US 4,613,764 A · Rain detector for irrigation control system

Abstract

A rain detector is provided for preventing operation of an irrigation system upon detection of an adjustably selected amount of rainfall. The rain detector is designed for use with an automatic irrigation control system of the type including a clock controller to electrically operate one or more normally closed valves for programmed supply of irrigation water to sprinklers individually or in selected groups. The rain detector comprises a switching circuit connected electrically in series with the sprinkler valves, with the switching circuit including spaced sensors extending for an adjustable depth into a collection tray exposed to rainfall. The switching circuit is normally closed in the absence of rainfall to permit normal programmed operation of the sprinkler valves. However, when rainfall within the collection tray reaches a level bridging the sensors, the switching circuit is triggered to form an effective open circuit condition between the clock controller and the sprinkler valves, thereby closing the sprinkler valves pending evaporation of the rainwater to a level below the sensors.

Claims21

Dependent claims

A rain detector responsive to rainfall for preventing operation of an irrigation system having a controller for electrically operating at least one sprinkler valve, said rain detector comprising:

a detector housing;
a switching circuit disposed generally within said housing and including means for electrical connection in series with the controller and at least one sprinkler valve, said switching circuit further including a pair of conductive sensors protruding in spaced relation from said housing;
a support plate movably mounted within said housing and carrying said sensors;
a rainwater collection tray supported from said housing in a substantially upwardly open position exposed to rainfall, said sensors protruding from said housing downwardly at least partially into said collection tray;
and
means accessable from the exterior of said housing for movably positioning said support plate for adjustably selecting the depth of protrusion of said sensors into said tray for bridging of said sensors by an adjustably selected amount of rainfall collected within said tray;
said switching circuit including means for providing a normal closed circuit condition between the controller and at least one sprinkler valve when the level of water within said tray in insufficient to bridge said sensors and for providing an effective open circuit condition between the controller and at least one sprinkler valve when the level of water within said tray is insufficient to bridge said sensors.

4 more elements

A rain detector responsive to rainfall for preventing operation of an irrigation system having a controller for electrically operating at least one sprinkler valve, said rain detector comprising:

a generally hollow detector housing having a sensor opening formed therein and an elongated guide track formed thereon;
a circuit board supported within said housing for generally pivoting motion about one end of said board to movably position the other board end, said other board end being generally aligned with said sensor opening;
a switching circuit supported generally on said circuit board and including means for electrical connection in series with the controller and at least one sprinkler valve, said switching circuit further including a pair of conductive sensors protruding in spaced relation from said housing through said sensor opening;
a rainwater collection tray removably supported from said housing generally in alignment with said sensor opening for at least partial extension of said sensors into said tray, said tray having a size and shape for substantially open upward exposure to and collection of rainfall;
a mounting base on said housing for mounting said housing with respect to a selected support structure in a position supporting said tray in a substantially upwardly open orientation;
and
a slide actuator movable along said guide track and operably coupled to said circuit board for movably positioning said circuit board to adjustably select the depth of sensor extension into said tray, said slide actuator being at least partially accessible from the exterior of said housing;
said switching circuit including means for providing a normal closed circuit condition between the controller and at least one sprinkler valve when the level of water within said tray is insufficient to bridge said sensors and for providing an effective open circuit condition between the controller and at least one sprinkler valve when the level of water within said tray is sufficient to bridge said sensors.

5 more elements

Dependencies are inferred from the claim text.

Rain detector for irrigation control system

Life of this patent

Rain detector for irrigation control system

Life of this patent

Abstract

Claims21