Author Topic: The $250 electronics lab, a suggested setup for beginners.  (Read 33406 times)

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Offline Lightages

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The $250 electronics lab, a suggested setup for beginners.
« on: July 22, 2013, 08:39:44 am »
So as an answer to Dave's lab equipment video I thought I would set myself a challenge to make a very useable lab for under $100. Sorry can't be done. So I went for the minimum I would consider as a well equipped enough lab and it can come under $250 delivered to your door!

Now I know that there are many people who would not go near www.dx.com but I have had only a couple of less than acceptable things from them and they have always compensated for my problems. They sell some relatively good stuff, some OK stuff, and some outright junk. I hope to guide the beginner here to buying a complete lab from at least OK stuff from them. I have not touched everything I am going to list but I am fairly confident that it won't be junk.

What is my idea of a minimum lab for a beginner? Well it might be a bit higher than what some people started out with but the price is not that high. If you exclude one of the items that people might not think is necessary, a USB oscilloscope, then you end up with much less than $180 shipped to your door. If you omit the second DMM, then it drops to less than $160 shipped to your door. If you want to drop the USB scope, then that is up to you. I sincerely believe that the second DMM is very much worth having. Here is the list in links to the dx.com listing:

http://dx.com//p/128293   Uni-T UT136B DMM with capacitance                $20.80
http://dx.com//p/168367   Uni-T UT136C DMM with temperature               $21.70
http://dx.com//p/1874       Kada 936D soldering station                            $45.70
http://dx.com//p/39508     0-15V variable power supply                            $43.90
http://dx.com//p/107293   Helping hands with magnifier                           $11.60
http://dx.com//p/173773   Desoldering pump                                              $3.10
http://dx.com//p/145819   Desoldering wick                                                $2.30
http://dx.com//p/4643       0.6mm solder                                                     $9.99
http://dx.com//p/19908     Flush cutting side cutters                                   $3.39
http://dx.com//p/3552       Tweezer set                                                       $2.32
http://dx.com//p/7066       Small needle nose pliers                                    $3.03
http://dx.com//p/30601     31 piece screw driver set                                 $10.14
http://dx.com/p/830-point-solderless-breadboard-118354   Experimenter breadboard                                   $5.40
                                                                                           Total              $183.37

http://dx.com//p/201072   48 MS/s USB oscilloscope                                 $70.70   (optional)
                                                                                           Total              $254.07

>A suggestion from AG6QR, an Elenco power supply kit:
http://www.testequipmentdepot.com/elenco/power-supplies/xp720.htm
which is especially good for those in North America. $50 plus shipping.

Now I know this will open a hornet's nest of opinions and comments, but this is what I think a good beginner's lab could use. Keep in mind this is from the viewpoint of a starved student, or a spouse nagged beginner, or a teen spending from an allowance or a part time fast food job.  I am sure someone will have a problem with one, or even all of my selections. Too bad! This would make a really useful beginner's setup IMHO. I would have killed for something like this when I was 15. Just don't use the multimeters suggested here in the wall socket.

If you are reading this, then you have a computer already to use the USB scope but almost all of the experienced electronics people here started out without an oscilloscope.  Having said that an oscilloscope is very useful even if it is a cheapo USB one. I would also strongly push having two meters so you can measure volts and amps at the same time.

P.S.
This list is not meant to represent the pinnacle of quality. It is a list of useable gear that is available world wide at the same price for everyone, shipped to your door. The power supply and soldering station are for 220VAC.

