After decades of seeing projects and circuits using ever increasingly complex integrated circuits, I yearn for simpler times. As a teenager, I built fascinating and wondrous circuits using just a few transistors. My flashlight controlled relay could control a buzzer; music from my cassette tape player played on my radio with a two-transistor circuit; my amplifier could drive a speaker. These circuits were from dusty hobby books found at my local library with names like "29 transistor circuits" or "electronic hobby circuits."
Transistor Clock
To return to those glory days, I decided to build a digital clock using only transistors as the active elements. After a few years of “work” (it felt more like play), the final parts count is 194 transistors, 566 diodes, 400 resistors, and 87 capacitors.
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This is an electronic kit for the experienced hobbyist. The result is a wall hanging clock that shows 1,250+ parts in all their glory. There are no integrated circuits; all functionality is achieved using discrete transistor-diode logic. The included assembly manual has a logic tutorial and circuit descriptions that attempt to explain how the clock works.
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The kit comes with all parts and the printed circuit board (PCB) with the part symbols showing the values of the components for easy assembly. Solder and solder-wick are included, along with spare parts for most items (we all make mistakes). All you need is a soldering iron, some basic soldering skills, and a few tools.