Where to go to learn how to build electronic circuits, gates, etc.?

December 27, 2004 5:06 AM

Do Radio Shack's "50 in 1" electronic kits really teach EE skills? I'd like to be able to understand and build circuits, gates, etc. Experiences? Recommendations?
posted by skallas to sports, hobbies, & recreation (20 comments total)

Not that I've had much experience with the Radio Shack electronic kits... but am definately interested in the results of this question. I've always had a difficulty understanding gates and logic, and how to apply it. Something I found recently that has made it more clear, not crystal, but not quite as muddy, is BugBrain. In which you build "brains" to run a bug. The brains consist of various inputs, run through logic gates to produce a desired output, a bug walking on a branch and eating the nymphs, stopping when a bird is near.

For me it jumped to quickly from teaching you how to build basic gates to application, such that I needed all the hints to solve the easiest puzzles. I'd love to find more like this.
posted by TuxHeDoh at 5:34 AM on December 27, 2004

I had one of these as a young child and it certainly helped learn about the basic components of electronics (resistors, capacitors, potentiometers, etc.). I think I learned more (and remember more) about these things when I was eight years old from my Radio Shack board than from high school physics nine years later. Logic gates and tying things together, not so much. One of the final projects was building a crystal radio by hooking stuff all over the board together and I couldn't figure out how it worked.

Rocky's Boots is an excellent game for learning about how logic gates and higher order systems work. There's an Apple II emulator on the web site--hopefully it will work for you.
posted by grouse at 5:41 AM on December 27, 2004

It's a good way to get the absolute basics down, but unless you're doing some reading along with it, you won't really learn squat.
posted by cheaily at 6:28 AM on December 27, 2004

I had one of these when I was a kid. I found that while I didn't learn that much about electronics, it really drove home the "electronics is like math" idea, basically overwriting my previous belief which was "electronics are like magic." Being able to build a little radio, wire a light switch and figure out the way electricity flowed through various systems demystified a lot of electronic stuff. I also had a Dad who really understood that stuff and explained to me what was going on which was helpful. I feel that it was a more useful set of lessons for an eight year old than, say, a 30 year old, but there are more high tech electronic kits out there that might be a bit more challenging as you learn more.
posted by jessamyn at 6:33 AM on December 27, 2004

Right, you might learn a bit of the mechanics of stringing together electrical components, that is, some practical nuts and bolts knowledge. But you probably won't learn much about theory.

To learn about theory, particularly digital logic theory, I would probably recommend something more like a real time simulator. These are a lot less manual labor to build more and more complicated circuits, test ideas out, etc.

Note that in general there is a HUGE difference between analog and digital circuits and than in general knowledge in one is not likely to improve knowledge in the other.

Experiences and recommendations? There are lots of good circuits textbooks (check your local library or local universities bookstore, pick up the sophomore circuits book). Actual classes are a waste of time for some, illuminating for others, depending largely on temperament I think. Luckily for most basic circuit stuff math is not a huge component (although you need to be able to solve systems of equations)
posted by RustyBrooks at 6:38 AM on December 27, 2004

I had one (as mentioned in this thread), but all it taught me was how to follow instructions. I wish it had taught me more. They may be different now though.
posted by Bdave at 6:55 AM on December 27, 2004

I second grouse's reply - I got a Radio Shack (160 in one, i think) analog experiment kit when I was 7 or 8 and I credit that with sparking my interest in technology. I learned a lot from that kit, and later related theories I was studying to my experiments with the kit. Later I had a video game on the TRS-80 CoCo that I remember being called "Robotropolis" but this review sounds like the same or similar game. I learned a lot about digital logic circuits from that game and another digital logic experiment kit I had.
posted by one at 7:05 AM on December 27, 2004

I think one of the radio shack kits would work well in conjunction with some sort of text. I had an analog kit when I was about 11 and it was quite fun to tinker with, but the manual did not do a good job of teaching why a given circuit does what it does. However the kits are a lot easier to use than cutting wires and putting everything on a bread box. It also depends on what you want to learn. Some kits deal with analog circuits while other kits deal with digital circuits. Which kit you choose will be motivated by what you want to do with your newly acquired EE skills.
posted by kscottz at 7:11 AM on December 27, 2004

All I learned was how to follow technical instructions. I couldn't redo a project without reading that crumbled up piece of paper.

