BRUSHLESS DC MOTOR CONTROLLER FOR OUTDOOR AIR CONDITIONER

摘要

PURPOSE:To safely operate a motor by detecting a generating current when the motor is rotated by an external force in a non-operating state, and inhibit the driving of the motor for a predetermined time. CONSTITUTION:A driving circuit for a brushless DC motor has a bridge circuit made of upper and lower transistors Q and a diode D, motor windings M1-M3 connected to the output side of the bridge circuit, a current transformer CT, a current detector PI, and a motor driver CDR. When the motor is stopped, a current is detected by a current detector PI. When a large current in a case that the motor is rotated by natural wind, a signal is output to the driver CDR. As a result, the transistor Q is set not to be turned ON to prevent a short- circuiting current, thereby avoiding the damage of the transistor Q of the motor.