This nonlinear gain circuit was found in a 1965 Electronic Design. The configuration can be used as a basis for modern designs with equivalent transistors.
Suggested by Radio Electronics from the 90s, this circuit activates a buzzer and an LED when the...
We find this circuit in a 1980s documentation. The integrated circuit used is unusual today. The...
We find this circuit in an old American manual from the 80's. The circuit has a memory that keeps...