By the way, the most complicated thing I did with a Radio Shack kit was an AM radio. All they played back then was static.
posted by icontemplate at 7:12 AM on December 27, 2004

The Art of Electroncs is about as complete as you could want, but is very dense and sometimes the authors do things that are intentionally clever without telling you what or why.

You'd be better off with some of the books by Forrest Mims. He used to put together these small, digestable, mini notebooks. They are collected in 3 volumes here.

The billion-in-1 kits are more like Erector sets when you build only from their suggested kits. You learn how to tighten little nuts and bolts and not about structure or engineering.

Instead, I'd get the Mims books, find out what you want to build and then invest in this, this, this, and whatever specific parts you will need to build the projects you want. The breadboard makes it go a lot faster and less error-prone than point-to-point soldering.

This approach will let you do more than the canned kits without getting your hands too, too dirty at a fairly reasonable cost. Later, if it still holds your interest, you can see about building kits from Ramsey and then stepping up to hand wiring your own or etching your own boards or having someone else etch them.

I've done all these things personally and really enjoyed doing the etching myself when I was younger and had time, but I also ended up destroying some of the plumbing in our house, which I think my dad has finally forgiven me for. Today, I would build a prototype using a breadboard, make a PCB via expresspcb and solder the parts myself.
posted by plinth at 7:18 AM on December 27, 2004

I have my doubts about the kits... Not useless, but not wonderful at all. As jessamyn says, maybe not for an adult.

Along with the amateur radio site linked, there are other ways to get into it that might interest you. If you are interested in audio a do it yourself project like a chip amp would be a good place to start. UIRT2 is a very interesting project too. Of course there are also the people who do robots wars stuff. These hobbies all have well attended user forums with people that would be happy to help you along.

If you want to learn the fundamentals I think you really have to hit a textbook. Any Introduction to Electronic Circuits book might be useful, or for the logic stuff Introduction to Computer organization. Check out US military publications like the NEETS series (Navy Electricity and Electronics Training Series). Any US government material that is not classified is free to do what you want with, no copyright restrictions, so check out alt.binaries.e-book.technical.

While searching around for a free NEETS download link I found Physics Java Applets by C.K.Ng (worthy of a front page post all on its own) with some interesting electronics simulations you can play around with.
posted by Chuckles at 7:26 AM on December 27, 2004

Although I loved the 50-in-one thing, I don't think it taught very much (other than, perhaps, hyper-trial and error patience).
posted by ParisParamus at 8:24 AM on December 27, 2004

What exactly do you want to know about EE? "Classical" EE is about doing so much calculus that your mind bleeds. Gates are either an excercise in materials-physics or discrete math.

The kits might help you understand that "DC circuits are like math" but they will strongly reinforce that "AC circuits are magic. BLACK magic." From an EE's perspective, digital circuits are just analog circuits with even more restrictions. To learn something about digital circuits requires an op-amp & breadboard (should be less than $20 at radio shack) and a scope and function generator (could be as little as $1k each, could be up to $20k each).

An EE 101 course plus the corresponding lab will probably be cheaper than buying the necessary test equipment.
posted by b1tr0t at 9:19 AM on December 27, 2004

I liked the book Code which may or may not be what you're going for. I would recommend it addition to actually doing it on a board or whatever. I'm definitely not an EE person but Code at least let me understand the basic concepts of gates, circuits and such. If I remember correctly, I lost interest at some points where it got technical but you may enjoy it.
posted by geoff. at 9:54 AM on December 27, 2004

Although of course digital circuits are analog at their core, and every EE student (myself included) had to learn about the analog basis of them, it's not necessary or even particularly useful to do so, in my opinion, if you're just interested in learning more about digital logic. In fact, to get into microprocessor design these days you don't need to know much analog.

AC circuits only seem like black magic if you're extremely familiar with DC circuits, ironically. This is because components you are very familiar with (capicitors, inductors) behave very differently in AC. Also, terms you are familiar with (voltage, amperage) are referred to differently, which can be confusing.

I'd have to say again, before I went out and bought any physical equipment, I'd play around in a good simulator. SPICE is great for analog circuits, for digital I used to use a simulator for unix called, simply "diglog" or "digilog" (the analog version was called, well, analog). It was extremely easy to use. SPICE is a pain in the ass to use. PSPICE is better since it puts a nice gui front end on it.

