A system for controlling LED lighting

Abstract

A modular horticultural LED lighting system comprises at least one lighting unit constructed to allow it to be separated into two or more units, an input power supply, a ballast 10 through which input

Description

FIELD OF THE INVENTION The present invention relates to a system for controlling LED lighting. More particularly the invention relates to system of LED lighting control for use in the hydroponics. BACKGROUND TO THE INVENTION LED bars are commonly used in hydroponics. They generally consist of LED bars that extend between end frames that hang above the growing media to form an LED panel. These LED panels are often large, and therefore utilise a hinge mechanism at its centre to allow the panel size to be halved. However, when full extended, this results in large modular panels which emit an uneven distribution of light intensity onto the growing media. The Photosynthetically Active Radiation (PAR), emitted by the LED, refers to the range of light wavelengths that plants can use for effective photosynthesis and is crucial factor in stimulating plant growth. This emitted light must then travel to the surface of the plant, during which time the photon number drops. The amount of PAR that is received by the plant each second is known as the Photosynthetic Photon Flux Density (PPFD). The PPFD will vary with the plant’s distance from the light and the intensity of the light emitted by the LED. As such, an uneven distribution of light intensity reduces the efficiency of the photosynthesis stimulating system. The LED lights are typically driven by a ballast that is mounted on the rear of the LED bars or which can be remote from the LED assembly. These ballasts are often powered by a singular power pack or mains supply which can only output power across a few fixed discrete intervals. The light intensity emitted from the LED is directly proportional to the square root of the power input. Therefore, varying the power input can also the light intensity emitted by the LED lights to be controlled to optimise the PAR and therefore the PPFD. The present invention provides a system for controlling LED lighting, comprising modular LED panels, power supply and ballast. The circuitry within the ballast regulates the power input from the power supply to match the required output to generate a specific light intensity from the LED. The modular LED panels utilise connecting clips, to allow easy physical and electrical connection of one or more module to extend the area covered by the lighting assembly. This also provides a more uniform distribution of light, over a larger area, using the same number of LED light bars and power packs. BRIEF DESCRIPTION OF DRAWINGS At least one embodiment of the invention will now be described with reference to the accompanying figures, in which: Figure 1 illustrates a single LED light module constructed in accordance with the invention; Figure 2 is a perspective view of the module of figure 1; Figure 3 is an exploded view of the connecting ends of the module frames; Figure 4 illustrates three modules connected together; Figure 5 illustrates two modules connected together in a spaced arrangement; Figure 6 is an exploded view from above showing the means by which the assembly is hung above growing media; and Figure 7 is a view of the hung assembly from below. Figure 8 illustrates 2 LED modules which may be clipped together to form a panel, in accordance with the invention; Figure 9a is a diagrammatic representation of the light distribution emitted from existing modular LED lighting apparatus; Figure 9b is a diagrammatic representation of the light distribution emitted from the present invention using the same number of LED bars as Figure 9a; and Figure 10 is a perspective view of the connecting means positioned at the end of each LED module; STATEMENTS OF THE INVENTION According to a first aspect, there is provided, an LED lighting system used for inter alia horticulture, the system comprising: at least one lighting unit constructed to allow it to be separated into two or more units; an input power supply; a ballast through which input power is delivered to the or each lighting unit; a computer processor run by software for monitoring and regulating the ballast; wherein: the software includes means to identify when a lighting unit has been separated at which time the processor acts to increase the power supplied from the ballast to the separated units up to a pre-set power value; and the software includes means to identify if the power supplied exceeds set limit at which time the processor to acts to reduce the power load to the pre-set power value or below. Preferably, the system further including means to alert the user when the pre-set power value is exceeded. Preferably, each unit comprises two or more LED bars extending between end frames; each frame having means to be separably connected, both physically and electronically, to a frame of another unit. Preferably, the end frames of each unit are electronically connected by jumper cables connected between each neighbouring frame. Preferably, open-end faces of the end frames of each unit panels provide connecting means. Preferably, each open-end face has both male and female connecting member profiles extruding from its surface. Preferably, the male connector is formed with a protruding edge complimentary to the groove of the female connector on the opposing face, such that it will securely connect units together. Preferably, the end frames including having an aperture near the open-end face, such that a fastening means can be received to secure the male and female connecting members, when they connected in vertical alignment. Preferably, each end frame includes at least one slot to receive a hanging member to hang one or more connected modules. DETAILED DESCRIPTION OF THE INVENTION Figures 1 to X disclose the components comprising a system by which LED lighting can be controlled. Figures 1 and 2 illustrate a single LED light module of a modular lighting assembly of the invention. The module comprises two or more parallel spaced LED bars 2 connected at each end to an end frame 4 such that the bars 2 extend perpendicularly between the frames 4. The LED bars 2 are formed of an array of LEDS 6 located within a panel frame 8 (see Figure 8). As can be seen best in Figure 2, the LED bars 2 are driven by a ballast 10 secured to underside of the LED bar framework 8. Solid State Electronic Devices (SSED) are integrated into the ballast circuitry allowing the impedance in the circuit to be varied in order to increase or decrease the current flow. At a fixed voltage, an increase in current flow will proportionally increase the power generated. Power is directly proportional to the square of the light intensity. As such, by varying the current input to the LED bar, the light intensity produced can be controlled. The SSEDs are controlled via software, which monitors the system, and adjusts the impedance of the ballast circuitry accordingly. The software has means to identify the number of LED bars 2 in use, and type of input power, and vary the power