts to decent stockpile, best approach?
« Reply #101 on: May 01, 2016, 09:19:59 pm »
In The Netherlands, farnell will sell to private people but only for orders of 50 euro or more and then you get free shipping.

The free shipping part is not the big problem. It's access to components that is, beeing able to order from them.
Farnell have a Norwegian department and norwegian prices, so one doesn't get extra taxes as you get with Mouser, Digikey, RS etc.. (And the extra fee from the company collecting the tax.. )
 

Online Cliff Matthews

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Re: From no parts to decent stockpile, best approach?
« Reply #102 on: June 29, 2016, 10:55:46 pm »
FWIW: Ebay buying experience and ratings list by GreenPhotons keeps getting better:
http://www.sciencetronics.com/greenphotons/?page_id=855
It's a linked list of sellers. Think of it as "the good, the bad, and the ugly" list  :-+
 
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Offline ez24

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Re: From no parts to decent stockpile, best approach?
« Reply #103 on: July 04, 2016, 09:02:44 am »
YouTube and Website Electronic Resources ------>  http://www.eevblog.com/forum/other-blog-specific/a/msg1341166/#msg1341166
 

Online wraper

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Re: From no parts to decent stockpile, best approach?
« Reply #104 on: July 04, 2016, 09:24:42 am »
FWIW: Ebay buying experience and ratings list by GreenPhotons keeps getting better:
http://www.sciencetronics.com/greenphotons/?page_id=855
It's a linked list of sellers. Think of it as "the good, the bad, and the ugly" list  :-+
That good list is not so good. I know for sure that gc_supermarket as example sells tons of counterfeits (personal experience). Also if you take some time searching what they are selling, easy to find very obvious fakes, especially opamps.
 

Offline TomS_

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Re: From no parts to decent stockpile, best approach?
« Reply #105 on: July 15, 2016, 10:30:34 pm »
Translation: Have extras on hand to replace the ones you fry during experimentation.  ;D :-/O

This ^^

I've been hitting RS and Digi-Key over the past month buying bits to put together a prototyping environment. Also my local "retail electronics" chain store, but trying to avoid then add they are much more expensive.

Already fried an LED and transistor. ;D

Transistors I bought 20 of each NPN and PNP for pence a piece. Also a bunch of N and P channel logic level MOSFETs. The MOSFETs are all SMD but I found some little DIP adapter boards with Digi-Key, so that was a nice excuse to do some SMD soldering.

I like RS because they ship next day for free for almost everything (even if you only spend 20p!!!). If you can get enough parts together with Digi-Key they are generally a bit cheaper but only do free shipping over a certain cart value. Seems they originate everything from the US whereas RS has a warehouse in the UK.

Gotta love electronics, been having a lot of fun lately. :)
 

Offline JoeN

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Re: From no parts to decent stockpile, best approach?
« Reply #106 on: July 16, 2016, 03:39:25 am »
Transistors I bought 20 of each NPN and PNP for pence a piece. Also a bunch of N and P channel logic level MOSFETs. The MOSFETs are all SMD but I found some little DIP adapter boards with Digi-Key, so that was a nice excuse to do some SMD soldering.

Every adapter board I have ever seen at a professional distributor like DigiKey has been hideously overpriced compared to what you can find from Chinese sellers on eBay.  Prototype boards don't have to be military/space quality to work.  The Chinese boards are all adequate quality from what I have seen and I have bought hundreds of them.  Also, if you ever want to get into doing PCBs, designing your own adapters is a good place to start.  Hopefully Britain has something like OSHPark.  OSHPark is $5 per square inch for three, postage paid, within the US.  For small parts it is very reasonable to make your own custom adapters.
Have You Been Triggered Today?
 

Offline TomS_

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Re: From no parts to decent stockpile, best approach?
« Reply #107 on: July 16, 2016, 11:27:39 pm »
Yeah. TBH I did kind of use them to bulk up my cart a bit to qualify for free shipping, which otherwise would have cost £12. The adapters together were less than £12, so win win. Otherwise yes they are quite pricey on an individual basis.

I ordered some more adapters from ebay just the other day, they should arrive early next week and I may likely do that again in the future if they turn out to be decent enough quality.

 

Offline Trigger

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Re: From no parts to decent stockpile, best approach?
« Reply #108 on: August 20, 2016, 12:23:47 am »
And I always purchase *a lot* more of the a bit more specialized parts (ICs, power fets) than I actually need, because If I need them today I most likely will use them again in the future.
Translation: Have extras on hand to replace the ones you fry during experimentation.  ;D :-/O

P.S. I think someone needs to create a "magic smoke" smiley.

A wizard tapping a chip with his wand and smoke popping out.
 

Offline jonovid

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Re: From no parts to decent stockpile, best approach?
« Reply #109 on: August 28, 2016, 02:10:10 am »
IMO cheap surplus Chinese electronic components from aliexpress works for me, Ok for most hobby electronics.  but the professionals use DigiKey. as  for electronic test equipment you'v come to the right place. Dave would know!  :)   as for my hobbyist lab all basic. tools , 3 millimeters one is analog,  one 10MHz oscilloscope  ,power supply's    battery's also make good bench power supply's   2 soldering irons , one sucker thing.  a solder pot.  cheap $20 Chinese videoscope /  microscope that saves video  for SMD work  , 2 desktop computers  25 or more electronic teardowns from off the street & numerous garage sales. - aliexpress also has bulk resisters & caps  as with all cheap surplus test everything before using. as many Chinese transistors are testing E-C-B not E-B-C  also many Chinese SMD components are in unmarked in rolls. Up-date- My system of organization is to use airtight Plastic food storage containers with lids in 2 Litre = .5 US-Gallons & 10 or 7 Litre.= 2.6 or 1.8 US-Gallons. No dust or lost sub miniature components screws or washers. also 10 Litre tubs can hold a whole electronics teardown in its entirety.  So my new components are organized into resealable zip plastic bags  taged with self-adhesive labels then put into the storage containers. I have tried mini storage Drawers, but I found them taking up too much space & letting the dust get in. still on the lookout for an ice cube tray with lid for un-striped SMD components.
« Last Edit: September 25, 2016, 03:26:54 am by jonovid »
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Online blueskull

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Re: From no parts to decent stockpile, best approach?
« Reply #110 on: August 28, 2016, 03:13:49 pm »
A wizard photonicinduction tapping a chip with his wand and smoke popping out.
SIGSEGV is inevitable if you try to talk more than you know. If I say gibberish, keep in mind that my license plate is SIGSEGV.
 
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Online Cliff Matthews

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Re: From no parts to decent stockpile, best approach?
« Reply #111 on: August 30, 2016, 12:43:00 am »
Optical drives are common trash, but contain more re-usable parts per square inch than most finds. This Instructables article is one of the most photo-rich I've seen. http://www.instructables.com/id/Disassembling-a-CDDVD-reader-and-reusing-its-parts/?ALLSTEPS
For those in countries blocking that site, I put the PDF here: http://docdro.id/PYtpmdE Cheers!  :-+
« Last Edit: September 07, 2016, 08:57:09 am by Cliff Matthews »
 

Offline jonovid

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Re: From no parts to decent stockpile, best approach?
« Reply #112 on: September 23, 2016, 11:54:48 am »
Quote
Optical drives are common trash, but contain more re-usable parts per square inch than most finds
whole computers have more re-usable parts per square inch than most finds but are not as common in the trash nowadays
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Offline ez24

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Re: From no parts to decent stockpile, best approach?
« Reply #113 on: November 18, 2016, 04:49:06 am »
Another way to see a "list" of stuff is to look at Dave's meter and scroll down to

"Customers Who Bought This Item Also Bought"

It seems like a reasonable list of things bought by people who bought his meter.  It is a list of decent stockpile of parts and tools.
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Offline TheDane

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Re: From no parts to decent stockpile, best approach?
« Reply #114 on: December 12, 2016, 03:21:06 am »
AliExpress and Ebay is certainly an option if you want to keep the stockpile yourself  :-+.

