| 摘要 |
PURPOSE:To decelerate the brake operation limiting speed of a single phase condenser type induction motor by employing a brake control circuit having hysteresis and an AC/DC converter having good response using an operational amplifier. CONSTITUTION:An AC voltages generated at a tachometer generator 4 is converted by an AC/DC converter to a DC speed detection signal A, compared and amplified with a speed set signal from a variable resistor 7 and by an error amplifier 6, thereby obtaining a speed error signal B. This amplifier 6 limits the output voltage to the negative output polarity of the signal B, and the input voltage to the brake phase control circuit 10 is limited, thereby limiting the maximum braking torque, the output voltage is limited to the positive output polarity, and the magnitude of the error signal is limited to the value lower than the saturation point of an operating phase control circuit 8, thereby improving the response characteristic. |
