The Chinese motor fan manufacturer, the rotor can automatically start under the action of the rotating magnetic field. After starting, when the speed rises to a certain level, the start winding is disconnected by means of a centrifugal switch or other automatic control device installed on the rotor. Only the main winding works during normal operation. Therefore, the start winding can be made into a short-time working mode. But there are many times, the starting winding is not disconnected. We call this kind of motor a capacitive single-phase motor. To change the direction of this kind of motor, it can be achieved by changing the position of the capacitor in series. In a single-phase motor, another method of generating a rotating magnetic field is called the shaded pole method, also known as a single-phase shaded pole motor. The stator of this kind of motor is made of salient pole, and it has two poles and four poles. Each magnetic pole has a small slot at the 1/3--1/4 full pole face, as shown in Figure 3. The magnetic pole is divided into two parts, and a short-circuit copper ring is fitted on the small part, as if this part The magnetic poles are the same, so they are called shaded pole motors. The single-phase winding is sleeved on the entire magnetic pole, and the coil of each pole is connected in series, and the polarities generated during the connection must be arranged in order of N, S, N, and S. When the stator winding is energized, the main magnetic flux is generated in the magnetic poles. According to Lenz's law, the main magnetic flux passing through the short-circuit copper ring generates an induced current in the copper ring with a phase delay of 90 degrees. The magnetic flux generated by this current The flux also lags behind the main magnetic flux in phase, and its function is equivalent to the start winding of a capacitor motor, which generates a rotating magnetic field to make the motor rotate.
