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.
Found in an Electronic Design from the 90's, this circuit uses an SCR according to the controlled power....
This circuit was found in an English publication from 1967. The circuit is for listening on a...
This is the traditional configuration of an OR gate using a voltage comparator, but it can also be...