Technical field

The disclosure herein generally relates to a lighting system and a method of operating a lighting system.

Background

Before installing lighting in a building, for example, it is best practice to perform an analysis to determine the power and colour temperature of the lights to use. The analysis, however, may be quite complex in which case a lighting engineer or architect, for example, may be required to perform the analysis. Furthermore, the analysis may assume a particular usage for the room (for example as a romantic dining room, an office, or a workshop for fine work) which may not in fact be a valid assumption for the entire working life of the room. Consequently, such an analysis may be burdensome, expensive and ultimately of limited use if the intended use of the lit area changes. Summary

Disclosed herein is a lighting system. The system comprises a light generator operable to generate a light at any one of a plurality of light colour temperatures. The system comprises a power control system configured to receive light colour temperature information indicative of a light colour temperature and light power information indicative of a light power and power the light generator to generate the light, the light being of the light colour temperature indicated by the light colour temperature information and the light power indicated by the light power information.

Embodiments may be installed without an analysis to determine a suitable power and light colour temperature. The light power and light colour temperature of the generated light may be experimentally determined, which may be performed quickly and easily. The light power and the light colour temperature of the generated light may be changed if the use of the lit area changes.

In an embodiment, the light generator is operable to generate a white light at any one of a plurality of light colour temperatures. In an embodiment, the light generator comprises a plurality of light emitters of various light colour temperatures. The power control system is configured to power at least one of the plurality of light emitters to generate light of the light colour temperature indicated by the light colour temperature information. The plurality of light emitters may comprise a plurality of white light emitters of various light colour temperatures.

Using a plurality of light emitters of various light colour temperatures may be more efficient and cost effective than a single light that has a tuneable light colour temperature.

In an embodiment, each of the plurality of light emitters has a respective one of a plurality of light colour temperatures. The light colour temperature information may be indicative of one of the plurality of light colour temperatures. The power control system may be configured to power one of the plurality of light emitters to generate the light of the light colour temperature indicated by the light colour temperature information. The power control system may comprise a current switch and a digital circuit configured to use the light colour temperature information to cause the current switch to power one of the plurality of light emitters to generate the light of the light colour temperature indicated by the light colour temperature information.

In an embodiment, the plurality of light emitters comprise a first light emitter operable of a first light colour temperature, and a second light emitter of a second light colour temperature. The light colour temperature information may be indicative of one of the first light colour temperature and the second light colour temperature The power control system may be configured to power one of the first light emitter and the second light emitter to generate the light of the light colour temperature indicated by the light colour temperature information. The digital circuit may be configured to use the light colour temperature information to cause the current switch to power one of the first light emitter and the second light emitter to generate the light of the light colour temperature indicated by the light colour temperature information. In an embodiment, the first light emitter may comprise a first group of lights. The second light emitter may comprise a second group of lights. Using a group of lights, rather than a single light for each light colour temperature, may reduce displeasing light distributions (e.g. dark regions) on the light generator, which may improve aesthetics. Each of the first group of lights may be of the first light colour temperature. Each of the second group of lights may be of the second light colour temperature.

In an embodiment, the first group of lights may be distributed amongst the second group of lights. The first group of lights may be distributed to be indistinguishable from the second group of lights. The first group of lights and the second group of lights may be distributed across a majority of a lighting system window. In an embodiment, the first group of lights and the second group of lights each comprise at least one of 3, 10, 15 and 20 lights. The greater the number of lights the smaller and the less noticeable any dark regions on the light generator there may be, which may improve aesthetics.

In an embodiment, the power control system comprises an alternating current (AC) to direct current (DC) power converter. The lighting system may be retrofitted in existing houses, for example.

In an embodiment, the power control system has a dimmer circuit. The dimmer circuit may be arranged to dim the light when so generated by the light generator.

In an embodiment, the power control system comprising an electromagnetic interference filter.

An embodiment comprises a light generation unit. The light generation unit may comprise a housing in which the light generator is disposed. The power control system may be disposed in the housing. The housing may be a light bulb housing. The light bulb housing may be configured to be inserted in an electrical light socket.

Alternatively, an embodiment may comprise another housing in which the power control system is disposed.

In an embodiment, the plurality of light emitters of various light colour temperatures are attached to a printed circuit board. The printed circuit board may be disposed in the housing. The printed circuit board may be in electrical communication with the power control system.

