The structure and principle of AC induction motor

The structure and principle of AC induction motor

Most electric fan motors use AC induction motors, which have two windings (coils). Its structure and principle are as shown in the figure.
The main winding is usually used as the running winding, and the other auxiliary winding is used as the starting winding. The AC supply voltage is added to the starting winding through the starting capacitor. Due to
the action of the capacitor, the phase of the current added in the starting winding is 900 degrees ahead of the running winding. A starting torque is formed between the stator and the rotor
, causing the rotor to rotate. The external AC voltage causes the stator coil to form a rotating magnetic field. Even if the current in the starting winding decreases, it does not affect
the rotation of the motor. In fact, after starting, the current in the starting winding decreases because the starting capacitor is charged .