Automatic irrigation water conservation controller
Contents
1. ent on the anode of the appropriate triac It also pro vides system 9 with the facility of filtering erroneous signals caused by electrical noise spikes or transients that would send the system incorrect information Once the input signals are electrically conditioned by peak detector circuits 25 27 they are compared by analog comparator 28 with a reference signal main tained by threshold circuit 30 to determine if the system will consider them to be valid or not If the conditioned signal is greater than the reference negative threshold the analog comparators will output a digital logic 1 to buffer 29 If a valid conditioned signal is not present the output of comparators 28 is approximately 0 2 V Tristate buffer 29 is digitally controlled and will allow the output signals of comparators 28 or the indi cations of valid input signals for zones 1 7 in addition to the status of the bypass switch 31 to be placed on the system inputs Bits 0 7 of the buffer 28 represent zones 1 7 and bit 7 indicates the status of bypass switch 31 with a logic 1 meaning an ON status Negative threshold circuits 30 serves as a voltage reference which is applied to the negative inputs to analog comparators 28 for the conditioned input signals provided by peak detectors 25 27 to provide the system with reliable and consistent data another form of data filtering An input signal must be greater than one forward diode voltage drop of a2. IS THIS BEGINING OF WATERED CYCLE IS ZONE 0 WORD CLEARED U S Patent SET UP VARIABLES CALL ONE SEC ROUTINE YES LEARN RESET May 1 1990 Sheet 7 of 15 INITIAL VARIABLES CALL SEC SET ZONE ZONI 2 TIMES 0 OFF FOR SWITCH WORD AAN DEBOUNCING SET RETURN ADDRESS TO RESETTER IS IT START OF NEW CYCLE Fig 3E 4 922 433 ROUTINE USED FOR PRODUCTION TESTING ee U S Patent CALCULATE ZONE DURATIONS IS PRESENT lt MULTIPLIER PRESENT DRY DIVISOR WET DRY REG 8 7 ZONES STORE INDEX INTO COUNTER TABLE STORE INDEX INTO DURATION TABLE Fig 4 May 1 1990 0 MULTIPLIER MULTIPLIER Sheet 8 of 15 GET DURATION FOR ZONES OUT OF TABLE MULTIPLIER DURATION MULTIPLIER x 8 BITS MULTIPLIER 16 BITS PRODUCT 24 BITS BY DIVISOR 8 BITS GET INDEX INTO COUNTER COUNTER QUOTIENT 16 BITS INCREMENT COUNTER INDEX BY 2 INCREMENT DURATION INDEX BY 2 Fig 5 4 922 433 DECREMENT REG ZONES US Patent May 1 1990 Sheet 90f15 4 922 433 DECREMENT SAVE 20 MINUTE Acc ON STACK TIMER HAS 20 MIN ELAPSED LOAD LAST RESPONSE INTO
3. If it is that much greater then go to step 56 46 If it is not that much greater then the system will wait for the beginning of a new sensor zone cycle wa tering cycle 47 The system outputs data to the ports Output and Output 2 and there is a one second delay 48 Input data from port Input zone is read 49 The most significant bit is masked out 50 The input word is compared to the word read one second before 51 If the words are not the same then return to step 47 52 If the words are the same which means the input is valid then update the value of the Process Control Word Pcwreg 53 system checks for the instance when the sensor zone begins a new cycle See step 23 54 If it is not a new cycle then return to step 47 55 If it has started a new cycle then return to step 1 56 Input data from port Input port is read 57 The most significant bit is masked out 58 The input word is compared to the word read one second before 59 If the words are the same then go to step 65 60 If the words are not the same then check to see if there is a valid wet reading 61 If there is a valid reading then return to step 36 62 If there is not a valid reading then output data to ports Output and Output 2 and there is a one sec ond delay 63 The system then increments the duration by 1 for zones that are turned on and on their first cycle 64 Return to step 56 65 The
4. ZONECOUNT 7 i BITNUM 0 COUNTER COUNTER I IS CLEAR COUNTER CARRY SET CARRY BIT U S Patent May 1 1990 GET PCWREG AND SAVE ON STACK MASK OUT ZONE AND RESTORE PCWREG CLEAR Acc A B LOAD LOOP COUNTER SEND START CONVERSION TO A D CALL ONE SEC GET MOISTURE READING ADD IT TO PREVIOUS MOISTURE READING DECREMENT LOOP COUNTER Sheet 13 0f15 4 922 433 AVERAGE MOISTURE READING SAVE AVER MOISTURE READING IN AccA RESTORE CURRENT PCWREG WORD EXIT Fig 13 HAVE WE TAKEN 4 READINGS US Patent May 1 1990 Sheet 14 of 15 4 922 433 SET REMAINDER REMAINDER FROM DIVISOR RESULT A SET QUOTIENT QUOTIENT 00 TO IS REMAINDER 1 2 DIVISOR lt gt NO NO YES IS QUOTIENT 120 SECS 1 HAVE WE ADD ONE SHIFTED EXIT 24 TIMES TO QUOTIENT U S Patent May 1 1990 Sheet 15 0115 4 922 433 LOAD LOOP COUNTER SAVE A COPY RESPONSE LOAD MASK 40 IS ZONE N ON ADD JUST TURNED OFF YES IN RESPONSE WORD ZONE TO WATERED TAKE ADD ZONE ZONE N YES OUT OF PCWREG HAS ZONE TO DECREMENT JUST TURNED OFF PCWREG LOOP COUNTER NO HAVE ALL ZONES Yes BEEN CHECKED FOU i ADJUST MASK Fig 15 4 922 433 1 AUTOMATIC IRRIGATION WATER CONSERVATION CONTROLLER
5. 15 May 1 1990 US Patent 4341 YOLVIIGNT SSVdAg 1 YOLVOIONI 6 1 NI Aldans 3 OGA 6 IVAOZI 539018 YIKLO OL YOLV NIJIU Alddns Y3MOd AS 13538 Ge HOLIMS SSVdAG I 180d u3340n8 JIVISIYL AYOWSW AKINO 38 1109819 ANAL LVE 39019 ZHWO b be LINDO q IOHS38H1 3AI1V93N YOLIOVd VI ONIHLOOWS 4 JO 1 YOLVYVdWO SOTVNV HOLV 1 ANd 2 30 1 HOLV TOSI WOILdO 8 ve E HOLV7 5 18304 HOY ost NOLLVMIJO zandino 14 6 831114 ssavaav SSvd 91 JO SILAB 821 YSLYSANO9 JONVLSISSY 1vLI910 OL 9NI1V9S YOLV 111950 ONINNAY 33833 ZHX00S I 134 3419348 SAVM I 10193136 4 201 YATIONLNOO SILAFJNV 5 SI YOSNIS US Patent SET STACK POINTER TO 007 SET ALL ZONES TO OFF STATE CLEAR INTERRUPT FLAG YES NO SET UP FOR SELF TEST TEST CHECKER BOARD TEST FORWARD AND REVERSE PATTERNS DI
6. Pcwreg and Watered registers due to the new change in the input word see step 23 66 The system checks to see if the sensor zone zone is still off 67 If the sensor zone is still off then return to step 60 68 If the sensor zone is on then check to see if there is a valid wet reading 69 If there is a valid reading then go to step 85 70 If there is not a valid reading then update the Pcwreg register to keep the sensor zone off 71 Data is output to ports Output and Output 2 and there is a one second delay 72 Decrement to twenty minute timer 73 If there is twenty seconds left on the timer then turn the sensor on 74 Check to see if the twenty minute timer has timed out 75 If the twenty minutes has not timed out then go to step 79 5 10 15 20 25 30 14 78 If it is greater and therefore valid then go to step 85 79 Data from port Input Zone is read 80 The most significant bit bit 7 and the least signifi cant bit bit 0 that are the Bypass and sensor zone respectively are masked out 81 The input is now compared to the word read one second before 82 If the words are not the same then return to step 71 83 If the words are the same then update the Pcwreg register to keep the sensor zone off 84 Return to step 71 CONSERVATION PHASE 85 The memory location that contains the system status of the Conserve LED is set to the enabled or on state and the status
7. bit is masked out 28 The input word is compared to the word read one second before 29 If the words are not the same then return to step 25 30 If the input word is valid then compare it to the previous valid input word 31 If the words are the same then return to step 25 32 If the words are not the same then update the Pcwreg and Watered registers due to the change in the input word A 1 0 in a bit of Watered signifies that the respective zone has completed one cycle The least significant bit is the sensor zone 33 The system checks if the sensor zone is still on 1 34 If the sensor zone is still on then return to step 25 35 If the sensor zone is off then start the twenty minute timer 36 Data is output to ports Output 24 and Output 2 and there is a second delay 37 The system then increments the duration by 1 for the zones that are turned on and within their first cycle 38 Decrement the twenty minute timer 4 922 433 13 39 If there is 20 seconds left on the timer then turn on the sensor 40 Check to see if the 20 minute timer has timed out 41 If the 20 minutes has not elapsed then go to step 56 42 If the 20 minutes has elapsed then a moisture reading is taken by reading the input port Getad See step 15 43 The reading is stored in memory denoted as wet reading 44 Check to see if the value in wet reading is greater than the value in dry reading plus six 45
