| 摘要 |
PURPOSE:To prevent a switching noise from generating by counting a frequency signal generated from a frequency generator in response to the rotation of a rotor, and forming a quasi-sinusoidal drive signal by the counted value. CONSTITUTION:The counter output of a counter 48 is applied to an encoder 50, which generates an approximate sinusoidal binary data in response to the counted value. This encoded output is converted through a D/A converter 52 to an analog drive signal waveform, the drive signal waveform is applied to drive amplifiers 56A, 56B, 56C, and the drive currents of the field coils 4A, 4B, 4C become quasi-sinusoidal waves. The abrupt change portion is eliminated by driving the motor by the quasi-sinusoidal drive signal to prevent a switching noise from generating. |
