PURPOSE: To reduce mechanical vibrations by halving the number of magnetic poles and salient poles and constituting a rotor so as to receive magnetic attracting force in one direction at all times without denying magnetic attracting force.

CONSTITUTION: In a two-phase reluctance type motor, a rotor 1 has salient poles 1a..., and the salient poles are disposed respectively at regular pitches by the phase difference of 350°. Magnetic poles 16a-16d are arranged to a fixed armature 16 in width thereof at the equal separation angles of 180°. The width of the salient poles 1a... and the magnetic poles 16a-16d is equalized at 180°, and five salient poles and four magnetic poles are installed. The magnitude of exciting currents for assigning output torque is chopper-controlled by inductance and processed independently, and the large inductance of the magnetic poles is utilized effectively for output torque. The conduction angle of the exciting coil is brought to 180° at an electrical angle, and phase-advanced at approximately 30° and conduction is conducted, thus inhibiting the generation of reverse torque.