Programmable Irrigation Computer

Abstract

A programmable computer for operating sprinklers or other watering devices of an irrigation system in predetermined sequence which in a first mode, supplies a series of stepping pulses and interruptions for addressing each sprinkler of the system and, in a second mode, supplies sprinkler operating pulses of preselected duration to those sprinklers of the system that are to be operated when addressed. The stepping and operating pulses are established in a predetermined sequence by a programmer which includes a matrix of gate means, one corresponding to each sprinkler of the system, that enable the second mode by coincidence of at least two control signals. Sprinkler address means provides a first interrogation signal in sequence to each sprinkler gate means and enables both modes for each sprinkler address. A programmable register provides a second timing signal to the matrix for a preselected watering time only for each sprinkler to be operated. The timing signal disables the first stepping mode and enables the second sprinkler operating mode.

Description

This invention relates generally to irrigation control systems and more particularly to a programmable computer useful in supplying in predetermined sequence the stepping pulses and operating pulses for an essentially two wire control system of the type disclosed in W. E. Davis, et al. U.S. Pat. No. 3,521,130 issued July 21, 1970 for Sequential Operating System.

One object of this invention is to provide a solid state device for commanding a two wire irrigation control system of the type disclosed in U.S. Pat. No. 3,521,130, as well as other types of electric or hydraulic control systems.

Another object of the invention is to provide a solid state device wherein general increases or decreases in irrigation time are easily made without the need to separately adjust the operating time for each watering device in the system.

An object of the invention also is to provide a solid state device that is easily manipulated for changes in the irrigation program such as selection of watering devices to be operated, or location and duration of syringe cycles, watering of greens and tees as distinguished from fairway watering for example, in golf course sprinkling systems.

Other objects and advantages of this invention will become apparent from a consideration of the following description in connection with the drawings wherein

FIG. 1 is a schematic block diagram of the programmable irrigation computer of this invention;

FIG. 2 is a typical output pulse train produced by the computer and illustrates the pulse time, shape, and voltage parameters;

FIG. 3 is a schematic circuit diagram of the output module of the power means;

FIG. 4 is a schematic circuit diagram of the output control module of the power means;

FIG. 5 is a schematic circuit diagram of the control logic of the programmable register;

FIG. 6 is a schematic circuit diagram of the variable divider of the programmable register;

FIG. 7 is a schematic circuit diagram of the time gate of the programmable register;

FIG. 8 is a schematic circuit diagram of the program schedule logic of the programmable register;

FIG. 9 is a schematic circuit diagram of the increment logic in the sprinkler address means; and

FIG. 10 is a schematic circuit diagram of the sprinkler timing logic of the gate means matrix.

The described embodiment of the invention controls forty of the sprinklers in a golf course irrigation system in one of two automatic watering programs or manually by means of the pulse train, a typical part of which is shown in FIG. 2.

In a first mode power means 1 of the computer supplies stepping pulses 10 at an intermediate voltage level of about 19 volts and intervening interruptions 11 at 0 volts. These stepping pulses typically have a period of 0.75 seconds and a duration of 0.72 seconds. The corresponding stepping interruption 11 to the 0 volt level is for 0.03 seconds. The stepping pulses 10 with the corresponding interruptions 11 may be used, for example, to step through the control units for those sprinklers which are not to be operated in a particular watering schedule as is more fully described in Davis, et al. U.S. Pat. No. 3,521,130.

Power means 1 of the computer in a second mode supplies sprinkler operating pulses 12 of preselected duration at a higher operating voltage level shown in FIG. 2 at 35 volts. These operating pulses typically are variable from 5 to 30 minutes in duration in 5 minute increments. The described power means also provides a delay in the rise time of each operating pulse above the 19 volt level in the order of 2 to 3 times the time constant of the individual sprinkler control units to allow the capacitors in preceding control units to charge to the full 35 volt level without upsetting the system also as is more fully described in Davis, et al. U.S. Pat. No. 3,521,130. This gradually rising leading edge 13 of the operating pulse shown in FIG. 2 is of about 2 seconds duration.

The pulses which the power means does produce, are established in a predetermined sequence by a programmer which includes a matrix of gate means 2, sprinkler address means 3, and a programmable register 4. The gate means matrix 2 enables the second or sprinkler operating mode of the power means by coincidence of two control signals at a particular sprinkler address. The matrix includes one gate means for each sprinkler in the system.

