Abstract: An adaptable controller for controlling variable numbers of switches is disclosed. Specifically the controller is useful in an irrigation system having a number of water sprinklers whose operation may be controlled by user-defined programs. The system has a processor unit, an interface unit and a number of add-on units. Switches for actuating electrically-operated devices such as sprinklers are located on the interface unit and the add-on units. The controller allows a user to enter operating parameters relating to the switches in the form of the user-defined programs. The processor is capable of ascertaining the number of switches on the interface unit and the add-on units and limiting the number of switches selected and controlled by the user-defined programs.

Abstract: System and method for supplying water to plants. A photodetector detects light adjacent the plants and a threshold circuit generates a first signal representative of a first state when the level of illumination of the detected light is less than a threshold level and generates a second signal representative of a second state when the level of illumination of the detected light is greater than the threshold level. A processor is responsive to the first and second signals for anticipating approximately when the detected light will next change from the first state to the second state and approximately when the detected light will next change from the second state to the first state. A counter circuit responsive to the processor generates an initiate signal and a terminate signal.

Abstract: Paint flow control interface circuitry for passing electrical signals across a paint booth barrier including a feedback signal indicating a paint flow parameter from a parameter transducer within the paint booth, includes passive resistive intrinsically safe barrier circuit elements coupled with buffer circuitry for minimizing the voltage drop across the interface circuitry. Light filtering of the buffer circuitry output signal with minimum filter lag yields an accurate indication of the paint flow parameter with high signal to noise ratio and minimum signal lag, for application in closed-loop paint flow control. Additional transducer voltage supply signal feedback provides for closed-loop voltage supply control across the interface circuit.

Abstract: A capacitive moisture sensor has two conductors encased in a dielectric material and oriented to minimize the dielectric effect of the moisture-absorbent medium in which the sensor is placed. The conductors, the casing, or both have one or more physical dimensions that vary monotonically across the length of the sensor. The physical dimensions vary in a manner that produces a linear relationship between moisture level and sensor impedance. The physical dimension may be the thickness of the dielectric casing or the spacing between portions of the conductors. In another aspect, the present invention has an irrigation control system with a central control unit and multiple remote units. Each remote unit has a moisture sensor and transmits a measured moisture level to the central control unit. In response to the measured moisture level, the central control unit determines whether to open or close a valve controlling the irrigation of the area in which the sensor is located.

Abstract: A sprinkler system controller comprising temperature sensor means for monitoring air temperature and transmitting an affirmative temperature indication signal when a given preset temperature is exceeded; light sensor means for monitoring light intensity and transmitting an affirmative illumination indication signal when a given preset intensity is not exceeded; moisture probe means for monitoring ground moisture and transmitting an affirmative moisture indication signal when a given preset moisture level is not exceeded; conjunctive means coupled to the temperature sensor means, light sensor means, and moisture probe means for transmitting an affirmative timer activation signal upon receipt of an affirmative temperature indication signal, an affirmative illumination indication signal, and an affirmative moisture indication signal; timer means coupled to the conjunctive means for receiving an affirmative timer activation signal and transmitting an affirmative sprinkler valve activation signal for a preset peri

Abstract: A moisture control system which overrides power supplied to electrically operated irrigation control valves such that a preset amount of moisture content of soil is not exceeded. The system is composed of two components, a remote detector, which is disposed in soil distant from its controller, and a controller which is placed near the valve it controls or the valve's source of power.The controller is electrically placed between the source of power for a valve, such as a time clock, or 24 VAC transformer and the valve. The controller receives its power from the source of power and the valve receives its power from the controller. The controller supplies electrically isolated power to the remote detector, sets the desired moisture level at the remote detector, and controls power to the valve.

Abstract: Moisture sensor devices, systems and methods of making and using the same employ a pair of elongated, probe-like, conductive sensor elements, coupled as part of an LC oscillator circuit. The use of an LC oscillator circuit can minimize adverse effects of conductivity variances in the medium being monitored, because the resistance of the medium (and, thus, the medium's conductivity) has minimal or no effect on the resonant frequency of an LC oscillator circuit. An LC oscillator circuit of suitable stability for moisture sensing applications includes first and second comparators connected such that the output of the first comparator is coupled to the inverting input of the second comparator. An inductor is coupled between the output and inverting input of the first comparator and a capacitance C is provided between the output of the second comparator and the inverting input of the first comparator.

