| 摘要 |
PURPOSE:To exactly control the torque of the motor by selectively switching energizing state and non-energizing state by an N type gate thyristor and forming a rush- current preventive capacitor. CONSTITUTION:When a current I of a current and the like main circuit of the motor 2 is increased, it increases the terminal voltage V2 of a resistor R0 of a detecting circuit 5 and a thyristor PUT increases the anode voltage (V2+V3) higher than a gate voltage V1 to thereby conduct the PUT. When the resistance values of the resistor (R3, R4 are so increased as to ignore the value of the resistor R0, it becomes constant voltage determined by the voltage of a battery 3 and the value of the resistances of the resistors R3, R4. Since a transistor Q1 is turned on and a transistor Q2 is turned off upon conduction of the PUT, a relay 7 is opened to stop the motor 2. The capacitor C eliminates the rush current due to the closed switch 1 to set the voltage V1 to the value determined by the resistors R1, R2, VR after predetermined time if the gate voltage V1 is increased higher than the anode voltage (V2+V3). Accordingly, it can exactly control the torque of the motor. |
