This Kirlian machine circuit uses a car ignition coil. The circuit is from a Radio Electronics from May 1986. It is mentioned in an article that teaches how to obtain photographs.
Found in Motorola documentation from the 90s, this circuit makes use of a triac from that time. The...
This transistorized signal injector was one of the first that we found using the well-known...
This 200-mW amplifier uses one of the first commercial power transistors. The circuit is from a...