GB2187866A

GB2187866A - Lighting control system

Info

Publication number: GB2187866A
Application number: GB08705621A
Authority: GB
Inventors: David Frederick Andrew Leevers
Original assignee: BICC PLC
Current assignee: Balfour Beatty PLC
Priority date: 1986-03-12
Filing date: 1987-03-10
Publication date: 1987-09-16
Anticipated expiration: 2007-03-10
Also published as: GB8705621D0; GB2187866B; GB8606140D0

Abstract

In a lighting control system, switches (A,B) send signals to electronic processing units (6;60,61) over a low voltage network (7,8). The electronic processing units control the operation of luminaires (1,2,3) in accordance with instructions programmed in a read only memory (10), and data regarding the status of the switches (1,2,3) stored in a random access memory (9). The number of luminaires illuminated as well as the time for which they are lit can be controlled by the electronic processing units, and varied depending on the status of other switches in the system. <IMAGE>

Description

SPECIFICATION Lighting control system This invention relates to lighting control systems, and particularly to systems for controlling the lighting of large areas such as warehouses, workshops, offices, factories etc.

Most areas are lit with luminaires which are controlled by switches on a one to one basis, such that one switch is dedicated to the switching on and off of one particular luminaire. It is an object of the present invention to provide a lighting control system which has a much greater degree of flexibility than the simple system described above.

Accordingly there is provided a lighting control system comprising one or more electronic processing units; a plurality of switches adapted to send signals to the one or more electronic processing units via a low voltage network; and a plurality of luminaires adapted to be controlled by signals from the one or more electronic processing units, the electronic processing units having a random access memory and a read only memory, the read only memory having stored therein data determining the operation of the luminaires for each of the combinations of two or more of the plurality of switches, the random access memory storing the status of each of the two or more switches such that the actuation of a switch causes the operation of one or more of the luminaires in accordance with the data stored in the read only memory and the status of one or more of the other switches.By the term "data" there is herein meant to include both an operating programme, and information regarding the intended function of the luminaires.

Conveniently the data determining the operation of the luminaires determines the number of luminaires to be illuminated. In this way the number of luminaires switched on or off by any particular switch can be made to vary depending on whether other switches in the system are themselves on or off. In particular, there is provided a lighting control system including first and second luminaires and first and second switches; the data stored in the read only memory of the one or more electronic processing units being such that actuation of the first switch into an "off" condition causes operation of the first and second luminaires into an "off" condition when the second switch is in an "off" condition, and operation of only the first luminaire into an "off" condition when the second switch is in an "on" condition.A particular application for the above described system is in the lighting of areas in which some luminaires are used to assist in the lighting of more than one position. In these conditions the number of lights extingui'shed by turning off a particular switch can be made to depend on whether or not an adjacent position is occupied.

Alternatively or additionally, the data determining the operation of the luminaires determines the timing of the illumination of the luminaires. In particular, there is provided a lighting control system including first and second luminaires and first and second switches; the data stored in the read only memory of the one or more electronic processing units being such that actuation of the first switch into an "off" condition causes immediate operation of the first luminaire into an "off" condition when the second switch is in an "on" condition, and operation of the first luminaire into an "off' condition after a predetermined delay when the second switch is in an "off" condition.By including a delay in the case where the other switch is "off", the person operating the switch has time to leave the area or perform other operations such as locking up, in lighted conditions, rather than being plunged into total darkness as soon as the switch is operated. Should the second switch be in an "on" condition, the area will not be in complete darkness hence no delay is required.

In a similar arrangement, the data stored in the read only memory of the one or more electronic processing units is such that actuation of either switch into an "off" condition causes immediate operation of one of the luminaires into an "off" condition when the other switch is in an "on" condition, and operation of other switch is in an "on" condition, and operation of one of the luminaires into an "off" condition after a predetermined delay when the other switch is in an "off" condition. This arrangement is suitable for an area having more than one exit, the operation of either switch initiating a delay should the switch be the last to be turned off.

