The Joy of Electronics

It's hard to believe it's already a year since I received one of the best Christmas gifts I've ever gotten, one that has lasted me all year.  The gift itself wasn't a surprise--I'd asked for it specifically--but the amount of enjoyment I've gotten out of it, a full year's worth of use.

What was this great gift?  An electronics experimentation kit from Radio Shack.  Though appropriate for older kids, there is nothing wrong with an adult using it.  In any case, a bit of reversion to when I was younger was in order.  For when I was a kid, I had another similar electronics kit.  I remember it well; made by the Heath Company, the electronic components were contained in little Lego-like blocks, placed on a board and connected to each other with metal pins.  I also got this for Christmas.  Since my family opened our gifts on Christmas Eve, I was too tired to use it right then, but I remember that my dad couldn't resist making a siren circuit that first night.  I had plenty of my own fun with it and still remember it fondly.  I hoped that my new kit would provide me similar enjoyment.  I also hoped that at my older age I might absorb some of the lessons better.

I've been fascinated with electronics as long as I can remember.  However I've always felt more comfortable with software than hardware.  I have always enjoyed looking at the components, but never really wanted to get my feet wet.  I was always particularly afraid of soldering.  This kit is perfect for me, as I can't damage anything as long as I follow the instructions (and eventually I got confident enough to try a few things on my own), and no soldering is necessary.  Everything is done on a so-called breadboard, an array of holes wired together so that soldering is never necessary.  Furthermore, the components can be taken out at the end of an experiment and reused at will.

I soon learned that it was very important to push the component leads into the breadboard holes very straight.  The leads are very thin and fragile.  If not plugged in straight, the leads would bend easily, which made them even harder to plug in the next time.  Fortunately the kit supplied plenty of extra components, so when one wore out, there was usually a replacement to use.  A needle nose pliers could also be used to some degree to straighten bent leads.  By the time I'd gotten through the last experiment, even the breadboard holes had gotten somewhat ratty, but not enough to degrade the contacts.

One of the most difficult things about the kit for me was to distinguish between different values of resistors.  These components are distinguished by a code of colored bands.  Different colors translate to different resistor values.  However in bad lighting it can be hard to distinguish between colors such as red and orange.  Some capacitors were also hard to tell from each other.  To prevent myself from going insane trying to find the right specific component each time, I finally got myself a little set of drawers with which I could organize the parts.  This made it much easier to find my components quickly.

The set of two manuals are written by a minor celebrity in popular science circles, Forrest Mimms.  He has written "Amateur Scientist" columns for Scientific American.  More oddly, he is also known to be a creationist.  Of course that makes no difference in writing an electronics kit manual, but his eccentricity comes through.  In this computer age, the entire two-volume set is handwritten, about 200 pages worth of freehand diagrams and notes.  To his credit, I only found a very few errors.  The manuals are short on principles or mathematics (for instance, the discussion of Ohm's law is relatively perfunctory); they're mostly about just building useful circuits.



Instead of mathematical principles, I suspect the organization of the manual is more based on fundamental circuit building blocks.  Mimms starts with an LED flasher project (if you like flashing LED's, this kit is for you, as Mimms must show at least 5 different ways of making a flasher circuit).  I suspect that it's meant to generate initial interest, as the circuits that immediately follow are much more elementary and begin to introduce the basic components one by one before beginning to combine them again into more advanced circuits.

In spite of this building up of circuits, I don't get much a sense of overall organization.  The workbooks are written mostly circuit by circuit.  Many common types of circuit, such as the aforementioned LED flashers, are represented multiple times, built in different ways.  It would be nice if Mimms mentioned specifically that certain fundamental types of circuit can be made many ways.  In other cases, certain building blocks are not really discussed as a matter of principles.  The 555 timer integrated circuit is extremely flexible, and Mimms does show several of the many ways it can be used, but I think it deserves better discussion as a very fundamental component of more complex circuits.  Toward the end of the first manual, he discusses the 4046 phase locked loop integrated circuit, but I can tell that it is a much more interesting and versatile circuit than Mimms lets on.

Most of the experiments worked as expected, with the exception of some of the audio circuits.  The worst were ones that used the earphone as a type of microphone.  These were supposed to amplify sounds in the earphone to a speaker, but I never got any good results.  Perhaps my earphone was just defective.  It didn't matter much, as these were the least interesting experiments to me.  On the other hand, some of the "music machine" experiments led to some fun sound effects.

I had an easier time with the second manual, covering digital circuits.  For the most part these circuits worked exactly as specified, once I'd verified the wiring.  On the other hand, the wiring was generally more intricate for the digital circuits.  Many required a lot of short wires that had to be connected to very specific pins on the integrated circuits.  Any mistakes would cause failures, but the circuits worked perfectly when wired correctly.  I also had a much easier time understanding the digital circuits than the analog ones; this may be the way my mind works.  On the other hand, I did feel like I learned more while working through the analog circuit manual.  On the other hand, I'd already known more in advance, enough to know for instance that what he called a "full adder" is generally considered a half adder (and his half adder is just an exclusive OR gate).

One of the best things about this kit is that I could do just a few experiments per weekend.  Even when I knew what a circuit would do it was satisfying to actually handle the parts and have it eventually in operation.  To get through the two manuals took me almost the full year, not bad for a Christmas present!  After this, I tried a few experiments on my own, some of my own design and others circuits I got off the Internet.  My most complex circuit has been one that counted up from 0 to 9 and back down again.  Another (from the net, but with significant modifications on my part) simulated a traffic light, a type of machine I have been fascinated with since childhood.  My favorite circuits have continued to be those that flashed LED's in some way or another.  I guess I've always been a fan of blinking lights.  It's been a most versatile present!

I have gotten a great deal of pleasure from this present.  It has also motivated me to take the next step.  There are several directions I could go.  I could have begun to work with circuits that require soldering, getting past my fear of it, but I did like the ability to make and tear down circuits at a whim.  Another option would have been to get a "microprocessor trainer", a simple computer chip with only a keypad and a small display to work with.  By modern standards it would be very primitive, but it would recall the time when I first began to be interested in electronics at all (when such trainers were about the only computer equipment many hobbyists could get their hands on), and it would give me a chance to really interact with a computer at the lowest level.

But the direction I ultimately chose, the present I wound up asking for and getting this Christmas, was a small robot kit.  Robots have fascinated me for many years as well, so from electronics to robotics is a natural evolution for me.  I've already had quite a bit of fun with this kit, and expect to have more for some time to come.  I imagine that there will someday soon be a "joy of robotics" article for me to write.