Electromagnetic rotating apparatus

Electromagnetic rotating apparatus comprising a rotating shaft, a bipolar permanent magnet fixed to said rotating shaft and radially magnetized, a fixed coil disposed to interlink with the magnetic flux of said permanent magnet, symmetrically with respect to said rotating shaft, the fixed coil providing a magnetic field perpendicular to the axis of said rotating shaft when energized, first and second stoppers to limit the rotation of said permanent magnet within an angular range of less than 180 degrees and stop the rotation thereof before said permanent magnet reaches a position where the number of magnetic flux interlinking with said fixed coil becomes maximum, a starting energizing circuit to energize said fixed coil while said permanent magnet moves halfway from a first stop position to a second stop position defined by the first and second stoppers, thereby providing energy for permitting said permanent magnet to rotate from the first stop position to the second stop position, a damping circuit to feed said fixed coil with a current to damp said permanent magnet from the completion of energizing by said starting energizing circuit to the arrival at the second position, and a holding energizing circuit to feed said fixed coil with a current flowing in the same direction as the current fed by said starting energizing circuit when said permanent magnet reaches the second stopper, thereby holding said permanent magnet in the second stop position.