WO2015140580A1

WO2015140580A1 - Improved irrigation components and systems

Info

Publication number: WO2015140580A1
Application number: PCT/GB2015/050849
Authority: WO
Inventors: Tony WARE
Original assignee: Tonick Watering Limited
Priority date: 2014-03-21
Filing date: 2015-03-23
Publication date: 2015-09-24
Also published as: GB201405111D0

Abstract

An electrical component for an irrigation system is provided wherein at least one electrically-switchable optical element is disposed in front of a visual indicator such that in the absence of electrical power to the electrical component the electrically-switchable optical element obscures the visual indicator behind it. This provides a visual means for quickly identifying when power to an electrical component of an irrigation system is interrupted by obscuring one or more visual indicators that would otherwise be visible.

Description

Improved Irrigation Components and Systems This invention relates to the field of irrigation systems and particularly to providing a visual indicator that an irrigation solenoid or an irrigation decoder is receiving electrical power. The control of irrigation valves is often done by a central controller selectively activating wires with typically 24VAC. This voltage is sent through a plurality of buried wires, one dedicated to each solenoid and one common to all solenoids. The solenoid is a component of an irrigation valve. This latter is typically below ground in a covered chamber near to the water emitters. When the voltage is present, a plunger within the solenoid lifts due to the magnetic attraction from the AC power in its coil. The plunger so lifting, uncovers a hole in the control chamber of the valve, allowing the main water path in the valve to open. Once open, water flows to the emitters which then irrigate. An alternative control system uses a plurality of electronic pre-numbered irrigation decoders connected to a common two conductor electrical cable from the controller. Each decoder is interposed between the cable and a solenoid. On the cable is carried an AC voltage, superimposed, when needed, with a modulated digital data message

commanding a particular decoder to energise or de-energise its solenoid output. Those decoders whose pre-numbered addresses correspond with the number in the control message will act on it. The others will ignore the message. If a valve fails to operate there could be a number of reasons. These comprise: (a) the central controller may be faulty, (b) the wiring between the controller and the solenoid or decoder may be open-circuit, (c) the solenoid coil may be open-circuit, (d) the plunger may be mechanically jammed, (e) the valve control action may be faulty, (f) the main pipe to/from the valve may be blocked. It is the job of the person servicing to identify which of these is causing the problem. By far the most common causes of failure are (b) the wiring open-circuit and (c) the solenoid coil open-circuit. Wiring open-circuit is usually caused by mechanical damage or corrosion of non-waterproof wiring joints. Solenoid open-circuit is often caused by damage from a voltage surge induced into the wiring from a nearby lightning event. As part of this differential diagnosis, it is necessary to check if AC power is being applied to the solenoid or decoder. Normally, this entails disassembling the waterproof joints that connect the controller's wiring to the solenoid and checking to see if 24VAC is present using a volt meter or a spare solenoid. This is a messy and time consuming process, usually requiring the scrapping of the existing waterproof joiners. Accordingly, it is an object of at least one aspect of the present invention to provide an electrical component, such as an irrigation solenoid or irrigation decoder, that obviates and/or mitigates one or more disadvantages of known/prior components. Further aims and objects of the invention will become apparent from reading the following description. Summary of the invention According to a first aspect of the invention, there is provided an electrical component for an irrigation system, the electrical component comprising;

one or more visual indicators; and

one or more electrically-switchable optical elements;

