Pedagogy: Learning – and failing to learn – about Electronics
I always like this quote from major league baseball player and manager Yogi Berra –
“You can see a lot just by observing.”
Many people say the world isn’t interesting. Nothing could be further from the truth. The world is full of interesting things – if you just take the time to look.
For some, electronics is a hobby. For these folks, they are not professionals; they do not have four-year college degrees in electronics or electrical engineering. They just want to learn about electronics as a hobby. Over the years I’ve watched individuals (including myself) learn about electronics as a hobby. Generally, they try to do it on their own, outside a classroom setting – flying by the seat of their pants.
How do the variety of individual go about learning about electronics? Here is where I appeal to Yogi Berra – “You can see a lot just by observing.”
By careful unscientific and ad hoc observation, this is what I’ve observed over the years regarding people trying to learn about electronics outside a traditional classroom setting.
1. Lost-in-time Thomas Edison approach. Thomas Edison said, “Success is 10 percent inspiration and 90 percent perspiration.” For this set of individuals, learning about electronics is more about doing rather than thinking. They have the “lets see what happens” approach. They try one thing then another thing and observe the results. This is what Thomas Edison did when he was trying to find what would work as a filament in a light bulb. From Edison, “Before I got through, I tested no fewer than 6,000 vegetable growths, and ransacked the world for the most suitable filament material.”
I call this approach by those trying to learn electronics as the “Lost-in-time” Thomas Edison approach because, 100+ years later, electronics is a mature disciple. At the level of pedagogy, there is no real need to “experiment” at a very basic level, For example, if you want to learn how to bias a transistor for a simple class A audio amplifier do you really want to just try combinations of resistors until it works? How many combinations will you try? “Before I got through, I tested no fewer than 6,000…”
With an emphasis on “doing” and “building” rather than thinking, this group of individuals avoid hitting the books. Simple things like the theory and practice of biasing a transistor for various classes of amplifiers is well-known. Do you start with the practice or the theory? Do you start with an experiment or do you start with the theory? For the folks that take the “Lost-in-time Thomas Edison” approach doing trumps thinking. Doing trumps using the resources ready-and-available. There will be little success or progress for these folks.
2. The Math Guy. This approach is just the opposite of the Lost-in-time Thomas Edison approach. Math Guy approaches electronics with the full-weight of the best mathematics and all known theory. One thing Math Guy knows is that, Electronics is Physics. In fact, to Math Guy, everything is Physics. And, if you set up the equations correctly, crank the math, then that’s how it works – in the real world.
Math Guy generally never builds anything. There is no need to. If you design it according to the math, that’s good enough, “I’m done. Let the technician take it from here – all the ‘real work’ – all the ‘important work’, is done.” Math Guy knows a lot about electronics but has little practical knowlege. Math Guy would learn how to ride a bicycle by doing the physics.
3. “A little bit of Monica; a little bit of Erica”. Mambo No. 5 by Lou Vega got it right. An effective strategy for learning electronics is an incremental cycle of theory and practice. To be specific, for basic electronics, theory precedes practice. This gets past the sub-optinal approach’s of both Lost-in-time Thomas Edison and Math Guy.
How to hit the sweet spot of Theory and Practice in Learning Electronics
A little bit of Monica in my life; A little bit of Erica by my side
There are literally thousands of books on electronics – from textbooks at all levels to cookbooks of circuits where little theory is given. Don’t forget the application notes from various vendors of electronics parts which will show practical test jigs and sample real-world circuits in which to use their products. In the Internet age, the number of technical resources, is nearly limitless. There is no reason you should not be able to get your hands on theory appropriate to your level.
Practice (Erica) – The Challenge of the Electronics Lab
With the limitless pedagogic resources on electronics at your fingertips (the Internet, the public library, the bookstore) how do you set up a lab in which to try out the theory you learned as practical circuits that perform some useful function? How do you do the “practice” part of learning without a thousand dollars of lab equipment?
I found this in a book review at Amazon.com (empathesis mine)
In the customer review section for the book: Hands-on electronics : a one-semester course for class instruction or self-study
This book is well thought out, organized, and thorough. It provides excellent hands-on exercises that help you to really understand in a functional way how electronics work. The mathematical explanations and exercises may be challenging to folks who haven’t used their college calculus/algebra/trig skills in a while (me included) – though they will serve those seeking to understand the underlying fundamental calculations.
With all those positives, why a 3 star rating? Well, the book assumes that you have ready access to a ~$1,000 oscilloscope and a ~$500 proto-typing bread board. On top of that, you need all of the bits and pieces to actually do the experiments – those are relatively cheap, but not always readily available (at a local store). All of the required equipment and supplies can be obtained on-line, but it will take a concerted effort, a chunk of cash, and some lead time to get all of this stuff. There are alternatives to the expensive oscilloscope and proto-board, but this path requires some assumed additional knowledge and may prove challenging as it deviates from the proscribed curriculum.
