| 摘要 |
PURPOSE:To protect the servo motor by preventing the maximum power from being fed into the motor, by detecting the overstroke and restriction of a pen with the output voltage of summing amplifier which adds the input voltage and feedback voltage from potentiometer. CONSTITUTION:An amplifier A1 functions as a summing amplifier which adds the input voltage ei from input eteminal IN and feedback voltage ef delivered by potentiometer PM. It is so designed that the output of the summing amplifier A1 is reduced to zero by adding negative feedback voltage ef through rotations of motor M. When an input exceeding the full scale voltage is applied as input ef or pen P is restricted, the output voltage eA of the summing amplifier A1 is saturated, which is applied to an integrator IG, which composes a protective circuit MP. Thus, reducing the voltage applied to coils W1, W2 of the motor M, and decreasing the current flowing in the coils W1, W2, the motor M is protected. |