wherein at least one of the electrically-switchable optical elements is disposed in front of at least one of the visual indicators and is adapted, arranged or configured such that in the absence of electrical power the at least one electrically-switchable optical element is substantially opaque. In the absence of electrical power, the electrically-switchable optical element therefore obscures any visual indicators behind it. The above invention provides a visual means for quickly identifying when power to an electrical component of an irrigation system is interrupted by obscuring one or more visual indicators that would otherwise be visible. Accordingly, it is most preferable that the at least one electrically-switchable optical element may be substantially transparent in the presence of electrical power. In this way, the visual indicator will be visible if electrical power is currently being supplied to the electrical component. Alternatively, the at least one electrically-switchable optical element may be configured to remain substantially opaque after electrical power to the electrical component is resumed. In this way, the visual indicator will remain obscured if electrical power is interrupted and may therefore provide a quick way of indicating the presence of an intermittent fault in the electrical power supply to the electrical component. Note that the term substantially may be interpreted in the context of this application as meaning sufficiently opaque to obscure any visual indicators behind it or sufficiently transparent to render any visual indicators behind it visible. For the avoidance of doubt, sufficiently opaque shall include translucency which is sufficiently low to obscure at least one visual indicator. Preferably, the at least one electrically-switchable optical element may be in electrical communication with an electrical supply to the electrical component. Optionally, the at least one electrically-switchable optical element may be electrically connected to the electrical power supply and may be connected in parallel with the electrical component. Preferably, the at least one electrically-switchable optical element may comprise smart glass. Preferably, the at least one electrically-switchable optical element may comprise one or more polymer dispersed liquid crystal films. Polymer dispersed liquid crystal films are transparent when a potential difference is applied, and opaque in the absence of a potential difference. Alternatively, the one or more electrically-switchable optical elements may comprise one or more films or windows selected from the group comprising; suspended particle devices; electrochromic devices; micro-blind devices; and nanocrystal coated or embedded glass. Preferably, the visual indicator comprises one or more indicia selected from the group comprising; a legend, a symbol, a colour, a display and a light source. The visual indicator may comprise any combination of indicia selected from the group. For example, the visual indicator may be a coloured symbol, or an illuminated display. Optionally, the visual indicator comprises a fluorescent colour. The visual indicator may be adapted, arranged or configured to be visible only when the one or more electrically-switchable optical elements are transparent. Optionally, the electrical component may further comprise a spacer, which may be located between one or more of the visual indicators and one or more of the electrically-switchable optical elements. The presence of the spacer may serve to improve the obscuration of a visual indicator when the one or more electrically-switchable optical elements are opaque. The spacer may be transparent. Preferably, the electrical component further comprises a protective cover for one or more of the electrically-switchable optical elements. The protective cover may be transparent. Optionally, the protective cover comprises a transparent encapsulant. Optionally, the visual indicator comprises a coloured metal foil. Optionally, the visual indicator provides an electrode for one or more of the electrically-switchable optical elements. In a preferred embodiment of the first aspect of the invention, the electrical component is a solenoid or decoder for an irrigation system which comprises a polymer dispersed liquid crystal film overlaying a fluorescent indicia, the polymer dispersed liquid crystal film element arranged on or in the electrical component and connected in parallel with the electrical component to an electrical supply such that the polymer dispersed liquid crystal film is substantially transparent when electrical power is supplied to the electrical component to reveal the fluorescent indicia, and substantially opaque to obscure the fluorescent indicia in the absence of electrical power. A spacer may be provided between the polymer dispersed liquid crystal film and the fluorescent indicia to improve the obscuration of the fluorescent indicia when the polymer dispersed liquid crystal film is opaque. According to a second aspect of the invention there is provided an irrigation system component comprising;

one or more visual indicators; and

one or more electrically-switchable smart glass elements;

wherein at least one of the electrically-switchable smart-glass elements is disposed in front of at least one of the visual indicators and is in electrical communication with an electrical supply to the electrical component such that in the absence of electrical power the at least one electrically-switchable smart glass element is substantially opaque. Embodiments of the second aspect of the invention may comprise features corresponding to the preferred or optional features of the first aspect of the invention or vice versa. According to a third aspect of the invention there is provided an irrigation control system comprising one or more components of the first and or second aspects of the invention. Embodiments of the third aspect of the invention may comprise features corresponding to the preferred or optional features of the first or second aspects of the invention or vice versa. According to a fourth aspect of the invention there is provided a switchable indicator for an electrical component of an irrigation system comprising a visual indicator and an electrically-switchable optical element which is disposed in front of the visual indicator and is connectable to an electrical supply such that in the absence of electrical power it is substantially opaque and obscures the visual indicator. Embodiments of the fourth aspect of the invention may comprise features corresponding to the preferred or optional features of the first, second or third aspects of the invention or vice versa. According to further aspects of the invention, there is provided an electrical component, an irrigation system component, an irrigation control system and a switchable indicator substantially as herein described with reference to the appended drawings. As used herein, terms such as "bottom", "lower", "below", "behind" and the like are descriptive of a feature that is located (relatively) towards a first end or side of a system or component while terms such as "top", "upper", "above", "in front of" and the like are descriptive of a feature that is located (relatively) towards a second, opposing end or side of the system or component. For the avoidance of doubt, the skilled person will realise that use of these terms shall not limit the invention to any particular vertical or horizontal configuration or orientation. For example, a device may be inverted without departing from the scope of the invention herein defined. Throughout the specification, unless the context demands otherwise, the terms "comprise" or "include", or variations such as "comprises" or "comprising", "includes" or "including" will be understood to imply the inclusion of a stated integer or group of integers, but not the exclusion of any other integer or group of integers.