Abstract: A system is disclosed comprised of several inputs in the soil that send a current into the soil and measure the resulting resistance in the soil. The soil resistance varies inversely with the level of moisture in the soil. Two voltage comparators are used to determine whether the soil has reached a pre-determined level of saturation or dryness. If the pre-determined level of dryness is exceeded, then a signal is sent through a switch and a latch, and activates the sprinkler solenoids. Once the pre-determined level of saturation is reached, a saturated signal is sent through the switch and latch in order to de-energize the solenoids. The system includes an over-watering prevention feature wherein a clock circuit is used so as to pulse the sprinklers in order to allow the water to permeate the soil between the sprinkler pulses.

Abstract: There is provided a system for monitoring moisture level in soil and controlling application of water to the soil. The system includes a moisture level sensor which generates a small voltage through the Volta effect. This voltage is amplified and is then used to trigger a switch typically connected to a standard watering timer. The sensor signal may be compared to a present voltage level through a comparator, and in this way the amount of moisture in the soil which will determine the "on" condition can be selected. The preferred sensor in the present invention is a bimetallic element, the soil functioning as an electrolyte in contact with the bimetallic element such that a Volta effect electromotive force is produced in the bimetallic element. A temperature sensor is also included, and functions in parallel to the moisture sensor such that both moisture level and temperature level must be within a present range in order for the comparator to pass an output signal on to the switch.

Abstract: An improved irrigation control apparatus for use in controlling an irrigation valve. The apparatus includes a soil moisture sensor for generating an output signal indicative of the soil moisture level. The output signal is sent to a control unit that inhibits valve operation if the soil is considered wet. The control unit has a control circuit that applies a relatively short duration power pulse to the sensor to obtain a moisture reading during the pulse. In addition, the control unit includes display lights which are part of a manually actuable test circuit that displays a wet or dry soil indication received from the sensor.

Abstract: An improved irrigation control apparatus for use in controlling an irrigation valve. The apparatus includes a soil moisture sensor for generating an output signal indicative of the soil moisture level. The output signal is sent to a control unit that inhibits valve operation if the soil is considered wet. The control unit has a control circuit that applies a relatively short duration power pulse to the sensor to obtain a moisture reading during the pulse. In addition, the control unit includes display lights which are part of a manually actuable test circuit that displays a wet or dry soil indication received from the sensor.

Abstract: An irrigation system for controlling the operation of a number of control valves each of which controls the flow of water in a corresponding branch pipe leading from a common supply pipe. The system comprises a pair of control lines which extend along the supply pipe and branch pipes to carry a control signal to operate a control unit which operates a corresponding control valve using a low voltage power supply. The control signal is coded by a data generator according to predetermined conditions and is decoded by each of the control units, the coded signal being received at each control unit, and the specified control unit operating only.

Abstract: A fluid control system for controlling one or more branches of a fluid delivery system, which can be manually controlled or, under general operating conditions, automatically controlled by ambient moisture conditions. When applied to sprinkler and irrigation systems, for example, the system will include a ground moisture sensor which, with associated means, can modify or adjust the preset watering times in accordance with soil needs as sensed by the sensor structure. The programmable timer is used for respective watering stations; the timers can be separately set to desired average watering time needed for particular stations. Sequencing functions and apparatus are also provided.

Abstract: A sensor is disposed in an earth patch for sensing the amount of moisture in such patch by providing a capacitance having a variable value dependent upon the sensed moisture. The variable capacitance is included in an oscillator which produces a signal at a frequency variable in accordance with variations in the capacitive value. The oscillator is energized by a direct potential passing through a cable from a potential source at a central station. A rectifier and a filter capacitor prevent the signal produced in the oscillator from interfering with the energizing of the oscillator by the direct potential. The signal from the oscillator passes through the cable to a stage at a controller. The incoming signal is prevented from interfering with the energizing voltage source by a filter inductor. A first controller stage reestablishes the incoming signals relative to a ground potential. The signal is the converted to a direct voltage which varies as a function of signal frequency.

