BRUSHLESS DC MOTOR VOLTAGE CONTROL DEVICE AND AIR-BLOWING DEVICE EQUIPPED WITH SAME

摘要

A brushless DC motor voltage control device (20a): stores the value of one cycle of a periodic voltage variation in a smoothed voltage; uses a duty adjusted on the basis of the stored smoothed voltage value to delay the application of a pulsed motor voltage VM for the duration of a delay time, the delay time being the difference between the amount of time from when the smoothed voltage is output by a smoothing circuit (14) until the smoothed voltage is output, via an inverter circuit (1), to a brushless DC motor (2), and the amount of time from when the smoothed voltage is output by the smoothing circuit (14) until the duty is output, on the basis of the smoothed voltage, to the inverter circuit (1); and accurately estimates the position of a rotor (4).