Originally published on Mon, 01/06/2014 - 02:01
In 2013, I immersed myself in electronics of various sorts. Great fun. A contracted project calls for innovative thinking and development for omni-channel marketing. Most of the work is software (and very much pushing the state-of-the-art) but some custom hardware is required including computer control of lighting with individually addressable LEDs and device control (servos, motors, etc.) for product demonstrations in a new retail environment.
Headspace Sprockets embarked on a path filled with Raspberry Pis, Arduinos, Gertboards, UDOOs, and lots of custom circuitry. I created a lab bench in my office with lots of equipment and set to re-learning things that I had not touched seriously since college. Everything is new – including a Rigol DS1102E 100MHz oscilloscope, a nice GW Instek analog function generator, a lab quality power supply with 3 current limited outputs, a soldering station, and various other tools and materials. (I could use a logic analyzer but for now, what I have suffices).
Even more gratifying than the equipment are the materials that I used to re-familiarize myself with electronic design. I watched many videos on YouTube (particularly enjoying those of David Jones and his blog at www.eevblog.com). I bought and read some great books; I recommend The Art of Electronics by Paul Horowitz and Winfield Hill, despite some sections that are obsolete and The Circuit Designer’s Companion by Peter Wilson.
As an undergraduate at MIT I had taken two of the core EE courses: 6.011, Circuit Theory and 6.012, Semiconductors. Dry dry dry. Back then, I was a physics and math guy but I had a lot of interest in electronics. This year, I pulled the texts for these courses back out (they were collecting dust on my bookshelf), and most things came back quickly. The solid state physics from 6.012 I had also covered in other courses and knew well from stochastic calculus (diffusion and drift and all that). The circuit analysis techniques mostly involve some rules (KVL, KCL, device models, etc.), some tricks (such as small signal analysis and op amp analysis), a little calculus, and a lot of turn-the-crank algebra. Automated programs such as SPICE are in common use today but it is important to have a feel for circuit behavior by doing most of the work manually.
Before MIT, I had done a lot of hobby electronics. Mostly, I was building some simple circuits, usually from a schematic published in Popular Electronics, but I had also done a lot of digital design. I got the obligatory ham radio license also.
My Dad supported me in my various projects. Particularly when I was in grade school, he would arrive home from work with something that would capture my imagination. One evening when I was (probably) in fourth grade he showed up with an oscilloscope – an EICO 460. Now, these days this is merely an antique. At 5 MHz bandwidth for a single analog channel it can’t be used very effectively for much of anything. But it was to me a magic machine. I could see signals and play with Lissajous patterns and amaze my friends. I used that oscilloscope (along with some other equipment he gave me such as a function generator and a VTVM) for many years. I still have an old multimeter that my Dad and I bought at Radio Shack one Saturday afternoon when he explained to me what impedance was and how it was important to minimize the effects that probes and equipment would have on a circuit under test. I use a much better digital multimeter now but the old one is still out and alive.
Oh, and about that EICO 460, I finally threw it out five years ago but not without a sharp pang of nostalgia.