Sprinkler address means 3 of the programmer provides a first interrogation signal in sequence for each sprinkler address. These signals enable the computer in both modes and initiate stepping pulses 10 and interruptions 11 at the intermediate 19 volt level. Programmable register 4 in the programmer provides a second timing signal to the matrix only for those sprinklers of the system selected for operation. The timing signal is "on" for the operating sprinklers for a preselected time duration, typically from 5 to 30 minutes in 5 minute increments depending on the length of time selected for operation of a particular sprinkler. Power means 1 produces operating pulses 12 under command of the programmer only upon coincidence of the interrogation signal from the sprinkler address means 3 and the timing signal from the programmable register 4 at the gate means in the matrix for a particular sprinkler. Upon coincidence of these two control signals the power means supplies operating pulse 12 for the duration of the timing signal from programmable register 4.

When the timing signal from the programmable register 4 selected for that particular sprinkler times off, the sprinkler operating pulse 12 drops to 0 volts. Then the sprinkler address means 3 interrogates the next sprinkler gate means. If there is no coincidence at that sprinkler address with a timing signal from the programmable register, sprinkler address means 3 increments to the next address at which there is one and stops there. In the meantime, as the prior timing signal times off power means 1 first produces a delay 14 of sufficient length to reset all control units in the irrigation system and then produces stepping pulses 10' and interruptions 11', as shown in FIG. 2, to step through all sprinklers in the system without operating any until it reaches the next sprinkler to be operated which by then is being addressed by sprinkler address means 3. The reset delay typically is about 5 seconds.

In this manner sprinkler address means 3 of the programmer interrogates each sprinkler gate means of the matrix in sequence. Where interrogation coincides with a timing signal, address incrementing stops and power means 1 produces an operating pulse at the 35 volt level to turn on that sprinkler for the time duration selected for it. Where there is no coincidence with the timing signal, address incrementing continues until there is such coincidence and the power means produces corresponding stepping pulses up to that same sprinkler address. After interrogation of each sprinkler of the system, the programmer resets for the next watering cycle.

POWER MEANS

The power means 1 includes output module 15; output control module 16; a power supply 17 that provides 35 volts d-c to the output module and 12, 7 and 5 volts d-c to the other components of the computer; a sprinkler address encoder 251; and an output counter 252.

OUTPUT MODULE

FIG. 3 illustrates the output module circuit. Depression of a start pushbutton on the computer control panel 83, energizes relay 18 and connects the output module 15 to the pair of conductors 19, 20 that supply all sprinkler control units of the system in series. The described embodiment controls 40 sprinklers. Line 20 is at system ground and the d-c voltage on conductor 19 may be any of 0, 19 or 35 volts with respect to that system ground. A pair of quick acting bi-directional gas diodes 21, 22 across the conductors in combination with the current delay provided by inductance 23, 24 protect the computer against transients induced by lighting or other causes in the lengthy and spread out twin conductors 19, 20 as is more fully disclosed in copending Ser. No. 126,220 for Transient Protection For Electrical Irrigation Control Systems by Wayne E. Davis filed on Mar. 19, 1971. Capacitor 25 connects across the output conductors 19, 20 and conductor 19 is fused at 26.

A first control line 27 from output control module 16 joins the node between resistors 28 connecting the 12 volt supply and resistor 29 connecting the base of switching transistor 30. Its emitter is at system ground and its collector connects through capacitor 31 to ground and through resistors 32, 33 to the 35 volt supply. The node between resistors 32, 33 directly connects one base of Darlington coupled transistors 34, 35 and to the collector of another switching transistor 36. The base of transistor 36 through resistor 37 connects to the 12 volt supply via resistor 38. Through resistor 39 the base of transistor 36 connects the base of switching transistor 40. The collector of the latter through resistor 41 connects output conductor 19 and the emitter of Darlington coupled transistor 35. The emitters of both of transistors 36, 40 are at system ground and that of the latter also connects to output conductor 20. A second control line 42 from output control module 16 connects the node between base resistors 37, 39 of switching transistors 36, 40.

A low voltage on control line 42 switches transistors 36, 40 off. With a high voltage simultaneously on control line 27, transistor 30 continues in saturation. Resistors 32, 33 form a voltage divider with their node at a design voltage of about 19 volts. Darlington coupled transistors 34, 35 furnish that 19 volts at about 250 milliamps to output conductor 19 in the first or stepping mode of the computer.

