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Building a lab. Essential components?
Posted by
dog80
on 09 Oct, 2013 17:03
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Many times I see some interesting circuit on the net, but there will always be some component that I will not have, so I can't build it. Usually it will be something simple and common like a zener or a coil.
Local shops are crap so my only choice is Digikey or some similar e-shop. But they usually charge an arm and a leg for shipping so it doesn't make sense to order a component that costs a few pennies and pay 20+ euros on shipping.
I am trying to make a big list of essential components so I can place a single big order.
Any help?
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#2 Reply
Posted by
Dave
on 09 Oct, 2013 17:23
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I usually build an order in Farnell's shopping cart over the course of weeks, and when there is enough stuff in there, I submit my order. It's a good thing the shopping cart doesn't get reset there, so you can have items in there for as long as you want, you won't lose anything.
When I order components, I usually order as many as I need, times two (or more - if they are cheap; or the exact amount needed - if they are super exotic and cost a lot). Do this a couple of times and you should have an assortment of components you can work with.
Pick a couple of circuits you want to make and buy the components in bulk. Buying "beginner assortments" is pure nonsense, because you will never use half of the stuff you will pay. But that's just my opinion.
No matter how hard you will try to think of everything you will need, you will ALWAYS forget to order SOMETHING and realize that an hour after you have placed your order. It's REALLY irritating, it used to drive me mad, but eventually I just got used to the fact that Murphy will screw with me every single time.
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#3 Reply
Posted by
Grobalo
on 09 Oct, 2013 17:51
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Someone on the forum recommended this address:
http://futurlec.com/ValuePacks.shtmlIt's really cheap, and shipping cost are affordable too. I just bought 50$ of mixed components, only 5$ shipping to Europe.
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Someone on the forum recommended this address: http://futurlec.com/ValuePacks.shtml
It's really cheap, and shipping cost are affordable too. I just bought 50$ of mixed components, only 5$ shipping to Europe.
I'd suggest googleing "Futurlec complaints". I've had problems ordering from these mysterious folks.
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I usually build an order in Farnell's shopping cart over the course of weeks, and when there is enough stuff in there, I submit my order. It's a good thing the shopping cart doesn't get reset there, so you can have items in there for as long as you want, you won't lose anything.
When I order components, I usually order as many as I need, times two (or more - if they are cheap; or the exact amount needed - if they are super exotic and cost a lot). Do this a couple of times and you should have an assortment of components you can work with.
Pick a couple of circuits you want to make and buy the components in bulk. Buying "beginner assortments" is pure nonsense, because you will never use half of the stuff you will pay. But that's just my opinion.
No matter how hard you will try to think of everything you will need, you will ALWAYS forget to order SOMETHING and realize that an hour after you have placed your order. It's REALLY irritating, it used to drive me mad, but eventually I just got used to the fact that Murphy will screw with me every single time.
True that !!! I do the same with the Mouser folks. Waiting on parts drives me NUTS! I will usually have 3-4 different circuits in progress, so that I can be working on SOMETHING while waiting...waiting....
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#6 Reply
Posted by
olsenn
on 09 Oct, 2013 18:29
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My two favourite sites for purchasing bulk components are futurlec.com and dipmicro.com. Futurlec (as some have mentioned already) have some poor business practices (make substitutions of out-of-stock items without letting the customer know, etc) but they are mostly pretty good, and their prices are MUCH cheaper than anywhere else. It sounds like you don't have a specific project in mind but rather want to stockup on bins worth of random items... Futurlec is great for this!
Dipmicro has an excellent 0.5-watt 1% metal-oxide resistor kits with 20 of each E12 resistor value. They also have great kits available for 0.5mm/0.3mm LED's, Zener diodes, electrolytic capacitors, crystal oscillators, etc. They also have really cheap prices on 1N4148 etc diodes, 2N3904/2N3906/TIP31/TIP32 transistors, schottky diodes, etc.
I mostly only use mouser/digikey for specific items that I can't find elsewhere. They're more professional, faster shipping, and have a wider variety of items; however, they're also more expensive. However, for some items that I buy in bulk, I do use these for (UA741 op-amps, Atmega328P MCU, etc).
If you're serious about setting up a lab, spend between $500 - $1000 on components. That sounds like a lot, but why spend that much on an oscilloscope or multimeter and not on the components you'll actually need. Make sure this includes hook-up wire, ALL E12 resistors and capacitors, inductors, header pins, switches, pushbuttons, breadboards, connectors/jacks/plugs, digital logic IC's, op-amps, tranistors, (power/small-signal/zener/schottky)diodes, crystals, potentiometers, protoboards, LED's, phototransistors, and anything else you might need. And for the love of god, buy bin-arays to store these components in! Don't (for example) mix up all the resistors and then try to decipher color codes every time you need one!
