| 摘要 |
A sealed plastic case (1) has mains water inlet (4) connected to the delivery outlet (5) via an electronically controlled valve. Optionally the control is applied to pumping from a reservoir. A tell-tale (3) lights when the low voltage DC supply (2), from a mains transformer/rectifier, or solar recharged battery, is connected. An electronic timer imposes a valve or pump cycle of e.g. 3 minutes ON, 5 minutes OFF, subject to the overriding control of a remote sensing unit, connected by cable (6) or radio link. This has a humidity-sensing soil probe under a light detector, the humidity setting being adjustable (11). With several delivery circuits, the respective control valves are switched, singly or in groups, successively, for intermittent operation.
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