On the other hand with a low voltage on line 42, a low signal on control line 27 switches transistor 30 off. Capacitor 31 charges to the full supply potential of 35 volts. Darlington connected transistors 34, 35 then provide 35 volts to output conductor 19 to drive conductors 19, 20 in their operating mode. Capacitor 31 is sized to provide the delay 13 in rise time of the 35 volt operating pulse 12 as is illustrated in FIG. 2.

High voltage signals on both control lines 27 and 42 from output control module 16 switch transistors 36, 40 on and clamp output conductor 19 to the 0 volt level. This provides the interruption 11, 11' between stepping pulses or reset delay 14, as the case may be.

OUTPUT CONTROL MODULE

The output control module 16 shown in FIG. 4 includes delay circuit 45 which develops delay 14 for resetting all control units in the system after each sprinkler operating pulse times off, supplies a load pulse to output downcounter 252 and starts oscillator 46 at the stepping pulse frequency. The oscillator output shaped by multivibrator 47 supplies the combination of control signals gated by control gates 48, 49 to control lines 27, 42 to the output module. Oscillator 46 also provides stepping pulses at the same repetition rate to decrement output downcounter 252.

Sprinkler timing signals from the increment logic 230 at 50 for automatic control or at 51 for manual control set or disable control flop 52 of the delay circuit 45. While a timing signal is on and operating a sprinkler for its selected duration, all inputs to control gates 48 and 49 are high and the corresponding low outputs on lines 42 and 27 produce the sprinkler operating pulse 12 across lines 19, 20 from output module 15. Line 53 normally supplies a high signal to control gate 48. It is grounded out only by depression of a "rain" pushbutton on control panel 83 or remote control module 89 to disable control gate 48 when no irrigation is required because of rain. When the sprinkler operating pulse 12 is on, line 54 from delay circuit 45 to control gates 48 and 49 is also high. So is line 55 from multivibrator 47 that is at 5 V. when the oscillator 46 is not running.

When the operating sprinkler times off and the signal at 50 or 51 goes low, flop 52 is set and through resistor 56 switches transistor 57 off. At the same time line 54 goes low to disable output gates 48 and 49 and terminate the sprinkler operating pulse 12 supplied by output module 15. Capacitor 58 charges from the 12 volt supply in about 5 seconds to a value high enough to trigger unijunction 59. Its positive base pulse is supplied directly as a load pulse at 60 to output downcounter 252. That pulse also in inverted and resets control flop 52 through line 61 and sets control flop 62 in oscillator 46 to start the stepping function of the output module after the described 5 second delay 14 during which all sprinkler control units have reset.

Setting of control flop 62 through resistor 63 cuts off transistor 64. Capacitor 65 then charges from the 12 volt supply to a level sufficient to trigger unijunction 66 at which time capacitor 65 discharges until unijunction 66 cuts off. This cycle repeats until control flop 62 is reset by emptying of output downcounter 252 which event supplies a reset pulse at 67. Setting of control flop 62 to turn on the oscillator also supplies a low signal through line 68 to switch gate 49 output high. The oscillator output pulses through line 69 decrement the output downcounter 252 to a count corresponding to the next sprinkler to be operated.

The oscillator output through capacitor 70 and diode 71 starts one shot multivibrator 47 comprising transistors 72, 73, capacitor 74, resistors 75, 76 and diode 77. The multivibrator square wave output at the stepping pulse frequency passes through diode 78 and line 55 to alternately enable and disable output gate 48 and supply a corresponding train of high and low values on control line 42 to produce the stepping pulse output of output module 15 at 19 volts with intervening 0 volt interruptions.

The sprinkler address encoder 251 and output downcounter 252 of power means 1 and their functions are described hereinafter in connection with various components of the programmer consisting of gate means matrix 2, sprinkler address means 3, and the programmable register 4.

PROGRAMMABLE REGISTER

The programmable register 4 develops the timing signals supplied to the gate means matrix 2 and coordinates with them the functions of sprinkler address means 3 and power means 1.

