Abstract: An electric motor has three windings which are supplied by a three-phase source of electricity that has one polarity during a first half-cycle and another polarity during a second half-cycle. The motor is controlled by an apparatus that has three thyristor switches coupling the phases of the source to the motor windings. A switch controller triggers the thyristor switches to apply electricity that produces movement of the motor. One thyristor switch is operated to be in a first non-conductive state during a portion of every first half-cycle and in a second non-conductive state during a portion of every second half-cycle. The first non-conductive states are longer in duration than the second non-conductive states. A current sensor provides a first value that indicates the magnitude of the DC component of electric current flowing through one motor winding that is connected to the one switch.