8. cycle Each of the two types is connected between the system power source or clock and the electrically operated water valves or solenoids The controllers may then break the connection between the clock and solenoid valves to override the power source so that the system will water less The primary function of these systems is to allow users to adjust the amount of watering by turning the systems on and off at predeter mined moisture levels that are determined by the user Two examples of the type of system which continu ously monitors moisture level are the Hydrogene Ion Moisture Sensor MHIMS 200 available from PEPCO Products Extruded Products Inc and the Hydroturf System available from Hydrodyne Products Inc The MHIMS 200 consists of a single adjustable monitor contained in a plastic case with a passive sensing unit which operates with an electric or hydraulic controller The monitor has a dial adjustment which may be varied 30 from one to eight cups of water depending on the de 55 sired moisture level and an indicator light to indicate moisture above the level indicated on the dial The sensing unit can be located 2 000 feet from the monitor The Hydroturf System employs a plug in meter which displays the soil s saturation level which is recorded using a solid state soil moisture sensor that statistically determines the percentage of the soil s pore space The sensor can be located up to 150 feet from the Hydroturf w
9. fre 10 15 20 25 30 35 40 45 50 quency of 1 0 Megahertz The clock is generated by an external 4 0 Megahertz crystal 0 000525 tolerance which the microprocessor internally divides by 4 With the application ROM installed in the board the proces sor will poll Input Port I once each second for a trig ger signal Upon a valid trigger signal 8 bit digital bit pattern occurring on Input Port I the processor will input data from Input Port II The processor will then make a series of calculations and send the appropriate output response to Output Port 24 While only two embodiments of the present invention have been shown and described it will be obvious that many changes and modifications maybe made there unto without departing from the spirit and scope of the invention What is claimed is 1 A water conservation apparatus for controlling duration of irrigation watering cycles of a timed irriga 65 16 tion system having control valves that deliver water to preselected ground zones comprising moisture sensing means disposed in contact with at least one ground zone for detecting moisture con tent of the at least one ground zone central processing means coupled to said sensing means for processing data on the moisture content of the at least one ground zone solid state memory means coupled to said central processing means and having a stored applications program for sampling the groun
10. oscillator 13 A preferred operat ing range of 500 KHz 20 was found to be desirable for oscillator 13 Analog to digital converter 14 samples the analog voltage reading from moisture sensor 11 digitizes it and outputs an equivalent 8 bit binary word to the ad dress bus of microprocessor 36 Converter 14 preferably has a maximum input range of approximately five volts and a maximum sampling frequency of approximately ten KHz There is also provided a gain scaling amplifier 15 to adjust the maximum threshold of analog to digital con verter 14 The threshold output voltage of amplifier 15 is set to 3 of the full scale voltage input of analog to digital converter 14 Amplifier 15 not only adjusts the maximum voltage measurement of converter 14 but establishes the setup size for a single bit A low pass filter 16 coupled to the output of amplifier 15 and hav ing its output connected to converter 14 removes high frequency noise and random signals from the input system coupled to sensor 11 The zero threshold circuit 17 also coupled to converter 14 adjusts the lowest read ing from the analog to digital converter or the zero output Triac pump controller 18 is used in conjunction with optical isolator 19 to gate the 24 VAC power to the master pump controller not shown of irrigation sys tem 8 The master pump controller is only ON when there is a zone ON Optical isolator 19 provides elec trical isolation between the gate
11. push button controls the interrupt signal to microprocessor 36 Once microprocessor 36 detects the pressing of this button the system will abort its current activity and perform a self check It then clears the memory RAM or in other words erases all characteristic variables it had used previously including clock durations and moisture levels The system will then begin to relearn the irrigation environment The user is required to de press learn pushbutton 33 only when the soil is consid ered to be dry Upon a successful completion of this test the system will turn on indicator LED 21 via output port 24 to assure the user of system integrity Absence of this signal will alert the user that something is not working correctly and that he should consult the user s manual When power is supplied to the unit power circuit 35 consisting of an RC network provides a delay of the execution of the system program until all the electrical hardware is at full operating capacity thus assuring a consistent and reliable system Address and control lines of MPU 36 are channeled through a decoder 37 and through MSI circuits to provide microprocessor 36 with the facility to address and control the I O ports of circuits 14 20 24 and 29 and the retrieval of instructions from the application ROM 38 The application program is permanently stored on the ROM 38 as well as the 35 40 45 55 60 65 jump vectors for power up circuit
12. 35 and learn button 33 The learned indicator LED 39 is turned on by the system once it has obtained the complete set of irriga tion environment characteristics LED 39 provides the user with the reassurance that the system has shifted into the conservation phase of operation Battery back up circuit 40 provides the system with the feature of retaining the irrigation characteristics in the event of a power failure by battery backing up the memory locations where these variables are stored A Ni Cd battery is trickle charged when the system is powered on via the 9 V DC power supply of power supply 24 This charging process requires approxi mately 14 hours and will be able to supply the memory with approximately 6 hours of back up time The 9 volt power from the battery is resistively divided and regu lated to 5 volts by a zener diode A 5 volt power supply regulator 41 supplies all components on the circuit board with a regulated 5 VDC The regulator inputs 9 volt DC unregulated from supply 42 scales and regulates it to a for 5 volt DC output In addition there is distributed capacitance on the supply line for noise and transient filtering Ex ternal power supply 42 uses the 120 VAC line voltage from a standard outlet rectifies and filters it to produce a 9 volt DC output The output is coupled to 5 volt supply 41 The power supply is preferably rated at 120 volt AC and one amp The learning phase is initialed by depressing lea