The programmable register includes a 15 second time base clock 80 which develops a continuous train of pulses having a 15 second period and supplies them through control logic 81 to variable divider 82. The clock may be a mechanical or electronic device supplying a continuous train of positive pulses having a 15 second period. The variable divider 82 passes only those pulses occurring at a repetition rate preselected by a time base selection switch on control panel 83. In the embodiment described, the time-base selection switch divides the 15 second time base by 2, 3, 4, 5, 6, 7 or 8 to enable selective changes in timing for the entire system.

Divide-by-five counter 84 counts the periodic pulses passed by variable divider 82 and its output supplies time gate 85 with pulses reoccurring at intervals greater by a factor of five than the variable divider output. Divide-by-five counter 84 is a modulo-5 counter which has only five states and these are achieved without resetting. With a normal setting of the panel mounted time base selection switch to divide the 15 second time base by 4, the divide-by-five counter 84 converts that 1 minute pulse train to a series of pulses occurring once every 5 minutes. With these timing pulses time gate 85 typically furnishes time gate control signals of 5, 10, 15, 20, 25 and 30 minutes duration.

"A" and "B" program pin boards 86, 87 patch the time gate timing signals into the sprinkler timing logic of gate means matrix 2 in a predetermined pattern controlled by program schedule logic 88 in one of two programs "A" or "B," respectively. Control panel 83 or remote control module 89 establish the patterns in program schedule logic 88.

In each of the pin boards 86, 87 one pin for a given one of the forty sprinklers controlled by that board connects any selected one of the six time gate control signals normally of 5, 10, 15, etc. minutes duration to gate means matrix 2. The time gate control signal enables that particular sprinkler for the selected time when it is addressed by the interrogation control signal from sprinkler address means 3. The time gate signals are "not" signals in the sense that they are "on" when they are at a low level. If a particular sprinkler is not to be operated, no pin is inserted in the pin board for it.

CONTROL LOGIC

FIG. 5 illustrates the control logic 81. When the computer is not running a positive signal in line 85 comprises one input to a run gate 86. A positive pulse on the other input at line 87 from a start push-button on control panel 83 or remote control module 89 produces a low gate output that couples through capacitor 88 directly to set initiate flop 89 of the control logic. The positive output of initiate flop 89 enables nand gate 90 and occurrence of a pulse from the 15 second time base clock 80 at clock line 91 passes an inverted single pulse to control logic output gate 92. When the computer is not running, gate 92 also receives a low signal from the sprinkler address means 3 as at 93. The initiate flop 89 inputs are wired so that it always tries to turn off and does so upon occurrence of the first fifteen second time base clock pulse.

The positive output of the initiate flop 89 simultaneously enables run flop 94 to "set" on the clock pulses supplied to it from the 15 second time base 80 through line 91. When the run flop 94 has been set, its positive output enables control logic gates 95 and 96 to pass 15 second time base clock pulses supplied to them by clock line 91 to variable divider 82.

The negative output of run flop 94 couples through capacitor 97 to gate 98 to enable the timing functions in the sprinkler address means 3 at 99. That negative output directly disables run gate 86. The negative outputs of initiate flop 89 and run flop 94 through nand gate 100 as at 101 enables relay 18 in the output module 15 of FIG. 3 to connect the computer output to lines 19, 20 which extend to the sprinkler control units of the system.

Coincidence of reset signals from the program schedule logic 88 at 103, reset circuitry as at 102 and from the sprinkler address means 3 at 93 through stop gates 104, 105 reset run flop 94 at the end of an operating cycle.

VARIABLE DIVIDER

The control logic supplies 15 second time base clock pulses through control logic gate 95 at 110 to the flops 111, 112 and 113 comprising counter register 114 in variable divider 82 of FIG. 6 and through control logic gate 96 at 115 to each of its cluster of output gates 116 - 122. The time-base selection switch mounted on control panel 83 sets the time base for the system by selectively connecting +5 volt d-c to any one of gates 116 - 122 in the output cluster at 123 - 129 respectively. For example, connection of +5 volt d-c to gate 118 at 125 increases the period of the timing pulse train by a factor of four for a time base of 1 minute. Connection to gates 116, 117, 119, 120, 121 or 122 increases the period by factors of 2, 3, 5, 6, 7 or 8, respectively.