Brief description of the drawings There will now be described, by way of example only, various embodiments of the invention with reference to the drawings, in which: Figure 1 shows the construction of a laminate of PDLC film with transparent spacers top and bottom and a legend or symbol or coloured area underneath, in accordance with an embodiment of the invention; Figure 2 shows a typical irrigation solenoid with no AC applied, in accordance with an embodiment of the invention; Figure 3 shows the solenoid having AC applied with the legend visible through the top, in accordance with an embodiment of the invention; and Figure 4 shows an irrigation decoder receiving AC power with the legend visible through the top, in accordance with an embodiment of the invention.

Detailed description of preferred embodiments Further to the discussion in the background to the invention above, it would be an advantage to see visually if AC volts were in fact present on the solenoid or the decoder. However it is of great importance that the visual indication method should not be itself damaged from surges and should be at as least as rugged as the solenoid coil or decoder itself. Were this not the case, the person servicing the system would wrongly assume that the wiring has been damaged. The present invention proposes using a Polymer Dispersed Liquid Crystal film, or similar, which changes its transparency from translucent to transmissive when the AC voltage is applied to the solenoid or decoder, so revealing a symbol or legend or colour. Behind the Polymer Dispersed Liquid Crystal (PDLC) film is a symbol or legend or colour which will only be clearly visible when the film is transmissive. The AC to the film is connected in parallel to the AC which powers the solenoid coil or the decoder. The assembly of PDLC and legend is attached to some part of the solenoid or decoder body, such that the presence or absence of AC may be determined at a glance. Polymer Dispersed Liquid Crystal film (PDLC) is made in commercial quantities. A common application is for altering the transparency of windows for privacy or filtering of solar radiation. PDLC consists of micrometer sized bubbles containing liquid crystals, the bubbles being rigidly suspended in a polymer. Both sides of the polymer sheet are coated with a transparent conductor, commonly Indium Tin Oxide (ITO). Wth no AC voltage applied between the faces of the sheet, the liquid crystals within the bubbles are of random orientation, causing the sheet to be translucent. When AC is applied, the crystals align along the path of the electric field and the sheet becomes transparent. In this state, characters or symbols or coloured areas behind become clearly visible. Using the PDLC film confers the advantage of simplicity, there being no extra protection components needed, the wires to the sheet being connected in parallel with the external wires to the solenoid coil or decoder, as appropriate to the type of irrigation control system. The PDLC film is inherently resistant to voltage surges. Any voltage breaking down the insulation of the polymer sheet will cause self-healing by the same mechanism as that in a plastic capacitor. This may disfigure the indicator in a small way, but will not destroy it. Thus the indicator will be as rugged as the coil inside the solenoid or the decoder. The PDLC film is inherent low power, being a equivalent to a small capacitor. This is important in a decoder system where standby (listening) supply current must be kept as low as possible. In figure 1 , a PDLC film 1 is sandwiched between a transparent top protective cover 2 and a bottom transparent spacer 3. This spacer 3 may be advantageously 1 mm - 2mm thick to enhance the obscuration of the legend 4 when the film 1 is translucent. Connections to the ITO coatings top and bottom of the PDLC film are advantageously made by depositing conductive ink 5, to which wires 6 are soldered. These wires 6 are then connected in parallel to the incoming wires to the solenoid coil shown as 8 in figures 2 and 3 and the decoder input wires 13 in figure 4. Note that the top protective cover 2 may be replaced by the use of a transparent encapsulant. This may, for example, be a UV cure encapsulant. In figure 2, a typical solenoid is shown 7 with its wires 8 onto which 24VAC is applied to retract the plunger within. The indicator as described in figure 1 is embedded into the top of the solenoid body 7 and is indicated by 2. In figure 3, the solenoid 7 has 24VAC applied to wires 8. This voltage is also connected internally to wires 6 in Figure 1 and is indicated by 2. As a result, the PDLC film 1 in Figure 1 has become transparent and the legend 4 depicted here as 9 is visible through the transparent top protective cover 2. In figure 4, the solenoid 7 is connected with its wires 8 using waterproof connectors 11 to a decoder 10 and its output wires 14. The decoder is connected to the common two conductor cable 12 through further waterproof connectors 11. Embedded into the top of the decoder is the PLDC film assembly referred as 2. As AC voltage is present on the conductors 13 fed by 12, the legend 9 is visible on the top of the decoder. Note that the bottom ITO coating may be replaced by a coloured metal foil, or the like, which may serve as both electrode and coloured indicator. An electrical component for an irrigation system is provided wherein at least one electrical ly-switchable optical element is disposed in front of a visual indicator such that in the absence of electrical power to the electrical component the electrically-switchable optical element obscures the visual indicator behind it. This provides a visual means for quickly identifying when power to an electrical component of an irrigation system is interrupted by obscuring one or more visual indicators that would otherwise be visible. The foregoing description of the invention has been presented for the purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise form disclosed. The described embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilise the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Therefore, further modifications or improvements may be incorporated without departing from the scope of the invention as described herein.