Abstract: A includes a first capacitance plate, a dielectric covers a first capacitance plate, second capacitance plates are formed by moisture in an area. The capacitance value, dependent upon the second plate formation, controls the frequency of signals produced by an oscillator. This frequency controls the opening and closing of a first switch. A second switch is in a circuit with the first switch and a solenoid. The closing of the second switch is dependent upon the operation of circuitry energized by an alternating voltage. The alternating voltage is modified to extend the zero voltage level period which occurs at the zero cross-over in the negative direction. When this condition occurs, a pulse is generated by the detection circuitry and this pulse causes the second switch to remain closed. When the first switch operates to indicate no need to water the area, the solenoid is energized and an associated relay is opened.

Abstract: An irrigation control system includes a soil moisture sensor (S) that controls the common lines of various irrigation valves (VA) being controlled by a conventional irrigation time based controller (TC). The sensor is in a first zone of primarily shallow rooted plants. A timer (TR) is activated whenever the soil moisture sensor allows the first zone to be watered. The timer (TR) increments a counter (CR) which closes after a pre-set number of irrigation cycles of the first zone having been completed. When the counter (CR) close contacts (C), then the irrigation valves feeding a second zone of primarily deep rooted plants are activated.

Abstract: An injection control system selectively to activate circuitry for controlling injection of additive chemicals into an existing automatically timed irrigation system having an irrigation timer. This control system includes a plurality of storage reservoirs for storing one or more additives. Conduits deliver these additives to the existing irrigation system. The control system includes a central processor programmed for intended operation, and sensors sensing the flow condition valves in the existing irrigation system. The control system thereby controls supply of additives during the operation of the existing system.

Abstract: A system is described for monitoring moisture level in soil and controlling the application of water to the soil or other growing media. The system includes at least one sensing unit which is disposed in the soil and is adapted to periodically monitor moisture content in the soil. The sensing unit is powered by low voltage, low current, alternating current having a frequency in the range of 1.0 to 10 KHz and utilizes a square wave with fifty percent duty cycle. A control means is electrically connected to the sensing unit and is adapted to (a) compare the moisture content in the soil to a preset moisture requirement, and (b) control the application of water to the soil.

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

Abstract: An improved automated irrigation system having localized moisture needs input to the control function. There is a sprinkler head connected to a supply of water under pressure by a pipe having a valve therein. A moisture sensing probe is placed in the soil adjacent the sprinkler head for developing an electrical signal representing the moisture content of the soil surrounding the probe. There is irrigation bypass logic disposed at the probe and operably connected to the valve and the probe for comparing the moisture content of the soil surrounding the probe to pre-established limits and for preventing the valve from supplying water to the sprinkler head when there is sufficient moisture in the soil. A timer controller can be employed to provide operating power to the system only at preferred times for watering. The moisture parameters for watering are adjustable. There is a wirelessly connected version eliminating wires between the probes and the valves.

Abstract: Soil moisture control system senses subsoil moisture by AC conductivity and turns on irrigation valve when the sensor indicates the need for additional moisture. An adjustment is connected to the sensor to adjust the level at which adequate soil moisture is signaled.

Abstract: A control system and circuit for use with one or more inductance-type actuators, such as solenoid controlled water sprinkler valves, having a relatively low impedance at low frequencies, which serves to operate the actuators, for example, when ground moisture falls below a preset level. A sensor having a relatively high impedance at low frequencies, and which for example may be moisture variable, is provided for each actuator. The control circuit is connected to the actuator over appropriate electric leads, and the same leads are used to connect the sensor back to the control circuit thereby obviating the need for extra wires and difficult retrofits.

Abstract: An automatic water-sprinkling controller, with a peculiar main-valve connected with water supply, for controlling a water-sprinkling system which includes sprinklers, hose or pipes connected between said main-valve and said sprinklers, and a pilot tube for operating said main-valve. In the automatic controller, when the shortage of water of the ground is sensed by a moisture sensor comprising a ribbon which expands and contracts as a humidity, a microswitch is turned on by the contraction of the ribbon to feed an instant electric current for a electronic circuit and to start a timer circuit. The electric current is instantly fed to a solenoid, which is mounted in a microvalve unit, to open this unit, through the electronic circuit. When the microvalve is opened, a pilot water in the pilot tube, which is connected between the microvalve and the main-valve, starts to flow, and the main-valve is opened.