Edit:
Added an incredible oversight! I added a solderless breadboard that is an obvious need. It pushes the end price to over $250 by $4, but it is almost necessary.
« Last Edit: July 24, 2013, 08:26:01 pm by Lightages »
 

Offline jancumps

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #1 on: July 22, 2013, 09:43:29 am »
The wick and solder are consumables. You can leave them out and spend 12$ on something else.
Creative bookkeeping :)
 

Offline ElectroIrradiator

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #2 on: July 22, 2013, 10:10:04 am »
*) Scope: Free. Find a working <= 20 MHz dual channel analog oscilloscope, which the owner will give a beginner for free. They are free, because shipping will cost more than selling them online will bring in.
*) PSU. I doubt the unit you link will deliver the promised amount of current. The TO-3 pass transistor/IC is mounted on the top of the chassis back, which is unlikely provide enough cooling for that.
*) A dual rail PSU is also very handy to a beginner, even early on. For instance they are nearly mandatory, once you start to work with opamps. Yes, you can create a virtual ground, but that just makes things harder for no apparent gain.
*) DMM: Two DMM's is way overkill for a beginner. Settle on one model.
*) Helping hand: Never had an use for those, way too flimsy for my liking. I use a vice when I need stuff held.
 

Offline Psi

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #3 on: July 22, 2013, 10:13:16 am »
Yeah, don't bother with cheap desoldering wick, its not worth wasting even a cent on.
Get chemtronics or one of the other good brands as that stuff actually WORKS :)
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Offline Lightages

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #4 on: July 22, 2013, 10:19:02 am »
Maybe the solder and wick aren't "kit" but they would be needed to start. I have no experience with the cheap wick I have listed so I will not vouch for it. As far as dual rail supply for op amps, a couple of 9V batteries work very well and it is very hard to find dual output supplies under $200 themselves.
 

Offline ElectroIrradiator

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #5 on: July 22, 2013, 11:01:52 am »
(Snip.) As far as dual rail supply for op amps, a couple of 9V batteries work very well and it is very hard to find dual output supplies under $200 themselves.

The catch is that people very quickly tire of buying new batteries, as you really cannot power much from those for very long. So the experimenters end up spending time and effort to 'redesign'/asking for help with the dual rail examples in their books, instead of just building them.

I would suggest the PSU should be the crowning jewel in any beginner setup, and yep, it will cost you. Few people, who are experienced enough to ask for a dual rail supply, will be happy with a One Hung Lo design. So the multi rail supplies tend to cost up around $100 per rail, as they actually have to perform to the manufacturer's claims regarding specifications.

Find a good dual rail supply to include in the kit, and spend the rest of the budget on cheap sh!t. ;)
« Last Edit: July 22, 2013, 11:04:39 am by ElectroIrradiator »
 

Offline jancumps

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #6 on: July 22, 2013, 12:36:54 pm »
Maybe the solder and wick aren't "kit" but they would be needed to start.
yes they are needed.
But if you count them in, you are out of budget and have to stop.
If you don't count them as lab gear you have a small budget of 12$ to spend wildly on fun stuff  ;)
 

Online madires

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #7 on: July 22, 2013, 01:22:04 pm »
I think that the shopping list is quite realistic.

*) Scope: Free. Find a working <= 20 MHz dual channel analog oscilloscope, which the owner will give a beginner for free. They are free, because shipping will cost more than selling them online will bring in.

If you're lucky. Over here not just a few ebay sellers try to rip you off with 15+ years old Hamegs (HM203 ...).

Quote
*) PSU. I doubt the unit you link will deliver the promised amount of current. The TO-3 pass transistor/IC is mounted on the top of the chassis back, which is unlikely provide enough cooling for that.

I'd assume the PSU has to dissipate 20W for the worst case and the metal box isn't that bad. Our beginner could add a heatsink as one of his first projects :-)

Quote
*) A dual rail PSU is also very handy to a beginner, even early on. For instance they are nearly mandatory, once you start to work with opamps. Yes, you can create a virtual ground, but that just makes things harder for no apparent gain.

IMHO, 15V and 1A is totally fine for a beginner. I've started with the simple PSU I got with the model railway.

Quote
*) DMM: Two DMM's is way overkill for a beginner. Settle on one model.

Maybe, but a DMM and an AMM would be a nice combination.

Quote
*) Helping hand: Never had an use for those, way too flimsy for my liking. I use a vice when I need stuff held.

They're quite useful for smaller PCBs.
 

