MOTOR DRIVER

摘要

A motor driver for driving a motor having a rotor and phase coils for generating a magnetic field to rotate the rotor by using a PWM switching action. The motor driver comprises transistors acting as switches for switching current supply paths to the coils, position sensing means for determining the rotational position of the rotor from the terminal voltages of the coils, and switching control means for allowing the transistors to perform switching actions associated with switching between the on-state and off-state according to the result of the determination by the position sensing means so as to rotate the rotor at a predetermined rotational speed. The switching control means further controls the transistors so that the transistors are forcedly kept off for a predetermined period of time at predetermined cycles. The position sensing means senses the position during the time when the switching control means forcedly keep the transistors off.