| 摘要 |
PURPOSE:To remove a variation of starting stabilization time of a motor by adding a preset function through a comparison signal to a frequency divider of reference signal. CONSTITUTION:A signal corresponding to a rotational speed of motor 10 is converted into a comparison pulse signal 2a by an amplifier 2. A synchronous detector 5 compares said comparison pulse signal 2a with a reference clock 3a so that a preset signal 6a is generated from a preset circuit 6 when said pulse signal enters a synchronous frequency range. According ly, a binary counter 4 is preset at a given count value. Therefore, a phase difference output of a phase comparator 7 starts always from a value set at a preset value directly after said comparison pulse signal has entered the synchronous frequency range. In this case, outputs of the phase comparator 7 and F/V converter 8 take values fixed at maximum or minimum output levels unless they are included in said synchronous frequency range. |
