Suggested by Sprague in the 90's documentation, this circuit applies to AC motors. The documentation does not indicate the maximum engine power that can be controlled.
This two-transistor amplifier has good gain but delivers a fraction of a watt of power. The...
This circuit was found in the 1969 RCA thyristor manual. The circuit has a limiter (clipping) with two 12...
This small amplifier, with output less than 1 W, was found in a 1960 transistor manual from...