13. Acc B IS TIMER 15 SEC REMAIN UPDATE LAST RESPONSE W PRES RESPONSE Acc A RESTORE Acc B Fig U S Patent May 1 1990 Sheet 10 of 15 4 922 433 SAVE Acc A B AND INDEX DELAY SEC LOOP RESTORE INDEX LOAD PCW COMPARTMENT PCW TURN ON ON LED OUTPUT TO PORT 1 PCWREG ARE ANY ZONES ON OUTPUT 2 PUMP YES OUTPUT TO PORT 2 RESTORE U S Patent May 1 1990 PRODUCT Q 24 BITS GET MULTIPLIER PRODUCT MULTIPLIER MULTIPLIER RIGHT BIT INTO CARRY MULTIPLIER TO PARTIAL PRODUCT MULTIPLY MULTIPLIER BY 2 Sheet 11 of 15 4 922 433 ENTER ANY ZONES NEED TO BE TIMED NO GET BASE LOOP COUNTER MASK DOES ZONE N NEED TO BE TIMED DECREMENT TIME COUNT FOR ZONE N DECREMENT LOOP COUNTER HAVE ALL ZONES BEEN UPDATED US Patent May 1 1990 LEFT SHIFT CARRY INTO NEWWATER INCREMENT COUNTER INDEX BY 2 ZONE COUNT ZONECOUNT l IS ZONECOUNT 20 YES UPDATE WATERED BY WATERED NEWWATER NO BITNUM BITNUM 1 UPDATE PCW BY PCW PCW NEWWATER g EXIT Sheet 120115 4 922 433 DECREMENT ZONE NEWWATER Q DECREMENT BITS PCW WATERED STORE INDEX INTO COUNTER TABLE
14. D RAM TEST PASS NO YES CLEAR ALL RA LOCAT M IONS TURN ON SENSOR CALL A D AND AVERAGING ROUTINE RESETTER May 1 1990 INITIAL VARIABLES ARE THERE VALID MOISTURE READINGS LEARNING PHASE COMACTS MANDATORY BYPASS MODE 3A Sheet 3 of 15 IS IT BEGINING CYCLE Ug STORE DRYREADING TURN 0 SENSOR CALL ONE SECOND DELAY ROUTINE CALL VALIDATE RESPONSE ROUTINE 4 922 433 15 RESPONSE VALID YES CHANGE PROCESSOR CONTROL WORD PCW NO YES CALL ONE SECOND DELAY ROUTINE CALL INCREMENT DURATION COUNTERS ROUTINE INPUT ZONE FLAGS CALL VALIDATE RESPONSE ROUTINE U S Patent May 1 1990 SET UP 20 MINUTE TIMER CALL ONE SECOND DELAY ROUTINE Sheet 40115 4 922 433 IS RESPONSE NEW WORD oT CALL INCREMEN DURATION COUNTERS YES ROUTINE IS ZONE EDET Q FLAG Eg 7 DECREMENT STILL ON NO 20 MINUTE a 22 TIMER WET SUB ROUTINE HAS 20 TURN ON SENSOR MINUTES YES A D INPUT WET ELAPSED IS AVERT amp LINEAR MOISTURE NY BATION ROUTINE READING VALID COMPARED TO DRY YES NO CALL INCREMENT a PA COUNTERS READING TURN ROUTINE OFF SENSOR CALL ONE CALL S
15. ECOND VALIDATE DELAY RESPONSE ROUTINE ROUTINE IS RESPONSE YALID IS THERE VALID YES 7 WET READING D Fig 3B U S Patent May 1 1990 Sheet 5 0715 4 922 433 UPDATE PCW AND WATERED WORDS IS WET MOISTURE READING VALID UPDATE PCW WORD YES CALL ONE SET LEARNING SECOND PHASE DELAY COMPLETE ROUTINE IS WET READING VARIABLE VALID COMPARED TO DRY INITIALIZE VARIABLES CALL WETSUB ROUTINE AS 20 MINUTES VALIDATE ELAPSED RESPONSE IS RESPONSE MASK ZONE 0 AND BYPASS FLAGS CALL VALIDATE RESPONSE ROUTINE IS RESPONSE NO NEW WORD NO NO g IS RESPONSE VALID HAS ZONE 0 FLAG YES UPDATE TURNED ON PCW NO WORD YES Fig 3C 2 U S Patent SET PCW 8 WATERED WORDS TO TURN ON SENSOR CALL A D INPUT AVERT amp LINEAR IZATION ROUTINE MOISTURE READING TURN OFF SENSOR CALL CALCULATE DURATIONS IS PCW HAVE ANY ZONES TIMED OUT Fig 3D May 1 1990 UPDATE PCW WORD CALL ONE SECOND DELAY ROUTINE CALL DECREMENT ROUTINE TIMERS REMOVE ZONE FROM PCW amp SET BIT IN WATERED Sheet 60f15 4 922 433 UPDATE PCW WORD CALL ONE SECOND DELAY ROUTINE
16. FIGS 3A 3B 3C 3D and 3E consist of flow charts showing the operation of the inventive program ac cording to the invention FIGS 4 5 and 6 are subroutine flow charts for calcu lating zone durations FIG 7 is a subroutine flow chart for wet calculation with a twenty minute timer FIG 8 is a multiplication subroutine chart used in flow charts of FIGS 3A 3B and 3C FIG 9 is a one second subroutine flow chart FIG 10 is a validate subroutine FIG 11 is an increment counter subroutine FIG 12 is a decrement subroutine FIG 13 is an add subroutine FIG 14 is a divide subroutine and FIG 15 is a change process control word subroutine DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS 1 and 2 there is shown the con ventional irrigation controller 8 having for example in this instance seven zones which are capable of operat ing seven solenoids 7 which are located in different places in the ground to allow water to reach sprinkler heads as is well known in the prior art The inventive control system 9 is coupled to each output of the irriga tion controller 8 so as to be in series with each of sole noids 7 A moisture sensor 11 is also coupled to two terminals of the inventive control system 9 and is gener 20 25 40 45 50 55 65 6 ally disposed in the soil adjacent to the first zone which is controlled by the first solenoid The base unit 9 has two controls a bypass switch 31 and a lear
17. The present invention relates to a control system for 5 water irrigation and more particularly to an automatic control system for water irrigation which conserves the use of water BACKGROUND OF THE INVENTION 10 Presently many water irrigation systems provide independent zones which may be programmed manu ally to activate at specific day and hour settings and for specific durations These systems once set will perform their watering tasks automatically without regard to the 15 soil s moisture level The controller system of the pres ent invention has been designed to work in conjunction with these existing systems to allow the irrigation sys tem to water only when necessary to optimize water consumption The inventive controller system can regulate multiple zones and learn the moisture requirements of any irrigation environment This learning ability is a dy namic feature that allows the inventive controller sys tem to perform equally as well for all types of soils and applications such as a homeowner s lawn a golf course an athletic field or a farm DESCRIPTION OF THE PRIOR ART There are various prior art systems that attempt to provide water conservation schemes for timed control ler irrigation systems The two most common types of irrigation controllers monitor moisture levels during the irrigation cycle when the sprinkler heads are on and those that monitor moisture only at the beginning of the irrigation
18. United States Patent ro Mark 54 AUTOMATIC IRRIGATION WATER CONSERVATION CONTROLLER Arnold Mark 2485 Malibu Rd Bellmore N Y 11710 21 Appl No 137 457 76 Inventor 22 Filed Dec 23 1987 51 Int 1 5 G06F 15 46 A01G 25 16 52 U S CL 364 510 364 420 364 141 364 153 340 602 73 73 137 624 2 239 63 239 71 58 Field of Search 364 420 509 510 138 364 141 152 153 340 604 602 73 73 74 77 137 624 18 624 2 239 63 71 56 References Cited U S PATENT DOCUMENTS 4 165 532 8 1979 Kendall et al 364 510 4 176 395 11 1979 Evelyn Veere et al 364 510 4 189 776 2 1979 Kendall wee 364 510 4 423 484 12 1983 Hamilton ve 364 420 4 567 563 1 1986 Hirsch w 364 420 4 569 020 2 1986 Snoddy et al 364 510 4 626 984 12 1986 Unruh et al vou 364 420 4 646 224 2 1987 Ransburg et al 364 420 4 799 142 1 1989 Waltzer et al 364 420 Primary Examiner Parshotam S Lall CLOCK DURATION SETTINGS 1 2 34 5 6 720 KJON OFF 4 922 433 May 1 1990 11 Patent Number 45 Date of Patent Assistant Examiner Brian M Mattson Attorney Agent or Firm Collard Roe amp Galgano 57 ABSTRACT A water conservation system that connects between a standard irrigation system that is controlled
19. by a clock and the water control valves of that system in order to limit the flow of water during timed irrigation cycles When the timed watering cycles are initiated by the standard irrigation system the water conservation de vice senses the moisture in the soil and compares it with preset wet and dry moisture limits and scales back each of the watering cycles in proportion to the moisture content of the ground to thereby conserve irrigation water that is applied to a ground area The device in cludes a moisture sensor a central processing unit and a solid state memory that is connected to the central processing unit and the moisture sensor When the de vice of the invention is initialized the solid state mem ory samples and records the wet and dry moisture read ings of the ground zone and stores the resultant wet and dry readings in the memory so that each time the timed irrigation system cycles the water conservation device senses the moisture compares it with the wet and dry readings and scales back the amount of water applied to the ground area 15 Claims 15 Drawing Sheets Q lt 39 LEARNED 32 502 BYPASS ON 2 3 1 2 4 922 433 Sheet 1 of 15 May 1 1990 U S Patent SSVdA8 1 lt 330 68 2095 26 205 ple L 9 S t Z 34O NO O INOZZ 9 S pe zt SONILL3S NOILVYNG 2019 4 922 433 Sheet 2 of
