| 摘要 |
PURPOSE:To save electric power consumption and improve reliability by a method wherein a core is attracted by closing a non-contact switch when the voltage exceeds a predetermined value and afterwards a chopper circuit is activated by a timer circuit to open and close the non-contact switch interruptedly and the core is kept attracted by interrupted current. CONSTITUTION:Until the voltage of a voltage detecting circuit 11 reaches a certain value, DC current is applied to resistors 17, 18 through a diode 21 and a transistor 15 is made ON and a transistor 8 is made OFF. Therefore, no current is applied to an operation coil 1. When the voltage reaches the certain value, the current applied to the resistors 17, 18 is cut off and the transistor 15 is made OFF and the transistor 8 is made ON. Therefore, DC current is applied to the operation coil 1 and the coil 1 starts attracting the core. After some time passes, a timer circuit 12 activates a chopper circuit 13 to produce an interrupted signal. The interrupted signal is applied to the resistors 17, 18 through a diode 22 so that the transistor 15 repeats ON-state and OFF-state. Therefore, the transistor 8 also repeats ON-state and OFF-state. |