The flops in the counter register 114 count the time base pulses supplied to them from control logic gate 95. When a number of counts accumulates in the register that corresponds to the setting on the time base selection switch, the appropriate one of gates 116 - 122 is enabled and the clock pulse then occurring is inverted by that gate and passed to a common "or"-tied output gate 130. There it is again inverted and at 131 sent to divide-by-five counter 84.

While the output of the "or"-tie is low, capacitor 132 discharges through resistors 133, 134 to ground. Thus, as the time base clock signal falls to ground, the "or"-tie becomes high through the selected one of seven parallel collector resistors 135 - 141 of transistor 142 all connected to the +5 volt supply. This furnishes enough drive to saturate transistor 142. The counter advances one state, but only momentarily to pass a single clock pulse because saturation of transistor 142 jam-resets the counter flops through reset line 143.

In this manner the time-base selection switch converts the fifteen second time base into a pulse train having periods of from 30 to 120 seconds depending on which of gates 116 - 122 it enables periodically to pass single clock pulses.

TIME GATE

Time gate 85 shown in FIG. 7 is a modulo-7-counter. Its zero state is inactive and states one to six are decoded and "or" tied to produce time gate signals of 5, 10, 15, 20, 25 and 30 minute duration from the typical input pulses supplied by the divide-by-five counter 84 which normally occur once every 5 minutes.

Each divide-by-five counter pulse at 150 is inverted through gate 151 which is enabled by the sprinkler address means 3 as at 152. The three flops 153 - 155 in the counter register count the 5 minute periodic pulses. Their states are decoded in nand gates 156 - 161 and those states are "or" tied by output gates 162 - 167 to produce gate signals normally of 5, 10, 15, 20, 25 and 30 minutes duration, respectively. These gate signals supply one input to a series of power gates 168 - 173 which at about 100 ma. drive the sprinkler timing logic gates via pin board 86 for the "A" program and to a series of power gates 174 - 179 that drive the sprinkler timing logic gates via pin board 87 for the "B" program.

The program schedule logic 88 of FIG. 8 enables power gates 168 - 173 for the "A" program at 180 and power gates 174 - 179 for the "B" program at 181. The time gate is reset at 182.

PROGRAM SCHEDULE LOGIC

The particular program schedule logic 88 shown in FIG. 8 establishes the pattern in which the programmer schedules the "A" or "B" programs or the order in which the programmer passes through them if both are to be performed. It also can be augmented to schedule only tee and green sprinklers, syringe cycles, etc. These aspects are not shown in detail.

Push-buttons indicated in FIG. 8 at A, B, AB or BA mounted on control panel 83 or at Remote A, Remote B, Remote AB or Remote BA mounted on remote control module 89 command the program schedule logic 88. Depression either of the remote or control panel button for program A, for example, schedules only that program. On the other hand, depression of the control panel or remote push-button AB schedules the A program followed by the B program. The others operate in similar fashion.

Depression of a particular push-button through one of input gates 190 - 193 for remote push-buttons or directly for a control panel push-button applies ground to the logic network including diodes 194, 195 and 196, "or" gate 197, and relay control gates 198 - 203 to set the appropriate schedule on the relay register comprising relays 204 - 206. Setting of any particular relay switches the relay contactor from a normally grounded storage contact and with +5 volt potential supplied to the normally open contact as shown in FIG. 8 to the reverse condition, with the storage contact at +5 volts and the normally open contact grounded by the relay contactor. Reversal of the relay potentials supplies the network of input logic gates 207 - 217 that set flop 218, for example, to produce an enabling output at 180 for the "A" program or set flop 219 to enable the "B" program at 181. The input logic gates also set program counter flop 220 if both of the "A" and "B" programs are to be run.

A day wheel control signal at 221 connects directly to input logic gates 211, 212 and after inversion connects input logic gates 208, 215. An alternate mode signal at 222 from a mode switch either on remote control module 89 or on control panel 83 directly enables input logic gates 208, 211, 212, 215 and after inversion enables program counter-flop 220 and input logic gates 210 and 214. This switch enables programmer command by remote control module, control panel or manual control. The single starting clock pulse passed by gate 92 in the control logic 81 sets the program schedule logic flops at 223. They are reset at 224. The negative output of program counter flop 220 at 103 enables stop gate 104 in the control logic 81.