20. d moisture content detected by said sensor means means for initializing said solid state memory means to take a plurality of samples of dry and wet mois ture readings and averaging and storing resultant dry and wet readings in said memory means control means coupled to said central processing means said control means sensing by means of said moisture sensing means moisture content in the at least one ground zone and scaling back the amount of water distributed by the irrigation system in proportion to the moisture content in at least one ground zone as determined by the stored wet and dry readings in said memory means said control means thereby shortening or shutting off the water cycles of the irrigation system as the ground mois ture content increases 2 The water conservation apparatus as recited in claim 1 wherein said means for initializing comprises a learn button for resetting and recycling said stored applications program to reestablish dry and wet mois ture readings for the at least one ground zone 3 The water conservation apparatus as recited in claim 2 additionally comprising an indicator light cou pled to said central processing means for indicating a resetting of wet and dry moisture limits of the at least one ground zone area 4 The water conservation apparatus as recited in claim 3 wherein the stored applications program of said solid state memory means includes a 20 minute delay following the irrigation waterin
21. es and an analog to digital converter for converting the ground resistance readings into digital data 11 A method for conserving irrigation water by controlling duration of irrigation water cycles of a timed irrigation system having control valves that de liver water to preselected ground zones comprising the steps of sensing with a sensor at least one ground zone for providing wet and dry data of moisture content of the at least one ground zone processing the data received from said sensor using a processor to determine the moisture content of the at least one ground zone initializing a solid state memory means by taking a plurality of samples of dry and wet moisture limit readings and averaging and storing the resultant dry and wet moisture limit readings in said solid state memory means comparing the dry and wet moisture limit readings in the solid state memory coupled to the processor and using a stored applications program for sam pling ground moisture data produced by the sen sor and operating said sensor to measure the moisture content in the at least one ground zone and scaling back the 10 20 25 30 35 45 50 55 65 18 amount of water distributed by the irrigation sys tem in each irrigation cycle in proportion to the moisture content in the at least one ground zone by shutting off the control valves of the irrigation system for each of the watering cycles 12 The method as recited in c
22. esses the Learn pushbutton on the unit s front panel when the ground is dry and in need of water The inventive controller system immediately takes four soil resistance readings averages them and stores the dry readings in memory The unit is now operating in the Learning phase The unit stays in the learning phase until the zone where the sensor is located is wa tered At the end of its irrigation cycle the inventive controller system waits twenty minutes and takes four further soil resistance readings averages them and stores the average in memory as a wet reading To measure the wet reading the user stops watering his lawn or garden after it is sufficiently wet and at this moisture level he would not want the irrigation system to water further None that when a valid wet reading a valid wet reading is one that is approximate five Kilo ohms of resistance less than the dry reading is achieved the systems are then finished with the learn ing phase An LED will light on the front planel to indicate that the controllers have received valid wet and dry readings If the units do not obtain valid wet and dry readings it will stay in the learning phase and recycle the next time the automatic irrigation system timer comes on During the first full irrigation cycle of the clock during the learning phase the inventive controller system also times the duration in second
23. g cycle for measuring the wet moisture limit 5 The water conservation apparatus as recited in claim 1 wherein said control means comprises triac solenoid controllers coupled between the irrigation system and the at least one ground zone for controlling the water delivered to the at least one ground zone 6 The water conservation apparatus as recited in claim 1 additionally comprising bypass switch means coupled to said central processing means for bypassing the stored applications program and permitting the timed irrigation system to water the at least one ground zone 7 The water conservation apparatus as recited in claim 6 wherein said bypass switch means includes a bypass indicator light for indicating that the bypass has been turned on 8 The water conservation apparatus as recited in claim 1 wherein said solid state memory means com prises a ROM 9 The water conservation apparatus as recited in claim 1 additionally comprising a battery backup cir cuit coupled to said central processing means and said solid state memory means for providing power during a power interruption 10 The water conservation apparatus as recited in claim 1 wherein said moisture sensing means comprises a pair of spaced apart electrodes disposed in the at least 4 922 433 17 one ground zone a scaling resistance circuit coupled to said spaced apart electrodes for adjusting resistance of the at least one ground zone between said electrod
24. ist than the wet read ing the system will not water any zones for that water ing cycle Conversely if the system finds that the pres ent reading is drier than the dry reading it will allow the zones to be watered for their full normal duration If at any time during this conservation phase of oper ation bypass switch 31 is turned on the inventive con trol system will allow irrigation system 8 to water the zones for any duration for which it is set When how ever bypass switch 31 is turned off the inventive con trol system will return to its conservation mode of oper ation The inventive control system also has a battery backup circuit 40 that will retain the soil s moisture characteristics and normal duration settings in the event of a power failure Thus when power is restored the system may circumvent the learning phase and go di rectly to the conservation phase This feature allows the system to recover from a power failure without any manual requirements from the user 1 Referring to FIGS 3A B and C and 4 15 when the control system is powered up or has been reset the stack pointer 51 is initialized to the highest random access memory address 2 Power to all zone solenoids 7 is turned off The control of power to the existing irrigation system s sole noids is performed by outputting an 8 bit data word to the port output The lowest seven bits are for the seven zones A logic O 1 to the port enab
