Speed control method for a monophase asynchronous motor

摘要

The speed control varies motor torque by modifying opening and closing times of two switches (T1, T2) each in series with an auxiliary winding (B1, B2) of the motor. Switching is controlled to create a current shifted by 90 degrees in the auxiliary winding. The principal winding (BP) is supplied directly with alternating current, with the auxiliary windings supplied through a full-wave rectifier.