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 circuit was found in an 80's Electronic Engineering. The circuit uses operatives of the time...
The selected circuit was obtained in a Texas Instruments opto-electronics manual. The transistors can be...
In short wave receivers or in the recovery of signals from scratched discs this circuit can be...