Patent ID: 8258734
Filing Date: 2012-09-04
Classification: H02P

Abstract:
1. An electromechanical apparatus comprising: magnetic coils of N phases (N is an integer of 3 or more); magnets; a PWM drive circuit that drives the magnetic coils of N phases; and a control unit that controls voltage to be applied to the magnetic coil, wherein the magnetic coil of each phase can be independently controlled by the PWM drive circuit, and the control unit applies voltage to the magnetic coil in an excitation interval that is symmetric about a π/2 phase point when a position at which the polarity of a waveform of induced voltage induced in the magnetic coil due to the movement of the magnets is reversed is defined as a π phase point, does not apply voltage to the magnetic coil in a non-excitation interval that is symmetric about the π phase point of the waveform of the induced voltage, and makes the length of the non-excitation interval greater as the electromechanical apparatus rotates at high revolution.