We found this circuit in an American publication from 1966. The transistor fires when it detects a hysteresis problem in a circuit.
This is the basic configuration of an operational amplifier sample & hold circuit. The FET and...
Found on 80's Popular Electronics, this circuit uses an uncommon integrated today. Programming is done...
Found in a 1968 Mullard manual, this circuit can function as an infrared audio link. The...