PURPOSE: To reduce vibration and noise by controlling individual speeds of zones by rotating angle detection signal obtained electrically and independent controllers provided for zones of electric angles partitioned by the rotating angle detection signal.
CONSTITUTION: One set of input changeover switch 4a and output changeover switch 4b of a controller 4 is selected from the input changeover switches 4a and the output changeover switches 4b of the controllers 4 provided in number corresponding to the number of zones partitioned by the outputs of position detectors 1 by the output of the position detector 1, a deviation between the output of a speed detector 2 and a speed command value signal 3 is calculated, and a compressor 7 is driven through a PWM generator 5 and an inverter 6. As a result, a torque responsive to torque change due to a load for each zone divided from one revolution of a motor 7 can be generated. Thus, a speed variation during one revolution is suppressed, and vibration and noise are reduced.
USHIJIMA KAZUFUMI
HIRATSUKA KAZUHIRO
Next Patent: DC MOTOR CONSTANT SPEED CONTROL CIRCUIT