Johnson Electric International Ag

Guodong Liu

Chiping Sun

Haibo Jiang

Shinghin Yeung

Shujuan Huang

Yunlong Jiang

Zhiwang Chen

A motor-driven fan device includes a motor, a processor, a storage with a lookup table stored therein, and a speed detection unit. The processor queries the lookup table or calculates to acquire the target driving voltage and a corresponding target rotating speed of the motor. When the rotating speed difference is not within the range of the preset rotating speed difference, the processor repeatedly adds a gain value to the target driving voltage to acquire a new target driving voltage, acquires the actual rotating speed and the target rotating speed, and determines whether the rotating speed difference is within the range of the preset rotating speed difference. The processor maintains the operation of the motor at the target rotating speed at that point by using the constant speed control method when the absolute value of rotating speed difference is within the range of the preset rotating speed difference.

Fan device, air flow adjustment device and air volume control method thereof

A motor, a driving circuit thereof and a driving method thereof are provided. The motor driving method includes: during a motor starting stage, when a detected rotor magnetic field is a first polarity and a polarity of an AC power source is positive, or the detected rotor magnetic field is a second polarity and the polarity of the AC power source is negative after a zero voltage crossing point of the AC power source, instantly sending a trigger pulse to a controllable bidirectional AC switch connected in series with a motor winding at both ends of the AC power source; during a motor operating stage, after the zero voltage crossing point of the AC power source, sending a trigger pulse to the controllable bidirectional AC switch after a delay time after the zero voltage crossing point. This method can provide a large torque during the motor starting stage.

Motor driving circuit, motor driving method, and motor utilizing the same

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Shenzhen, China

Guodong Liu