Irrigation control system
First Claim
1. An irrigation control device comprising:
- at least one sprinkler valve;
at least one soil moisture sensor for measuring the level of moisture in the soil surrounding the sensor, the sensor being inserted into the soil in close proximity to the sprinkler valve; and
circuit means responsive to the sensor for initiating at least one pulsed sprinkler cycle when the soil moisture sensor detects a low soil moisture level, and repeating the cycle until the sensor detects a saturated soil condition, and further wherein the pulsed sprinkler cycle is comprised of the activation of the sprinkler valve for a first predetermined time period, and a subsequent deactivation of the sprinkler valve for a second predetermined period of time;
said circuit means further comprising means for applying current to the soil moisture sensor, means for measuring a resultant current from the moisture sensor, a current to voltage converter for converting the measured resultant current to a converted voltage, a dry threshold voltage comparator for comparing the converted voltage to a predetermined high voltage level, and producing a dry soil signal when the converted voltage is higher than the predetermined high voltage level, a saturated threshold voltage comparator for comparing the converted voltage to a predetermined low voltage level, and producing a saturated soil signal when the converted voltage is lower than the predetermined low voltage, and means for initiating the pulsed sprinkler cycle in response to the dry soil signal, and for terminating the pulsed sprinkler cycle in response to the saturated soil signal.
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Accused Products
Abstract
A system is disclosed comprised of several inputs in the soil that send a current into the soil and measure the resulting resistance in the soil. The soil resistance varies inversely with the level of moisture in the soil. Two voltage comparators are used to determine whether the soil has reached a pre-determined level of saturation or dryness. If the pre-determined level of dryness is exceeded, then a signal is sent through a switch and a latch, and activates the sprinkler solenoids. Once the pre-determined level of saturation is reached, a saturated signal is sent through the switch and latch in order to de-energize the solenoids. The system includes an over-watering prevention feature wherein a clock circuit is used so as to pulse the sprinklers in order to allow the water to permeate the soil between the sprinkler pulses.
55 Citations
19 Claims
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1. An irrigation control device comprising:
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at least one sprinkler valve; at least one soil moisture sensor for measuring the level of moisture in the soil surrounding the sensor, the sensor being inserted into the soil in close proximity to the sprinkler valve; and circuit means responsive to the sensor for initiating at least one pulsed sprinkler cycle when the soil moisture sensor detects a low soil moisture level, and repeating the cycle until the sensor detects a saturated soil condition, and further wherein the pulsed sprinkler cycle is comprised of the activation of the sprinkler valve for a first predetermined time period, and a subsequent deactivation of the sprinkler valve for a second predetermined period of time; said circuit means further comprising means for applying current to the soil moisture sensor, means for measuring a resultant current from the moisture sensor, a current to voltage converter for converting the measured resultant current to a converted voltage, a dry threshold voltage comparator for comparing the converted voltage to a predetermined high voltage level, and producing a dry soil signal when the converted voltage is higher than the predetermined high voltage level, a saturated threshold voltage comparator for comparing the converted voltage to a predetermined low voltage level, and producing a saturated soil signal when the converted voltage is lower than the predetermined low voltage, and means for initiating the pulsed sprinkler cycle in response to the dry soil signal, and for terminating the pulsed sprinkler cycle in response to the saturated soil signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A multichannel irrigation control system for an area having a plurality of zones comprising:
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a plurality of sprinkler valves, at least one of the sprinkler valves being located in each of the zones; a plurality of soil moisture sensors, at least one of the sensors being located in each of the zones, wherein each of the soil moisture sensors corresponds to one of the sprinkler valves; circuit means for monitoring the soil moisture sensors and selectively activating said sprinkler valves;
said circuit means further comprising;an input selector for sequentially selecting one of the soil moisture sensors as a selected sensor; means for applying current to the selected sensor; means for measuring a resultant current from across the selected sensor; a current to voltage converter for converting the resultant current to a converted voltage; a dry threshold voltage comparator for comparing the converted voltage level to a predetermined high voltage level, and producing a dry signal when the voltage is higher than the predetermined high voltage level; a saturated threshold voltage comparator for comparing the converted voltage level to a predetermined low voltage level, and producing a saturated signal when the voltage is lower than the predetermined low voltage level; means for storing the dry signal and the saturated signal for the selected sensor; means for scanning the storage means for reading the stored signals; and means for initiating at least one pulsed sprinkler cycle in response to reading a scanned stored dry signal, and repeating the cycle until a saturated signal is read, and further wherein the pulsed sprinkler cycle is comprised of activation of the sprinkler valve for a first predetermined period of time, and a subsequent deactivation of the sprinkler valve for a second predetermined period of time. - View Dependent Claims (12, 13, 14, 15, 16, 17)
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18. A method of controlling an irrigation system comprising the steps of:
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inserting soil moisture sensors into the ground, the sensors being spaced apart conductive plates; installing at least one corresponding sprinkler in close proximity to each of the sensors; applying current across the plates of the soil moisture sensor; measuring the resulting current; converting the resulting current to a voltage; comparing the voltage to a predetermined dry voltage level to produce a dry signal when the voltage reaches the predetermined dry voltage level corresponding to undesired soil dryness; comparing the voltage to a predetermined saturation voltage level to produce a saturated signal when the voltage reaches the predetermined saturation voltage level corresponding to soil saturation; activating a pulsed sprinkler cycle when the dry signal is detected; and deactivating the pulsed sprinkler cycle when the saturated signal is detected. - View Dependent Claims (19)
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Specification