GB2395374A

GB2395374A - Lighting control system

Info

Publication number: GB2395374A
Application number: GB0321992A
Authority: GB
Inventors: Barry Chuter; Adam Osborn
Original assignee: Kigass Electronics Ltd
Current assignee: Kigass Electronics Ltd
Priority date: 2002-09-20
Filing date: 2003-09-19
Publication date: 2004-05-19
Anticipated expiration: 2023-09-19
Also published as: GB0221911D0; GB2395374B; GB0224899D0; GB0321992D0

Abstract

A lighting control system for a battery powered lighting system, comprises a plurality of lamp controllers for controlling the energisation of respective lamps by DC power supplied by the battery. At least one lamp controller is a lamp dimmer and at least one other lamp controller is a switch. A control unit controls the respective lamp controllers. The control unit is operable to selectively cause the least one lamp dimmer to energise its associated lamp(s) at a selected brightness, and selectively cause the at least one suited to energise its associated lamp(s). The lights may be controlled in different modes, for example a security mode where entrance lights are dimmed or a mode where light intensity is dependent on remaining battery power.

Description

r01 s24l&B LIGHTING CONS ROL SYSTEM

This invention relates to a lighting control system. In particular, the invention it relates to a lighting control system for a vehicle.

s Known lighting systems use dedicated security lighting circuits to provide low brightness lighting. The security lighting can be activated when the main lighting system fails or can be switched on when the object of the illumination is to be left unattended.

Such known lighting systems require additional light units and wiring to provide the security lighting. An additional drawback of such systems is that a separate power 0 supply is necessary for the security lighting circuit.

According to the present invention, there is provided a lighting control system for a battery powered lighting system, comprising a plurality of lamp controllers for controlling the energisation of respective lamps by DC power supplied by the said battery, 15 at least one lamp controller being a lamp dimmer and at least one other lamp controller being a switch, and a control unit for controlling the respective lamp controllers, the control unit being operable to selectively cause the least one lamp dimmer to energise its associated lamp(s) at a selected brightness and selectively cause the at least one switch to energise 20 its associated lamp(s).

In an embodiment, the control unit is operable in a security lighting mode in which it causes a selected one, or ones, of the said lamp controllers to energise their associated lamp(s). Thus, the security lighting function can be provided by the said lamps without the need for a separate security lamp or lamps and separate wiring. The 25 security lamps may be dimmed to reduce battery drain.

An embodiment of the invention provides a control unit that controls a plurality of lights and controls the brightness of a group of lights selected from the plurality of lights according to the voltage supplied to operate the lights.

In an embodiment of the invention some of the lights are controlled by a dimmer 30 switch and some of the lights are main lights controlled by a relay switch.

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In an embodiment of the invention the control unit, in response to a receiving a signal indicating a low voltage from the supply, can switch off one or more of the main lights and, optionally switch on one or more of the dimmer controlled lights.

In an embodiment of the invention each light has a unique code and the central 5 control unit can use the unique codes to address one light, or any combination of lights, from the plurality of lights to alter the brightness of the addressed light or lights.

In an embodiment of the invention each of the plurality of lights has a priority rating and the lights are switched on or off in an order in accordance with the priority rating. lo In an embodiment of the invention, if the power supply goes from a low voltage to a normal voltage level, the central control unit can switch back on any of the lights switched off when the voltage went from the normal to the low level.

In an embodiment of the invention the power supply for the lighting system comprises one or more batteries.

5 For a better understanding of the present invention reference will now be made by way of example to the accompanying drawings in which: Figure 1 is a schematic illustration of a lighting control system; Figure 2 is a schematic illustration of an example address code for a addressing a main light; and 20 Figure 3 is a schematic illustration of an example address code for an addressing a dimmer controlled light.

Figure 1 illustrates a lighting control system. A number of lamps (10,12, 14,16) are connected together by a bus (6). The bus may be, for example, a two-wire bus (6).

Alternatively, the lamps could be controlled directly from a microprocessor or other logic 25 circuitry, in place of the bus. The lamps operate from an electrical supply (not shown) which may be a DC power supply. Preferably the power supply comprises one or more batteries. The system illustrated uses a 12 Volt battery (not shown) however the system is not limited to one particular voltage and other voltages may be used according to the power rating of the lamps. By way of example only, four lamps are illustrated but the 30 number of lights is not limited except for the need to provide at least two lamps.

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In an embodiment of the invention the lamps are controlled in two different ways: for example there may be main lamps (10,12) which can be switched on and off via a relay unit (2,3); and security lights (14,16) that are controlled by dimmer units (4,5).

