This circuit is from an American documentation from the 90's. The SCR can be of any type and the diodes must have current according to the controlled motor.
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...