My final thought on this book is that it is quite excellent in a classroom / lab setting, but is not very “practical” for the hobbyist.
Where there is a will there is a way
So, looks like the self-learning of this individual will be stopped dead in its tracks since this guy does not have… “ready access to a ~$1,000 oscilloscope and a ~$500 proto-typing bread board. On top of that, you need all of the bits and pieces to actually do the experiments – those are relatively cheap, but not always readily available (at a local store).”
But suppose that you did have an oscilloscope, signal generation, and just about every piece of test equipment needed PLUS you had an infinite parts bin? And, that you had it all for free? Possible?
SPICE to the rescue (Rita and Tina)
The review above was written in 2006. SPICE, a circuit simulation program, has been available since the mid 1970’s. Admittedly, SPICE was not pretty back in those days before the easy-to use-Graphical User Interfaces. Input was in the form of a text file Netlist which you had to do by hand. But it could do analog circuit simulations on a mainframe or a midrange computer – if you had one.
Skip ahead 30+ years and you will find many variations of SPICE (Commercial and Free) that are GUI-based and a dream to use.
For a person just starting out, a free SPICE-based circuit simulation program is the next best thing (better, I would say) than having the multi-thousand dollar electronics lab that the book reviewer above wished he had, doesn’t have, and may never have. Perhaps he has abandoned his quest to learn about electronics because of the lack of lab equipment. That’s too bad.
Where do I get all this stuff?
A very usable and free version of SPICE (LT SPICE) is available here –
At the site above you will find LT SPICE, full documentation, and sample circuits
You can watch some YouTube demos here –
Circuit Simulation Applet by Paul Falstad.
So lets have some real run right off the bat – you won’t have to install anything – it will run right out of your web browser.
If you are not ready for the full-blown SPICE and want to play around you can find resources on a great web site by Mr Paul Falstad. This applet-based circuit simulator is highly graphical and can do basic circuit simulation with these capabilities:
- Signal generators, Voltage sources, and Current sources
- Resistors, Capacitors, and inductors
- Manual SPST/SPDT Switches, and SPST/SPDT relays
- Diodes, BJ Transistors, and MOSFETs
- Speakers, Buzzers, and LEDs
- ADCs, and DACs
- Logic gates: AND, OR, NAND, NOR, XOR
- JK and D Flip-flops
Start here – http://www.falstad.com/circuit/
There are tons of sample circuits that can be simulated right from your browser
Download the Java applet (executable and source) and build your own circuits (all sample included in the download that you can modify)
Tons of more fun complements of Paul Falstad – (Thank you for all your hard work – Mr. Falstad)
Basic Electronics using Simulation
Too lazy to get a book? Check out the free lecture notes from Electronics: Principles and Applications by Charles Schuler
(Each chapter has lecture notes as PowerPoint presentations. Use Open Office (free) if you don’t have Microsoft PowerPoint)
Resources for another circuit simulator (MultiSim) with examples from the book cited above
Don’t forget about free electronics education from the Military – you paid for it; use it
The EEVBlog (Electronic Engineering Video Blog)
Be sure to check out David L. Jones’ video blog – http://www.eevblog.com/
There are lots of ways of learning about electronics – if you have that desire as a hobbyist. I would not suggest a “trial and error” lost-in-time Thomas Edison approach when in fact there are so many resources available to you. I can appreciate people who want to “do things” and “build things” but without any foundation in theory you will make little progress – you will end up a “sorcerer’s apprentice“. Find a book or other resource on electronics that is suitable to your level of understanding at any moment. When starting out, use a book slightly below your level of competency just to make sure you understand all the basics; move on from there.
You don’t need thousands of dollars of lab equipment – if you are learning on your own you probably won’t have that available to you – use an analog simulation program like LT SPICE. SPICE can be used as a tool for pedagogy as well as a tool for prototyping small projects that you plan to build before you buy all the parts. SPICE can simulate many real devices including conditions of breakdown. Theory, simulation, and build would be a good strategy for people starting out.
Electronics is a mature discipline with nearly infinite resources for learning the theory. Match this up with the many circuit simulation tools that are available free on the Internet and there really is nothing to stop you. Build some small projects (in the real world) to solidify your knowledge, confirm your understanding, and develop that “intuitive knowledge” you will get only by building real projects.
There is nothing stopping you but yourself. Good luck. “Godspeed, John Glenn”
Mambo No. 5 – http://www.youtube.com/watch?v=uz4eHPD40w4