The transmission of the motor uses the connection mode of changing the winding, that is to say, the rotating speed of the motor is changed by the pole of the rotating magnetic field of the motor.
Two speed motor (fan) usually has low speed, sometimes the fan will turn at a high speed, mainly through the following external control circuit switching to change the winding connection mode of motor coil to achieve.
1, there are two embedded in the stator slots were not homopolar logarithmic winding, through an external switching control circuit to change the stator winding connection method to achieve change poles;
2, in the stator slots embedded with independent winding two not homopolar logarithm;
3, in the stator slots embedded with independent winding two unifying the logarithm, and each winding can have different connection.