Ham fests/auctions, or joining local electronic oriented clubs can be an interesting option as well, if you 'only' need a single (+ a few to blow up) item, for your prototype needs.
Beware that most of the stuff out there are mostly second hand, through hole and 'old tech' (No 0402 smd, fast flash micros, huge eeproms, etc).
Ham operators gone 'silent key' (dead&burried) can also be a good source, and huge caches of components can be had for no price for just carrying it all away, to relatives wanting outrageous prices  - depending on relations, etc. Be aware

Polyfuses are extremly usefull and recommended, when you start working on stuff and find that not everything wants to play as you want  :palm:

Getting a decent workshop takes a LONG time - and a lot of work. Happy hunting - sometimes gold awaits around the corner (and yeah - it's literally gold plated  ;D) you just have to find it.
« Last Edit: December 12, 2016, 03:28:24 am by TheDane »
 

Offline cdev

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Re: From no parts to decent stockpile, best approach?
« Reply #115 on: January 01, 2017, 03:22:30 am »
What are the best "Grab bags" or assortments out there?

 Ive bought several of these in the past, and although they are not good if you want a specific part they are good for when you need something, don't have it somewhere else, often you can find something that will work in your junkbox, the bigger it  is the better for that..

and also for serendipity, you might get a random part that leads you into learning something new that you would not have ever considered were you not presented with it.
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Offline jazer

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Re: From no parts to decent stockpile, best approach?
« Reply #116 on: January 15, 2017, 06:46:27 pm »
Old/broken electronics for donor parts are better than grab bags, which seem like floor sweepings more than anything else. You get random parts and they generally don't cost anything. Keeping stockpiles of broken electronic stuff has its downsides of course.

Depending on what you do, you'll find that you tend to go back to the same well over and over. For example, there are hundreds of resistor values available, but (especially if you mostly design your own stuff) you end up using the same half dozen or so for most things. Once you figure out which are you go to items, buying a bunch from ebay and the like is cheapest.
 

Offline jazer

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Re: From no parts to decent stockpile, best approach?
« Reply #117 on: January 16, 2017, 06:25:49 am »
If you don't have any test instruments at all, a DMM is more than a little handy.  Also, having more than one is useful when monitoring something.

They can be had at very low cost, and free if you're in the US and have a Harbor Freight store nearby.  They give them away just for walking in their store.  See attached printable coupon or link:

http://www.hfqpdb.com/coupons/11_FREE_7_FUNCTION_DIGITAL_MULTIMETER_1482355038.9542.JPG

There's a teardown thread for it on this forum with lots of good info:
http://www.eevblog.com/forum/reviews/harbor-freight-cen-tech-90899-small-teardown/

It's not the best DMM in the world, of course, and Dave probably hates it, but it's useful for secondary measurements and much better than having no DMM at all.
 
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Offline eugenenine

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Re: From no parts to decent stockpile, best approach?
« Reply #118 on: January 17, 2017, 02:46:22 am »
I gave most of my grab bag and pulls from old stuff to my kids.  I had so much odd value, odd size stuff that it wasn't worth the time and space.  When I'm working on something I order extras. 
 

Offline ez24

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Offline james_s

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Re: From no parts to decent stockpile, best approach?
« Reply #120 on: January 23, 2017, 09:14:13 am »
I keep a stock of resistors, capacitors, IC sockets, LEDs, connectors and other bits that I use in lots of projects on hand but other stuff I usually buy as needed. The most challenging for me was actually connectors, there is an overwhelming variety of them available so what I've tended to do is find a series I like and then buy a selection of the most commonly used sizes along with the crimper or punchdown tool for them.

For random parts I also regularly pick through the E-waste bin at work and drag home various discarded equipment to tear down and harvest interesting bits from. That's a handy way to get stuff like crystal oscillators, inductors, relays, buttons/switches and heatsinks. You do need to be careful though, for reasons I don't understand, some companies frown upon salvaging junk. Drives me nuts because I despise waste and firmly believe that the most efficient form of recycling by far is re-use.
 

Offline jazer

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Re: From no parts to decent stockpile, best approach?
« Reply #121 on: January 23, 2017, 06:46:36 pm »
Dave did a video showing the guts of stuff from the white van speaker scam that showed what looked like recycled parts inside some dubious quality audio components.

I've never seen something like that in person, but I suppose there might be a thriving Chinese component recycling market to do that on any large scale.

I agree that re-using components is the best form of recycling, rather than a land fill, or indiscriminately melting down piles of e-junk and using mercury for gold extraction, poisoning whole towns.

Semiconductors are probably OK since most have very long useful lives, but recycling electrolytic caps is bad news; they barely last in new stuff.
 

Offline Skyfox

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Re: From no parts to decent stockpile, best approach?
« Reply #122 on: January 24, 2017, 03:00:26 am »
For my stockpile I've been collecting junk circuit boards since I was a kid and desoldering parts from them.  Only within the past year have I finally started trying to organize by labeling a couple of storage trays for 24-series resistors and capacitors, and getting other drawer units to start decluttering and unpacking my original overloaded storage things.  Also within the past year I've started looking up datasheets on parts so I have some information on what they are.  Oh, and wire...I've been collecting scrap wire since I was a kid whether it's multi-stranded stuff or solid core phone/data wire.

In recent years I started actually spending a little money on cheap parts from Tayda Electronics and Digikey, when I needed things I simply didn't have and didn't want to rig up something out of what I did have.  The EEVblog videos have helped greatly in understanding this stuff, even though I'm still at a very beginner level of knowledge.
 

Offline james_s

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Re: From no parts to decent stockpile, best approach?
« Reply #123 on: January 24, 2017, 03:57:12 am »
I don't generally salvage electrolytic capacitors but there are exceptions based on where it's used in the circuit. It's been my experience that larger, higher value capacitors used in low frequency applications are usually in good shape. Output filter capacitors in switchmode regulators take a beating. Other types of caps are generally fine to salvage.
 

Offline jazer

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Re: From no parts to decent stockpile, best approach?
« Reply #124 on: January 28, 2017, 02:55:52 pm »
This has been touched on before here but in ancient threads, and it's tangentially apropos for this discussion:

What's the prevailing wisdom for flux when soldering:
paste, liquid rosin, no-clean, flux-pen, harvested from your backyard pine tree, hope and prayer?

Any good sources? Name brand stuff vs. Chinese/ebay witches' brew?
 

Offline james_s

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Re: From no parts to decent stockpile, best approach?
« Reply #125 on: January 28, 2017, 07:43:10 pm »
I normally just use the flux that's in the core of the solder. Sometimes I use a bit of additional liquid rosin flux for heavily oxidized connections.
 

Offline JoeN

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Re: From no parts to decent stockpile, best approach?
« Reply #126 on: January 28, 2017, 07:51:03 pm »
I normally just use the flux that's in the core of the solder. Sometimes I use a bit of additional liquid rosin flux for heavily oxidized connections.

That works great for through-hole soldering.  For drag-soldering on SMT parts I tend to flux the heck out of the parts and board that then put the solder on with a chisel tip.  That works the best for me on SMT parts, especially when you are talking about QFP-100, QFP-144 type parts.
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Offline james_s

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Re: From no parts to decent stockpile, best approach?
« Reply #127 on: January 28, 2017, 08:10:01 pm »
Yeah I was assuming through-hole. I do the same thing when I hand solder SMT parts, dab on a bit of liquid flux with a Q-tip and stroke a small blob of solder along the pins.
 

Offline jackzzj

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Re: From no parts to decent stockpile, best approach?
« Reply #128 on: February 12, 2017, 06:23:05 pm »
I just bought some kits from ebay... have to wait for a long time :=\
 

Offline VEGETA

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Re: From no parts to decent stockpile, best approach?
« Reply #129 on: February 15, 2017, 03:20:25 am »
how do you organize these parts? I mean in a cheap way that anyone can buy

Offline eugenenine

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Re: From no parts to decent stockpile, best approach?
« Reply #130 on: February 15, 2017, 07:46:44 am »
how do you organize these parts? I mean in a cheap way that anyone can buy

I use stuff like this
http://www.cabelas.com/catalog/browse/tackle-storage/_/N-1100377

 

Offline VEGETA

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Re: From no parts to decent stockpile, best approach?
« Reply #131 on: February 15, 2017, 10:45:52 am »
I meant something like dividing and sorting resistors and capacitors. Other chips as well.