25. it Bypass is masked out 20 The input word is compared to the word read one second before This system only considers a word valid if it s the same for two consecutive seconds This is to insure a stable input from the automatic irrigation sys tem 8 21 If the words are not the same then return to step 18 _ 22 If the words are the same which means the input is valid the value is stored in the Process Control Word Pewreg which is the status register of the seven sole noids 7 23 The system checks for the instance when the existing automatic irrigation wants to turn on the sole noid 7 of the zone where the moisture sensor 11 is lo cated This is done by checking if the least significant bit of the Pcwreg has changed value from a logic 0 off to logic 1 on This zone is referred to as either the sensor zone or zone 9 A change of value from 0 to 1 signifies the beginning of a cycle for the zone 24 If the sensor zone bit is off 0 or already on 1 then the system mimics the operation of the solenoids 7 according to the automatic irrigation system by return ing to step 18 25 Data is output to ports Output and Output 2 to turn on the solenoids 7 and there is a one second delay 26 The system then increments the duration by 1 for one second for those zones that are and are within their first cycle 27 Input data from port input zone is read See step 19 27A The most significant
26. ithout any effect on the readings A 5 increase in the readings occurs at a distance of 1 000 feet or greater The meter has adjustable upper Off and lower On settings The system can be used with or without a time managing clock 20 25 35 40 45 50 60 65 2 A common problem with the two conventional sys tems described above is their inability to compensate for water settling time During the watering cycle the sensor receives a premature saturation reading due to the fact that the water saturates the soil around the sensor very quickly after the sprinkler system is turned on Both of these systems fail to take into account the fact that the water will drain down into the soil shortly after the sprinkler system has been shut off Both of these systems take their moisture readings very shorty after the sprinkler head is shut off In the Hydroturf System the reading is taken after only ten seconds It has been found through experimentation that reading the moisture level immediately after the sprinkler is shut off will give a false reading of saturation Moisture readings taken ten to twenty minutes after the sprinkler is shut off are more stable and lower in moisture level than those taken immediately after the sprinkler is turned off Such inaccurate readings by these systems may cause the systems to oscillate between the wet and dry cycles The premature shut off can also cause an underwatered soil condition which c
27. laim 11 wherein said step of initializing comprises depressing a learn button to reset the stored applications program of the solid state memory in order to reestablish the dry and wet moisture limit readings of the at least one ground zone 13 The method as recited in claim 12 additionally comprising turning on a learn indicator lamp when the applications program of the solid state memory has completed its initialization of establishing the dry and wet moisture limit readings 14 The method as recited in claim 13 wherein said step of initializing comprises delaying reading of the wet limit reading a sufficient time to allow moisture to sink into the at least one ground zone before the wet limit reading is taken 15 The method as recited in claim 14 wherein said step of initializing comprises taking a plurality of read ings with said sensor combining the readings taken by said sensor to provide an average reading of dry or wet moisture levels and feeding the average reading to said processor and memory to determine the dry or wet moisture levels of the at least one ground zone
28. les disables the power to the respective zone solenoids The most significant bit is used to keep the Normal LED 21 on at all times except when there is a malfunction A logic Ok 1 keeps the light on off 3 Power to the pump master control 18 and sensor 11 is turned off and the Conserve LED 39 is turned off 4 922 433 11 This is performed by outputting an 8 bit data word to port Output 2 20 The least significant bit bit O is the Conserve LED A logic 0 1 turns the LED on off The next least significant bit bit 1 controls the pump master 18 A logic 0 1 enables disables the power to pump master 18 If any zone is being provided with power then the pump master must also be enabled The next significant bit bit 2 of the port Output 2 20 is used to control sensor 11 A logic 1 0 enables disables sensor 11 The sensor is enabled twenty seconds prior to a moisture reading then disabled at the completion of the reading 4 processor s interrupt is enabled to allow the detection of a power failure to the system 5 The system determines whether this power up is 10 following the recovery of a power failure to the system and if the system has stored the desired moisture charac teristics of the soil and the individual zone s cycle dura tions The moisture characteristics are two 8 bit data words dry reading and wet reading that are stored in memory The magnitude of the wet readi
29. mp con trol and Conserve LED denoted by Pewreg Pump and Learncmplt respectively are set to their disabled or off state 12 The status of the sensor control is set to its enabled or on state 13 The system controls the existing automatic irriga tion system operation by outputting two 8 bit words to ports Output and Output 2 as described in steps 2 and 3 The system also utilizes a one second delay loop at this time which allows the system to learn that a zone was turned on and for how long 14 The initial on state of the sensor 11 is maintained for 20 seconds 15 After 20 seconds a moisture reading is taken by reading the input data at port Getad The reading is performed once every four consecutive seconds The 20 25 30 40 45 50 55 60 65 12 value of the moisture reading that is used is the average value of the four readings 16 The reading is stored in a memory location de noted by dry reading 53 17 The sensor state is set to disabled or off 54 18 The system outputs data to ports Output 24 and Output 2 20 19 Input data from port input zone 55 is read The data word is 8 bits with the lower seven bits represent ing which state the existing automatic irrigation system wants the solenoids 7 to be in A logic 1 0 is to turn on off the solenoid 7 The most significant bit is for the Bypass switch 31 19A The most significant b
30. n button 33 There are also three LED indica tors on 21 bypass 32 and learned 39 When switch 31 is turned on the system will allow the irrigation system 8 to run without any control from system 9 In this mode of operation system 9 will be overridden and no water conservation will occur This feature allows the user to manually override system 9 without making any physical changes to the configura tion This may be important during special watering situations such as a freshly fertilized or seeded lawn Moisture sensor 11 is constructed of a series of metal conductive spikes that are placed in the soil where moisture sensing is desired As the soil moisture varies the resistance measured between opposed conductive spikes will vary proportionally Although this resis tance is not a linear relationship with respect to mois ture content there is a large linear region of resistance Sensor 11 is adjusted to operate within that linear por tion of resistance The output of sensor 11 is coupled to the input of scaling resistance 12 The range and sensitivity of soil moisture sensor 11 can be adjusted to within the linear range by resistance 12 Moreover the larger the value of this resistance the higher the resistance range of moisture sensor 11 There is also provided a free running square wave oscillator 13 having its output coupled to an analog to digital converter 14 Converter 14 derives its set up and sampling timing from
