| 摘要 |
PURPOSE:To suppress generation of a 'beat' at the time of low speed rotation by selecting a voltage waveform to be applied to a brushless motor, and driving the motor in response to the output of this voltage waveform selecting means. CONSTITUTION:Waveform memory circuits 23a-23c store, for example, three types of waveforms in which the output waveform of a drive input control circuit 150 is altered in response to the output voltage of a rotating speed setter 100. If the set speed of a brushless motor 6 is low, a sine waveform is output. If the set speed is intermediate, a trapezoidal wave is output. If the set speed is high, a rectangular wave signal is output. Accordingly, a drive being important to reduce a beat generated in the winding at the time of low speed rotation can be performed. |
