| 摘要 |
PURPOSE:To reduce the cost and size by forming a lock detector of an integrator for integrating the output signal of a phase comparator, and a comparator for binarizing the output signal of the integrator with a reference voltage, thereby simplifying the circuit configuration. CONSTITUTION:The output of a speed detector having a detecting coil 10 and a waveform shaper 11 and the output of reference signal generating means having a crystal oscillator 13 and a frequency divider 14 are input to a phase comparator 12 to compare the phases to operate a pulse-width modulator 15 by the output signal, thereby controlling ON and OFF the coil excitation of the motor. Further, the output signal of the comparator 12 is input to an integrator having a resistor 31 and a capacitor 32, the integrated value and a reference voltage divided by resistors 33, 34 are input to a comparator 35, compared to obtain different output signals at asynchronous and synchronous times. |
