DRIVER OF ELECTRIC MOTOR

PROBLEM TO BE SOLVED: To satisfy both silence and drive continuity of an electric motor by performing optimal control of power supply state of the electric motor in the relation of the temperature of an element for driving the electric motor and the guarantee upper limit temperature in the driver of the electric motor. SOLUTION: The microprocessor of a driver for an electric motor acquires the temperature of a switching element or some temperature correlated with that temperature (step 104), determines a first drive request for requesting power supply by PWM control with a duty ratio less than 100% as a drive request for a motor control section after a moment in time when power supply to the electric motor is started before the temperature acquired by a temperature acquisition means reaches a first judgment temperature from a state of lower temperature than the first judgment temperature, and determines a second drive request for requesting 100% supply of DC power supply voltage as a drive request for the motor control section when the acquired temperature is above the first judgment temperature (steps 108, 110 and 116-120). COPYRIGHT: (C)2008,JPO&INPIT