| 摘要 |
PURPOSE:To lower a signal frequency and eliminate fear of mistake in response of a control system even during high speed revolution by dividing a signal of a magnetoelectric converting element to 1/(n-2) to form a number-of- revolutions detecting signal. CONSTITUTION:A stator 4 winding a coil 3 for each phase is arranged at the inside of a rotor magnet 2 of rotatable rotor 1 and the coil 3 is commutated by a magnetoelectric converting element 6 such as a hall element for each phase provided to a printed circuit board 5. An output signal of the magnetoelectric converting element 6 for commutation is used as the signal for detecting the number of revolutions. Particularly, the number of poles of motor is reduced to 1/(n-2) so that one pulse signal is outputted for a single rotation in order to eliminate influence of fluctuation of magnetization pitch of the rotor magnet 2. Thereby, a control circuit can easily be formed in the high speed region without lowering the rotating accuracy and moreover effect of low cost may be obtained since the magnet for detecting the number of revolution and coil are no longer necessary. |
