| 摘要 |
PURPOSE:To reduce the consumed electric-power of a coil by forming the coil for operating a movable iron core from a starting coil and a retention coil and allowing the starting coil to be operated for a short time on starting. CONSTITUTION:The coil for operating a movable iron core is composed of a starting coil SOL.1 and a retention coil SOL.2, which are connected in parallel to power sources 24 and 25. When a solenoid valve is brought into conduction in such a constitutuion, a semiconductor switching circuit Tr1 is brought into conduction for only several m.sec- several hundresth m.sec which is set by a diffeential circuit 21, and the starting coil SOL.1 is excited, while the retention coil SOL.2 is excited during the time in which a current flows in the solenoid. Therefore, a large attractive force is generated during the time when both of the starting coil SOL.1 and the retention coil SOL.2 are excited, so transfer of the movable iron core is not obstructed, and thereafter the movable iron core can be retained by the conduction of the retention coil SOL.2 only. |
