Found in old documentation, this circuit uses an SCR like the TIC106 that must be equipped with a heat sink. The motor can be up to 3A.
This amplifier with differential input uses two old op amps but can be implemented with modern op amps....
This circuit is suggested by the National Semiconductor Linar Applications Handbook, controlling a DC motor...
This useful inductance bridge was found in a Radio Electronics from September 1963. The...