This circuit was found in Motorola's 1968 documentation. It can be built on current equivalent components. The bridge diodes and the SCR must be in accordance with the current of the controlled motor.
This circuit with transistors was found in an old Japanese publication, translation of an American...
This 8 W amplifier with germanium transistors was found in a Japanese documentation from 1967. The...
This circuit of the 80's makes use of components of the time. The circuit is from an American...