METHOD FOR CONTROLLING ROTATION OF SENSORLESS MULTIPHASE DC MOTOR

PURPOSE:To dissolve the dead point of start by performing the reverse excitation drive, where the direction of an exciting current reverses substantially without including a pause period, in order in plural phases. CONSTITUTION:A controller 10 controls the start of a motor and the rotation after start. That is, an exciting counter (MC) 10e is set to +4, and a step timer (UT) 10f to T1. Hereby, an exciting current is supplied only for a time T1 in the order of coils u v, v w, and w u. Moreover, the MC 10e is set to +4, and the UT 10f to T2. Next the MC 10e is set to +4, and the UT 10f to T3, T4, and T5, and an exciting current is supplied only for times T3, T4, and T5 in the order of coils u v, v w, and w u. In such a current application process, reverse excitation drive, where an exciting current reverses from negative to positive without including a pause period, is performed in order in the order of coils u, v, and w.