input into the LEDs accordingly. Traditional power packs used for horticultural lighting modules have industry standard settings of outputs of 400w, 600w and 720w. Traditionally, the units would be powered by a single power pack ballast of 720w spread evenly over the fixture. This means that separating a unit in half would be mean that the ballast would only run at half power, providing 360w. There is a peak current which each LED light can withstand before it blows. This limits the maximum input power under which the LED can run, and therefore the maximum light intensity offered. In existing LED lighting systems, there is no protective circuitry or software to prevent the LED from blowing in the event that the power supplied exceeds its current threshold. The software controlling the circuitry within the ballast 10 of the present invention, ensures that if the LED lights are set receive too much power through the power pack, the lights are dimmed and then safely turned off. This notifies the user of the error in input power and protects the LED bars 2 which comprise the module. However, halving the power of the ballast from 720w to 360w provides an unnecessary limitation on the unit as it is able to receive a higher current from the ballast without damaging the chips or unit. To accommodate this, the software identifies when a unit is split and acts to increase the power from the ballast to each part to a pre-determined level that would not damage the unit, for example, to a 400w ballast setting (equating to a 450w power output). Further, the software identifies when a user attempts to set the power setting higher than the pre-set level (for example to the 600w or 720w ballast setting) and acts to dim the unit to reduce the power output and place the unit in safe mode to protect the unit from damage. At the same time, the software will trigger and audible or visual alarm to alert the user that the setting the user chose was incorrect. In this way, a standard 720w light unit can be split and, using two power packs instead of one, 900w of light (450w multiplied by two) can be obtained increasing the light produced and spreading evenly over a greater area. The ballast 10 has outwardly extending flanges 12 extending from or near each end. The ends of each flange 12 are secured to the LED bar frame 8 on that side. The ballast 10 is electronically connected to the end frame 4 via a cable 11, to provide power to the ballast 10 (see Figure 3C). One or both ends of the end frame 4 is provided with a socket to receive mains supply 14 (see figure 4). In this embodiment, further ballasts 10 can be secured between adjacent LED bar frames 8, powered by the continuous electronic link from the mains power 14 to and through each end frame 4 (see Figure 3C) An alternative embodiment is shown in Figure 8, wherein LED modules can be supplied power from a power pack via the ballast. It is an industry standard that power packs used offer a maximum power output of 650w to 720w. However, in the present invention, circuitry within the ballast 10 allows the maximum power output from the ballast 10 and input to the LED to be increased from 360w, in existing LED lighting apparatus, to 480w. Additional power input to the LED results in a higher current flow and therefore greater light intensity. Each individual module is constructed and designed to be able to connect to another module in order to increase the number of LED bars 2 in an assembly. One embodiment of the connection mechanism is shown in Figure 3. In this embodiment, the ends of each end frame 4 have male and female connecting profiles respectively. The male connector is formed as an inverted L-shaped block 16 having a rectangular recess (not shown). An aperture 18 extends through the block 16 into the recess. The aperture 18 has an internal thread along its bore to receive a threaded bolt 20, or similar fastener. The female connector, which is provided on the opposing end of the end frame 4 to that of the male connector has a complimentary L-shaped block 22 with a rectangular connecting section 24 with a complimentary profile to be received within the recess of a male connector. The connecting section 24 has a threaded aperture 26 into which can be received the end of the bolt when connecting section 24 is in the recess and the apertures 18, 26 are vertically aligned. An alternative embodiment of the connection mechanism is shown in Figure 10. Each open-end face 50 is comprised of a raised female connecting member 51 and a male connecting member 52. The female member 51 has a groove 53 within it, corresponding with the protruding edge 54 of the male member 52. To connect two modules, they should be orientated such that the female member 51 on the end face one module aligns with the male member 52 on the end face of the other module. The male 52 and female 51 members on the respective end faces will then slot together such that the protruding edge 54 of the male member 52 fits into the groove 53 of the female member 51. A screw or other fastening means can then be used to ensure the connection is secure. Alternatively, connecting blocks with male and female connectors as described in either embodiment of the connecting mechanism, may be attached to each end. Through the connectors described, any number of LED might modules can be connected in linear alignment. The modular nature of the LED panels allows the distribution of light from the system to be more uniform (see Figure 9a and 9b). The current state of the art teaches large, hinged panels 40 comprising LED bars, which produce an uneven light intensity over the growing medium, as a result of the LED bar spacing (see Figure 9a). The present invention seeks to reduce the areas of high light intensity caused by uneven LED bar spacing to uniformly stimulate photosynthesis in the growing medium below (see Figure 9b). Furthermore, by regulating the separation of the LED modules, the total area illuminated by a fixed number of LED bars can be increased (see Figure 9a and 9b) As can be seen in Figure 5, LED bars 2 can be spaced across the module group by spacers 32 that connect across and between end frames 4 of modules. The spacers 32 take the same form as the end frames 4 with connecting means at the open-end face. This allows the separation of the LED bars to be varied to minimise the areas which are illuminated by multiple LED bars and therefore have a higher PAR. Furthermore, the LED bars can be separated to ensure the vertical and horizontal distance between the growth medium and an LED light is regulated. This distance effects the PPFD and therefore the efficacy of the LED light growing system. End caps 30 are provided to be secured to or over the end of the last modules in the group assembly. As shown in Figures 6 and 7, the modules can be hung above growing media using a simple forked wire hanger 34 the arms of which are received in slots 36 located within the end frames 4 of each module, either side of the LED bars 2. Hanging points can be selected at various lengths along a plurality of connected modules to ensure stability and linear alignment across the entire length.

