Bistable light relay (CB21708E)

This circuit was found in an internet documentation. The relay must have voltage according to the supply.

Electronic Morse Key (CB4196E)
This electronic Morse Key for telegraph message transmission was found in an American 1980s...
DC Motor Control (CB5376E)
This PWM control circuit was found in an old documentation, but appears elsewhere on this site...
Remote temperature sensor (CB8713E)
Found in a 90s Radio Electronics, this circuit uses an AD590 or AD592 for remote temperature...