Offline eugenenine

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Re: From no parts to decent stockpile, best approach?
« Reply #132 on: February 15, 2017, 01:55:37 pm »
The plastic divided boxes, one holds resistors, one capacitors, etc.  Then they are divided out in each box with the separators.
 

Offline mdijkens

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Re: From no parts to decent stockpile, best approach?
« Reply #133 on: February 17, 2017, 12:10:59 am »
For components with lots of values like resistors and capacitors I use these small plastic bags sorted  in small cardboard boxes my mobile(s) came in. Cheap, doesn't take much space and easy to find right values.
 

Offline RCHRDM

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Re: From no parts to decent stockpile, best approach?
« Reply #134 on: February 20, 2017, 03:20:23 am »
There are some good basic capacitor, resistor, diode, and transistor kits on Amazon.com by Elenco.

Mouser is a good place to buy too.  You can buy a small quantity (10 or so) of parts like resistors and op amps.  The have a $4.99 USPS shipping option, which is very reasonable.  The advantage over eBay is that you can buy exactly what you need from one vendor, rather than searching all over eBay for your parts.
 

Offline VEGETA

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Re: From no parts to decent stockpile, best approach?
« Reply #135 on: February 21, 2017, 03:18:39 am »
There are some good basic capacitor, resistor, diode, and transistor kits on Amazon.com by Elenco.

Mouser is a good place to buy too.  You can buy a small quantity (10 or so) of parts like resistors and op amps.  The have a $4.99 USPS shipping option, which is very reasonable.  The advantage over eBay is that you can buy exactly what you need from one vendor, rather than searching all over eBay for your parts.

Good for you in USA xD. However, me in Jordan I can't get anything from Digikey or Mouser but to pay 75$ shipping for it. I discovered a solution for that which involves another storage company.

Offline gowithyourself

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Re: From no parts to decent stockpile, best approach?
« Reply #136 on: February 21, 2017, 10:00:22 am »
Don't get caught up in parts, equipment and setup. At the end of the day it's learning and making things that counts. A lack of parts or equipment usually isn't the problem, it's a lack of time or direction.
 
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Offline james_s

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Re: From no parts to decent stockpile, best approach?
« Reply #137 on: February 21, 2017, 01:34:05 pm »
That depends. When I was a teenager I had lots of time but very little money with which to obtain parts of equipment, I had to scavenge most of my parts from discarded electronics and build my own equipment like power supplies, logic probe, signal generator, etc.

Now that I'm older I'm most limited by time.
 

Offline gowithyourself

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Re: From no parts to decent stockpile, best approach?
« Reply #138 on: February 21, 2017, 11:21:40 pm »
Sure, but I don't think that has so much to do with age as the time one lives in. There used to be limited ways to learn something. You either learned by yourself with what you had available or you went to school. Since we entered the information age, and with the rise of globalization, the things available to us have increased by many orders of magnitude. While this has made it easier to learn things, it has also made it harder to learn the right things.

I think there's a number of other reasons why not to build a stockpile as a beginner. Like that you don't know which parts to get, you'll progress to other parts quickly, it will be a mess to keep track of everything, you still have to order things you won't have etc. But hey, everyone learns differently.

It's also sort of ironic that that the same factors that makes it easy to build a stockpile has made the stockpile itself redundant. But it's the same with many things, like music.
 

Offline JenniferG

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Re: From no parts to decent stockpile, best approach?
« Reply #139 on: February 26, 2017, 08:51:32 pm »
Look up 500pcs 50 values resistors on ebay.  I think it was like $1.50.  Also 170pcs 17 values transistors for $3.00.
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Re: From no parts to decent stockpile, best approach?
« Reply #140 on: February 27, 2017, 02:45:11 am »
Thanks, finding good key word sequences really makes short work. I don't mind paying a bit more, giving preference to a seller some reputation to guard (better chances of getting something, which is better than nothing..)

I also tried "120 value 50v electrolytic capacitor" or just "value 50v electrolytic capacitor"
 

Offline JenniferG

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Re: From no parts to decent stockpile, best approach?
« Reply #141 on: February 27, 2017, 04:09:04 am »
Thanks, finding good key word sequences really makes short work. I don't mind paying a bit more, giving preference to a seller some reputation to guard (better chances of getting something, which is better than nothing..)

I also tried "120 value 50v electrolytic capacitor" or just "value 50v electrolytic capacitor"

Yeah I generally try to buy the one that is most affordable, which a lot of other people buy from as well (shows # sold), and I take a look at the seller feedback as well.  With any luck I'll have decent components :)
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Offline SingedFingers

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Re: From no parts to decent stockpile, best approach?
« Reply #142 on: February 27, 2017, 05:06:01 am »
I just buy what I need for a project/experiment. You eventually end up with a good stock of parts.
 

Offline james_s

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Re: From no parts to decent stockpile, best approach?
« Reply #143 on: February 27, 2017, 05:12:33 am »
It's really handy to have a good stock of resistors and capacitors though. I really hate sitting down to build something and then finding I forgot to order one particular value resistor, or accidentally got 470K instead of 470 Ohm and then having to spend a half our rifling through boxes looking for that one 2 cent part. Now I have a notebook full of SMD resistors and capacitors and a bag of through hole resistors for just such an occasion.
 

Offline SingedFingers

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Re: From no parts to decent stockpile, best approach?
« Reply #144 on: February 27, 2017, 05:19:51 am »
You can actually make do with a very limited selection of parts. 10, 22, 47 from each decade is enough for most things. Series and parallel combinations allow all intermediate values to within 5% or so which is plenty accurate enough.
 

Offline james_s

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Re: From no parts to decent stockpile, best approach?
« Reply #145 on: February 27, 2017, 06:43:06 am »
I don't want to series/parallel resistors and capacitors, especially with SMT stuff that just gets messy. It's one thing to do a temporary hack to test out something I'm repairing but I like to do clean, professional work.
 

Offline SingedFingers

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Re: From no parts to decent stockpile, best approach?
« Reply #146 on: February 27, 2017, 07:13:56 am »
For repair and production yes but do you give up designing something because you don't have an E96 value in stock?
 
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Re: From no parts to decent stockpile, best approach?
« Reply #147 on: March 07, 2017, 07:55:33 pm »
You can actually make do with a very limited selection of parts. 10, 22, 47 from each decade is enough for most things. Series and parallel combinations allow all intermediate values to within 5% or so which is plenty accurate enough.

When I built my basic stocks,
a resistor assortment (10ea everything from 1Ohm to 10M) - overkill, ideally 30ea of the 1 / 2.2 / 4.7s would have been more use
an electrolytic assortment (0.1 -> 1000uF)
a ceramic assortment (22 pf-> 1uF)
a semi assortment (with a ton of things I never touch), and I still split this 50/50 with a friend.

If I were building a kit for beginners from scratch, it would have
  • resistors (10/ea)  1, 4R7, 10, 22, 47, 1M, 2M2, 4M7
  • resistors (25/ea) 100, 220, 470, 1k, 2k2, 4k7, 10k, 22k, 47k, 100k, 220k, 470k
  • caps (ceramic, 5/ea) 22p / 47p / 100p / 220p / 470p / 2n2 / 4n7 / 22n / 47n
  • caps (ceramic, 20/ea) 1n, 10n, 100n
  • caps (electrolytic, 16-25v, 5/ea) / 0.47 / 1u / 2u2 / 4u7 / 10u / 22u / 47u / 100u / 220u / 470u / 1000u (maybe a 10/ea of the 10, 100uF)
  • diodes (15/ea)  1N4004, 1N4148
  • transistors/fets (10/ea) 2N4401, 2N4403, 2N7000 (maybe more 01s fewer 03s)
  • power fet (5/ea) IRLB8721

It's been a while since I've used something other than one of these basic jelly-bean parts  in a tinkering project.