31. n this phase of opera tion that the control system will provide the water conservation and bypass switch 31 is in the off posi tion Each time the sensor zone is activated to start a wa tering cycle by the irrigation system the inventive con trol system will take a moisture reading of the soil to determine the moisture content This reading is called the present reading and is used in conjunction with the readings acquired during the learning phase the 20 25 35 40 45 50 60 65 wet and dry readings to determine how long all the zones should be watered for this particular watering cycle The inventive control system will take this pres ent reading and see where it falls between the dry reading where the soil needs a full duration of watering and the wet reading where the soil is moist and does not require any watering For example if the present reading is 30 of the wet reading for this particular watering cycle the inventive control system will scale the recorded zone times to 70 of their normal dura tions and allow the zone to be watered when activated only as long as this newly calculated duration is based on the amount of water that is actually needed original normal duration is always stored by the system so that it may repeat this process at every start of a watering cycle In the event that the present reading indicates that the soil is more mo
32. nd with the next new activation of the sensor zone Within the wa tering cycle each zone should be programmed to acti vate only once The control system will then begin to monitor prior to the activation of the zones by the exist ing irrigation system The system will then wait for the beginning of a watering which starts with the existing irrigation system activating the sensor zone Until this occurs the control system of the invention will simply turn on the same zones that the existing irrigation system has activated Once the new watering cycle has begun the control system of the invention will continue to monitor the irrigation system driver signals and turn on any zone which is activated includ ing the sensor zone At the same time however the control system will record the duration in which the zone is control system can handle recorded readings for a duration of two minutes to fifteen hours with a one second resolution The control system will thus determing the normal or full duration of watering time set by the existing irrigation system Using the calculated duration values the system will interrupt the power to the zones once the proper amount of watering has occurred This procedure will reduce the water consumption of the irrigation system by allowing the zones to be watered for only the exact amount of time necessary Also since the driver signals are supplied from irrigation system 8 inve
33. ng at Counter for each zone is calculated This duration is how long a zone will stay on during this new cycle The calculation is as follows wet reading present reading wet reading dry reading duration cycle duration This is done for all seven zones The cycle duration is always a fraction of the original duration 102 Return to step 86 103 Update register and Pcwreg to reflect the change of input data 104 Data is output to ports Output and Output 2 and there is a one second delay 105 Check to see if the Pcwreg is zero all zones off 106 If it is zero then return to step 86 107 If it is not at least one zone is on then decre ment the cycle durations of those zones that are on 4 922 433 2 15 108 If any zone s cycle duration has timed out then update the Pcwreg and Watered registers to reflect this change A zone that times out is then disabled 109 Return to step 86 BYPASS MODE 110 The Pcwreg is updated to the value just read at the input In the Bypass mode the system enables what ever zones the existing automatic irrigation system wants to turn on 111 Data is output to ports Output and Output 2 and there is a one second delay 112 Data is read from the port Input Zone 113 The input word is compared to the input read one second before 114 If the words not the same then return to step 111 115 If the words are the same then check t
34. ng is always greater than the dry reading The individual zone s cycle durations are each 16 bit data words A value of 350 represents that the cycle s maximum duration is 350 seconds The seven durations are stored in consecutive memory locations with the lower numbered zones being at the lower addresses 6 If the system already has the desired characteris tics the program jumps to the conservation portion of the program step 85 7 If the system does not have the characteristics the program then performs a test on the memory of the system to verify its operation A checkerboard memory test is performed on the 128 bytes of RAM 36 Random Access Memory This test involves writing the hexa decimal AA 10101010 and 55 01010101 into alternate memory locations The memory locations are then read back to verify the correct operation of the RAM The pattern is then reversed with the writing of 55 and AA into alternate locations which is then read back 8 If the test fails then the system goes into the bypass mode where it simply mimics the operation of the exist ing automatic irrigation system The normal LED 21 will be turned off alerting the user of a malfunction LEARNING PHASE 9 If the test passes then all RAM locations are initial ized to 00 10 The system now enters the Learning phase of the program _ 11 Memory locations that contain the system s sta tus of the seven zone s solenoid lines the pu
35. ntive system 9 will not water longer than the time duration set on the irrigation system The system will continue to follow this pattern until the start of the next watering cycle the sensor zone being again activated When this occurs the inventive control system has acquired all the normal time dura tions for the zones and its dry reading Since all the zones are now watered to their proper level the system will take another moisture reading referred to as the wet reading The storage of this wet reading will mark the end of the learning phase The system will then examine the dry and wet readings to make sure that the range between them can be used in the system s calculations If the wet dry range can be used the conservation phase is entered and learned LED 39 is turned on If not the learning phase is re peated to acquire more adequate moisture readings After the learn cycle has been completed the inven tive control system s algorithm will set the system into its conservation mode of operation Therefore the con 5 10 trol system will never be in the learning phase for more than one watering cycle Moreover during this phase of operation bypass switch 31 does not effect the system s ability to correctly perform its tasks The inventive control system will remain in the conservation phase of operation until the system is powered down or learn button 33 is again depressed It is i
36. o see if the Bypass switch is still on 116 Ifit is on then return to step 110 117 If the Bypass switch is off then check to see if the zone 0 flag is off 117a If it is not then go to step 117 117b If it is then clear the zone 0 word 117c Check to see if this new valid response is the same as the previous valid response 118 If it is not new then return to step 110 119 If the words are different then check to see if the sensor zone is on 120 If it is not then return to step 110 121 If the sensor zone is on then check to see if it just turned on 122 If it did not just turn on then return to step 110 123 If it did just turn on then return to step 85 THIS IS THE END OF BYPASS MODE In an actual embodiment of the system the unit used a single printed circuit card microprocessor based sys tem having the power supply section DC power sup ply regulator and battery backup circuits the central processing unit microprocessor read only memory ROM and address decoding logic and the I O sec tion two input ports one 8 bit digital and one 8 bit analog to digital and an output port 8 bit digital The central processing unit consists of the following Motorola 6802 8 bit microprocessor with 128 bytes of internal random access memory RAM Texas Instru ments TMS2523 4096 byte read only memory ROM dual 2 to 4 decoder 741 5139 and quad 2 input gate 74LS00 The processor operates at a clock