Offline liquibyte

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #8 on: July 22, 2013, 02:34:57 pm »
Please point me in the direction of the person that would give away an o-scope.  I consider myself newish on the equipment side and have basically decided the only way I'll ever own one is to try and build it.  Same with power supplies.  I do have a Craftsman 82139 DMM which seems to work ok fwiw.  My soldering iron is a cheap Weller that takes (and eats through rather fast) the MT-1 tips.  I also have the required hand tools plus many that aren't.  I have found that a nice set of jewelers screwdrivers that can do flathead, phillips, torx, and hex are invaluable for taking things apart.  A really good set of wire cutters is essential to me.

See, I'm poor but I make due.  I have the wonderful state of MA to thank for this because in their infinite wisdom I don't have the required experience to keep my CDL which I've had since 2006 so I can't get work to make money to buy the nice things.  I envy those with multiple instruments in excess but I've relegated myself to looking at things and slowly figuring out how they work enough to duplicate them.  I actually have a setup that would come in under $100 and it works for me.
 

Offline Kernel

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #9 on: July 22, 2013, 03:12:24 pm »
Wow that website is very Australia friendly, jeez I'm glad I haven't bought anything more than a brand new Atten soldering station from local suppliers and of course solder. Think I'll see what stuff they have for me to kit the rest of myself out with :)
 

Offline Bored@Work

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #10 on: July 22, 2013, 05:09:09 pm »
http://dx.com//p/39508     0-15V variable power supply                            $43.90

Of all the *cough* quality *cough* stuff you selected this is probably the worst of the worst. Metal enclosure, but as you can see from the image, no PE connection.

http://img.dxcdn.com/productimages/sku_39508_2.jpg

I happen to have seen the inside of similar "mobile phone repair" PSUs. They aren't double-isolated, far from it. They need ground.
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Offline Lightages

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #11 on: July 22, 2013, 06:38:20 pm »
Yes, that power supply is scraping the bottom, but not many choices in that price range. I guess that could be another "first project", to replace the power cable with an earthed version. They are free if you look around and find a discarded appliance some times.

As far as quality goes, yes the list includes some questionable things but it is what you get when you have low funds.
 

Offline edavid

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #12 on: July 22, 2013, 07:06:37 pm »
I think the UT136B is a good choice, but the second DMM could be a $4 version.

The helping hands are probably good for a beginner who might burn him/herself, but they are cheaper on eBay.  I think of them as a $3 swap meet item, but I guess they've gone up.

What about wire strippers?  They are a higher priority than the screwdriver set.

A plain soldering iron would be OK to start off.

The power supply could be replaced by an ATX supply, or a set of wall warts (2 12V, 1 5V).
 

Offline edavid

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #13 on: July 22, 2013, 07:09:50 pm »
Please point me in the direction of the person that would give away an o-scope.

Go directly to craigslist.  Post a want ad saying you want to learn electronics and you only have $20 or whatever to spend on a scope.

Quote
I have the wonderful state of MA to thank for this because in their infinite wisdom I don't have the required experience to keep my CDL which I've had since 2006 so I can't get work to make money to buy the nice things.

But leave this out, no one wants to hear excuses.
 

Offline Lightages

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #14 on: July 22, 2013, 07:14:55 pm »
What about wire strippers?  They are a higher priority than the screwdriver set.

Wire strippers are nice to have, but you don't need then. It is easy to strip wires with side cutters or a knife. But why not? Sure throw in a cheapo set of wire strippers if you really want them.
 

Offline AG6QR

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #15 on: July 22, 2013, 07:19:26 pm »
Yes, that power supply is scraping the bottom, but not many choices in that price range.

Well, for only a wee bit more, (about $60) you can get the Elenco XP-720K, which has positive and negative variable rails, and a separate fixed 5V rail, a properly earthed line cord, a rugged metal enclosure, and a very detailed construction manual giving the theory of operation.  It does lack some common features of a "proper" bench supply (no meters, no adjustable current limit, no voltage adjustment below 1.25V), but if you can live with those limits, I'd have no problem recommending it as a beginner's first kit assembly project.