Anybody else have go-to parts they can't live without ?

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Offline SingedFingers

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Re: From no parts to decent stockpile, best approach?
« Reply #148 on: March 07, 2017, 08:23:48 pm »
That's a pretty good list to be honest.

I'd add a few cheap cermet or carbon trimpots (2 each 100R, 2k, 5k, 10k, 50k, 100k) as well which are rather handy to have floating around. I tend to use them to measure impedances on the breadboard.
 

Offline TheAmmoniacal

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Re: From no parts to decent stockpile, best approach?
« Reply #149 on: March 07, 2017, 08:31:23 pm »
In The Netherlands, farnell will sell to private people but only for orders of 50 euro or more and then you get free shipping.

The free shipping part is not the big problem. It's access to components that is, beeing able to order from them.
Farnell have a Norwegian department and norwegian prices, so one doesn't get extra taxes as you get with Mouser, Digikey, RS etc.. (And the extra fee from the company collecting the tax.. )

How are you able to order parts from Farnell in Norway? Whenever I try to register on the site to order something, they want a company registration number. The only parts vendor I'm able to use here is Digikey! Even with the VAT it's usually the cheapest. But for test gear I don't have any options really.
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Offline neslekkim

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Re: From no parts to decent stockpile, best approach?
« Reply #150 on: March 07, 2017, 09:02:47 pm »
In The Netherlands, farnell will sell to private people but only for orders of 50 euro or more and then you get free shipping.

The free shipping part is not the big problem. It's access to components that is, beeing able to order from them.
Farnell have a Norwegian department and norwegian prices, so one doesn't get extra taxes as you get with Mouser, Digikey, RS etc.. (And the extra fee from the company collecting the tax.. )

How are you able to order parts from Farnell in Norway? Whenever I try to register on the site to order something, they want a company registration number. The only parts vendor I'm able to use here is Digikey! Even with the VAT it's usually the cheapest. But for test gear I don't have any options really.

I have registered with my firends regnumber, after registering on farnell, putting items in the basket many times and not buying, they actually called me, and I told them my problem.. And gave me the idea to use my friends regnumber, and it works fine.
Elfa is another option that works fine for all.

How is digikey working?, can you order and pay norwegian vat directly, or are you billed from the courier?
 

Offline TheAmmoniacal

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Re: From no parts to decent stockpile, best approach?
« Reply #151 on: March 07, 2017, 09:13:21 pm »
In The Netherlands, farnell will sell to private people but only for orders of 50 euro or more and then you get free shipping.

The free shipping part is not the big problem. It's access to components that is, beeing able to order from them.
Farnell have a Norwegian department and norwegian prices, so one doesn't get extra taxes as you get with Mouser, Digikey, RS etc.. (And the extra fee from the company collecting the tax.. )

How are you able to order parts from Farnell in Norway? Whenever I try to register on the site to order something, they want a company registration number. The only parts vendor I'm able to use here is Digikey! Even with the VAT it's usually the cheapest. But for test gear I don't have any options really.

I have registered with my firends regnumber, after registering on farnell, putting items in the basket many times and not buying, they actually called me, and I told them my problem.. And gave me the idea to use my friends regnumber, and it works fine.
Elfa is another option that works fine for all.

How is digikey working?, can you order and pay norwegian vat directly, or are you billed from the courier?

I just get an invoice/bill from the courier 2-3 days after delivery. Has always been VAT only, no other nonsense.

Elfa is crazy expensive, especially on parts (2.25 NOK per resistor, 30 NOK for a single linreg etc. Basically 3-30 NOK a piece for jellybean stuff). And thoses prices are excluding VAT!
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Offline neslekkim

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Re: From no parts to decent stockpile, best approach?
« Reply #152 on: March 08, 2017, 12:35:28 am »
I just get an invoice/bill from the courier 2-3 days after delivery. Has always been VAT only, no other nonsense.
Hm, Elfa bills me directly, courier not involved at all, so you say the courier only bills you the invoice/vat?, no extras?, very strange..  Need to try that.

Elfa is crazy expensive, especially on parts (2.25 NOK per resistor, 30 NOK for a single linreg etc. Basically 3-30 NOK a piece for jellybean stuff). And thoses prices are excluding VAT!
Nah, not that bad:
https://www.elfadistrelec.no/no/motstand-30-ohm-ohm-rm0207sfcn30r1t52/p/16070536

I bought my 34461A for 6494 eks vat when it came, about 2k lower than the "official" supplier..

 

Offline JossDalVera

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Re: From no parts to decent stockpile, best approach?
« Reply #153 on: March 23, 2017, 06:53:46 am »
I have seen on ebay at times big boxes just full of "mixed components" which pretty much are just random. they are cheap however you have to sort them out :-//
 

Offline Neganur

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Re: From no parts to decent stockpile, best approach?
« Reply #154 on: March 23, 2017, 04:34:04 pm »
Don't buy that "mixed grilled" stuff unless you want a hobby like collecting and sorting stamps...
your time is used better in actual project in my opinion. I think it's better to buy proper assortments.

It can ofc be fun to sort stuff but in reality it's very rare you get parts that are actually useful unless you see something in a pile that makes it a bargain.
 

Offline Mr. Scram

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Re: From no parts to decent stockpile, best approach?
« Reply #155 on: March 25, 2017, 02:06:48 pm »
Not too long ago I started stockpiling too and have found that is it really nice to have the common passives at hand. For those I can regularly find all sorts of uses. I also bought a large amount of classic op-amps and other ICs that seemed common or interesting. Those get used a lot less, because I tend to reach for superior modern day chips that are ordered specifically for the project, rather than building something with an outdated LM358. They are cheap as chips, though, and storing them takes little room, so it does not hurt to have them. They can be useful fixing things, but they are not as useful as the common passives.
 

Offline TheUnnamedNewbie

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Re: From no parts to decent stockpile, best approach?
« Reply #156 on: March 25, 2017, 07:28:23 pm »
I don't know how common this is, but at my university, you can order parts from some suppliers, including farnell and RS, through our assembly/logistics team inside ESAT (EE dep.). This is, to my knowledge, is actually cheaper than getting stuff yourself from those distributors because the university gets price deals. There is a slight fee for the department, but even with that, I've orderd 15 euro's worth of parts on farnell and ended up having to pay 12 euros, even though the farnell price is without taxes and such (and if I orderd for myself I also had to pay shipping and stuff!). I believe this service is available to anyone, not just staff and students.

I have some basic parts, mainly through hole, if I want to breadboard stuff. Cheap, crappy chinese kit boxes of capacitors because I don't really care about how long they last.

Sure, I can get next day delivery on stuff, but when I'm working on a project on saturday, I want to work on my project then. As, for now, my projects aren't that complex, they can usually go from "Idea" to "finished breadboard and ready to design a pcb" in one weekend, next-day delivery still isn't quite enough. On day's I'm in my uni, I can also rely on the parts store in my department, where I can go buy stuff. Usefull for stuff like high-power resistors. They also store hundreds of 4000 and 7400 logic IC's, zeners, ....

For the same reason, I don't really stock SMT stuff, since I don't build my own PCB's either (get them from the same department at my uni, no soldermask tho...). If I have to wait a few days for them to build my pcb, I can also wait for 24 hours to get those parts.
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Online boffin

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Re: From no parts to decent stockpile, best approach?
« Reply #157 on: March 27, 2017, 06:40:57 am »
Based on top my list above of basic passives/basic transistors, what would everyone add as basic starting components.  555?  TL071?  4016?  PC817?

I'm wondering if there's enough demand for someone to say to one of the Shenzen suppliers "make this pack for me", and sell them for $30



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Offline james_s

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Re: From no parts to decent stockpile, best approach?
« Reply #158 on: March 29, 2017, 05:16:34 am »
The basic passives are the most useful by far, resistors and capacitors in a whole range of values and a few different types, and organize them. I've spent countless hours of my life searching for that one resistor I forgot to order, maybe I need a 470 ohm and I'll find I ordered a 470k, then I'll rummage through my boxes and find 4.7 ohm, 47 ohm, 4.7k, 47k, everything but the part I need. It may only cost 2 cents but that's little help when I don't have it.

