| 摘要 |
In a motor speed controll apparatus for a DC motor, there are provided a frequency signal generating circuit for outputting a signal at a time period corresponding to a rotation speed of a motor, a sawtooth wave output circuit for outputting a sawtooth wave, the voltage of which increases in a constant time-constant at said time period, a holding circuit for holding a substantially peak voltage of said sawtooth wave as a signal voltage corresponding to the rotation speed of the motor, a differential amplifier circuit for comparing said signal voltage with a speed setting voltage and for outputting a speed control signal in accordance with a difference in this comparison, said speed control signal being supplied to a motor drive apparatus, an amplifier circuit interposed between the output of said holding circuit and input of said differential amplifier circuit, and an operation control circuit for controlling said amplifier circuit to an operative mode and a non-operative mode selectively, the motor being driven by switching said amplifier circuit into the operative mode by means of said operation control circuit.
|
