SENSORLESS DRIVING DEVICE AND SENSORLESS DRIVING METHOD FOR BRUSHLESS MOTOR

摘要

The present invention relates to a sensorless driving device and a sensorless driving method for a brushless motor. If it is detected that the rotation speed of the brushless motor is higher than a preset speed when the brushless motor is operated with a square wave, thereafter, the sensorless driving device converts square wave driving into sinusoidal wave driving when it is detected that an angle of a rotor of the brushless motor becomes a preset angle. The brushless driving device sets an angle to convert a conductive mode in the square wave driving or an angle to form motor torque with a peak value in the square wave driving as the preset angle. [Reference numerals] (213) Controller; (216) Rotor(permanent magnet); (219) Power supply voltage; (AA) BLM drive circuit; (BB) Gate signal