In an embodiment, the light generator comprises a plurality of light emitting diodes (LEDS). LEDs may be more efficient than other sources of light. The plurality of light emitting diodes may comprise at least one ring of light emitting diodes. The plurality of LEDs may be distributed across a majority of a lighting system window. An embodiment has an attachment mechanism configured for attachment of the housing. The housing may be conveniently attached to, for example, a ceiling, wall or stand. The attachment mechanism may comprise a clamping mechanism. The clamping mechanism may comprise at least one biased arm.

An embodiment comprises a wireless signal receiver arranged to receive a wireless signal carrying the light power information and the light colour temperature information. The wireless signal receiver may be arranged to extract from the wireless signal the light colour temperature information and the light power information. The wireless signal receiver may be disposed in the housing. The wireless signal receiver may be centrally disposed in the housing. The plurality of light emitting diodes may enclose the wireless signal receiver. An embodiment comprises a wireless control unit operable by a user to select the light power and the light colour temperature, and generate the wireless signal. The light generator may be conveniently remotely controlled using the wireless control unit.

An embodiment comprises a power control unit spaced apart from the light generation unit and comprising the power control system. The power control unit may be arranged to be in electrical communication with the light generation unit. The power control unit may be located within a cavity, for example, separate from the light generation unit. Spacing the light generation unit from the power control system may improve thermal management, ease of installation, and/or the ability to install the lighting system in otherwise awkward locations.

Disclosed herein is method of operating a lighting system comprising a light generator and a power control system. The method comprises the step of the power control system receiving light colour temperature information indicative of a light colour temperature and light power information indicative of a light power. The method comprises the step of the power control system powering the light generator to generate light of the light colour temperature indicated by the light colour temperature information and the light power indicated by the light power information.

In an embodiment, the light generator comprises a plurality of light emitters of various light colour temperatures, and comprises the step of the power control system powering at least one of the plurality of light emitters to generate the light of the light colour temperature indicated by the light colour information. In an embodiment, each of the plurality of light emitters is of a respective one of a plurality of light colour temperatures, and the light colour temperature information is indicative of one of the plurality of light colour temperatures, and comprising the step of the power control system powering one of the plurality of light emitters to generate the light of the colour temperature indicated by the light colour temperature information. Each of the plurality of light emitters may comprise a respective group of lights.

In an embodiment, the plurality of light emitters may comprise a first light emitter of a first light colour temperature, and a second light emitter of a second light colour temperature. The light colour temperature information may be indicative of one of the first light colour temperature and the second light colour temperature. The power control system may power one of the first light emitter and the second light emitter to generate the light of the light colour temperature indicated by the light colour temperature information. The first light emitter may comprise a first group of lights and the second light emitter may comprise a second group of lights.

An embodiment comprises the step of the power control unit converting an alternating current to a direct current.

An embodiment comprises operating a dimmer circuit to dim the light generated by the light generator. An embodiment comprises the step of reducing electrical interference with an electromagnetic interference filter.

An embodiment comprises the step of operating an attachment mechanism to attach a housing in which the light generator is disposed. A clamp mechanism may be operated to attach the housing in which the light generator is disposed. An embodiment comprises the step of a wireless signal receiver receiving a wireless signal carrying the light power information of the light colour temperature information and extracting from the wireless signal the light colour temperature information and the light power information.

An embodiment comprises the step of a user operating a wireless control unit to select the light power and the light colour temperature, and generate the wireless signal.

Any of the various features of each of the above disclosures, and of the various features of the embodiments described below, can be combined as suitable and desired.

Brief description of the figures

Embodiments will now be described by way of example only with reference to the

accompanying figures in which:

Figure 1 shows a block diagram of an embodiment of a lighting system.

Figure 2 shows a perspective view of the lighting system of figure 1. Figure 3 shows a layout of an example of a printed circuit board for the lighting system of figure 1.

Figure 4 shows an alternative block diagram representation of the system of figure 1.

Figure 5 shows a diagram of an example of a circuit for the lighting system of figure 1.

Figure 6 shows an exploded perspective view of another embodiment of a lighting system.

Figure 7 shows a perspective view of a printed circuit board of the lighting system of figure 6.

Figure 8 shows a diagram of another example of a circuit for the lighting system of figure

6.

Description of embodiments

Figure 1 shows a block diagram of an embodiment of a lighting system, the system being generally indicated by the numeral 10. The system 10 has a light generator 12 that is operable to generate a light 20 at any one of a plurality of light colour temperatures. The system 10 has a power control system 14 which is configured to receive light colour temperature information 16 indicative of a light colour temperature. The power control system 14 is configured to receive light power information 18 indicative of a light power. The power control system 14 is configured to power the light generator 12 to generate light 20 having the light colour temperature indicated by the light colour temperature information and the light power indicated by the light colour temperature information.