Or if that's beyond your budget, getting a UL-listed DC wall-wart style fixed DC supply and adding a LM-317 based regulator is a safe alternative.  There are plenty of sources (Adafruit among them) of kits for the regulator portion, or you can roll your own as a first project in prototype construction techniques.  The basic schematic is on the LM317 data sheet.
 

Offline Lightages

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #16 on: July 22, 2013, 07:25:25 pm »
Yes, that power supply is scraping the bottom, but not many choices in that price range.

Well, for only a wee bit more, (about $60) you can get the Elenco XP-720K, which has positive and negative variable rails, and a separate fixed 5V rail, a properly earthed line cord, a rugged metal enclosure, and a very detailed construction manual giving the theory of operation.  It does lack some common features of a "proper" bench supply (no meters, no adjustable current limit, no voltage adjustment below 1.25V), but if you can live with those limits, I'd have no problem recommending it as a beginner's first kit assembly project.

Now that is a really good alternative to the dx.com PS especially if you are in North America and have 110VAC.
http://www.testequipmentdepot.com/elenco/power-supplies/xp720.htm
 

Offline Dave

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #17 on: July 22, 2013, 07:30:56 pm »
I would try to avoid a USB oscilloscope (they are a pain to use) and instead go for a second-hand analog. You can find plenty at HAM fairs or eBay. Just remember, patience is key - if you keep looking for long enough, you will eventually find a good one for a decent price. :-+
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Offline liquibyte

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #18 on: July 22, 2013, 07:35:30 pm »
Please point me in the direction of the person that would give away an o-scope.

Go directly to craigslist.  Post a want ad saying you want to learn electronics and you only have $20 or whatever to spend on a scope.

Quote
I have the wonderful state of MA to thank for this because in their infinite wisdom I don't have the required experience to keep my CDL which I've had since 2006 so I can't get work to make money to buy the nice things.

But leave this out, no one wants to hear excuses.

I think building one would be more rewarding at least as a learning experience though certainly not top of the line.

Second point. It's not an excuse, it's the truth.  We have one car and there is nothing within walking distance that is hiring.  I went to not one but two driving schools and have been driving commercially for six years.  The state requires I have two years verifiable employment history plus driving history plus the medical certification to convert my license.  This is akin to them refusing you a license because you haven't been driving for two years in their state or working for two years anywhere.  I plan on fighting and getting their requirements nullified because unlike your license, mine is a federal document.  How would you feel if you moved to another state and they said that they wouldn't convert your license without taking all of the tests again including the road test?  See the double standard?  I'm not applying for a job with them and their requirements are, in my opinion, illegal.
 

Offline PA4TIM

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #19 on: July 22, 2013, 07:42:50 pm »
PSU: first project, my first was made with a transformer with two outputs and  two LM317
Wick, have it but almost never use it, Have done many years without it. Used a cheap solder sucker a long time (now a pace desolder station)
screwdrivers, important if you do repair, but buy a set of small watch screwdrivers and a cheap bitset to start
Good sidecutter, tweezer and plyers are important
Scope, my most important piece of kit, I have bought only 3, I have around 15....... So do not say they are not free around. This week I turned an offer for two Free Teks down, asked around, nobody was interested. Now they probably end up scrapped. If I wanted I could have 30 scopes by now. (but the free ones most times need work and often are big or tube equiped. A 50 or 100 MHz is rare, but not impossible (in my case a Tek 465 and 453) Just got a free capacitance Bridge and a Tek spectrum analyser (but needs repair).
Solderiron and very good solder:  I have some stations but also two very old (>25 year)  ESRA 16W irons, they are still in production, tips are for sale (mine still has the firts tips) and they are really great , use them when I need to solder outside my lab and I manage to solder SMD on a groundplane with them with ease. When I started I bought a cheap iron, it sucked, then a second, even worse, then a friend gave me the two Esra. Used them much until I bought a Weller station.
Multimeter: yes but a decent (expensive) one or the cheapest one you can get because under 50 bucks the sucks ;-) (go agaid, hang me, I do not care) , current meter,  Why ? Just measure the voltdrop over a resistor, the multimeter does it the same way. Buy a 1, 10 and 100 Ohm  1% (power)resistor, put bananabusses on them and mount them on a metal plate or old heatsink
breadboard ? why ? just learn to solder deadbug
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Offline liquibyte

