Most fan motors use AC induction motors, it always has two windings (coil). Primary windings are usually used as running winding, another auxiliary winding is used as a start winding. AC supply voltage is applied to start winding through the starting capacitor. Under the action of capacitor, so the phase of applied current in start winding is ahead of 900 the run winding . Between the stator and the rotor, there is forming a starting torque, thus making the rotor work. Under the action of external AC voltage, the stator coil forms rotating magnetic field, even if the current in start winding reduces and it does not affect the rotation of the motor. In fact after the start, due to the start capacitor is charged and the start winding current is reduced.
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