Connected to the bus is a Central control unit (1) for controlling the brightness of 5 the lamps. The control unit (1) is supplied with a signal from a voltage sensor (18) which monitors the voltage being supplied by the battery or bakeries. The control unit controls the brightness the lamps, in response to the voltage sensor signal, by sending a control signal via the bus (6) to the lamps.

The control unit comprises logic circuitry such as a microprocessor.

lo Each lamp has a logic unit (20) for receiving the control signal. Each logic unit (20) has a unique predetermined identification code that can be addressed by the control signal. The control signal is a code comprising for example a header portion which includes an address code and a control portion which includes a control code. The 5 control signal may also include an error correction and/or detection code. When a logic unit receives a control signal the logic unit compares the address code in the header portion with its unique identification code. If the address code matches the unique identification code then the logic unit will act on the information in the control portion of the control signal. Preferably the codes used in the control signal are binary codes.

20 A header portion consisting of e-bits supports (2n-1) address codes and therefore can uniquely address (2n-1) different lamps. Figures 2 and 3 illustrate examples of control signals having 3-bit header portions thereby allowing seven different lamps to be addressed. Figure 2 illustrates an example of a control signal for addressing a main light (10).

25 The main lights (10,12) have either an on or off state as determined by the position of a respective associated relay (2,3). Therefore, the control code needs to be only one bit long with binary one "1" causing the relay, and hence the lamp, to be in the on state and binary zero "O" causing the relay, and hence the lamp, to be in an off state. The skilled person wi]] appreciate that control codes of opposite polarity to those stated could be used 30 to determine the on and off states.

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Figure 3 illustrates an example of a control signal for addressing a dimmer controlled lamp (14). The length of the control code determines the number of different brightness levels that the dimmer controlled lamps can be set at; n bits giving (2n-1) different brightness levels. Figure 3(a) illustrates a control signal with a control code of 5 "1111", this code sets the dimmer controlled lamp unit (14) at maximum brightness.

Figure 3(b) illustrates a control signal with a control code of "0000" to set the dimmer controlled lamp (14) at minimum or zero brightness. Control codes with bits set at different values will cause the dimmer light to be at an intermediate brightness in accordance with the numeric value of the code. The skilled person will appreciate that lo control codes of opposite polarity to those stated could be used to set the maximum and minimum states or that other binary codes could be used to set these states.

The central control unit can be configured to operate in a number of modes. The modes can be selected by a user via a control panel on the control unit or they may come into effect automatically in response to predetermined stimuli.

5 The control unit may be placed in "normal" mode. In this mode the lamps may be turned on or off as selected by a user or by a program.

The control unit may be placed in "security lighting" mode. In an example of this mode only dimmer controlled lamps operate. The level of the brightness of the dimmer controlled lamps can be predetermined or set by the user when the security lighting mode 20 is initiated. In another example of this mode a number of main lights are lit in key areas, either instead of or in addition to the dimmer controlled lights. If the light control system is fitted to a vehicle such as a boat or motor home, for example, then the key area may be a doorway area of the motor home or a gangway on the boat.

When the lighting system is installed on a vehicle, the "security lighting" mode 25 can be activated when the vehicle is to be left unattended. This mode is advantageous since battery drain can be minimised since the lighting system is in a low power consumption configuration. The "security lighting" mode can be initiated by an input from example a user, a timer or a light sensitive device.

The control unit may be placed in a "power save" mode. This mode may be 30 activated if, for any reason, the battery voltage falls to below a critical level when the lamps are in use. In power save mode a number of the main lamps are switched off and a

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number of the dimmer lights are switched on. In a first example of this mode all the main lights are switched off and some or all the dimmer lights are switched on. This first example has the advantage of maintaining some light for an extended period of time before the battery is run flat. In particular, if the level of the dimmer switches is s controlled to produce the minimum amount of usable light, the amount of time that usable light is provided is maximised. In a second example of this mode, the main lamps are graded according to the importance of the position illuminated by the lamp. and the lights are turned off in order of their grading as the voltage level of the battery drops. In a third example of this mode, alternate lamps, then every third lamp, then every fourth 0 lamp etc., are left lit according to the voltage level of the battery.

