| 摘要 |
PURPOSE:To prevent electric power efficiency from lowering by switching a basic pulse for starting the operation of an electromagnetic solenoid over to a maintenance pulse, based on difference in the terminal voltage of a minute resistor provided in series with said electromagnetic solenoid. CONSTITUTION:An exciting coil 12a of an electromagnetic solenoid is connected in series to a battery 19 through a driving transistor 17 and a minute resistor 18. A driving circuit has an operation commanding circuit 21 for a solenoid valve, a basic pulse generating circuit 22, a maintenance pulse generating circuit 23, a detecting circuit 24 for the operation of the solenoid valve, and a switchover controlling circuit 25 which switches the basic pulse signal and the maintenance pulse signal. A detecting circuit 24 for the completion of the operation of solenoid valve includes a differentiating circuit, to which a current feedback signal I detected in a minute resistor 18 is fed.
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