It's daunting; however, if you're like me, you won't have the motivation to build something unless you already just-so-happen to have the required components on hand. Leave specific/rare items until you actually need them though.
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#7 Reply
Posted by
odv000
on 09 Oct, 2013 19:29
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just get some old TV!
you will find almost everything you would need for beginner hobby projects there!
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Dave's remark about always forgetting something an hour after placing your order made me chuckle.
Nothing is truer! There have been times when I've had 3 separate active orders from Mouser all in transit to my house at the same time because I kept forgetting something!
I agree, there isn't much sense in buying the "component kits" that are targeted toward beginners. I make my own kits based on what I need. Sure, you're gonna pay in shipping costs for placing an order every time you need something new, but in this case, you pay for convenience, and if you want a well stocked lab with all the necessary components you can think of, be prepared to fork over some cash, cuz it ain't gonna be cheap! Do what Dave suggested and build up a shopping list over the course of two or three well planned out projects, then place the order.
Besides that, salvaging old equipment is an excellent source of components. Look for electronics from the 80's. They're a good source for 7400 series logic chips!
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I usually build an order in Farnell's shopping cart over the course of weeks, and when there is enough stuff in there, I submit my order. It's a good thing the shopping cart doesn't get reset there, so you can have items in there for as long as you want, you won't lose anything.
When I order components, I usually order as many as I need, times two (or more - if they are cheap; or the exact amount needed - if they are super exotic and cost a lot). Do this a couple of times and you should have an assortment of components you can work with.
Pick a couple of circuits you want to make and buy the components in bulk. Buying "beginner assortments" is pure nonsense, because you will never use half of the stuff you will pay. But that's just my opinion.
No matter how hard you will try to think of everything you will need, you will ALWAYS forget to order SOMETHING and realize that an hour after you have placed your order. It's REALLY irritating, it used to drive me mad, but eventually I just got used to the fact that Murphy will screw with me every single time.
True that !!! I do the same with the Mouser folks. Waiting on parts drives me NUTS! I will usually have 3-4 different circuits in progress, so that I can be working on SOMETHING while waiting...waiting....
Lucky for me I am within 1 day shipping range of Mouser no matter what shipping option I choose.
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#10 Reply
Posted by
robbag
on 10 Oct, 2013 02:29
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There is always eBay, but be prepared to wait for it if shipping from china. It's surprising how much you can get for so little cost on eBay, but beware of non-genuine parts.
Otherwise there is element14, for fast shipping and reasonable pricing.
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#11 Reply
Posted by
rexxar
on 10 Oct, 2013 03:32
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If you mail a check to DigiKey, you get free shipping, but then you have to wait twice as long for your check to get to them, then for your stuff to get to you.
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#12 Reply
Posted by
sleemanj
on 10 Oct, 2013 04:15
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Resistor selection, I have a few hundred through hole, and a few thousand 1206 size.
I keep the 1206's in 7 day pill organisers (4 compartments per day), the ebay selections etc I think tend to have too many, or too few, or not the sort of combination that would be "efficient", I only keep certain values which I selected myself....
1, 10, 100, 1k, 10k, 100k,
1r5, 15r, 150r, 1k5, 15k, 150k,
2r2 ... to ... 220k,
2r7 ... to ... 270k,
3r3 ... to ... 330k,
3r9 ... to ... 390k,
4r7 ... to ... 470k
5r1 ... to ... 510k,
1M,
120R, 180R, 240R, 300R, 360R, 430R (useful inbetweeners in the "typical LED current limiting" area).
The through holes are just some random sample pack, ebay, futurelec, somewhere like that.
Add some trimpots as well, up to 1k.
Capacitor pack, again, random sample pack from ebay, futurelec etc. Electrolytics and ceramic.
Linear regulators - 12, 5, 3.3 and adjustable, always handy.
Transistors/Mosfets - the transistor selections you can buy on ebay IMHO tend to have too many different ones, especially if you are mostly dealing in mainly low speed digital electronics, you might not find too much use for 80% of the pack. Here are what I have around...
100mA: 2n2222 (NPN), 2n2907A (PNP) - (SMD equivalent eg MMBT2222A, MMBT2907A)
10mA: 2n3904 (NPN), 2n3906 (PNP) - (SMD equivalent eg MMBT3904, MMBT3906)
Darlington Array - (available in SMD also)
2N7000 mosfet (N Channel) - (SMD equivalent 2N7002)
Maybe a few discrete power transistors and mosfets, but those are more the sort of thing you might get for a specific project (since they can be costly).
If you are looking at SMD, then I'd also suggest as potentially useful and cheap from china:
SS8050LT1 (NPN, 600mA - 1500mA), SS8550LT1 (PNP complement of that), SI2302DS (N Channel Mosfet), AP2305(A)GN (P Channel Mosfet)
Normal Diodes: 1N4007 (or 1N4004, whatever is cheapest on the day), 1N5819
Zener Diodes: Whatever you think might be useful, 5v1, 5v6, 3v6, 6v8, 15v
Light Emitting Diodes: A selection, through hole in 5mm and/or 3mm, and if you like SMD (1206 size or smaller).
