This current switch was found in a Radio Electronics from November 1957. It triggers the current determined by the electromechanical sensor, a polarized relay of the time.
The components of this circuit are still common today. The circuit is from a 1967 publication by...
This analog TV circuit can be used on a small transmitter. The circuit is from an 80's American...
We found this circuit in a 1976 documentation. The FET can be BF245 or MPF102 and the power supply...