Motor drive unit used for camera and accessory thereof

摘要

A motor drive unit is provided with a bridge circuit including series connected first and second MOS transistors, series connected third and fourth MOS transistors, a DC motor connected between a junction of the first and second MOS transistors and a junction of the third and fourth MOS transistors, a power supply line connected to the first and third MOS transistors and a ground line connected to the second and fourth MOS transistors. The state of the DC motor is controlled by on/off controlling the MOS transistors of the bridge circuit. The MOS transistors are controlled such that the motor is continuously short-circuited when a power is supplied to the motor drive unit and the motor is not driven.