To suppress torque ripple and secure starting torque by making a current application block control circuit control the section where a current is applied to each drive coil by the current detection signal obtained by a current detection circuit.

This circuit is equipped with a position detecting means 2 which gets a three-phase power signal geared to the relative positional relation between a stator and a rotor, a drive current control circuit 4 which controls the current flowing to each drive coil 26, 27, and 28, a current detecting circuit 5 which detects the current flowing to the drive coils 26, 27, and 28, and a current application block control circuit 3 which decides the block where currents are applied to each three-phase drive coil 26, 27, and 28. Then, a current application block control circuit 3 controls the block where currents are applied to each drive coil 26, 27, and 28 by the current detection signals obtained by the current detecting circuit 5. Hereby, even if the current amplification factor of upper and lower drive transistors 20-25 are unbalanced, the starting torque can be secured, suppressing torque ripple.