| 摘要 |
PURPOSE:To maintain the torque pulsation constant by controlling the frequency of a triangular wave fed from a triangular wave generator in response to the pulsating component contained in a current flowed to a DC motor. CONSTITUTION:A current which contains pulsating component detected by a current detector 8 is inputted via an insulating amplifier 9 to an absolute value circuit 10. The output of the circuit 10 is inputted via a high pass filter 11 which passes only the pulsating component to a V/F converter 12. A triangular wave generator 6 outputs a triangular wave of the frequency corresponding to the output of the converter 12. A comparator 5 controls the ON/OFF time ratio of a switching element in response to the compared result of the deviation signal between the speed command signal VS and a speed detection signal and the triangular wave. In this manner, the torque pulsation produced from the DC motor can be maintained constant. |
