BRUSHLESS MOTOR DRIVE UNIT

PROBLEM TO BE SOLVED: To minimize operation in reverse rotation, by providing a drive unit that can detect reverse rotation of a brushless motor.SOLUTION: After positioning a brushless motor at an initial position by continuing one electrification mode (step S102), the brushless motor is started by switching the electrification mode (step S103). When the brushless motor is started, the voltage of a non-electrification phase in the electrification mode at that time is compared with a threshold for determining reverse rotation, thus determining whether or not there is reverse rotation (step S104). When reverse rotation is determined, the brushless motor is stopped temporarily by stopping electrification (step S105). Subsequently, the time for positioning at the initial position is corrected (step S106), and the brushless motor is positioned again at the initial position before being started (steps S102, S103).