Abstract: An electrically operated valve controls the flow of irrigation water. A clock controls the time of day and maximum irrigation time. The clock signal is serially connected through a control circuit which senses subterranean moisture and prevents solenoid actuation when moisture is adequate.

Abstract: A moisture sensor having an oscillator circuit with its output frequency directly proportional to moisture percentage present in the substance of interest, such as soil. The oscillator circuit includes two spaced plates in the substance which function as a capacitor. The frequency of the oscillations changes as the capacitance between the plates changes due to the moisture present between the plates. The sensor is particularly adapted for use as a soil moisture detector and provides indications of moisture percentage or end points such as wet or dry conditions.

Abstract: An automatic irrigation system in which a plurality of zones of a ground area are periodically watered for a predetermined time in a predetermined sequence. Located within each zone is a ground moisture sensor that overrides the automatic irrigation system and prevents watering if the sensed ground moisture is at or above a chosen value. Apparatus is provided which, from a central location, can bypass the automatic irrigation system and the ground sensors. A central transmitter coupled to a plurality of remote receivers enables simultaneous or sequential watering of all zones by actuating the remotely located valves regardless of the sensed ground moisture level.

Abstract: A moisture sensor having an oscillator circuit with its output frequency directly proportional to moisture percentage present in the substance of interest. The oscillator circuit includes two spaced plates in the substance and functioning as a capacitor. The frequency of the oscillations changes as the capacitance between the plates changes due to the moisture present between the plates. The sensor is particularly adapted for use as a soil moisture detector and provides indications of wet or dry conditions.

Abstract: An automatic irrigation control includes a pilot needle valve with a slidable stem and a block of material the dimensions of which change when exposed to moisture, arranged in a framework so that when the block expands it bears against the valve stem, closing the valve and shutting off a connected hydraulic valve. Preferably, an override lever, connected to a temperature-responsive device, is interposed between the block and the valve in such a way that when the temperature is above a predetermined height, the lever overrides the block and prevents the actuation of the hydraulic valve when the temperature is too high. An adjustable canopy regulates the rate of drying and wetting of the block.

Abstract: An automatic irrigation control system provides the improvement in the prior art, which has previously set irrigation time by a preset or predetermined amounts, by providing for feedback from the field by means of tensiometers or other types of sensors. The tensiometers are made completely automatic and have a continuous analog signal output by the use of a backward gage pressure transducer. The tensiometers also have remote refill capabilities so that they do not have to be manually filled. Energy is saved by time sharing irrigation. Water hammer is prevented by lagging the turn-off of the field which was previously being irrigated until turn-on of the next field. Water ponding is prevented by providing time lag to allow water to penetrate the soil.

Abstract: A system for groves, truck farms and the like for automatically irrigating and fertilizing in accordance with the requirements of the soil. A plurality of capacitance sensors are buried in the areas to be irrigated and fertilized. A computer periodically measures the equivalent capacitive reactance of each sensor to obtain an indication of soil moisture and the equivalent resistance of each sensor to obtain an indication of fertilizer levels in the soil. Water pumps and valves and liquid fertilizer pumps are controlled by the computer to operate only when the soil requires.

Abstract: An electronic valve control apparatus for operating a valve device connected to a water supply pipeline for spraying water over the field or land comprising: a solar battery; a secondary battery charged therefrom; an electronic clock; a calendar circuit; a logic circuit which delivers output valve control signals in response to a predetermined schedule; and a valve driving circuit which controls the valve device.

Abstract: Irrigation control apparatus includes a mast or masts, a soil moisture sensor or sensors associated with a lower portion of each mast, data transmission apparatus associated with an upper portion of each mast to transmit data continuously measured by the sensor, and circuitry to process that transmitted data.