In another arrangement there is provided three or more luminaires and three or more switches, the data stored in the read only memory of the one or more electronic processing units being such that the actuation of any of the three or more switches into an "off" condition causes immediate operation ozone or more of the luminaires into an "off' condition when at least one other switch is in an "on" condition, and operation of one or more of the luminaires into an "off" condition after a predetermined delay when all of the other switches are in an "off" condition. This particular arrangement is suitable for areas having a large number of individually illuminated positions, delayed lighting being provided for whichever of the operators are the last to extinguish the lighting of their particular position.This obviates the need for lights to be left on in order to see the way to the door, or to systematically turn on and off all lights between any particular position and the exit.

The read only memory of the one or more electronic processing units is preferably a repro grammable memory and the one or more electronic processing units may be accessed for reprogramming of the read only memory. The reprogrammable memory is typically a PROM, EPROM or the like. Access for reprogramming of the memory is conceivably physical access by an operator, or is alternatively or additionally electronic access from an external unit such as a central computer.

There is conveniently provided a plurality of electronic processing units, in communication one with another. Preferably one electronic processing unit is associated with each of the plurality of the switches. Each electronic processing unit is preferably located adjacent its associated switch for convenient access for reprogramming of the read only memory. Conveniently each electronic processing unit is provided with display means to assist in reprogramming of the read only memory. Where access for reprogramming is physical access, each electronic processing unit is conveniently provided with one or more push buttons by which means read only memory is reprogrammed.

Reprogramming of the electronic processing units allows the configuration of the lighting to be altered without the need for expensive rewiring operations. The number of luminaires operated by a particular switch, or the delay or timing of any particular luminaire or luminaires can be varied, simply by accessing the one or more electronic processing units and reprogramming the read only memory thereof. The ability to access the electronic processing units at the switches, as opposed to at some central location, allows easy individual reprogramming of the functions of a selected switch or switches. Preferably the one or more electronic processing units are microprocessors.

The invention further resides in a method of controlling a lighting system employing a control system as above described. In particular, a method of controlling a lighting system comprising a plurality of-luminaires and a plurality of switches comprises the steps of storing in the read only memory of one or more electronic processing units data determining the operation of the plurality of luminaires for each of the combinations of two or more of the plurality of switches, monitoring the status of each of the two or more switches, and controlling the operation of the plurality of luminaires such that the actuation of a switch causes the operation of one or more of the luminaires in accordance with the data in the read only memory and the status of one or more of the other switches.

The invention will now be further described by way of example only, with reference to the accompanying drawings in which; Figure 1 is a schematic diagram of a lighting control system according to the invention; Figure 2 is a schematic diagram of an alternative embodiment of lighting control system; Figure 3 is a schematic diagram of another alternative embodiment of lighting control system; and Figure 4 is a schematic diagram of an embodiment of lighting control system employing an electronic bus network.

Referring to Fig. 1, switches A and B actuate the lighting of an area shown generally at 5 by means of luminaires 1, 2 and 3. The switches A and B are connected to a microprocessor 6 by means of low voltage lines 7 and 8 respectively. The microprocessor 6 includes a random access memory 9, a read only memory 10 and a central prodessing unit (CPU) 11.

The power supply to each of the luminaires 1, 2 and 3 is switched by means of relay boxes 12, 13 and 14 from a mains line 15. The actions of the relay boxes 12, 13 and 14 are controlled by signals from the microprocessor 6 via low voltage lines 16, 17, and 18 respectively. The relay boxes, the mains line 1 5 and the low voltage lines are all concealed behind the ceiling shown schematically at 19, with only the luminaires being visible therebelow.

The luminaires 1, 2 and 3 are arranged to illuminate 2 positions, shown generally at 20 and 21, one position being generally adjacent each of the switches A and B. In order to illuminate position 20 light is required from both of luminaires 1 and 2, whilst light from luminaires 2 and 3 is required to illuminate position 21. The actuation of either of switches A or B causes a signal to pass via lines 7 or line 8 to the microprocessor 6, the random access memory 9 storing the status of switches A and B. The read only memory 10 has stored therein data determining the operation of the luminaires 1, 2 and 3 for each of the combinations of switches A and B. Thus for the situation outlined above, the data stored in read only memory 10 will be as shown in Table 1.

