| 摘要 |
PROBLEM TO BE SOLVED: To set the origin of a flow control valve, while preventing the step out and the occurrence of abnormal sound and vibration of a motor, as much as possible in a simple constitution, without requiring a means of detecting that the flow control valve has reached its original position. SOLUTION: When a fluid passage is interrupted, while an electronic circuit unit 50 including a microcomputer 51, etc. is receiving power from a power source, this device displaces the flow control valve in advance by a stepping motor 29 to a specified position slightly closer to the first end out of both ends of the movable range of the flow control valve in the fluid passage. When the supply of the power of a power source is resumed, after the stoppage of power of a power source to an electronic circuit unit 50, this device supplies the stepping motor 29 with a specified number of pulses that can displace the flow control valve to the original position from the first end so as to make the flow control valve to the original position, with the second end out of both ends of the variable range of the flow control valve as its original position of the flow control valve. COPYRIGHT: (C)2005,JPO&NCIPI |