Claims

1. A LED lighting system used for inter alia horticulture, the system comprising:at least one lighting unit constructed to allow it to be separated into two or more units;an input power supply;a ballast through which input power is delivered to the or each lighting unit;a computer processor run by software for monitoring and regulating the ballast;wherein:the software includes means to identify when a lighting unit has been separated at which time the processor acts to increase the power supplied from the ballast to the separated units up to a pre-set power value; andthe software includes means to identify if the power supplied exceeds set limit at which time the processor to acts to reduce the power load to the pre-set power value or below.

2. A system according to claim 1, further including means to alert the user when the preset power value is exceeded.

3. A system according to claim 1 or claim 2, wherein each unit comprises two or more LED bars extending between end frames; each frame having means to be separably connected, both physically and electronically, to a frame of another unit.

4. A system according to claim 3, wherein the end frames of each unit are electronically connected by jumper cables connected between each neighbouring frame.

5. A system of according to claim 3 or claim 4, wherein open-end faces of the end frames of each unit panels provide connecting means.

6. A system according to claim 5, wherein each open-end face has both male and female connecting member profiles extruding from its surface.

7. A system according to claims 6, wherein the male connector is formed with a protruding edge complimentary to the groove of the female connector on the opposing face, such that it will securely connect units together.

8. A system according to claims 7, the end frames including having an aperture near the open-end face, such that a fastening means can be received to secure the male and female connecting members, when they connected in vertical alignment.

9. A system according to any previous claim, wherein each end frame includes at least one slot to receive a hanging member to hang one or more connected modules.

Images