Having a few ICs is handy, 555, a few generic op-amps like the TL082, 2N3904 and 2N3906 transistors, some LM317s, depends what you're working on but those are parts I often use. I may find that I need something more specialized in the final circuit but I can do a lot with the basic stuff.

I agree that buying random assortments can be of limited value, although it's fun to go through them and see what there is. It's a great way for a kid with few resources who wants to experiment with electronics and it can be a creative process trying to design something interesting around an assortment of parts one already has, but I wouldn't buy a ton of random bits just hoping they'll be useful some day.
 

Offline scorched

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Re: From no parts to decent stockpile, best approach?
« Reply #159 on: April 08, 2017, 02:23:52 am »
I am by no means an expert, as I am just returning to the world of electronics from my days in the military 20 years ago.  But what I did to acquire my stockpile, was to find places that sold them as bundles.
And specifically I have bought several "boxes" of scrap parts, as well as some specific packages from gold mine. Sometimes they have deals that are worth taking many times not.

For $8USD I ordered this, and while a lot of it is junk, once I sorted it all, I ended up with a good amount of decent items.
http://www.goldmine-elec-products.com/prodinfo.asp?number=G9321
Here is an example, each pack is only $2.50USD
http://www.goldmine-elec-products.com/products.asp?dept=1053.
Also look in the assortments for specifics.
http://www.goldmine-elec-products.com/departments.asp?dept=1409
And for shear fun I purchased a surprise RCA parts box, mostly cap, coils, and resistors, but a few kinds each eeprom, transistors and such. Had over 150 items.
http://www.goldmine-elec-products.com/prodinfo.asp?number=G21550
If you get this pack, you get a little better selection but limited to 50 items but I did not acquire this one.
http://www.goldmine-elec-products.com/prodinfo.asp?number=G19894A

So all said, I spent about $30, and consider myself pretty much fully stocked for my return to electronics.

Already repaired my Denon AVR4806 with what I ordered, maybe I got lucky, but anyway I am happy.

Cheers!
 
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Offline dimkasta

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Re: From no parts to decent stockpile, best approach?
« Reply #160 on: April 08, 2017, 10:27:09 pm »
I did not read the entire thread, just the last page, so excuse me if it's already been mentioned.

Don't forget to get a bunch of the old trusty lm7805 and lm317s :)
 

Offline Mr. Scram

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Re: From no parts to decent stockpile, best approach?
« Reply #161 on: April 09, 2017, 05:59:39 am »
Don't forget to get a bunch of the old trusty lm7805 and lm317s :)
Other than them being well known, are they really still viable? The drop-out is quite high by modern day standards and they tend to piss away power too. It is good to get to know them, but they aren't really recommended for any circuit that has to perform.
 

Offline james_s

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Re: From no parts to decent stockpile, best approach?
« Reply #162 on: April 09, 2017, 06:27:37 am »
There's nothing wrong with a 78xx, I still see them occasionally in modern-ish devices. I wouldn't hoard hundreds of them but it's handy to have a few common types on hand. 7815 and 7915 are handy if you want to make analog audio devices, hard to beat an old fashioned linear power supply for clean DC.
 

Offline dimkasta

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Re: From no parts to decent stockpile, best approach?
« Reply #163 on: April 09, 2017, 09:24:48 am »
Other than them being well known, are they really still viable? The drop-out is quite high by modern day standards and they tend to piss away power too. It is good to get to know them, but they aren't really recommended for any circuit that has to perform.

All valid arguments, but I thought we were talking about a stockpile for general experimentation.
There is nothing wrong with them unless the design is sensitive to high-frequency dirt and noise. But then we would not be talking about quick experimentation using stockpiled stuff. We are talking about a device that needs a purpose-designed PSU.
Of course, some LT stuff might probably be a good idea too, but they tend to be lower voltage, way more expensive and far less available.
 

Offline TheUnnamedNewbie

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Re: From no parts to decent stockpile, best approach?
« Reply #164 on: April 12, 2017, 11:30:44 pm »
Other components that I like to keep around, that might not be so common: Some power resistors! They can serve as quick loads for testing powersupplies or power switching circuits. I like to keep at least 10 .1 Ohm, 1 Ohm and 10Ohm 2W resistors around, and am looking at stockpiling some more.
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Offline karoru

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Re: From no parts to decent stockpile, best approach?
« Reply #165 on: May 03, 2017, 03:45:53 am »
Other components that I like to keep around, that might not be so common: Some power resistors! They can serve as quick loads for testing powersupplies or power switching circuits. I like to keep at least 10 .1 Ohm, 1 Ohm and 10Ohm 2W resistors around, and am looking at stockpiling some more.

They're especially useful if you need to deal with AC from time to time and your schmick DC electronic load renders useless. I tended to use small halogen bulbs, but one learns quickly that they tend to get quite hot quite quickly and in the middle of experimentation it's surprisingly easy to forget that this tiny piece of glass has been glowing white and dissipating 10W few seconds ago. If someone deals with audio stuff then 4 or 8 ohm beefy non-inductive power resistors will serve dual role.
 

Offline dimkasta

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Re: From no parts to decent stockpile, best approach?
« Reply #166 on: May 03, 2017, 06:03:05 am »
And of course MANY 3mm screws (plastic and metal), nuts, washers, standoffs, and spacers.
Mica insulators for TO220 or whatever package you like using
Fuses and fuse holders
Battery clips
crimp connectors and a press
 

Offline Creative

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Re: From no parts to decent stockpile, best approach?
« Reply #167 on: May 19, 2017, 10:52:17 am »
Here is how I spent momey on my electronics lab.  When i design a circuit and I plan to bread board it (as opposed to the dead bug method) I use 1/2 watt resistors even if the power allows for a safety margin with a 1/4 watt equivalent because they make a better electrical connection. If i decided to make a permanent version I will go back to the 1/4 watt power rated resistors. 
  I store the 1/4 and 1/2 watt resistors of the same value in same drawer of my collection. I also use pegboard hooks and 10 compartment plastic boxes to store parts.  These boxes have a plastic hook for vertical mounting and label the side of the box with a general description of what is in the box.  I store switches, capacitors, bipolar transistors and other electromechanical parts in them I also have ESD safe plastic storage boxes storing jfets, micro controllers, and other static sensitive parts. I use a earth grounded wrist strap when working with esd parts on my grounded work mat.  These small parts boxes are nice because they do not take up much room on the bench and they easily hang out of the way
 

Offline KL27x

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Re: From no parts to decent stockpile, best approach?
« Reply #168 on: June 08, 2017, 02:51:12 pm »
Quote
I'm gradually migrating to use of a lot of Ziploc-style bags, of many different sizes, some quite small.  These waste virtually no space, if you press the air out before sealing.

The end game, imo, is a heatsealer. Polyethyne is great. U can size down the bags that digikey sends u, just big nuff to hold the entire part number and such. Metallic bags are extra special... u can partition them into multiple sections, and they dont fall apart. I will cut the end with a small incision to take out the cut tape or loose parts, and seal the end back up with soldering iron when done.
 
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Online Cliff Matthews

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Re: From no parts to decent stockpile, best approach?
« Reply #169 on: June 08, 2017, 09:26:53 pm »
A heatsealer, i have the nichrome wire.. Any chance you could post a photo of how you made yours?
Also, how do you stop the plastic from sticking to the wire?
 

Offline neslekkim

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Re: From no parts to decent stockpile, best approach?
« Reply #170 on: June 09, 2017, 12:35:59 am »
A heatsealer, i have the nichrome wire.. Any chance you could post a photo of how you made yours?
Also, how do you stop the plastic from sticking to the wire?

