Back in the day, 60 years ago, I built a lot of Heathkit test equipment including two oscilloscopes, two analog multimeters, an audio signal generator, an RF generator, an adjustable single-voltage power supply, and an automotive tester. I also built a Heathkit stereo receiver (that was a disaster), a digital clock with a Panaplex gas-discharge display (sure wish I still had that), and a microwave oven. Mid-century Heathkits were great because you learned a lot about electronics by building kits that were created by skilled engineers who had to develop working designs that could be assembled by neophyte high school students with hobby skills like me.
By building these several pieces of Heathkit equipment, I soon became familiar with the physical size and appearance of myriad electronic components including many transistor variants, diodes, resistors, capacitors, switches, relays, lights, and even vacuum tubes. If you’re familiar with Heathkit test equipment design, you’ll know that I also became quite familiar with rotary wafer switches. Heathkit must have ordered those switches by the bushel. Except for the digital clock, I don’t recall that any of these kits incorporated integrated circuits – they were that new back then – on the market less than ten years. (Yes, I’m that old.) By the time I started to earn my BSEE degree at college, I’d had a lot of assembly experience and felt ready to create my own designs.
Things just aren’t like that today. Heathkit exited the electronic kit business in 1992, thanks in no small part to at least three major forces: personal video games, computers, and surface-mount technology. The advent of video games and the explosion of the video game industry in the 1970s and 1980s sucked a lot of potential customers out of the kit-building market. It’s much easier and more gratifying in terms of dopamine highs to play video games.
For those people who still wanted mental exercise, personal computers made it easy for people to become programmers at home. Computer programming exercises many of the same creative mental muscles used by hardware design engineers.
Surface-mount technology shrank components so much that it became more and more difficult, and then impossible, to manually assemble circuit boards. You now need a robotic pick-and-place machine. (Although Heathkit has since been resurrected, your kit choices are currently limited to a digital clock and an AM radio receiver.)
Consequently, many budding hardware engineers lack the practical assembly training provided by kit building. I don’t mean to take anything away from wonderful 21st-century incarnations of Heathkit-like companies like Adafruit and Sparkfun, which provide stellar service to the maker and hobbyist communities, but working with Arduino and Raspberry Pi boards and pre-soldered component boards that allow you to work more easily with surface-mount components just isn’t quite the same. Considerations such as user interfaces, front-panel layouts, power supply design, battery selection, enclosure selection, and so on just can’t be learned as easily as in times of yore, not in my opinion anyway.
If you find yourself nodding to this depiction of today’s state of electronic design, then there’s a new book you need to know about: “Designing Electronics that Work” by Hunter Scott.
Scott is the director of hardware engineering at Reach Labs, a wireless power R&D company located in Emeryville, CA. Scott has an engineering degree from Georgia Tech, has founded two hardware startups, and has been designing electronics for over 10 years. As he writes on his book’s Web site:
“I’ve made a lot of design mistakes and debugged a lot of problems in that time, and I’ve learned from all of them. I wrote down everything I wish I’d known when I started my career and put it in this book.”
Scott writes well, and his book has a logical layout. Here’s the chapter list from the table of contents:
- What to Build and How to Plan for it
- Selecting Components
- Schematic Design
- Layout Design
- Cost Engineering
- Fabrication and Assembly
- Building a Lab
The book also includes an interesting and useful set of three appendices:
- Appendix A: Rules of Thumb
- Appendix B: How to Give a Demo
- Appendix C: Companies that can help
Scott has a clear, approachable writing style. For example, here’s his first paragraph from the book’s preface:
“Successful electronics design is all about the details. You will find yourself accumulating a variety of techniques and tricks as you design and implement different products and devices. Some of these details may seem minor at the time, but their careful application can save a huge amount of time and money. This book is a collection of tips, techniques, and tricks that generally take a small amount of time and effort to implement, but have a disproportionate effect on the outcome of a design. The guidelines in this book are immediately applicable and almost all of them were learned the hard way: by screwing it up the first time.”
Screwing up the first time happens to be the way I learned a lot from building Heathkits. I always made one assembly mistake per kit and had to troubleshoot my errors. It’s how you learn: the hard way.
For example, my first oscilloscope kit powered up the first time I switched it on. I was very excited – until I connected a test signal and discovered that the scope had no vertical deflection. Even the vertical control knob had no effect on the beam. I carefully scrutinized the schematic for quite a while and concluded that the problem component had to be the vertical amplifier tube. Sure enough, when I checked it, there was no tube in the socket. I found the tube on my bench, still packed in its cardboard box, plugged the tube into its socket on the circuit board, and my freshly built scope worked!
As though he knew my personal history, Scott wrote this later in the book’s preface:
“Inevitably though, mistakes will happen. It’s easy for novice and experienced designers alike to get frustrated at themselves when they discover they’ve made a silly mistake.”
One thing I especially like about this book is that it’s written from a designer’s viewpoint. It does not start by familiarizing you with components, the design, or the debugging process, it starts at the right place – with project requirements and specifications:
“Every design is driven by both a set of requirements and a specification. If you’re lucky, you’ll be given both a set of product requirements and specifications that are reasonable and achievable. More often than not, however, you will need to create at least the requirements or the specification, or both.”
I can see that Scott has ample real-world production experience. Here’s what he says about selecting and sourcing electronic components:
“…procuring the parts you have selected is an often overlooked but critical task. Always buy parts from an authorized distributor or the manufacturer directly. This keeps you from receiving counterfeit parts or parts that are damaged due to poor handling or incorrect storage. Before you buy from that questionable overseas distributor that isn’t authorized by the manufacturer, ask yourself, ‘is saving an extra n cents per part really worth the possibility of getting bum parts?’ Even worse than all of the parts failing, you may see intermittent failures if only some of the parts work. This can send you on a wild goose chase trying to debug your design or assembly process.”
In my days of building Heathkits, I never needed to worry about sourcing components or getting bad parts (not usually anyway, although there was this one time…). But today, bad and counterfeit parts are a reality, so I am very glad to see this advice in Scott’s book.
I could continue describing this marvelous book, but the PDF is free, so you should download a copy today and read through it yourself, whether you’re a maker, hobbyist, novice design engineer, or one of those seasoned gray hairs who know how to hold their tongue at exactly the right angle when making adjustments. Check out the book’s Web site, located here. You can also order a printed copy of the book from the same Web site. It should be in print by the time you read this review.