For example, depressing either the A or Remote A push-button sets relay 204 of the relay register on the "A" program only. The ground appearing at the output of gate 190 directly enables relay control gate 199 and after inversion disables relay control gate 198 to switch relay 204 from its normal storage position as shown in FIG. 8. This grounds the normally open terminal that was at +5 volts and opens the normally grounded storage contact to +5 volts. The reversal in potentials through the input logic gate network sets flop 218 to produce an enabling signal at 180 for the "A" program power gates 168 - 173 in time gate 85. The negative output at 103 of program counter flop 220 enables stop gate 104 in the control logic to stop the computer after it has passed through the "A" program.

SPRINKLER ADDRESS MEANS

Sprinkler address means 3 interrogates each sprinkler address in sequence. It comprises increment logic 230, sprinkler address counter and decode logic 231 and module counter and decode logic 232 that interrogate all sprinkler addresses in gate means matrix 2. The sprinkler address counter is a modulo-10 counter whose ten states are decoded, inverted and sent to the matrix. The last state also returns to increment logic 230 to enable module counter 232. That counter is a four state counter. Its four states are decoded and also sent to the gate means matrix to provide forty address capability. Its last state returns to the increment logic to initiate an end of program signal at 93 in the control logic to shut down the computer.

INCREMENT LOGIC

A start signal from the control logic 81 at 99 enables start gate 233 shown in FIG. 9. Any sprinkler timing signal gated from gate means matrix 2 and encoded in the sprinkler address encoder 251 also supplies the increment logic at 234. When an operating sprinkler times out, its trailing edge turns on start gate 233 through capacitor 235 to initiate the incrementing function. The output of gate 233 sets control flop 236 for the incrementing oscillator and passes directly to the output control module delay circuit at 50.

The negative output of control flop 236 through base resistor 237 biases transistor 238 off and initiates incrementing oscillations. Capacitor 239 then charges across the 12 volt supply until unijunction 240 triggers. At that time capacitor 239 discharges until unijunction 240 cuts off. This cycle repeats itself producing an incrementing pulse train which is inverted and supplied to "or" gate 241. "Or" gate 241 passes the incrementing pulse train to enable time gate 85 at 152, to sprinkler address counter at 242 and to enable gate 243 in the increment logic.

On the other hand, as any encoded timing signal turns on and returns at 234 it is inverted and resets control flop 236 to terminate the incrementing oscillations. The increment logic also can be reset manually at 244.

The computer also can be manually operated by one or more depressions of a manual push-button on either of control panel 83 or remote control module 89 each of which generates a single pulse supplied to "or" gate 241 in the increment logic and is passed to output control module at 51. The manually initiated pulses actuate the system in the same manner as is described for automatic operation.

The incrementing pulses generated by the oscillator comprising capacitor 239 and unijunction 240 are supplied at 242 to and counted by sprinkler address counter 231. For each pulse the decoded counter output supplies an interrogation signal in sequence through one of its 10 output lines to interrogate one sprinkler address in each of four modules of sprinkler logic in the gate means matrix. Simultaneously, module counter 232 interrogates all ten sprinkler addresses in one module. When sprinkler address counter reaches its tenth or last state the output also returns to the increment logic at 246 and through gate 243, which is enabled by the corresponding oscillator pulse, passes a pulse at 247 to module-counter 232 to shift it to its next state for interrogation of the next module.

Both counters in combination thus increment through each sprinkler address until the combination of their interrogation signals coincides with a timing control signal for the sprinkler at that address. Such coincidence enables the output gate in the matrix at the particular address as is hereinafter described and the encoded output of sprinkler address encoder 251 of the power means 1 returns to increment logic 230 at 234 to stop incrementing at that address. When the timing signal goes off at that address the control flop 236 is again set, the incrementing oscillator starts, and incrementing resumes to the next sprinkler address where there is coincidence with a timing control signal.

When the last state of module counter 232 has been set for the fourth module in the sprinkler logic of the matrix, the counter output also returns to the increment logic at 248 and enables gate 249. Then, upon occurrence of the last state for the sprinkler address counter at 246, gate 249 produces an end of program signal at 93 for the control logic to stop the computer.

GATE MEANS MATRIX

Gate means matrix 2 provides a plurality of gate means that receive timing control signals from pin boards 86, 87 in programmable register 4 and interrogation control signals from sprinkler address means 3. These gate means, one set for each sprinkler, provide an output when there is coincidence of the timing and interrogation control signals at a particular sprinkler address. The gate means in the logic of the embodiment shown in FIG. 10 are arranged in four modules of 10 sprinklers each. The output for all sprinklers is encoded in sprinkler address encoder 251 of the power means 1 in 6 bit binary.