Normal heatsealers for bags use some sort of teflon tape over the heatingwire
Loads of cheap "impulse sealers" on ebay
 

Offline CharlieWorton

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Re: From no parts to decent stockpile, best approach?
« Reply #171 on: June 09, 2017, 02:18:28 pm »
For new parts, AliExpress or BangGood are both good sources.  I have more success (lower prices, better selection) with AliExpress.  Both companies are equally reputable, I've never had a problem with either.  For used stuff, run a free ad in a local advertiser offering free pickup and disposal of unwanted electronics - old computers, printers, whatever.  There are decent stepper motors in some printers, the power supplies in old computers still work well (usually).  If you have more time than money, this can be a decent way to acquire some unusual stuff.  In addition, you might be able to repair and sell some broken electronics, if you're so inclined.
 

Offline brainwash

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Re: From no parts to decent stockpile, best approach?
« Reply #172 on: June 11, 2017, 08:34:02 am »
Not sure if this is new, it was probably discussed above, but stockpiling needs an organised approach:
- stockpile base components (capacitors, resistors, LM324, 74*, 555, resonators, fuses, SMD 0805, ....)
- do not stockpile 'best and greatest' components. That includes any ARM chip, any PIC chip, ADCs, FPGAs, ...
- stockpile connectors - they are likely to be needed at any time: USB, mini-USB, micro-USB male, USB cables, Sub-9, ...
- stockpile wires - any size, any number of conductors under the insulation, any color (preferably all, including dual-color)
- stockpile base logic: breadboards, Arduino Uno [clones], Digistamp [clones], BT, ESP8266

The above would let you fix a lot of issues if you have broken device. It will also let you prototype almost any idea.
Avoid buying into the latest and greatest, unless you are a technical head at some company. Most of the time, the things you will know how to use will be the ones that are the cheapest and people tend to use the most (ATMega328, ESP8266).
I have a pile of TI and Microchip stuff that I've rarely used. At least TI can be used with Energia, but most of the times you want to fail fast and fail often. This means you don't want to be wasting 1-2 days to get a chip working only to prove that your idea is wrong.

Aside from that, a good digital scope (or a mediocre analog one and a mediocre digital one) will get you far. You'll use the multimeter a lot more than those. You'll use your soldering station more. You'll use clips and clamps and wires even more. You'll use a digital analyzer, a hot-air station and signal generator a few times per year, at most. That is, considering your question. So plan your stockpile according to that.
 
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Offline schmitt trigger

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Re: From no parts to decent stockpile, best approach?
« Reply #173 on: June 24, 2017, 10:35:59 am »
This thread is loooong, and I essentially skimmed thru it.

But I think relays have not been mentioned. If you would like to control lights, motors, etc., in a safe and straightforward manner, relays are the way to go.
Get 5v-coil relays for the smaller sizes, and 12v-coil relays for the larger sizes.

From time to time you will find that your regulator, transistor, Triac, etc are overheating. Get some small TO220 heatsinks. It is surprising how much more power you can dissipate from a device with even a small heatsink, as compared to stand alone.
 

Offline brainwash

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Re: From no parts to decent stockpile, best approach?
« Reply #174 on: June 24, 2017, 10:47:34 am »
Cheap relays can be found from the scrapyard, you can get at least 10 for 1$. Some of them are timing relays (for example diesel heater) so not so easy to use. Anyway, most of the manufacturers these days have went the MOSFET way, and for a good reason: the old relays are both unreliable and fail in an uncontrolled way.
Still the cheapest and simplest way to get DPDT, if you need it. But in my experience relays tend to fail both randomly and in strange ways (i.e. one contact working 90% of the time).
 

Offline Jellysfish

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Re: From no parts to decent stockpile, best approach?
« Reply #175 on: August 18, 2017, 03:34:57 am »
My local melvac sometimes sells general electronics in a grab bag--slightly more expensive than online but at least these parts are more likely to be new
 

Offline TheDane

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Re: From no parts to decent stockpile, best approach?
« Reply #176 on: August 26, 2017, 05:22:27 pm »
Recycling old equipment is also a nice way to get components.

Instead of 'throwing' out old/broken stuff, I usually keep it around for scraps - and when I need something I don't have already in my assortments - I will take a look at the old junk, and surprisingly I often find what I am looking for.  :-+
 
If I can solder it in, I can solder it out  :-/O
 

Offline kobaz

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Re: From no parts to decent stockpile, best approach?
« Reply #177 on: September 26, 2017, 03:07:42 am »
Adding a question to the pool.

For capacitors and the like I get the importance of quality.  It's good to avoid the exploding type, etc.

Things like transistors.  How important is it to get high quality transistors from known brands?

For example if I wanted a PNP 2N3906:
https://www.digikey.com/products/en/discrete-semiconductor-products/transistors-bipolar-bjt-single/276?k=2N3906&k=&pkeyword=2N3906&v=497&pv69=80&mnonly=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=500

These are 44 cents each USD.  Versus:
https://www.amazon.com/dp/B06Y49GB3F

I can get 675 transistors at 2 cents each on amazon.  Are they going to catch my bench on fire?  Are they going to produce excessive noise?  Anyone familiar with these?

 

Offline JoeN

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Re: From no parts to decent stockpile, best approach?
« Reply #178 on: September 26, 2017, 08:24:18 am »
For example if I wanted a PNP 2N3906:
https://www.digikey.com/products/en/discrete-semiconductor-products/transistors-bipolar-bjt-single/276?k=2N3906&k=&pkeyword=2N3906&v=497&pv69=80&mnonly=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=500
These are 44 cents each USD.

3904/3906's can be 2 cents each if you buy in bulk/know where to look. 

http://www.newark.com/micro-commercial-components/2n3906-ap/bjt-pnp-40vdc-to-92/dp/69R6840

The SMT versions can be one cent each. 

http://www.newark.com/on-semiconductor/mmbt3906lt3g/bipolar-transistor-pnp-40v-sot/dp/98H0752

I would think the people building kits are getting components from sources that are buying in huge quantities.  The Chinese seem to do it that way (small guys knowing a big guy and getting in on orders so they can get big guy prices for kits to sell on eBay, etc.).  All the other transistors offered, I don't know, not much is as cheap as a 3904/3906.
« Last Edit: September 26, 2017, 08:32:52 am by JoeN »
Have You Been Triggered Today?
 

Offline TheUnnamedNewbie

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Re: From no parts to decent stockpile, best approach?
« Reply #179 on: September 28, 2017, 02:10:26 am »
Adding a question to the pool.

For capacitors and the like I get the importance of quality.  It's good to avoid the exploding type, etc.

Things like transistors.  How important is it to get high quality transistors from known brands?


To be honest, that seems like a very high price for a that transistor. Just a quick search on Farnell shows me that I can get them for a few cents each. I got most of my small-signal transistors for breadboarding from auction sales, but I know that you can order from farnell or RS here through the local component store or the local university. I wouldn't suggest getting unknown devices - when you are prototyping and debugging a circuit, the last thing you need is a shady transistor that might cause the problem.


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Offline adras

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Re: From no parts to decent stockpile, best approach?
« Reply #180 on: October 11, 2017, 12:48:59 am »
As a start I would buy everything in China. Of course it takes some time to arrive. But if you buy everything at once, after two weeks the first packages arrive. And almost everytime you come home there's a new surprise package waiting for you :). When you're done with prototyping and start with final production it makes sense to buy brand components.

  • To get started I suggest an Arduino kit, these kits have a lot of stuff. IR-Sensors, gyro sensors, more sensors, a breadboard, resistors etc, basically everything you need for a first small project.
  • Next comes the "Assorted XXX" search term. Great to get a stock of all kinds of resistors, diodes, capacitors etc
  • Breadboard jumper cables, you can never have enough of them, pretty cheap
  • Wire, from AWG? to AWG? from small to big - I'm always buying the wrong ones, even after looking at the datasheet :D
  • Maybe a cheap oscilloscope kit and a signal generator. Don't expect too much, but it's a start
  • Of course a soldering Iron and solder. And pretty important: Solder flux paste, makes soldering way more easy. I use a Rosin based flux since it's more healthy than some other stuff. I had one which may give you cancer, makes you impotent, and other stuff so I through it away right after opening the package.
  • One of those cutting mats. Great to save your bench from damage.
  • Maybe one of those ESD armbands, although I never managed to fry anything yet. But every professional considers those as mandatory

I think that's all you need to start, everything else can be bought on demand.

