| 摘要 |
PURPOSE:To shorten the time after a load varies to the time when the speed of a motor is recovered by composing a filter of a low pass filter and a differentiating circuit capable of bypassing. CONSTITUTION:A speed detector 20 generates a square signal D proportional to the rotating speed of a motor 10, and this signal D is applied to the trigger input terminal of a monostable circuit 30 and the first input terminal of a 2- input AND circuit 40. An inverted signal E of a monostable circuit 30 is applied to the second input terminal of the circuit 40. The output signal F of the circuit 40 is applied through a variable characteristic filter 50 to a driving circuit 60. The filter 50 is composed of a low pass filter 61 and a differentiating circuit 62 in series with each other. The circuit 62 is normally bypassed, and is inserted only when a filter control signal G is outputted from a monostable circuit 70 triggered by a head load signal H. |