37. of the pump master and sensor to the disabled off position Other memory locations are also initialized 86 Data from port Input Zone is read 87 The input word is compared to the word read one second before 88 If the words are not the same then return to step 86 89 If the word is valid then check to see if the Bypass switch Bit 7 is on 90 If the Bypass is set then go to step 110 91 If it is not set then compare this valid input with the previous valid input 35 40 45 50 55 60 76 If it has timed out then check to see if the value of 65 wet reading is greater than the value in dry reading plus Six 77 If it is not greater then return to step l 92 If the words are the same then go to step 104 93 If the words are not the same then check to see if the sensor zone zone 0 has turned on 94 If it has not turned on then go to step 103 95 If it has turned on then the status register and Pcwreg is updated to the value of the input data and the Watered register is cleared 96 The status of the sensor is set to on 97 This state is maintained for twenty seconds 98 After twenty seconds a moisture reading is taken by reading the input data at port Getad see step 15 99 The reading is stored in memory location present reading 100 The sensor s state is set to off 101 The cycle duration which are two bytes long that are stored in consecutive locations starti
38. of the soil Both sys tems have drawbacks in adjusting their moisture level settings In actual field tests the procedure was so diffi cult with the Moisture Sensor Inhibitor that the user eventually placed the system in the bypass mode For the Hydrovisor system the levels are preset and no user adjustment can be made There are three different ver sions of Hydrovisor systems that can be purchased de pending on the soil type sandy normal and clay This is a problem because soil types are not always easy to define Moreover both systems like the two previous systems can only control a single zone The present invention overcomes the disadvantages of the prior art by providing controllers that are micro processor based so as to optimize the irrigation process of existing automatic irrigation clocks The unique fea ture of the inventive controller system is its ability to adjust to different environments The system learns the moisture characteristics of any irrigation environment and the duration of the irrigation cycles for each of the seven or twelve zones of the in place irrigation system The major advantage of this system is that it prerecords moisture readings before the irrigation cycle begins to avoid the sensor saturation problems described previ ously and sets the duration of all zones from a single sensor This learning feature allows these systems to perform equally well in all types of soil applications such as a homeo
39. of the triac controller 18 and the digital controlled output port or latch 20 This digital output port latches the control states for sensor 11 logic 0 ON optical isolator 19 logic 0 ON and conserve indicator LED 39 logic 1 ON The system also provides a plurality of triac solenoid controllers 22 each connected to a solenoid 7 to gate 4 922 433 7 the power from the timer irrigation controller 8 to their respective zone solenoids 7 An optical isolator 23 com prised of a plurality of optically controlled triacs one for each solenoid provides electrical isolation between the gates of AC triacs controllers 22 and digital con trolled latch 24 Output port or latch 24 has the follow ing blocks latched at this digital port operation indica tor LED 21 logic 0 ON and optical isolators 23 for each of the solenoid zones logic 0 ON The 24 VAC power lines from irrigation controller 8 enter control system 9 via a terminal strip 6 and are connected to the anode of their zone triac These signals are fed to half wave rectifier 25 resistively scaled by divider 26 and electrically averaged or smoothed by capacitor 26 to provide the system information on which zones have been activated The combination of these three circuits comprising the peak detector 26 27 and 28 generate a signal that has a DC voltage level of approximately 2 5 volts when a 24 VAC signal is pres
40. ould cause the user to readjust his moisture level setting Thus this can create an off setting problem in which the sprinkler system will possibly continue to water when it is raining or very wet outside Another common problem of prior art systems is their inability to operate more than a single zone A zone normally consists of one to four sprinkler heads which provide watering coverage for a specific area of the user s lawn or garden All sprinkler heads in a zone are controlled by a single solenoid valve and therefore turn on and off together These systems cannot be con nected to more than one control signal or one zone at a time To allow operation with more than one zone the user must purchase additional units for each zone This can become a costly problem since most home owners with sprinkler systems have seven to twelve zones This not only increases material costs but has a much higher set up cost because sensors must be located under each zone The initial setting of the desired moisture level is also a problem in the conventional systems For the MHIMS 2000 system determining the wet moisture setting is very difficult The instructions state that the owner is to take a handful of soil wet the soil to the desired moisture level and then adjust the dial on the master monitor until the green light goes off This may not be an accurate measurement because the soil which is being measured is not in the ground surrounded by gra
41. pproximately 0 7 v set by this reference to trigger comparators 28 to signal the system that a valid signal for a zone exists Bypass switch 31 as indicated earlier is used to over ride the system allowing the timer controller to run without any intervention from the system When the user places switch 31 in the bypass position a 5 v signal is applied to buffer 29 thus causing a logic 1 on bit 7 of the digital word retrieved from that port The system application program stored in ROM 38 will recognize the user s request within one second and place itself in the bypass state When the system is placed in the by pass state bypass indicators LED 32 will be turned ON to provide the user with a visual reassurance that system 9 is in the overridden state When the system is in the water conservation phase bypass LED 32 will be off At the center of the control system of the invention is microprocessor 36 which executes the application pro gram of ROM 38 and provides all the system controls MPU 36 has preferably 128 bytes of RAM Random Access Memory which is utilized by the microproces sor to store the irrigation characteristics as well as vari 15 20 25 8 ous dynamic variables A 4 0 MHZ clock 34 provides the basic system timing for the execution of the system program and is coupled to microprocessor 36 There is also provided a learn pushbutton 33 that effectively resets the system This momentary
42. rn button 33 This phase is responsible for the learning of the soil moisture characteristics and the duration set tings on the existing irrigation system Learn button 33 is depressed when the soil is considered to be dry a condition where one would normally water if it were to be done manually 4 922 433 9 When the learn button is depressed the control sys tem will perform a quick self test to assure the integrity of the system Next the control system will sense the soil s moisture level and store the dry reading in the system s memory 38 Microprocessor 30 samples the soil for moisture readings and gauges the amount of time each individual zone has to be watered When the existing irrigation system decides to turn on or acti vate a particular zone or multiple zones it will make calculations using the soil moisture level as a variable to determine what proportion of the normal watering duration is necessary to sufficiently water the soil The System actually takes a series of dry readings and averages them before it stores a value in its memory 38 This procedure is performed every time a moisture reading is taken to assure that the system receives accu rate results After the calculations are completed the inventive system will allow the driver signal from the irrigation system to power zone solenoids 7 via triacs 22 The watering cycle will start with the activation of the zone containing sensor 11 and will e