Claims

Claims: 1. An irrigation system electrical component, the electrical component comprising; one or more visual indicators; and

one or more electrically-switchable optical elements;

wherein at least one of the electrically-switchable optical elements is disposed in front of at least one of the visual indicators and is adapted, arranged or configured such that in the absence of electrical power the at least one electrically-switchable optical element is substantially opaque.

2. The electrical component of claim 1 , wherein the at least one electrically-switchable optical element is substantially transparent in the presence of electrical power.

3. The electrical component of claim 1 or claim 2, wherein the at least one electrically- switchable optical element is configured to remain substantially opaque after electrical power to the electrical component is resumed.

4. The electrical component of any preceding claim, wherein the at least one

electrically-switchable optical element is in electrical communication with an electrical supply to the electrical component.

5. The electrical component of claim 4, wherein the at least one electrically-switchable optical element is electrically connected to the electrical power supply.

6. The electrical component of claim 5, wherein the at least one electrically switchable optical element in connected in parallel with the electrical component.

7. The electrical component of any preceding claim, wherein the at least one

electrically-switchable optical element comprises smart glass.

8. The electrical component of any preceding claim, wherein the at least one

electrically-switchable optical element comprises one or more polymer dispersed liquid crystal films.

9. The electrical component of any preceding claim, wherein the one or more

electrically-switchable optical elements comprise one or more films or windows selected from the group comprising; suspended particle devices; electrochromic devices; micro-blind devices; and nanocrystal coated or embedded glass.

10. The electrical component of any preceding claim, wherein the visual indicator

comprises one or more indicia selected from the group comprising; a legend, a symbol, a colour, a display and a light source.

1 1. The electrical component of claim 10, wherein the visual indicator comprises a

coloured symbol.

12. The electrical component of claim 10 or claim 1 1 , wherein the visual indicator

comprises an illuminated display.

13. The electrical component of any of claims 10 to 12, wherein the visual indicator comprises a fluorescent colour.

14. The electrical component of any preceding claim, wherein the visual indicator is adapted, arranged or configured to be visible only when the one or more electrically- switchable optical elements are transparent.

15. The electrical component of any preceding claim, further comprising a spacer

located between one or more of the visual indicators and one or more of the electrically-switchable optical elements.

16. The electrical component of claim 15, wherein the spacer is transparent.

17. The electrical component of any preceding claim, further comprising a protective cover for one or more of the electrically-switchable optical elements.

18. The electrical component of claim 17, wherein the protective cover is transparent.

19. The electrical component of claim 17 or claim 18, wherein the protective cover

comprises a transparent encapsulant.

20. The electrical component of any preceding claim, wherein the visual indicator

comprises a coloured metal foil.

21. The electrical component of any preceding claim, wherein the visual indicator provides an electrode for one or more of the electrically-switchable optical elements.

22. The electrical component of claim 1 , wherein the electrical component is a solenoid or decoder for an irrigation system which comprises a polymer dispersed liquid crystal film overlaying a fluorescent indicia, the polymer dispersed liquid crystal film element arranged on or in the electrical component and connected in parallel with the electrical component to an electrical supply such that the polymer dispersed liquid crystal film is substantially transparent when electrical power is supplied to the electrical component to reveal the fluorescent indicia, and substantially opaque to obscure the fluorescent indicia in the absence of electrical power.

23. The electrical component of claim 22, wherein a spacer is provided between the polymer dispersed liquid crystal film and the fluorescent indicia to improve the obscuration of the fluorescent indicia when the polymer dispersed liquid crystal film is opaque.

24. An irrigation control system comprising one or more electrical components of any of claims 1 to 23.

25. An electrical component, an irrigation system component, an irrigation control

system or a switchable indicator substantially as herein described with reference to the appended drawings.