| 摘要 |
An electrical control system for an automatic metering valve delivering a preset quantity of water and having a housing for the valve, a rotary impeller disposed within the housing and rotatable at a velocity in accordance with the rate of delivery of the water, and an automatic shut-off mechanism for turning-off the valve when the preset quantity of water has been delivered. The control system includes a sensible element disposed internally of the valve housing and rotated with the impeller, a sensor sensing the sensible element to produce electrical signals corresponding to the number of rotations thereof and of the impeller, a presettable counter circuit effective to count the latter electrical signals, a switching circuit effective to actuate the valve shut-off mechanism to turn-off the valve when the counter circuit reaches a preset number corresponding to the preset quantity of fluid to be delivered, and a presettable timer effective to actuate the valve shut-off mechanism to turn-on the valve after the elapse of a preset time interval.
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