Driving an AC motor using transistor as a switch
The capstan motor of one of my tape decks is speed controlled by a transistor that shorts a bridge rectifier - it should work for on-off control too.







simulate this circuit &ndash; Schematic created using CircuitLab

The tape deck uses a transformer to isolate the motor 9and the control circuit) from the AC mains, however, the same control could be achieved using an optocoupler to isolate the control circuit from the transistor and motor, which then can be connected directly to 220V.