| 摘要 |
PURPOSE:To facilitate the assembling and maintenance by double magnetizing the second magnet for detecting a rotation signal for the first magnet for a rotor, thereby reducing the number of parts. CONSTITUTION:When a stator coil disposed oppositely to the same magnet rotor 3 formed with the second magnet 11 at the outer peripheral surface side and formed with the first magnet 3A at the inner peripheral surface side is energized, the rotor 3 is rotated due to the presence of the first magnet 3A, the rotary signal of the frequency corresponding to the number of poles of the first and second magnets 3A, 11 is detected by a detector element 6a. Only the rotary signal corresponding to the second magnet 11 is extracted by a filter 20, supplied to a servo circuit 30, and the motor 1 is controlled at the speed. |