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #20 on: July 22, 2013, 08:11:00 pm »
Yeah, I've been cutting my teeth on linear regulators trying to figure out what works best etc.  I've built maybe six with the 317, 337, and 350's.  I really need to put together a load for testing and have a few in mind.  I usually just find junk and salvage what I need and so far it's worked out ok.  I suppose I might keep a post going for unwanted used bits on craigslist.  I always figured that I wouldn't really need an o-scope until I got to the point of knowing I needed one.  So far this hasn't happened and I'm not sure it ever will.  I get the usefulness of what they are, I just never saw the need for one other than  bragging rights.

I have plans for several things that I would like to try just to see if I could.  My recent want is to try and build a PD 2020B off of the schematic by getting the bits together a little at a time, kind of a one off clone minus the fancy dials etc.  From what I've heard, they seem well built and I'd like to see if that can be replicated.

Oh, and I'm not trying to make folks feel sorry for me or anything, just sharing my story.  I suppose I'm living proof that you can do much with very little and do it successfully.  Soldering iron, $35 multimeter and basic hand tools plus breadboards and perfboard is what I use and I have done many a successful project with just that.  It's fun and that's the point I guess.
 

Online Monkeh

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #21 on: July 22, 2013, 10:27:46 pm »
That crappy little PSU can be had for $26 elsewhere. Almost tempted, but there are nicer looking ones: http://www.ownta.com/index.php?dispatch=products.view&product_id=57416

Anyone used that site? Curiously low prices.
 

Offline edavid

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #22 on: July 23, 2013, 01:13:11 am »
That crappy little PSU can be had for $26 elsewhere. Almost tempted, but there are nicer looking ones: http://www.ownta.com/index.php?dispatch=products.view&product_id=57416

Anyone used that site? Curiously low prices.

Not really.  By the time you add shipping, that model is $10 more than on eBay.
 

Online Monkeh

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #23 on: July 23, 2013, 01:14:43 am »
That crappy little PSU can be had for $26 elsewhere. Almost tempted, but there are nicer looking ones: http://www.ownta.com/index.php?dispatch=products.view&product_id=57416

Anyone used that site? Curiously low prices.

Not really.  By the time you add shipping, that model is $10 more than on eBay.

Ah. The other one had no additional shipping charge. Interesting.

http://www.ownta.com/best-1501s-regulated-dc-power-supply.html

Again with the tempting at such a low price.
« Last Edit: July 23, 2013, 01:17:29 am by Monkeh »
 

Offline Rick Law

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Re: The $250 electronics lab, a suggested setup for beginners.
« Reply #24 on: July 23, 2013, 03:50:58 am »
Interesting.  $250-$300 is what I ended up spending when I decided to go back to do some EE for fun.

For real "limited budget power supply", get a pair of cheap Chinese Boost, Buck, or Boost+Buck board.  The 5W-10W Boost+buck with "constant current" is about 8$-$15.  The buck-only (2v-25vish) are under $5.  The "constant current" has a current limiter.  It gives some protection preventing huge current going into the circuit I am playing around with.  I have one that is boost only, and one that is boost+buck.  I use two separate unearth grounded wall-warts to feed these boards.  I choose unearth-grounded wall-warts so the two boards are floating/isolated.  I can use them in series to give me +/- supply, or use them separate as two individual power supplies.

Not a lot of power at 5-10W, 2.0v to 30v.  But enough to test little things and build little projects.
 


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