| 摘要 |
PURPOSE:To improve efficiency by holding a maximum value of input currents to an inverter to the phase of a position sensing signal and adding the maximum value and phase correction corresponding to the number of revolution. CONSTITUTION:A brushless DC motor is driven and controlled through a rectifier circuit, a smoothing capacitor 3 and an inverter 21 from an AC power. A control circuit controlling the speed of the motor is constituted of a microcomputer, a back electromotive voltage position detector 12 sensing the position of a rotor for the motor, a current control section, a base driver, etc. A position sensing signal correction circuit 13 is added to the back electromotive voltage position detector 12 at that time. The correction circuit 13 is organized of a peak holding circuit 19, analog switches 16-1-16-3, etc., holds the maximum value of input currents to the inverter 21 and adds phase correction corresponding to the number of revolution of the motor and the maximum value. The phase of a position sensing signal after correction is conformed to motor induced voltage phase. |