Abstract: A liquid tension-sensitive gas valve for use in an environment containing liquid includes an inlet connectable to a source of gas and an outlet connectable to a receiver of gas. An internal porous member disposed between the inlet and the outlet has a plurality of pores having pore openings which are closed when filled with liquid and which are open when the tension (negative hydrostatic pressure) of the liquid therein has increased past a predetermined level. The internal member prevents movement of gas between the inlet and the outlet when the moisture content of the internal porous member has increased to cause the liquid tension to decrease below the predetermined level, wherein moisture has closed the pores. Conversely, the internal porous member permits the movement of gas between the inlet and the outlet when the moisture content therein has decreased to cause the liquid tension to exceed the predetermined level, wherein the pores are open.

Abstract: An apparatus for automatically controlling a watering system in response to a comparison of an ambient condition with a time-varying reference level having an adjustable maximum value is disclosed. The invention includes an electrical circuit for monitoring and sensing the magnitude of the ambient condition and for converting the sensed magnitude into a proportional electrical signal. The invention further includes a first timer circuit for generating a triggering signal when the time-varying reference level exceeds the magnitude of the proportional electrical signal. This triggering signal is applied to a second timer circuit which actuates the watering system for a predetermined period of time in response to the triggering signal.

Abstract: The disclosed apparatus includes a detonation chamber constructed in the form of a barrel, a spark plug mounted in the barrel and powder feeding and gaseous mixture delivering systems communicating with the detonation chamber. The powder feeding system include a batchmeter communicating with the source of carrier gas by means of a gas conduit with a control member of the carrier gas feed controller for controlling the quantity of carrier gas delivered to the batchmeter within a unit of time mounted thereon. The apparatus also includes a control system having a powder detector for detecting powder in the detonation products, electrically connected with a control unit. The control unit effects switching on of the mechanisms and the systems in a predetermined succession and switching on of the actuating mechanism of the carrier gas feed controller, depending on the detector signal indicative of the powder presense in the detonation products.

Abstract: An irrigation system and method is disclosed having a water supply source for providing water under pressure to a plurality of dispensing devices located at spaced locations. The irrigation system and method comprises a distribution conduit grid in fluid communication with the water supply source and defining a closed conduit loop, thereby providing water flow upon demand within the distribution conduit in more than one direction. The distribution conduit grid is composed of arterial members formed in a closed conduit loop for supplying water to a plurality of dispensing conduit members, each dispensing conduit member having its ends interconnected between two spaced locations on the arterial conduit members, thereby providing water flow into the dispensing conduit members from more than one direction. The dispensing devices are mounted on the dispensing conduit members in water supply relation. The dispensing devices are operated between open and closed positions by a water operated pilot valve.

Abstract: A watering valve device includes a first electromagnetic coil for opening a valve to enable a sprinkling system and a second electromagnetic coil for closing the valve. An electronic circuit is provided for supplying current pulses for selectively energizing the two coils to control sprinkling in response to ground moisture and/or sunlight. The circuit includes a first timer for maintaining the sprinkling valve on for a predetermined timer period after sunlight occurs to assure penetration of the ground by moisture during night-time watering. The circuit includes a second timer for maintaining the valve on for a second predetermined time period following moisture detection by a ground probe to assure ground penetration by moisture during a moisture responsive, closed loop mode of control. The circuit and valve are operated by batteries that are charged by sunlight.

Abstract: An analog scanner for the control of various industrial, agricultural and domestic operations and processes comprising at least two pairs of probes utilized for measuring a physical property of a medium therebetween including at least a pair of control signal sources, at least a pair of reference level controllers, at least a pair of sensor selectors, and at least a pair of control actuators. A timing mechanism including a counter is connected to the signal sources for selectively energizing one of the signal sources associated with a particular position of the counter in sequence with the other of the sources. Each pair of sensor selectors senses the physical property of the medium between its probes and develops a voltage proportionate to the value of the physical property of the medium between the probes.

Abstract: An irrigation system controller that operationally ties the dispensing of water to the soil directly to the need thereof without requiring continuous monitoring by the irrigation manager. If a preselected water supply period is not sufficient to attain a desired moisture content in the soil due either to an insufficient estimate on the part of the manager or a power or equipment failure or unforeseen change in weather, a warning device or other electrically-operated signal calls attention to the need for the selection of a new longer water supply period or a correction of the power or equipment failure. A pushbutton switch resets the warning system. If the preselected water supply period is sufficient to maintain the desired moisture content, a feed-back loop automatically controls the dispensation of water to maintain the desired moisture content of the soil.