Table 1 Switch Status Luniinaire Status A Off 1 Off B Off 2 Off 3 Off A On 1 On B Off 2 On 3 Off A On 1 On B On 2 On 3 On A Off 1 Off B On 2 On 3 On The CPU 11 sends signals to the relay boxes 12, 13 14 to switch on or off the luminaires 1, 2 or 3 in accordance with the data in the ROM 10 and the RAM 9. Thus the switching off of switch A will cause luminaire 1 to be extinguished and luminaire 2 will also be extinguished if switch B is off. If switch B is on however, then luminaire 2 is not switched off as it is still required to be lit when position 21 is occupied. Similarly when switch B is switched off, the extinguishing of luminaire 2 will depend on whether position 20 is occupied as indicated by whether or not switch A is on.

It will be apparent that there are 2 zones of lighting, one dedicated to each of positions 20 and 21, which zones overlap such that luminaire 2 is shared between the two positions. It will be appreciated that the configuration of Fig. 1 may be extended to more complex lighting arrangements involving many luminaires. A lighting arrangement may be changed, merely by reprogramming the ROM with alternative data, thus avoiding the requirement for rewiring of the entire system.

Fig. 2 shows a similar arrangement to that of Fig. 1 in which each of the switches A and B is provided with its own dedicated microprocessor. Microprocessor 60 is located adjacent switch A and sends signals via lines 30 and 3 1 to relay boxes 12 and 13 to control the operation of luminaires 1 and 2. Similarly microprocessor 61 is located adjacent switch B and sends signals via lines 32 and 33 to relay boxes 13 and 14 to control the operation of luminaires 2 and 3.

The two microprocessors are in communication one with the other by means of lines 34 and 35 such that each microprocessor can monitor the status of both switches A and B.

As before, the operation of either switch will cause its microprocessor to send signals to control the operation of the luminaires, the signals depending not only on the preprogrammed data within the microprocessor, but also on the status of the other switch. The location of the microprocessors adjacent to the switches allows easy access for reprogramming of the read only memories in which the data governing the operation of the lighting is contained. Thus the operation of one particular switch can be altered by a simple reprogramming exercise by means of push buttons and an LCD display (not shown). Alternatively or additionally, one or more of the microprocessors can be individually reprogrammed through a central master control box (not shown). Thus all the switches in a lighting system can be individually reprogrammed, as and when necessary.

Fig. 3 shows a lighting system in which the timing, rather than the number, of luminaires is varied depending on the status of other switches in the system. A, B, C, D, and E are switches located adjacent positions 20 to 24 respectively. Signals from the switches are fed by a low voltage lines 50 to 54 to a microprocessor 6. A microprocessor sends coded signals via data line 56 to a decoder 57 which sends appropriate signals to relay boxes 70 to 74 via lines 80 to 84. The relay boxes govern the supply of power to illuminate luminaires 100 to 104.

As before a random access memory stores the status of each of the switches A to E and a read only memory contains preprogrammed data regarding the operation of the luminaires in response each of the combinations of the switches. In general the operation of any of the switches will cause the immediate illuminating or extinguishing of a particular luminaire, switch A lighting luminaire 100, B lighting 101 and so on. However if the random access memory indicates that a luminaire is to be extinguished and all of the other switches are in the "off" condition, then the microprocessor will send signals to extinguish the luminaire only after a predetermined delay. This gives the operator at a particular position a certain amount of light in which to leave the area, before the last of the lights are extinguished.For most configurations a delay of between 10 and 60 seconds will be sufficient to allow an operator to perform any final duties such as locking up etc and leave the area.

Thus an operator at position 23, finding himself the last to leave, may operate switch C and yet still have the light from luminaire 103 with which to leave the building, the luminaire being automatically extinguished after the preset delay time has expired. There is therefore no need for him to attempt to leave in complete darkness, or to switch on and off other switches to obtain light in which to see to leave.

From the foregoing, it will be appreciated that the delay associated with the extinguishing of one light may differ from that associated with another. Indeed the delay associated with the extinguishing of any particular light may depend on the distance of that light from the exit. It will also be appreciated that other configurations are possible, including for example a delay in the switching on of particular luminaires, or a delay as described with reference to Fig. 3 in combination with a variation in the number of luminaires which are actuated, as described with reference to Figs. 1 and 2.