There are some good programs for stuff like VLSI layout also although I'm way behind on that stuff. I used to use things like Magic.

Also, you may be interested in learning about VHDL which is a programming language used to design and test ideas within analog and digital hardware design. VHDL stands for Verilog Hardware Design Language. There are lots of unix tools and I don't think it costs anything.

I'd avoid radio shack 50 in 1 kits like the plague. I like their Basic Stamp kits though.
posted by RustyBrooks at 9:58 AM on December 27, 2004

I'll second or so the Art of Electronics. It's a really good book, I wish it's what we used when I was learning to be an EE. b1tr0t is also correct on the EE curricula, you'll only see more mathematics if you become a math major.

One other good book (or so I've been told by a few people I trust) is Bebop to the Boolean Boogie: An Unconventional Guide to Electronics. Some non technical folks that I respect used it to learn a little about circuits.


bi1r0t is wrong about the costs needed to learn electronics. First, you don't need an oscilliscope. Get a decent cheap digital DMM, I'd imagine you could get one made in China for 10 bucks. Even analog circuits are built around a very strong backbone of static direct current measurements. You can do audio stuff without an oscilliscope pretty easily. Use a speaker to hear the tones you generate and listen to the pitch as you change components.

It won't be exact but it'll give you a feel for how things mesh together and component values qualitatively affect the circuit.

Here's what you need:

1) A power supply. 9 volt and 1.5 volt batteries will do fine.
2) A bunch of leds. For digital circuits (which is what you asked about) you can use an LED to see if something is on or off or 1 or 0.
3) A bunch of resistors, one of those multi-valued packs from RadioShack would be fine. You'll want to limit current through the LEDs so that they're actually reusable devices rather than throwaway. You can get a bunch for a few bucks.
4) Gates: All you really need are a bunch of NAND gates. Every digital gate can be made from a NAND gates. Splurge and buy some other flavours though: NOR gates, inverters etc. You can get a lot of gates for 10 bucks.
5) A breadboard. Not strictly necessary but people laugh at me when I wirewrap these days. Of course I can still do more than the people laughing at me. This might be 10 or 15 bucks.
6) A cheap digital multimeter. Again, I'm sure you can get one for 10 bucks.

The first thing I'd do is use a NAND gate and 3 LEDs and figure out that a 0 means an LED is off, a 1 means an LED is on and that different combinations of "1" and "0" at the input to the NAND gate makes the output "0" or "1". Make a table (truth table) of what you see.

Next I'd use a few NAND gates and make an OR gate and repeat the above exercise.

Next I'd use a single NAND gate to make a NOT gate.

Next I'd make a slightly more complicated gate, a real circuit this time. If the third input is "1" and either of the other 2 inputs are "1" then the output lights up.

Make up other digital circuits and see if you can implement them.

Later on you can buy some transistors and build up logic gates from the transistors or use the gates you already purchased to drive say a small toy motor.

If you want to do analog stuff it's a little more involved but you don't need much more in the way of components. Just buy a few op-amps (you can get up to 4 in a single package for a few bucks)

A piezo speaker can be your tone monitor.

Later on if you want you can purchase an oscilliscope. I bought a 40 megahertz one off of eBay for 200 bucks. It's a nice scope for a hobbiest. It's not like the scopes I use at work with 10 gigahertz of bandwidth but I don't have 60 grand for one of those anyway.
posted by substrate at 10:10 AM on December 27, 2004 [1 favorite]

Heh, I built one of those AM/VHF radio kits once, and I must have screwed up, because all it played was FM.

More recently, I read up a bit on components, bought a bunch of 'em, and completely failed to get a simple LED flasher to work. All the components tested fine. Quite frustrating.
posted by squidlarkin at 10:49 AM on December 27, 2004

The Radio Shack kits are pretty much kid stuff.

You probably want to build some digital logic type stuff. Get:

Power Supply - cut the plug off a whatever (probably 5 or 6) volt consumer electronics transformer (wall wart). Find one that puts out like an amp, because if you use one that only does 2 or 3 hundred milliamps you're liable to run out of current, depending on the components you use, how bright you make your LEDs, and such.