43. rrigation system and re quires very little set up time and effort A single control ler can replace up to twelve prior art systems previously mentioned and provides a more precise method of 20 25 30 35 45 50 55 60 65 4 water conservation The seven zone and the twelve zone controllers operate on exactly the same concept Another advantage to the system is that moisture levels and durations are not only measured but stored in memory to be utilized later in arithmetic computa tions A third advantage is that there is a built in intelli gence which allows the coordination and management of numerous events and conditions These advantages overcome the many drawbacks of the prior art The first drawback that was overcome is the soil s water settling time The inventive controller system waits twenty minutes after the moisture sensor s zone is watered before taking a reading During this time the sprinkler head above the moisture sensor may not be turned back on The inventive controller system will mask this so that the reading taken after the water set tles in the soil will not be disrupted Preferably four moisture readings are taken and averaged by the unit This method of measurement provides a higher level of sensor stability helping to filter out any noise or ambig uous readings The system also automatically sets the moist Off and dry On levels These levels are determined after the owner depr
44. s of each of the zones that are operating in order to gather data for the water conservation cycles The inventive controller system enters the learning phase after the first zone is re energized by the clock thereby indicating that an entire irrigation cycle has been completed and that a new irrigation cycle is beginning The inventive controller system performs the water conservation algorithm on all irrigation cycles after the learning phase is complete At each re activation of the sensor zone the system automatically takes four soil moisture samples averages them and stores them in the memory as a present reading This reading is used to calculate each zone s duration for this irrigation cycle The system does this by calculating a percentage of time to water from 0 to 100 of the original duration now stored in memory for each zone The resultant duration is a fraction of the original duration for which the zone is watered By sampling before watering and then calcu 4 922 433 5 lating durations the problems described previously with the continuously sampling systems are overcome The system is also inherently stable since if it over waters or underwaters the next irrigation cycle will have either a shorter or longer duration respectively The system may also be placed in a bypass mode to allow the user to water even when the inventive con troller systems have disconnected it from the solenoid valves The ini
45. ss sand plants etc In the event of a desired change in the moisture level setting this process must be re peated The Hydroturf System adjusts the upper Off and lower On settings manually This manual setting is also inaccurate due to the lack of settling time The second type of systems are those that only moni tor the moisture level at the beginning of the irrigation cycle Two examples of the type of system which only monitors moisture level at the beginning of the irriga tion cycle are the Moisture Sensor Inhibitor available from Rainbird and the Hydrovisor available from Water Conservation Systems Inc The Moisture Sensor Inhibitor utilizes a sensor that measures the resistance of the soil The Hydrovisor measures the water availabil ity by reacting to changes in the soil potentials These prior art systems operate as follows When the irrigation cycle begins a moisture reading is taken If the moisture level exceeds a user determined moisture 4 922 433 3 level the irrigation cycle is inhibited and no watering occurs When the moisture reading is below the level set by the user the irrigation cycle occurs uninter rupted In other words the cycle either runs for its complete duration or does not run at all There is no time scaling in either system In the situation when the reading is 90 of the turn off level the cycle is oper ated for the entire duration This can resuit in over watering or unnecessary watering
46. tializing software runs a complete memory check of all locations and if successful flashes an LED on the front panel to alert the user that the unit is func tioning properly It is therefore an object of the present invention to provide a control system for a water irrigating system that not only senses the dryness of a soil area but limits the amount of water applied to the soil area based upon the moisture requirements of the soil and the existing dampness of the soil so as to conserve the amount of irrigation water applied to that area It is another object according to the present invention to provide a control system for a water irrigating sys tem that is simple in design efficient and reliable in operation and inexpensive in cost Other objects and features of the present invention will become apparent from the following detailed de scription considered in connection with the accompa nying drawings which disclose the embodiments of the invention It is to be understood that the drawings are to be used for the purpose of illustration only and not as definition of the limits of the invention In the drawings wherein similar reference characters denote similar elements throughout the several views FIG 1 is a system diagram showing the irrigation system of the present invention coupled to an irrigation controller and a soil sensor FIG 2 is a schematic diagram of the inventive con trol system of the present invention
47. wner s lawn a golf course fairway an athletic field etc The inventive system is installed be tween the user s existing clock and solenoid valves and therefore can measure each zone s duration just by being placed in the line SUMMARY OF THE PRESENT INVENTION The inventive controller system consists of the base unit and a moisture sensor The sensor can be installed by running a single pair of wires from the base unit to one of the designated zones and planting of the sensor under the surface of the soil at a predetermined depth This zone is referred to as the sensor zone The base unit is connected to the irrigation system by rerouting the driver signal lines for each zone and the master valve controller to the base unit instead of directly to the solenoids The microprocessor or central processing unit in the present invention permits the system to support many zones with the use of only a single controller and exter nal moisture sensor One model of the system supports seven independently controlled zones while the other supports twelve zones Each zone can be watered at different times and for different lengths of time while being controlled by a single sensor and controller This open ended design allows more zones to be added with minimal operating system changes If necessary two or more systems may be ganged together for a multi unit operation of many zones This offers the user a more cost effective solution to his i
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