Published in the August 1986 issue of Radio Electronics magazine, this circuit acts as a weapon, capable of delivering strong shocks to anyone who touches it. The circuit operates at 10 kHz.
This electronic Morse Key for telegraph message transmission was found in an American 1980s...
This PWM control circuit was found in an old documentation, but appears elsewhere on this site...
Found in a 90s Radio Electronics, this circuit uses an AD590 or AD592 for remote temperature...