| 摘要 |
PURPOSE:To prevent as much as possible the scattering in the torque of the title motor regardless of the rotating speed of the same, by a method wherein a waveform, generated by amplifying linearly a waveform obtained from a magnetism detector, is employed for a slant waveform in the vicinity of the switching of the phase of the motor. CONSTITUTION:Circuits 1, 2 constitute linear amplifiers, therefore, the output voltage of a Hall element H1, changed comparatively slowly in accordance with the rotation of a rotor, is amplified while maintaining the waveform thereof as it is and is outputted from operational amplifiers A1, A2. These output voltages mitigate the steep slope of the leading edge and trailing edge of the driving currents of coils L1, L2 which are out ON/OFF by transistors TR1, TR2 through resistors R10, R11. According to this method, electromagnetic sounds and the scattering in the torque may be prevented as much as possible and the mechanical vibration of the title motor may be reduced remarkably. |