You can use batteries when you need to go portable, but I prefer a power supply for stationary work since batteries cost money and the first time your batteries run low it could be an hour before you realize that is the problem.

Breadboards - these cost big bucks for simple pieces of plastic and metal, unfortunately. Look on eBay and online for less expensive ones.

Soldering Iron, Soldering Boards, Solder, etc. - you're going to want to have some things off the breadboard, like displays, control panels, and so forth, because it will be cumbersome or impossible to have them on the breadboard and to save on the amount of breadboards you must buy or steal.

Analog Components - get the big bag o' cheap 1/4 watt resistors, some capacitors, some potentiometers, switches and buttons...

LEDs - Your basic output device. Buy these online. Best Hong Kong sells fancy LEDs (bright, blue, purple, etc.) on the cheap, and right now they actually have mundane LEDs on sale for 2 cents each in a pack of 1000. (Radio Shack would charge at least 50 times as much.) You're also going to want some seven segment numeric displays (along with an appropriate driver chip, which is a real simple but somewhat extensive arrangement of gates that takes a binary "9" and activates the LEDs that display "9"). Maybe some dot matrix LED displays too...

Digital Components - You probably want something like the 7400 series of TTL logic, along with some 555 timers and whatever RAM you can dig up. This is all somewhat obsolete stuff but you can still find it and it's still cool. For example I found references to a "2114" half-kilobyte memory chip I was using as a part in 70s/80s arcade games. But for my project that half-kilobyte was huge, and I only even bothered to make a quarter of it addressable since it meant one less chip. Make sure all the chips you buy are in a DIP package, since if you get something in any other package it's more or less useless to you.

I wouldn't get only NAND gates. You're going to want to have things like flip-flops and adders, and while you might want to build one of those once to see how it works, you're not going to want to spend hours wiring up a flip-flop over two breadboards when you can just pop one in, and you need ten flip-flops.

Multimeter - 5 volts is supposed to be on, and 0 volts is supposed to be off, so when you see 2.7 volts you know you've screwed up.

Here's some hints:

-Always put a resistor on your LEDs.
-Don't plug chips in backwards (5V to GND, 0V to VCC) or the smoke will escape.
-If you spring for a fancy power supply, don't get tired and accidentally turn it up to 20V, or the smoke will escape.
-Sometimes chips still work after the smoke escapes.
-Don't make any short circuits.
-Twist together six inches of wire, a resistor, and an LED. Plug one end into your 5V, touch the other to any other point of your circuit - poor man's logic probe.
-Find a ream of paper and a decent printer, because you will be printing out that many datasheets.
-Datasheets are on Google or manufacturer's websites, and are mostly equivalent between manufacturers - if you have a National Semiconductors 74LS85 and all you can find is a Motorola datasheet you're not really in trouble.
-If stuff's going haywire, it never hurts to just throw a capacitor between power and ground.
-Pre-made jumper wires are for losers. You ought to acquire a callus from cutting hundreds of tiny wires.
-Wires should run parallel to the sides of the breadboard, or as close as possible, and should be flat on the board, not arching through the air.
-You can't solder things to cardboard, but you can tape things on cardboard and then solder the wires to them.
-There is something called contact bounce. When you press and release a button, there is no smooth no current, current, no current change. The button will actually go on and off tens or hundreds of times. You need to correct for this on anything where one press can't be received as hundreds of presses.
-It will never ever work the first time.
posted by TheOnlyCoolTim at 5:02 PM on December 27, 2004 [2 favorites]

Most of the books and stuff out there seems to assume you will have a teacher to help you through the material and it can get quite dense. Navy Electrical Engineering Training Series (NEETS) explains it all in a format that anyone can understand, yet they do not spare the technical details. This site purports to have them for free download. The ratshack kits aren't awful and can be kind of fun, but the NEETS materials will give you a much better understanding of the subject.
posted by caddis at 8:02 AM on December 28, 2004

I had the 160 in 1, and as I think about it it's probably why I'm able to do all my own work on my guitars and amps today.

Definitely get it. Wish I knew where mine was, in fact - stuck here in San Diego with very little to do except vacate, which I suppose is the point of a vacation.
posted by ikkyu2 at 8:40 PM on December 28, 2004