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 circuit from a 2003 documentation, has a protection system that disarms the power supply if...
This circuit was obtained from an old American documentation, and practically any general-purpose transistor...
In the figure we have the circuit of a sweep generator obtained in an old publication. The central...