Fujitsu General Limited

Koichi Toda

Yoshio Ogawa

A control device for controlling a plurality of motors of an air conditioner comprises a plurality of power circuits each for supplying a corresponding DC voltage to drive a respective motor. Motor driving circuits, each having a plurality of switches, supply the DC voltage from a corresponding power circuit as an AC voltage to windings of the corresponding motor. A rotational position of each corresponding motor is detected, and a position detecting signal is generated dependent thereon. Switch driving circuits, each receptive of a corresponding driving signal, drives the plurality of switches of each corresponding motor driving circuit. A single microcomputer controls the rotation of each of the plurality of motors by generating the plurality of driving signals. Each driving signal is dependent on a respective position detecting signal to drive the plurality of switches of each corresponding motor driving circuit so that the DC voltage from each power circuit is converted and supplied as an AC voltage to the windings depending on the rotational position of each corresponding motor.

Control device for air conditioner

A control apparatus for controlling motors of an air conditioner comprises a converter circuit having switching circuitry for converting AC power to DC power and setting an input voltage of an input alternating current waveform to a sine wave of the same phase as that of an input voltage, first and second brushless motors for driving a compressor and a blower, first and second inverter circuits for converting the converted DC power to AC power and supplying AC power to the first and second brushless motors, and a microcomputer for controlling the compressor and the blower of the air conditioner. The microcomputer is constructed in such a manner that input and output operations which are necessary to control the air conditioner are executed for input and output circuits, thereby controlling at least the compressor and the blower of the air conditioner. To improve the input power factor from the AC power, a PWM signal for controlling the ON/OFF state of the switching circuitry of the converter circuit is generated by the microcomputer on the basis of the input alternating current of the AC power and the output DC voltage of the converter circuit. At the same time, PWM signals for controlling the ON/OFF state of switching circuitry of the inverter circuits are generated by the microcomputer to control the first and second motors.

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Kawasaki, Japan

Koichi Toda