Irrigation control apparatus responsive to soil moisture
First Claim
1. An improved irrigation control apparatus for use by an operator in controlling the operation of an electrically operated irrigation valve, which comprises:
- (a) a soil moisture sensor suited to be at least partially buried in the ground, the sensor having means for generating an output voltage when an input voltage is applied to an electrically conductive moisture sensing element in the sensor, the output voltage varying with the level of moisture in the soil; and
(b) a control unit suited to be operatively connected to the soil moisture sensor and a source of electrical power for controlling the operation of the valve in accordance with the soil moisture level, the control unit comprising;
(i) control circuit means having sensor input means for applying the input voltage to the sensor, logic means operatively connected to the sensor and responsive to the output voltage from the sensor for generating a wet soil signal or a dry soil signal depending on the relative level of soil moisture, and valve control means operatively connected to the logic means for allowing operation of the valve if a dry soil signal is sent by the logic means and for preventing operation of the valve if a wet soil signal is sent by the logic means;
(ii) a first power input operatively connected to the control circuit means;
(iii) means for applying electrical power to the first power input only during an irrigation cycle so that the control circuit means is activated only during such cycle;
(iv) display circuit means operatively connected to the logic means for providing a sensory indication to the operator of either a wet soil condition or a dry soil condition;
(v) a second power input operatively connected to the display circuit means by a selectively operable test switch; and
(vi) means for continuously applying power to the second power input so that the display circuit means may be activated at any time by closing the test switch, wherein the control circuit means is separately actuable from the display circuit means.
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Accused Products
Abstract
An improved irrigation control apparatus for use in controlling an irrigation valve. The apparatus includes a soil moisture sensor for generating an output signal indicative of the soil moisture level. The output signal is sent to a control unit that inhibits valve operation if the soil is considered wet. The control unit has a control circuit that applies a relatively short duration power pulse to the sensor to obtain a moisture reading during the pulse. In addition, the control unit includes display lights which are part of a manually actuable test circuit that displays a wet or dry soil indication received from the sensor.
82 Citations
15 Claims
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1. An improved irrigation control apparatus for use by an operator in controlling the operation of an electrically operated irrigation valve, which comprises:
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(a) a soil moisture sensor suited to be at least partially buried in the ground, the sensor having means for generating an output voltage when an input voltage is applied to an electrically conductive moisture sensing element in the sensor, the output voltage varying with the level of moisture in the soil; and (b) a control unit suited to be operatively connected to the soil moisture sensor and a source of electrical power for controlling the operation of the valve in accordance with the soil moisture level, the control unit comprising; (i) control circuit means having sensor input means for applying the input voltage to the sensor, logic means operatively connected to the sensor and responsive to the output voltage from the sensor for generating a wet soil signal or a dry soil signal depending on the relative level of soil moisture, and valve control means operatively connected to the logic means for allowing operation of the valve if a dry soil signal is sent by the logic means and for preventing operation of the valve if a wet soil signal is sent by the logic means; (ii) a first power input operatively connected to the control circuit means; (iii) means for applying electrical power to the first power input only during an irrigation cycle so that the control circuit means is activated only during such cycle; (iv) display circuit means operatively connected to the logic means for providing a sensory indication to the operator of either a wet soil condition or a dry soil condition; (v) a second power input operatively connected to the display circuit means by a selectively operable test switch; and (vi) means for continuously applying power to the second power input so that the display circuit means may be activated at any time by closing the test switch, wherein the control circuit means is separately actuable from the display circuit means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An improved irrigation control apparatus for use by an operator in controlling operation of an electrically operated valve in an irrigation system for irrigating a particular soil area, which comprises:
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(a) means for sensing the level of moisture in the soil area to be irrigated; and (b) a control unit operatively connected to the moisture sensing means and to an electrical power source for controlling the operation of the valve in accordance with the level of moisture in the soil, the control unit comprising; (i) control circuit means for sampling the level of moisture in the soil using the moisture sensing means and for opening the valve to allow irrigation to take place if the soil is dry compared to a reference value but otherwise for closing the valve to prevent irrigation if the soil is wet compared to the reference value; and (ii) display circuit means for sampling the level of moisture in the soil using the moisture sensing means and for providing a sensory indication to the operator of whether the soil is wet or dry, and wherein the display circuit means is selectively operable by the operator independently of the control circuit means to allow the operator to poll the moisture sensing means and display the wet or dry condition of the soil even if the control circuit means is not operable at that time. - View Dependent Claims (12, 13, 14, 15)
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Specification