PURPOSE: To obtain a permanent magnet motor in which the pole position can be detected even under stationary state without requiring any sensor by arranging permanent magnets and salient cores alternately on the surface of a rotor such that every other poles have same polarity and placing a single phase exciting winding and an armature winding in the stator slot.

CONSTITUTION: The stator has such structure as permanent magnets 2 are stuck to the surface of a rotor core 1 having really circular cross-section and the core 1 itself has salient poles 3 corresponding to the permanent magnets 2. The armature winding 5 of a motor and the exciting winding 6 of a resolver are contained in the slot 4 of stator core. The motor has 12 slots, a four pole exciting winding, and a three-phase two pole armature winding. In case of a two pole rotor, the exciting winding is arranged across three slots while the three phase armature windings U, V, W are overlapped while being shifted by 120° and a single phase high frequency current is fed to the exciting winding 6. A voltage is induced in the three phase armature winding 5 and since the magnitude thereof depends upon the rotor position, the rotor position can be detected.