| 摘要 |
PURPOSE:To shorten valve closing time and to perform valve opening and closing operations at a high speed, in returning an electromagnetic operating apparatus that has been operated, by supplying a reverse current, and instantaneously dissipating magnetic flux. CONSTITUTION:When a driving command S is imparted, a switching element 9 is turned ON. A plunger 102, which is engaged with a valve rod 107 of a solenoid valve, is driven, and the valve rod 107 is opened. Said plunger 102 is quickly driven. After a specified time T1, a base driving signal IB1 disappears. Therefore the switching element 9 is turned OFF, and the supply of exciting current to an exciting coil 101 is cut off. When the switching element 9 is turned OFF, a control device 14 supplies a base driving signal IB2 to a switching element 13. Then a power source voltage E2 from a DC power source 12 is applied to an exciting coil 101 at a reverse polarity with respect to a power source voltage E1. Therefore a demagnetizing current IF2 in the reverse direction with respect to said exciting current IF1 flows through the exciting coil 101. Thus the said iron core is demagnetized. Since the demagnetizing current IF1 in the reverse polarity is immediately supplied through the exciting coil after the disappearance of the exciting current IF1, the plunger 102 is quickly returned, and the quick valve closing operation of a solenoid valve is achieved.
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