In the power save mode, if the voltage supplied to the lamp battery recovers to a normal operating level then the control unit switches from power save mode to normal mode. The recovery of the supply voltage can occur due to, for example, charging of the battery via an alternator or mains supply, the battery being replaced by another battery or IS an additional battery being provided. By way of example only, if the battery is a 12 Volt battery then the power save mode may be initiated when the supply voltage drops below say 10.7 Volts and the central control may switch back to normal mode when the supply voltage rises say above 11.7 Volts. The level at which the central controller switches between the power save and normal modes is not critical and can either be set by the user 20 or be pre-programmed by in the control unit.

The lighting control system described is of particular benefit when used on a vehicle which utilises battery power, for example, a boat, motor home, caravan, van or car. Features of the invention provide the advantage of a central lighting control where 2s a single control can operate individual or pre-programmed groups of lights.

Features of the invention provide an "all lights off" function to eliminate battery drain on unattended vehicles.

Features of the invention provide a "security lights" function with low battery drain and no additional wiring or lamps required. The security lights function uses the 30 one or more of the controlled lamps 12, 14. Preferably it uses dimrnerable lamps 14 to s

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reduce battery drain. Thus, there is no need for a separate wired circuit to provide the security lighting function.

Features of the invention provide a "power save" mode where light can be provided for a maximum period of time with no additional wiring or lamp units required.

5 In so far as the embodiments of the invention described above are implemented, at least in part, using software-controlled data processing apparatus, it will be appreciated that a computer program providing such software control and a transmission, storage or other medium by which such a computer program is provided are envisaged as aspects of the invention.

i.

Claims

POl 5241GB CLAIMS

1. A lighting control system for a battery powered lighting system, comprising a 5 plurality of ramp controllers for controlling the energisation of respective lamps by DC power supplied by the said battery, at least one lamp controller being a lamp dimmer and at least one other lamp controller being a switch, and a control unit for controlling the respective lamp controllers, the control unit lo being operable to selectively cause the least one lamp dimmer to energise its associated lamp(s) at a selected brightness and selectively cause the at least one switch to energise its associated lamp(s).

2. A system according to claim 1, further comprising a bus connecting the control is unit to the lamp controllers.

3. A system according to claim 1 or 2, further comprising one or more batteries connected to the lamp controller.

20 4. A system according to claim 1, 2 or 3, further comprising a plurality of lamps coupled to the lamp controllers.

5. A system according to any preceding claim, wherein the control unit is operable in a plurality of operating modes, a said mode being selectable by a user or automatically 2s in response to a predetermined stimulus.

6. A system according to claim 5, wherein a particular said mode is selected by a user or in response to a timer or a light sensitive device.

30 7. A system according to claim 6, wherein in said particular mode the control unit is operable to set the brightness(es) of the lamp(s) controlled by the dimmer(s).

rol524lGs 8. A system according to claim 7, wherein said brightness is gettable by a user.

9. A system according to claim 7, wherein said brightness is predetermined.

5 10. A system according to any one of the claims 6 to 9, wherein in the said particular mode only lamp(s) associated with the light dimmer(s) are energised.

11. A system according to claim 5, wherein, in a said mode, at least one lamp associated with the at least one switch is energised.

12. A system according to claim 11, wherein in the said mode at least one lamp associated with a light dimmer is energised.

13. A system according to any one of claims S to 12, wherein a given said mode is IS selected in response to an indication that the voltage of the battery is less than a threshold level. ]4. A system according to claim 13, wherein said given mode is deselected in response to an indication that the voltage of the batteries is greater than a further 20 threshold level greater than the first-mentioned threshold level.

15. A system according to claim 13 or 14, wherein, in said given mode, the control unit causes the lamp controllers to switch offtheir associated lamps in accordance with a priority rating as the battery voltage reduces.

2s ]6. A system according to claim 13 or 14, wherein, in said given mode, the control unit causes the or at least one of the switches to deenergise its associated lamp 17. A system according to claim 13, 14 or 16 wherein, in said given mode, the control 30 unit causes the, or at least one of the, dimmers, to energise its associated lamp at a minimum usable brightness.

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18. A system according to any preceding claim, wherein the said control unit comprises a microprocessor.

s 19. A system according to claim 1, 2, 3 or 4, wherein the control unit is operable in a security lighting mode in which it causes a selected one, or ones, of the said lamp controllers to energise their associated lamp(s).

20. A lighting control system substantially as hereinbefore described with reference to l o the Figure I optionally together with Figure 2 and/or 3 of the accompanying drawings.

21. A vehicle in which is installed a lighting control system according to any preceding claim.

15 22. A vehicle according to claim 20, which is a boat, motor home, caravan, car or van.