| 摘要 |
PURPOSE:To control the rotating speed of a motor to synchronize with the phase of a reference signal to obtain a preferably control performance with less number of pulses. CONSTITUTION:A frequency signal generator 2 is composed, for example, of a frequency generator, a waveform shaper and a frequency divider, and an AC signal of the frequency proportional to the rotation of a motor 1 is shaped to a pulse signal. A frequency signal generator 4 is composed, for example, of another frequency generator, a waveform shaper and a frequency divider, thereby generating a frequency signal (b) lower than the frequency signal (a). A speed detector 3 detects the zero crossing time of the freuency signal (a), thereby obtaining an analog voltage signal corresponding to the time duration and holding to the next zero crossing time point. A synthetic filter 11 synthesizes the output (d) of the detector 3 and the output (f) of a filter 7 at the prescribed ratio and then amplifies in the prescribed frequency characteristics. |
