| 摘要 |
PURPOSE: To lengthen the life of switching operation by connecting a switch element to a coil in parallel, which obtains a conductive state when the operation voltage of the coil becomes higher than a predetermined voltage, and connecting a resistor in series to said parallel circuit. CONSTITUTION: If the portion between terminals S8 and S10 is turned on by operating an operation switch S1 , an electric charge stored in a capacitor S2 is discharged, and a transistor S7 and an SCR S6 are turned on. By doing this, a current flows to a coil 2 and the coil is excited, an electromagnetic device 2 is driven and its moving part is moved at a slow speed, a main contact portion 1 is turned off, and a load circuit L is closed-pole-controlled. When the operation voltage of the coil 2 becomes higher than a Zener voltage, a switch element 30 becomes conductive and no current flows to the coil 2 any more, and the operation voltage of the coil 2 will never get higher than the Zener voltage. Therefore, the moving speed of a moving part of the electromagnet device 2 becomes low and constant. Therefore, the main contact portion 1 is turned on when the load voltage is close to 0V, thereby prohibiting the flow of a rush current at all times.
|