The header of the next links is the search term I used, and the link is what the result may look like.

Arduino kit
http://www.ebay.com/itm/ULTIMATE-UNO-R3-Starter-Kit-for-Arduino-Keypad-RTC-1602LCD-Servo-Motor-Gas-Relay-/152145710940?epid=730831715&hash=item236c974f5c:g:tAUAAOSwhQhY7sYK

Assorted Resistors
http://www.ebay.com/itm/300x-30-Values-1-4W-1-Metal-Film-Resistors-Assorted-Resistance-Kit-Set-New-/112341051881?epid=735028540&hash=item1a280c69e9:g:gE4AAOSw4GVYJYyO

Assorted Capacitors
http://www.ebay.com/itm/60pcs-12-Values-1uF-470uF-Assorted-Electrolytic-Capacitor-Assortment-Kit-Radial-/192063668173?epid=1879167269&hash=item2cb7e2ffcd:g:D9oAAOSw5cNYYPFB

Assorted XXX is a great way to get the common parts, resitors, diodes, capacitors etc. Very cheap. Make sure there are values on the paper that holds resistors, otherwise you have to look at each color code to sort them which is a huge pain to me.

Breadboard
https://www.ebay.com/sch/i.html?_odkw=assorted+capacitors&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR1.TRC0.A0.H0.Xbreadbord.TRS0&_nkw=breadbord&_sacat=0

breadboard jumper
https://www.ebay.com/sch/i.html?_odkw=breadbord&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xbreadbord+jumper.TRS1&_nkw=breadbord+jumper&_sacat=0

oscilloscope kit
http://www.ebay.com/itm/Assembled-DSO138-2-4-TFT-Digital-Oscilloscope-Kits-DIY-Parts-1Msps-Probe-/162200576235?var=&hash=item25c3e860eb:g:r7wAAOSw2gxYuMrU
DSO 138 cheap oscilloscope, better than nothing. As a kit a very good practice for SMD soldering

signal generator kit
https://www.ebay.com/sch/i.html?_odkw=oscilloscope+kit&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xsignal+generator+kit.TRS0&_nkw=signal+generator+kit&_sacat=0
cheap as the oscilloscope, better than nothing. There are apps for your smartphone as well

Soldering iron
I've got a cheap chinese one. It's still working, and has a temperature control, awesome! Not imported, bought in Germany so I have warranty.

I'd also pick up some Mosfets. Are these some cheap "general purpose" high current Mosfets?
IRF9540N - P-Channel https://www.infineon.com/dgdl/irf9540n.pdf?fileId=5546d462533600a401535611caa31dc6
FQP30N06L - N-Channel http://cdn.sparkfun.com/datasheets/Components/General/FQP30N06L.pdf
RFP30N06LE - N-Channel http://www.sparkfun.com/datasheets/Components/General/RFP30N06LE.pdf
 

Offline james_s

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Re: From no parts to decent stockpile, best approach?
« Reply #181 on: October 11, 2017, 04:12:13 am »
I buy a lot of parts from China, you can get some good stuff but you have to be careful. Some of it is junk, especially older or more exotic parts are often counterfeit. A part that is fake or substandard can lead to great frustration when a project doesn't work.
 

Offline Old Don

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Re: From no parts to decent stockpile, best approach?
« Reply #182 on: October 11, 2017, 06:30:45 am »
If as you have stated taxes are high in Norway, a way to get cheap parts is to get free broken electronics stuff. Printers, dead computers and other circuit boards obtained from local sources that in many cases are glad to get rid of their E waste since they may have to pay to have it recycled. Strip them for their parts. A cheap hot air gun can strip a board quickly. Sensors and motors from printers can be used for robots. Better than a hot air gun is to invest in a hot air rework station for future BGA circuit work and with/without a large nozzle it with also strip a board. Also, check with local companies and they might have inventory reduction sales of components that they no long need.

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Offline VEGETA

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Re: From no parts to decent stockpile, best approach?
« Reply #183 on: October 11, 2017, 04:34:42 pm »
For me I bought stuff from Aliexpress but it is slow which is acceptable for the price. One thing I like about banggood is that they have warehouses for their stuff, so they are not just a frontend like Aliexpress.

One great benefit of that is that you get all your parts together, unlike Aliexpress where you get them one by one because they are from different sellers.

BTW, how do you sort your components and store them at the bench?

I need a good and cheap way to do it, since I live in Jordan and buying heavy storage tools is pricey.
 
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Offline Awesome14

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Re: From no parts to decent stockpile, best approach?
« Reply #184 on: October 12, 2017, 06:02:19 am »
I'd build your stock slowly. I only say that because building a stock of everything you might need is a naive dream.  However, one of the least time consuming means to build a stock is from salvaged PCBs using a solder pot:
« Last Edit: October 18, 2017, 02:10:12 pm by Awesome14 »
Anything truly new begins as a thought.
 

Offline asmi

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Re: From no parts to decent stockpile, best approach?
« Reply #185 on: October 14, 2017, 01:04:56 pm »
I tend to stockpile only parts that I use in many projects (things like connector strips, LEDs of different colors), and I accumulated many "one extra" parts, which came from following my rule of thumb (buy the amount of parts you need + 1 in case you mess something up). Also since buying powered vacuum pickup, reflow oven and stereo microscope I started using a lot of 0402 passives, so I slowly build up an inventory of them as they are very cheap if you buy them in reels - a 10K reel of 1% 0402 resistors is 10 CAD for almost all values on Mouser, 0402 caps are a bit more expensive, but in many cases you can find 10K reel for 30-40 CAD per reel), and a single reel will last till the end of times for me, and I don't have to worry about bumping one or two off my work table during assembly. Reels are very easy to store too - just put them on a metal rod of some kind.
Basically now whenever I need a value I still don't have, I buy a reel of that value in 0402 package unless any of this is true:
- the passive in question is a resistor which need to dissipate more power than 0402 package can handle
- I know for fact that I will have to de-solder and re-solder this part several times (for example voltage-setting resistors for DC-DC converters). In this case I use 0805 parts because most manufacturers put value label of them - so I can later easily identify values (0402 and most of 0603 parts don't have any labels)
- the component with that value actually exists in 0402 package - this is for caps, which have limits on capacitance and voltage
 

Offline iontodirel

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Re: From no parts to decent stockpile, best approach?
« Reply #186 on: October 19, 2017, 08:16:52 pm »
I personally recommend buying/stocking on a need basis only, don't get something if you don't think you'll need, and categorize components per projects; get components for multiple projects, IMHO you can wait a week for parts from digikey if you want to experiment with something new or work on a new project
« Last Edit: October 19, 2017, 08:18:45 pm by iontodirel »
 

Offline Mr. Scram

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Re: From no parts to decent stockpile, best approach?
« Reply #187 on: October 19, 2017, 11:58:31 pm »
I personally recommend buying/stocking on a need basis only, don't get something if you don't think you'll need, and categorize components per projects; get components for multiple projects, IMHO you can wait a week for parts from digikey if you want to experiment with something new or work on a new project
I've poured some money into a basic collection of classic jellybean parts and components. It has reached the point where I can build a PoC for most ideas with what's around. They are generally not the best performing parts for the job, but they will keep me entertained until I can draw up a schematic and order "real" parts.
 

Offline paulca

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Re: From no parts to decent stockpile, best approach?
« Reply #188 on: November 06, 2017, 07:28:15 pm »
Interesting thread.

Different hobby, but in the radio controlled space I was in for a few years I found over-buying parts in advance caused issues.  I would order stuff, sometimes in bulk, say buying 32 AA NiMh cells, then I discovered with a voltage regulator I could use much more convenient LiPos for that application, so I bought a bunch of pairs of those each and never used the NiMhs ever again.  I still have a bunch of 2000mAh AA cells around, but they aren't even useful for clocks or TV remotes due to their lower 1.2 voltage and high dissipation they only last a few months.

