To provide a simple power supply for driving a motor inexpensively while reducing power consumption.

A capacitor C is provided as an auxiliary power supply at a power supply section 11. When a motor M is not driven, the capacitor C is disconnected from the motor M and connected with the power supply 11 and charged. At the initial driving stage of motor M, the capacitor C connected with the power supply 11 is further connected with the motor M and the number of revolutions of motor M is counted. When a predetermined count is reached, subsequent charge/discharge operation of the capacitor through the power supply 11 is controlled until a stopping r.p.m. is reached. Consequently, the motor M can be driven through simple circuitry while reducing power consumption of a motor driver.