Increment logic 230 in the sprinkler address means 3 at 234 monitors all of the six encoded output states of sprinkler address encoder 251 and a sprinkler operating output on any one of them starts and stops its address increment function. The leading edge resets oscillator control flop 233 to stop incrementing and the trailing edge sets the flop 233 for incrementing as described above.

Output counter 252 of the power means 1 counts the encoded output from sprinkler address encoder 251. In the described embodiment it is a downcounter which decrements one count for every decrement pulse clocked in. The delayed load pulse at 60 in FIG. 4 from the delay circuit 45 of output control module 16 in coincidence with any of the encoded outputs of sprinkler address encoder 251 jam-sets the downcounter. The output control module oscillator 46 supplies the decrement pulses at 69 to decrement the downcounter to a count corresponding to the operating sprinkler address whereupon the counter resets oscillator 46 control flop 62 at 67 in the output control module 16 to terminate the stepping pulses 10, 11 and initiate a sprinkler operating pulse 12 from the output module 15.

FIG. 10 illustrates a portion of the gate means matrix 2 including all of the first and parts of its second and fourth modules. Time gate signals for each sprinkler address from the "A" pinboard 86 and the "B" pinboard 87 in programmable register 4 supply one of 40 "or" input gates 255 - 1 through 255 - 40. There is a time gate signal on either of the two lines for a particular sprinkler gate depending upon whether or not the pin for that sprinkler has been inserted in the program "A" or program "B" pinboard to connect the time gate control signals from power gates 168 - 179 for that sprinkler to the gate means matrix. The manual push-button on the control panel 83 or at remote control module 89 supplies a third input to enable all input gates 255 - 1 through 255 - 40 for manual operation.

The input gate for each sprinkler to be operated in one or both of the "A" or "B" programs or manually supplies one input to a corresponding one of nand output gates 256 - 1 through 256 - 40, one for each sprinkler. Each of the ten outputs from sprinkler address counter 231 connects to one of output gates 256 - 1, etc. in each ten sprinkler module. One of the four outputs from module counter 232 supplies a third input to all ten nand gates 256 - 1 through 256 - 10, etc. for a module of 10 sprinklers. Module counter input number 1 goes to the first module of 10 output gates, number 2 goes to the second module, etc. A coincidence of interrogation signals from both counters in the sprinkler address means 3 and a time gate signal from programmable register 4 passes an inverted signal through the addressed one of output gates 255 - 1, etc. for the duration of the timing signal. On the other hand, where there is no coincidence between sprinkler address interrogation control signals and a timing control signal, the output gate for that particular sprinkler is inactive.

The 40 sprinkler timing logic outputs then are encoded in 6 bit binary in sprinkler address encoder 251. The encoded output returns to actuate increment logic 230 at 234 and is supplied to output counter 252 of power means 1 to establish the production of stepping and operating pulses in the predetermined sequence.

Thus, the described computer can be used as the controller and power source or pulse generator to operate twin-wire sprinkler systems as described in the Davis, et al. U.S. Pat. No. 3,521,130. It also is useful in commanding other electrical or hydraulic irrigation systems. The specific components have been described for illustrative purposes only. Other features are easily incorporated in the system. For example, a syringe cycle of short watering duration, say of 5 minutes at each sprinkler address, is achieved by gating only 5 minute timing signals directly to the sprinkler increment logic at 234. Similarly only tees and greens or selected fairway areas on a golf course can be watered by patching only selected sprinklers from pin boards 86, 87 through a separately initiated tee and green program after normal irrigation for the whole system.

It will be apparent to those skilled in this art that other modifications to the components described may be made and equivalents substituted which are within the scope of the invention defined in the following claims.

Claims

I claim:

1. A programmable sprinkler operating computer comprising

power means supplying a sequence of stepping pulses in a first mode and sprinkler operating pulses in a second mode;

and a programmer for establishing said pulses in a predetermined sequence including

a matrix of gate means enabling said second mode, one gate means corresponding to each of a series of sprinklers and operable by coincidence of at least two control signals,

sprinkler address means providing a first interrogation control signal to said matrix in sequence for each sprinkler of the series and enabling said power means in its first mode; and

a programmable register providing to said matrix a second timing control signal for each sprinkler of the series to be operated in preselected sequence and for a preselected duration.