The system 10 has electrical wiring 21 that electrically connects the power control system 14 to the light generator 12. The electrical wiring 21, in this but not necessarily in all embodiments, comprises electrical wiring in the form of a copper electrical cable for communicating electrical power to the light generator 12. The electrical wiring also comprises, in this but not all embodiments, electrical wiring in the form of a copper data cable for communicating the light colour temperature information 16 and the light power information 18 to the power control system 14. The copper electrical cable and the copper data cable may be replaced by a single cable, or more than two cables. In alternative embodiments, the system may have, for example, an optical fibre or wireless connection for communicating the light colour temperature information and the light power information to the power control system 14. Figure 2 shows a perspective view of the lighting system 10. The system 10 has a housing 22 in which the light generation system 12 is disposed. The system 10 has another housing 24 in which the power control system 14 is disposed. The cable 21, which is concealed, runs between the housing 22 and the housing 24. The housing 22 and other housing 24 provide physical protection for the light generation system 12 and the power control system 14 respectively. The housing, in this but not necessarily in all embodiments, is a heat sink for heat generated by the light generation system 12 and may comprise a metal, for example aluminium which has a relatively high thermal conductivity, although any suitable material (copper, steel, polymer etc.) may be used. The power control system 14 is configured to receive electrical power in the form of alternating current from, for example, mains. Accordingly, a power plug 26 may, as in this embodiment, be in electrical communication with the power control system. An alternative embodiment may not have a plug and may require electrical connection to, for example, an electrical junction box.

In alternative embodiments, the power control system 14 is disposed in the housing 21. Attached to the housing 22 is an attachment mechanism in the form of a clamping mechanism 28. In this but not all embodiments, the clamping mechanism 28 comprises a plurality of biased arms 29. The bias may be provided by a plurality of resilient elements in the form of springs, however generally any suitable resilient elements, for example resilient bands, may be used as suitable. The clamping mechanism 28, may take any suitable form. In use, the clamping mechanism 28 clamps the housing 22 to a ceiling, wall or generally any suitable sheet of material. Generally any suitable attachment mechanism may be used, as is appropriate for the system's intended use, for example fasteners in the form of a plasterboard or hollow cavity anchor. In another embodiment, the clamp may comprise a clamping body having a passageway for passage of a supporting rod, and a set screw that penetrates the clamping body into the passageway for engagement with the supporting rod. The supporting rod may be part of a stand, for example.

Figure 3 shows an example layout of a printed circuit board 30 that is disposed behind window 25. The light generator 12 comprises the printed circuit board 30 which is disposed in housing 22. Mounted to the printed circuit board 30 are a plurality of lights in the form of a plurality of light emitting diodes (LEDs), for example lights 32 and 34. In this embodiment the LEDs are 0.5W surface mount LEDs. However, any suitable LEDs, incandescent or other light emitter type, may be used, for example 1W through-hole mountable LEDs. The plurality of lights are configured to emit light of various light colour temperatures. In this embodiment, the plurality of lights comprise a plurality of white lights of various light colour temperatures. For example light 32 is configured to emit a light having a warmer light colour temperature than light 34. In this but not necessarily in all embodiments, light 32 is configured to emit light of a warm light colour temperature ("warm white", say 3000 degrees Kelvin), and light 34 is configured to emit light of a cool light colour temperature ("cool white", say 6,500 degrees Kelvin). One of the lights may alternatively be "natural white", say 5,500 - 6,500 degrees Kelvin (or warm, natural and cool white lights may all be used). Also shown in figure 3 are those of the plurality of lights other than lights 32, 34. Adjacent to each of them is either the character "C" or the character "W" to indicate either a cool light or warm light. The lights configured to emit cool light constitute a first group of lights ("first light emitter 46") and the lights configured to emit warm light constitute a second group of lights ("second light emitter 48"). While the first light emitter and second light emitter each comprise a respective group of lights in this embodiment, in alternative embodiments the first light emitter and second light emitter may each comprise a single light emitting element, for example a single light emitting diode. In an alternative embodiment, one of the first light emitter and the second light emitter has a single light emitting element and the other has a plurality of light emitting elements.

There may be more than two groups of lights of various light colour temperatures. For example, there may be three groups of lights of three different light colour temperatures. Light of any one of the three different light colour temperatures may be generated, or a mix of light generated by the three groups of lights. Generally, there may be any suitable number of groups of lights of various light colour temperatures.

