Irrigation manager system with zone moisture control

• US 4,875,498 A
• Filed: 05/02/1989
• Issued: 10/24/1989
• Est. Priority Date: 05/02/1989
• Status: Expired due to Fees

• Current Assignee: Andrews T. Arthur, Gibson D. Glenn
• Original Assignee: Andrews T. Arthur, Gibson D. Glenn
• Inventors: Andrews, T. Arthur, Gibson, D. Glenn
• Primary Examiner(s): CHAMBERS, A MICHAEL
• Application Number:
  US07/345,902
• Time in Patent Office: 175 Days
• Field of Search: 137/624.11, 137/624.12, 137/78.3, 239/64, 239/70, 324/65 P
• US Class Current: 137/78.3
• CPC Class Codes: A01G 25/167 Control by humidity of the soil itself or of devices simulating soil or of the atmosphere; Soil humidity sensors
• CPC Class Codes: Y10T 137/189 Soil moisture sensing
• CPC Class Codes: Y10T 137/86389 Programmer or timer
• CPC Class Codes: Y10T 137/86397 With independent valve controller

Abstract

Irrigation controller apparatus for respectively controlling moisture content in a plurality of irrigation zones including an independently actuated moisture detection apparatus in each zone which stops and starts irrigation in that zone depending on moisture detected by the respective apparatus.

Claims

1. Moisture manager apparatus for independently managing the amount of moisture in respective zones of earth included within a plot of land being irrigated, said apparatus comprising:

(a) a monolithic electrical earth resistance detection body installed within the earth in a designated zone, said body being hermetically sealed against intrusion of liquids and air;

(b) said body having two electrical detection electrodes mounted to extend out of said body into intimate contact within the earth;

(c) said body having a first pair of electrical input connectors connected to receive AC electrical power from a central controller connected to control other said bodies in other said designated zones;

(d) said body having a second pair of electrical output connectors connected to supply electrical AC voltage to irrigating valve means;

(e) said body including a bipolar electrical resistance detection circuit means mounted on a printed circuit base and connected to said detection electrodes and to said input connectors, said detection circuit means being adapted to oscillate at frequencies governed by a fixed reference resistor and a varying resistance detected through the earth between said detection electrodes, said varying resistance being a function of water present in said earth;

(f) said body containing a switch relay means mounted on said base and connected to said integrated circuit and operative in response to the output of said detection circuit to open and to close said switch relay;

(g) said body being formed of a heat-hardenable liquid plastic poured in and around said detection electrodes, said input connectors, said output connectors, said integrated circuit, and said switch relay wherein the liquid plastic becomes hardened in place into an integral and monolithic solid body.

2. The apparatus of claim 1 wherein said central controller is operable to transmit AC electrical power to said input connectors responsive to switches mounted in said central controller, said switches being respectively opened and closed in response to a timing switch means.

3. The apparatus of claim 2 further including a metal shield mounted with said printed circuit base and adapted to shield said integrated circuit and said switch relay means against spurious external wave energy, said shield being connected to a common ground.

4. The apparatus of claim 2 wherein one switch of said switches is also a temperature sensing switch.

5. The apparatus of claim 2 wherein one switch of said switches is actuated in response to a light sensing means.

6. The apparatus of claim 1 wherein one of said detection electrodes, one of said input connectors, one of said output connectors, said integrated circuit, and said switch relay are connected to a common ground return.

7. The apparatus of claim 1 wherein said switch relay means is separately connected to a third input connector to receive a separate AC power voltage from said central controller through a manual override switch means.

8. The apparatus of claim 1 wherein said electrical output connectors are respectively connected to a plurality of solenoid valves.

9. Moisture detection apparatus for detecting the amount of moisture in the earth at a designated depth, said apparatus comprising:

(a) a monolithic and integral detection body adapted for installation below the surface of the earth, said body being hermetically sealed against intrusion of liquids and air;

(b) said body having two electrical resistance detection electrodes mounted to extend out of said body for intimate contact with earth enclosing said body;

(c) said body having a first pair of electrical input connectors adapted for connection to receive AC electrical power;

(d) said body having a second pair of electrical output connectors adapted to supply AC electrical power;

(e) said body including a bipolar electrical resistance detection circuit means mounted on a printed circuit base and connected to said detection electrodes and to said input connectors, said detection circuit means being adapted to oscillate at frequencies governed by a fixed reference resistance and a varying external resistance detected between said detection electrodes, said external resistance being varied as a function of the amount of moisture present in said earth;

(f) said body including a switch relay means connected to said resistance detection circuit and operative in response to a designated voltage occurring across said detection electrodes to open and to close a switch connected between said electrical input connectors and said output connectors; and

(g) said body being formed of a heat-hardenable liquid plastic poured in and around said detection electrodes, said input connectors, said output connectors, said detection circuit, and said switch means wherein the liquid plastic is hardened in place into an integral and monolithic solid body.

10. The apparatus of claim 9 wherein one of said detection electrodes, one of said input connectors, one of said output connectors, said integrated circuit, and said switch relay means are respectively connected to a common ground return.

11. The apparatus of claim 9 further including a metal shield mounted with said printed circuit base and adapted to shield said integrated circuit and said switch relay means against spurious external wave energy.

12. The apparatus of claim 9 wherein said switch is separately connected to a third input connector and adapted to receive a separate AC power voltage from said central controller through a manual override switch.

13. The apparatus of claim 9 wherein said switch relay means is a solenoid switch.

14. Moisture manager apparatus designed to independently control the amount of moisture in each respective zone of earth included within a plot of land wherein the various zones may require a different amount of irrigation, said apparatus comprising:

(a) a monolithic electrical soil resistance detection probe adapted for installation below the surface of the earth with said probe being sealed against intrusion of liquid and air;

(b) said probe having two electrical detection electrodes mounted to extend out of said probe for intimate contact with earth surrounding said body;

(c) said probe having a first pair of electrical input connectors adapted for connection to receive AC electrical power from a central controller operating to control other said probes in other said zones;

(d) said probe having a second pair of electrical output connectors adapted for connection to supply AC electrical current to irrigating valve means;

(e) said probe containing an integrated electrical resistance detection circuit mounted on a printed circuit base and connected to said detection electrodes, to said input connectors and said output connectors, said detection circuit being adapted to oscillate at varying frequencies governed by a fixed reference resistor and a varying external resistance detected between said detection electrodes, said external resistance being varied as a function of water present in said earth;

(f) said probe containing a switch relay means mounted on said base, connected to said detection circuit, and operative in response to the output of said detection circuit to open and to close a switch as connected between said electrical input connectors and said electrical output connectors; and

(g) said body being formed of a heat-hardenable liquid plastic poured in and around said detection electrodes, said input connectors, said output connectors, said integrated circuit, and said switch relay wherein said liquid plastic is hardened in place to an integral and monolithic solid body.

15. The apparatus of claim 14 further including a metal shield mounted with said printed circuit base and adapted to shield said detection circuit and said switch relay against spurious external wave energy.

16. The apparatus of claim 14 wherein one of said detection electrodes, one of said input connectors, one of said output connectors, said integrated circuit, and said switch relay are respectively connected to a common ground return.

17. The apparatus of claim 14 wherein said switch relay means is further connected to a third input connector and adapted to receive a separate power voltage from said central controller through a manual override switch means.