| 摘要 |
PURPOSE:To prevent a DC machine from being turned excessively when its torque or its current is controlled. CONSTITUTION:In the control circuit of a DC machine whose torque or current is controlled by the changeover of a changeover switch S,, the limiter of a torque control amplifier 3 and of a current instruction amplifier 16 is controlled by an amplifier 15 equipped with a gain-adjusting resistance R1 which has combined a diode D1 whose gain is changed when the rotation detection signal of the DC machine is compared with its rotation set value and its rotation exceeds the rotation set value. When the rotation is exceeded, a current instruction from the amplifiers 13, 16 is reduced, and it is limited that the DC machine is turned excessively during the control of its torque of its current. |
