This circuit was found in a 1965’s General Electric documentation. It is intended for low voltage brush motors. The SCR must be according to the engine controlled.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...