Fig. 4 shows one arrangement employing an electronic bus network, 200 to reduce the amount of wiring required. Electronic processing units 110 to 117 and 120 to 127 are interconnected by means of the bus 200. Switches 130 to 137 are connected to their electronic processing units 120 to 127 respectively by means of wires 140 to 147 respectively. The operation of any switch will cause the electronic processing units to signal on the bus, 200, to all the other electronic processing units. One or more of the electronic processing units 110 to 117 may be caused to switch lights 100 to 107 in accordance with the data in the memories of the electronic processing units. As before, each of the electronic processing units may be programmed by the user as to the number and timing of the lights to be switched.

Claims

1. A lighting control system comprising one or more electronic processing units; a plurality of switches adapted to send signals to the one or more electronic processing units via low voltage network; and a plurality of luminaires adapted to be controlled by signals from the one or more electronic processing units, the electronic processing units having a random access memory and a read only memory, the read only memory having stored therein data determining the operation of the luminaires for each of the combinations of two or more of the plurality of switches, the random access memory storing the status of each of the two or more switches such that the actuation of a switch causes the operation of one or more of the luminaires in accordance with the data in the read only memory and the status of one or more of the other switches.

2. A lighting control system according to claim 1 wherein the data determining the operation of the luminaires determines the number of luminaires to be illuminated.

3. A lighting control system according to claim 2 including first and second luminaires and first and second switches; the data stored in the read only memory of the one or more electronic processing units being such that actuation of the first switch into an "off" condition causes operation of the first and second luminaires into an "off" condition when the second switch is in an "off" condition, and operation of only the first luminaire into an "off" condition when the second switch is in an "on" condition.

4. A lighting control system according to claim 1 or claim 2 wherein the data determining the operation of the luminaires determines the timing of the illumination of the luminaires.

5. A lighting control system according to claim 4 including first and second luminaires and first and second switches; the data stored in the read only memory of the one or more electronic processing units being such that actuation of the first switch into an "off" condition causes immediate operation of the first luminaire into an "off" condition when the second switch is in an "on" condition, and operation of the first luminaire into an "off" condition after a predetermined delay when the second switch is in an "off" condition.

6. A lighting control system according to claim 5 wherein the data stored in the read only memory of the one or more electronic processing units is such that actuation of either switch into an "off" condition causes immediate operation of one of the luminaires into an "off" condition when the other switch is in an "on" condition, and operation of one of the luminaires into an "off" condition after a predetermined delay when the other switch is in an "off" condition.

7. A lighting control system according to claim 6 wherein there is provided three or more luminaires and three or more switches, the data stored in the read only memory of the one or more electronic processing units being such that actuation of any of the three or more switches into an "off" condition causes immediate operation of one or more of the luminaires into an "off" condition when at least one other switch is in an "on" condition, and operation of one or more of the luminaires into an "off" condition after a predetermined delay when all of the other switches are in an "off" condition.

8. A lighting control system according to any preceding claim wherein the read only memory of the one or more electronic processing units is a reprogrammable memory, and the one or more electronic processing units may be accessed for reprogramming of the read only memory.

9. A lighting control system according to claim 8 wherein each electronic processing unit is provided with display means to assist in reprogramming of the read only memory.

10. A lighting control system according to claim 8 or claim 9 wherein each electronic processing unit is provided with one or more push buttons by which means the read only memory is reprogrammed.

11. A lighting control system according to any preceding claim wherein there is provided a plurality or electronic processing units, in communication one with another.

12. A lighting control system according to claim 11 wherein one electronic processing unit is associated with each of the plurality of the switches.

13. A lighting control system according to claim 12 wherein each electronic processing unit is located adjacent its associated switch.

14. A lighting control system according to any of claims 1 to 13 wherein the one or more electronic processing units are microprocessors.

1 5. A lighting control system substantially as hereinbefore described with reference to the accompanying drawings.

16. A method of controlling a lighting system employing a control system according to any of claims 1 to 15.

17. A method of controlling a lighting system comprising a plurality of luminaires and a plurality of switches, the method comprising the steps of storing in the read only memory of one or more electronic processing units data determining the operation of the plurality of the luminaires for each of the combinations of two or more of the plurality of switches, monitoring the status of each of the two or more switches, and controlling the operation of the plurality of luminaires such that the actuation of a switch causes the operation of one or more of the luminaires in accordance with the data in the read only memory and the status of one or more of the other switches.

18. A method of controlling a lighting system according to claim 17 and substantially as hereinbefore described.