ICs: 555 timer of course, H-bridge driver (L293D, SN754410NE or similar), shift registers (SIPO, and PISO), some LM324 or similar op-amps, a micro controller or two of your favourite breed
Hardware: tact switches (in various shapes and sizes), screw terminals, 2.54mm headers (single straight ones (you can use two togethor for doubles), and some single/double angled ones; in both genders). You might want to keep a couple of larger potentiometers, and toggle switches around too.
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If you are buying lots of basic parts, Tayda Electronics is really cheap, and has better reviews than Futurlec. I believe they are located in China (India possibly?), so shipping takes a long time, but they have most of the basic parts you will need for cheap. I would recommend getting common parts here, like resistors, capacitors, etc. I haven't ordered from them personally, so I can't really comment on quality or anything.
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#14 Reply
Posted by
Psi
on 10 Oct, 2013 09:48
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One digikey order big enough to get free shipping would get you a HUGE amount of passive components of various values.
Probably cheaper than a passive component kit too.
Does anyone know if digikey frown on this sort of thing?
Ordering 1000x 2c items with QTY of 5 ?
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#15 Reply
Posted by
Fsck
on 10 Oct, 2013 09:52
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One digikey order big enough to get free shipping would get you a HUGE amount of passive components of various values.
Probably cheaper than a passive component kit too.
Does anyone know if digikey frown on this sort of thing?
Ordering 1000x 2c items with QTY of 5 ?
I don't think they have too much of a problem with it. I did that with basically every banana plug or banana jack/shrouded jack they had. just ordered 2 of every type I thought I'd like to investigate
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#16 Reply
Posted by
Stonent
on 10 Oct, 2013 11:16
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Sometimes I've found US seller eBay prices as good as low quantity Aliexpress prices or such a small difference it wasn't worth the wait. Plus find a local shop sometimes they'll get a bunch of surplus stuff and turn it around quickly.
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#17 Reply
Posted by
grego
on 10 Oct, 2013 15:12
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Digikey doesn't care. They'll happily take your money regardless.
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#18 Reply
Posted by
Jebnor
on 10 Oct, 2013 19:37
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How about BNC patch cables? I have been keeping my eye out for them, but I don't really know where to find them, other than the big guys like digikey. Anyone know of a less expensive source for BNC connectors, cables and accessories?
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#19 Reply
Posted by
dennisyuki
on 15 Oct, 2013 14:56
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Someone on the forum recommended this address: http://futurlec.com/ValuePacks.shtml
It's really cheap, and shipping cost are affordable too. I just bought 50$ of mixed components, only 5$ shipping to Europe.
Does anyone know where they ship from in the US? I saw that NY was their US headquaters, but it said no stock at loction. Just curious on delivery time.
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#20 Reply
Posted by
olsenn
on 15 Oct, 2013 15:06
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Does anyone know where they ship from in the US? I saw that NY was their US headquaters, but it said no stock at loction. Just curious on delivery time.
I don't know where their warehouse is; however, if you need these parts urgently, DON'T order from Futurlec! Shipping is very slow; they sometimes take several weeks just to post the parcel in the mail in the first place.
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#21 Reply
Posted by
JuKu
on 16 Oct, 2013 06:51
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Adafruit SMD kits are worth getting.
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#22 Reply
Posted by
ju1ce
on 16 Oct, 2013 07:55
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If you are buying lots of basic parts, Tayda Electronics is really cheap, and has better reviews than Futurlec. I believe they are located in China (India possibly?), so shipping takes a long time
Guess again
They're located in Thailand. I really recommend them over Futurlec, even though they've got quite a limited selection of components available. It's worth it to check their Facebook page before ordering as they have a discount coupon in there approximately once a month.
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#23 Reply
Posted by
olsenn
on 16 Oct, 2013 14:12
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SMD kits are, in my opinion, pointless (unless you are doing repair work for boards that use them). The OP's intended purpose was to equip a lab with all the basic parts to build some simple circuits he finds online, and mess around. This is screaming breadboard work, aka through-hole.
Once the ptototyping is complete and professional PCB boards are designed, they can be designed around SMD parts to save space and improve double-sided realestate.
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#24 Reply
Posted by
Rigby
on 16 Oct, 2013 14:55
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If you go to jameco.com and search for 'grab bags' and/or 'assortment' and you'll be able to find a lot of quick inexpensive purchases that will eventually suit you well, and will force you to learn proper organization in the meantime.
They have a completely random grab bag for $20 which is one of their best selling items. Bag full of random stuff from their catalog, I guess.