In the present embodiment, the first group of lights are distributed amongst the group of second lights. The plurality of lights comprise at least one - in this but not all embodiments two - rings of lights. There may be more or less than two rings of lights. The first group of lights of the first light colour temperature and the second group of lights of the second light colour temperature are interleaved. That is, in this embodiment, warm light and cool light LEDs alternate around the at least one ring. The spacing between adjacent lights in each ring is such that a person casually observing the lighting system 10 is unable to distinguish the adjacent lights, especially through a diffusing window 25 of the lighting system 10. This may provide a more uniform illumination, reducing the presence of dark patches on the light generator. The first group of lights and the second group of lights are distributed across a majority of the window 25. In an alternative distribution, lines of warm and cool lights may alternate. The first group and the second group, however, need not be interleaved. For example, the groups may not intersect. The more LEDs the more uniform the illumination may be. For example, for outdoor applications there may be 3 light emitters in each group, 10 or 15 for ordinary indoor applications, and 20 or more for applications were aesthetics are important (for example in dining rooms and hotels).. In this but not necessarily in all embodiments, the power control system 14 is configured to power one of the first light emitter and the second light emitter to generate the light of the light colour temperature indicated by the light colour temperature information. For example, if the light colour temperature information indicates a cool light colour temperature then the power control system 14 provides more power to the first group of emitters than to the second group of emitters. The power control system 14 may provide power to the first group of emitters and no power to the second group of emitters. If, however, the light colour temperature information indicates a warm light colour temperature then the power control system 14 provides more power to the second group of emitters than the first group of emitters. The power control system 14 may provide power to the second group of emitters and no power to the first group of emitters. The ratio of the power provided to the first light emitter and the second light emitter may be a function of the light colour temperature indicated by the light temperature information. For example, if the light colour temperature indicated is between that of the lights emitted by the first light emitter of the second light emitter, then both the first light emitter and the second light emitter may be powered by the power control system 14. Figure 4 shows an alternative block diagram representation of the system 10 of figure 1, and figure 5 shows a circuit diagram of the system of figure 1. The power control system 14 has a current switch 36 arranged to switch a current between the first emitter 46 and the second emitter 48. The power control system 14 has a digital circuit in the form of a microcontroller unit (MCU) 38. Generally any suitable digital circuit may be used, for example an ARM core processor, or an application specific circuit (ASIC). In alternative embodiments, the digital circuit may be replaced with an analogue circuit. The microcontroller 38 is configured to use the light colour temperature information to cause the current switch 36 to power one of the first light emitter and the second light emitter to generate light at the light colour temperature indicated by the light colour temperature information. The power control system 14 also has a dimmer circuit in the form of a shift block 44. In this embodiment, the shift block 44 is in the form of a half-full shift block. The current supplied to the first and/or second light emitter ("current set point") by the power control system is controlled by the microcontroller 38. An output terminal ("first output terminal") 58 of the microcontroller is in communication with the dimmer circuit 44. The microcontroller, to change the current supplied, changes a voltage at output terminal 58 which is transmitted via opto-coupler U3 60 to the gain terminal of transistor Q2 62. The voltage at terminal 58 is generally switched between a low and a high voltage. Switching Q2 62 switches a resistance provided by resistors R24/R25 66 in or out of being parallel with another resistance provided by other resistors R51/R50 68, which changes the supplied current. The resulting switching of transistor Q2 62 changes the amount of current supplied by the current supply controller between a high power setting and a low power setting. In this embodiment, in the high power setting 10W of electrical power is supplied to the light generator, and 5W in the low power setting. Other values may be used as appropriate and/or suitable, for example 0.1W and 100W. While the embodiment of figure 1 is arranged to have one of two selectable light powers, other embodiments may be arranged to have more than two selectable light powers. One alternative embodiment is arranged for the light power to be selected from a group of more than two selectable light powers, the group of selectable light powers comprising 70W, 80W, 90W, 100W, HOW, 120W, 130W, 140W, 150W, 160W, 170W, 180W, 190W and 200W. This alternative embodiment may have, for example, further resistors that can be switched into parallel with R51/R50 68 and R24/25 61 by at least one additional transistor. Another alternative embodiment has a continuum of selectable light powers, for example every light power between 10W and 100W. Generally embodiments may be arranged for selectable light powers as suitable and/or appropriate. The microcontroller 38 has an output terminal 54 ("second output terminal"). The output terminal 54 is connected to the gain terminal of transistor Ql 70 of figure 4 (Q4 of figure 5) that is configured to control the current through the second light emitter 48. Switching the voltage on output terminal 54 between high and low enables and disables the second light emitter 48. The microcontroller 38 has still another output terminal 56 ("third output terminal"). The output terminal 56 is connected to the gain terminal of transistor Q2 72 of figure 4 (Q5 of figure 5) that is configured to control the current through the first light emitter 46. Switching the voltage on output terminal 56 between high and low enables and disables the first light emitter 46. The microcontroller is programmed to switch the voltages on the output terminals 54, 56 to power the one of the first emitter 46 and the second emitter 48 to generate the light 20 having the light colour temperature and the light power.

