| 摘要 |
PURPOSE:To avoid the variation of the speed of revolution although the load of an engine changes, by regulating the speed of revolution in accordance with the level of the output obtained by integrating the difference between the voltage according to the speed of revoution and the set voltage and the output of the sawtooth wave corresponding to the revoution signal period. CONSTITUTION:The output of a signal generator 2 which produces the signals with the frequency proportional to the number of revolutions of an engine 1 turns on a transistor (TR)34 for a slight period of time. Thus a capacitor 36 is discharged, and a gradually increasing waveform 400 is suppleid to a comparator 37 to be compared with the constant voltage 102 to deliver rotational frequency voltage 100. The voltage 100 is supplied to an integration circuit, and the time integration is carried out for the difference between the voltage 100 and the set voltage 200 to deliver the comparison voltage 300. A comparator 9 compares the voltage 300 with the wave- form 400 and changes the duty of a driving pulse 500 according to the level of the comparison. Then an actuator 12 is operated to regulate the speed of revolution of the engine 1. |
