Found in old American documentation, this circuit is intended for the control of heating elements. The SCR must have current according to the controlled load. Transistors are from the time.
This photometer is based on a Wheatstone bridge that must be balanced by the linear potentiometer P1. The...
This 1997 documentation circuit was originally created for use with Camcorder type video cameras....
This simple circuit tests both monophonic and other two-wire audio cables. The circuit is powered...