The microcontroller also reads a toggle switch 52. The toggle switch is manually set. The microcontroller is configured to read the state of the toggle switch (either on or off). The state of the toggle switch indicates whether supplied power has been modified by an external dimmer circuit for dimming the light 20 when so generated.

The power control system 14 has an alternating current (AC) to direct current (DC) converter 40. Referring to figure 5, the AC to DC converter includes components labelled Ul, Ql, Tl, D7 and C9. The power control system 14 has an electromagnetic interference (EMI) filter 42 configured to supply power to the alternating current to direct current converter 40. The EMI filer 42 may be required for electromagnetic compatibility (EMC) compliance. The electromagnetic filter 42 receives power from the mains via the power plug 26. Alternative embodiments are configured to receive direct current. Also disposed in the housing 22 is a wireless signal receiver 50 in the form of a infra-red wireless receiver. In other embodiments, the wireless receiver may be a radio receiver, and may use a BLUETOOTH, ZIGBEE, DASH 7, or generally any suitable protocol. In this

embodiment, but not all embodiments, the wireless signal receiver is centrally disposed in the housing 22. For example, in this embodiment the wireless signal receiver 50 is disposed within the central cut out 52 of the printed circuit board 30. The plurality of light emitting diodes enclose the wireless signal receiver, which generally may reduce shadowing caused by the wireless signal receiver 50 blocking light emitted by the plurality of LEDs. The wireless signal receiver 50 is arranged to receive a wireless signal carrying the light power information and the light colour temperature information and extract from the wireless signal the light colour temperature information and the light power information. The wireless signal receiver is configured to communicate the light power information and the light colour information to the digital circuit 38 via a strip line. Communication between components in figures 4 and 5 is via electrical conduits in the form of, for example, strip lines.

The wireless receiver need not be in the housing 22. It may be external of it, or separate from the light generator and/or the power control system. It may be, for example, mounted on a ceiling or wall.

A wireless control unit 54, examples of which include but are not limited to a TV style remote control or smart phone running an appropriate application, is operable by a user to select the light power (for example between a high light power setting of, say, 10W and a low light power setting of, say, 5W) and the light colour temperature (for example between a warm white and a cool white setting) and generate the wireless signal having the light colour temperature information and the light power information. The wireless control unit 54 may, for example, offer other options for light power and light colour temperature. For example, a continuous range of powers from zero to a maximum power may be selectable. A continuous range of light colour temperatures between a minimum and a maximum light colour temperature may be selectable.

The power control system may alternatively or additionally be connected to a network, for example to the Internet. The lighting system, for example the power control system, may have network electronics including, for example, a Media Access Controller (MAC) that enables a data connection to the network. The light power information and light colour temperature information may be received over the network.

Figure 6 shows an exploded perspective view of another embodiment of a lighting system 100 in the form of a light globe. Parts of similar form and/or function to those in figures 1 - 5 are similarly numbered and prefixed with the digit Ί '. In this embodiment the light globe has a BR30 configuration, although any suitable configuration may be used. The light generator 112 and the power control system 114 are mounted within a light globe housing comprising a connector portion 184 and a bulb portion 186 having a diffusing window 182 for the egress of the generated light. The connector portion 184 is terminated with an Edison screw connector, for example an E26 or E27, although any suitable connector may be used for example a bayonet connector. The connector portion 184 may connect to an alternating current supply for example mains power, fed to the power control system 114. Figure 7 shows a perspective view of a printed circuit board of the lighting system of figure 6, with a plurality of lights configured to emit light of various light colour temperatures, for example 132,134 and a wireless signal receiver in the form of an infra-red wireless signal receiver 180. The circuit board is disposed between a heat dissipation unit in the form of a funnel-shaped heat dissipation unit 181 and the diffusing window 182.

Figure 8 shows a diagram of another example of a circuit for a lighting system. Variations and/or modifications may be made to the embodiments described without departing from the spirit or ambit of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Prior art, if any, described herein is not to be taken as an admission that the prior art forms part of the common general knowledge in any jurisdiction. In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word

"comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, that is to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.