2. The programmable sprinkler operating computer of claim 1 wherein the power means supplies said stepping pulses at an intermediate voltage level and said operating pulses at a higher voltage level.

3. The programmable sprinkler operating computer of claim 1 wherein the timing control signals provided by said programmable register are adjustable in duration.

4. The programmable sprinkler operating computer of claim 1 wherein the programmable register includes

time base means providing a continuous series of pulses having a constant repetition rate;

time gate means converting said series of pulses into a plurality of timing control signals of differing but fixed duration;

a set of output lines to said matrix of gate means, one line for the gate means of each sprinkler of the series; and

at least one pin board means enabling those of said lines corresponding to each sprinkler to be operated with one of said timing control signals in preselected sequence.

5. The programmable sprinkler operating computer of claim 1 wherein the programmable register further includes

means adjustably modifying the repetition rate of said pulses to establish a different time base for them.

6. The programmable sprinkler operating computer of claim 1 wherein the sprinkler address means includes

a set of output lines to said matrix of gate means, one of the set for each gate means in the matrix for each of the series of sprinklers;

counter means for supplying an interrogation control signal to each of the set of output lines in sequence;

an oscillator, which is responsive to an output from any of said gate means in the matrix, for incrementing said counter means when there is no output from any of said gate means and for setting said counter means in sequence at each gate means address in the matrix where there is an output.

7. The programmable sprinkler operating computer of claim 1 wherein the power means includes

an output module supplying said stepping pulses in a first mode and said operating pulses in a second mode; and

output module control means responsive to an output from any of said gate means in the matrix for enabling the output module in its first mode when there is no output from any of said gate means and in its second mode when there is an output.

8. The programmable sprinkler operating computer of claim 7 wherein the power means further includes

an encoder for the outputs of said gate means of said matrix providing a coded output corresponding to the number of gate means in the matrix that have previously enabled said second mode;

an oscillator in the output module control means enabling the output module in its first mode and simultaneously producing a counter decrement pulse for each stepping pulse;

and a downcounter for the output of said encoder which is decremented by said oscillator decrement pulses and is set by the encoder to disable said oscillator and to enable the output module in its second mode.

9. The programmable sprinkler operating computer of claim 8 wherein the output module control includes delay means inhibiting both modes of said output module for a sprinkler control unit reset time following each sprinkler operating pulse.

10. In a sprinkler operating computer having power means supplying a sequence of stepping pulses in a first mode and sprinkler operating pulses in a second mode,

a programmer for establishing said pulses in a predetermined sequence including

a matrix of gate means enabling said second mode, one gate means corresponding to each of a series of sprinklers and operable by coincidence of at least two control signals;

sprinkler address means providing a first interrogation control signal to said matrix in sequence for each sprinkler of the series and enabling said power means in its first mode; and

a programmable register providing to said matrix a second timing control signal for each sprinkler of the series to be operated in preselected sequence and for a predetermined duration.

11. The programmer of claim 10 comprising

a matrix of gate means enabling said second mode, one gate means corresponding to each of a series of sprinklers and operable by coincidence of at least two control signals;

sprinkler address means providing a first interrogation control signal to said matrix in sequence for each sprinkler of the series and enabling said power means in its first mode including

a set of output lines to said matrix of gate means, one of the set for each gate means in the matrix for each of the series of sprinklers,

counter means for supplying an interrogation control signal to each of the set of output lines in sequence,

an oscillator, which is responsive to an output from any of said gate means in the matrix, for incrementing said counter means when there is no output from any of said gate means and for setting said counter means in sequence at each gate means address in the matrix where there is an output; and

a programmable register providing to said matrix a second timing control signal for each sprinkler of the series to be operated in preselected sequence and for a predetermined duration including

time base means providing a continuous series of pulses having a constant repetition rate,

time gate means converting said series of pulses into a plurality of timing control signals of differing but fixed duration,

a set of output lines to said matrix of gate means, one line for the gate means of each sprinkler of the series; and

at least one pin board means enabling those of said lines corresponding to each sprinkler to be operated with one of said timing control signals in preselected sequence.