CONTROLLER FOR SENSORLESS DC BRUSHLESS MOTOR

摘要

PURPOSE: To obtain a sensorless DC brushless motor capable of obtaining stable rotation against the variations of load torque. CONSTITUTION: The title controller has a rotor position detecting means 1 which detects counter electromotive voltages of conducting phases 8, 9, 10, a pulse delaying means 2 which divides the period of rotation of the rotor into position modes 1-6 by the zero-cross points of each conduction phase, makes the time from a zero-cross point being a starting point of a mode in the former period of rotation of the rotor to an electric angle being a proper conduction control timing of a conducting phase to be conduction-controlled in the mode a delay time of the mode, and outputs a timing signal making this delay time a conduction control timing of this-time rotation period of the rotor from a zero-cross point being a starting point of the same mode, a conduction control signal generating means 3 which generates a conduction control signal of each conducting phase on the basis of this timing signal, and a conducting phase power supplying means 4 which supplies power to each conducting phase 8, 9, 10 on the basis of this conduction control signal.