The voltage regulation method and the thyristor speed regulation technology are adopted, which have the characteristics of simple circuit and small size of components. It is a simple and effective method of thyristor. When the single-phase current passes through the armature winding, the pulsed magnetic field is generated instead of the rotating magnetic field, so the single-phase asynchronous motor cannot start automatically. In order to solve the problem of starting, the asynchronous motor with single-phase AC power supply is usually made into two-phase. The main winding is directly powered by a single-phase power supply; the auxiliary winding is 90° spatially different from the main winding (electrical angle, equal to the mechanical angle divided by the number of pole pairs of the motor). The secondary winding is connected in series with a capacitor or resistance and then connected to a single-phase AC power supply, so that the current passing through it has a certain phase difference with the current in the main winding.