The other issue with over stocking is that stock management comes into play.  You order a whole assortment of stuff, use about 10% of it, then forget exactly what the other 90% was.  6 months down the road you need a particular component, either don't remember you have some or don't remember where exactly they would be and end up ordering more.  Of course after you hit "Buy Now" at checkout you remember where the stock pile is.   Battery connectors were an example.  I think I ordered bags of bullet connectors three times and now have about 200 of them.  Being meticulous about organising things into labelled parts trays and boxes would help, but that's not me.

Shipping cost tends to come into play and aggravate this.  If you are ordering 2 x 555 timer chips the postage is probably more than the chips by an order of magnitude.  You get a better price if you order 10 of them.  So you spend an evening "magpie-ing" around the online store going "one of them, two of those, three of that thing" to lower the differential between cost and shipping.  Then you realise if you order a few more expensive things you get free shipping.  You spend £100 randomly.  The stuff arrives, you flick through it and throw it in a box, happy with yourself.  You don't use much of it for 6 months and then have no idea what you actually have or where you put it all.  So you order it again.

I have plastic tubs and boxes full of RC electrical parts, high amp connectors, low amp JSTs, servo adaptors, battery charge adaptors and splitters, load testers, volt/ammeters, discharge loads, wall warts, you name it.  Most of it still in the plastic bags they came in.

Case in hand.... my ExTech multimeter hasn't arrived yet.  I did some bread boarding yesterday, building logic gates from transistors, figured I must have a volt/amp meter somewhere for RC stuff, but couldn't find anything after an hour going through boxes of stuff.... I'm sure it's there somewhere though.....  back to LEDs, trial and error, and screwing around with my phone camera on zoom to read resistor values.  Still managed to successfully build, ANDs, ORs, NOTs etc.  Though I nearly cooked a few transistors and without a multi-meter couldn't tell that I was driving the full power supply current though the base of the NPN.  No NPNs died though.

Yet, I don't learn my lesson.  I'm currently looking at assorted part kits.  Like a 2600 piece resistor pack.  1000 piece cap pack and still trying to find a sensible assorted pack of logic ICs.
"What could possibly go wrong?"
Current Open Projects:  3 Channel Audio mixer with DAC, BT, pre-amps and h/phone amp, WS281x LED controller Version 2 5V/5A w/Atmega328, FY6600 Power supply, 5A DC Load (Still!)
 
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Offline schenkzoola

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Re: From no parts to decent stockpile, best approach?
« Reply #189 on: November 13, 2017, 10:17:50 am »
I would recommend creating an inventory database of your IC's and more expensive passives.  This can be done with a simple spreadsheet, or a service like partsbox.io.  I find this useful if I am wanting to do a proof of concept, and want to quickly figure out if I have everything I need.

If you start building a commercial project, you will find that the inventory management skills you have developed on the way are invaluable.
 

Offline daedalux

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Re: From no parts to decent stockpile, best approach?
« Reply #190 on: February 21, 2018, 08:27:22 am »
In my experience you tend to stock anything you see use for and can get cheap, but that is not very useful.

What I've found useful to have around is:

- THT resistors kit in abundance. They are useful even to replace smd ones if needed. Higher power than 1/4W you'll have to stock some.
- Capacitor kits. In particular I've found that 1000uF 16V or 35V is very useful for fixing stuff. 100uF and 10uF also tend to appear a lot in designs. 100nF ceramics is a standard DC bypass device that you may buy 1000 units of.
- ICs. The less you have better. You'll never stock enough for fixing stuff. So have 5V 8V 12V 78 regulators, LM324, LM358 and some other op amp and not much else until you know that you need it. Don't stock discrete logic, limit to 74HC00N for example for tinkering
- Have the programable thing you like in abundance. All the same. I like chinese arduino nanos, they have all the peripherals on them and are the cheapest thing.
- Transistors. The most useful is 2N3904 for low power and below about 150Mhz. For medium power IRF510 IRF520 IRF540 mosfets that can even be used in some rf devices and easily fix some stuff. Have also small jfets because they tend to be similar and break easily.
-Have what you break or lose even if is not electronic, lots of fuses and small screws, insulators, solder tips, power resistors that you see on your devices.
-Have magnet wire and cores, and whenever you need a coil you can make your own (seldom), the magnet wire will be more useful for fixing PCBs.
« Last Edit: February 22, 2018, 02:19:05 am by daedalux »
 

Offline FrankE

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Re: From no parts to decent stockpile, best approach?
« Reply #191 on: March 03, 2018, 07:27:16 am »
I can't move in the house for components and things for repair
I keep finding reels of hook up wire, barely used. A single reel would have done, some of that rainbow  ribbon they sell to arduino tinkerers and whatever I can rip out of eWaste people put out in the street for disposal.
ICs, nah, they can go out of favour or simply won't get used. JIT for common stuff like that.

Bags of SMD samples and some through hole caps have been the most useful things to keep.

If I can't get schematics for big ticket items and they make use obscure parts it's handy to get spares of things like ASICs obscure transistors and FETs while it's still a production item. Manage the obsolescence.

I'd rather spend money on good kit, tools optics and have decent consumables than concern myself with waiting over a weekend for a part. If one's offering a commercial service of repairing a brand of something eg a brand of mobile telephone then there's more sense in stocking parts for turnaround and maintaining workflow.

There'll be as many Availability philosophies as there are people and circumstances though, so each to their own.

I bought 8 boxes of Jacob's biscuits for cheese (800g) in early January on sale, just for the boxes for components. I've eaten so much cheese as a consequence I have reflux. Oh, the sacrifices.
 

Offline whoKnows

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Re: From no parts to decent stockpile, best approach?
« Reply #192 on: March 25, 2018, 07:47:36 am »
easiest thing is to unsolder basically everything from every board you get
 ....
 

Offline tkamiya

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Re: From no parts to decent stockpile, best approach?
« Reply #193 on: June 07, 2018, 05:38:59 am »
I do, contrary to my own advise, buy from China often.  But I sometimes end up with parts that aren't usable.  One example is a 50 ohm BNC terminator.  Ebay seller had this bag of terminators for price less than one would cost from Digikey, so I bought 20.  Connection and performance is iffy, measured by me, so I took my hacksaw and found out why.

Inside was a regular 1/4 watt register.  The ground side is not soldered anywhere but wire simply folded back and forced into a heatsink look like area. 

Put it on a return bridge and wiggle....  or just let it sit.  I can see reflection changing wildly.  Basically unusable. 


So I have a reservation in buying large quantity from unknown sellers.  (basically all China sellers)  What's critical, I buy from Digikey.  Imagine if I bought 100 bag of these?
 

Offline ez24

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Re: From no parts to decent stockpile, best approach?
« Reply #194 on: June 07, 2018, 02:32:02 pm »
So I have a reservation in buying large quantity from unknown sellers.  (basically all China sellers)  What's critical, I buy from Digikey.  Imagine if I bought 100 bag of these?

I agree   What I do on Aliexpresss is sort on "Orders" and pick the seller with the most orders.   I think this helps
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Online HB9EVI

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Re: From no parts to decent stockpile, best approach?
« Reply #195 on: July 21, 2018, 05:12:21 am »
Isn't actually the worst thing in piling up tons of compenents the fact, that whenever you have an idea and want start from the scratch a new project, you realize, that this is missing and that is missing - and the more often that happens, the more you start thinking, it might actually be a good idea to have a proper stockage of "&+°?$.

So there you go, starting to buy the complete set of E24 1% resistors in through hole and today in SMD too, you buy caps in ceramic, foil and electrolyte, every kind of bjt and fets, opamps, logics, mcus and like me RF parts too. In the end you have the lab full with drawer compartments and boxes - and, with the next brilliant idea you sit down at the bench and realize, that half of the needed components are missing.

It simply never ends
 


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