GB2174222A

GB2174222A - Remote operation of an electrical light switch

Info

Publication number: GB2174222A
Application number: GB8510783A
Authority: GB
Inventors: Peter Stanley Phillips
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-04-27
Filing date: 1985-04-27
Publication date: 1986-10-29
Also published as: GB8510783D0; GB2174222B

Abstract

A remotely-operated light control system comprises an e.g. infra red transmitter T for use at a remote control point and a receiver R for responding to signals which it receives from the transmitter to control the light source S. The transmitter may be powered by rechargeable battery B and include a light cell L to convert light from the source S and/or ambient light into electrical power to recharge the battery. The transmitter/light switch and the receiver/light source may be positioned at will without the need to run cables between them. <IMAGE>

Description

SPECIFICATION Remote operation of an electrical light switch This invention relates to a remotely-operated light control system.

Electrical light system traditionally consist of two main elements, the light source and the remote control point. Domestic and commercial lighting installations predominantly use mechanical switches at the remote control point necessitating the laying of mains cables between the switch and the light source. Further should it be necessary to operate one or more light sources from one or more locations then the amount and complexity of the wiring can increase dramatically.

In accordance with this invention, there is provided a remotely-operated light control system comprising a transmitter for use at a remote control point, and a receiver for responding to signals which it receives from the transmitter and serving to control the light source.

There is thus no need for any physical connection to run from the control point to the light source. In particular the light source and control points may be placed in traditional positions or positions chosen freely, without any requirement to run cables between them.

The transmitter may be an infra red transmitter and the receiver an infra red receiver, but other forms of carrier radiation may be used.

Control of the light source is preferably obtained by transmitting a coded signal, which signal is decoded by the receiver to operate an electronic controller for the light source provided the correct code for that light source is received. The use of a coded signal enables one or more remote stations to control one or more light sources by a suitable arrangement of signal codes.

Preferably the electrical power for the transmitter is derived from rechargeable batteries located within the transmitter housing, these batteries being recharged from a transducer which converts light energy into electrical power. Thus the working life of the batteries is prolonged by converting some of the energy from the light source back into electrical power, and/or by converting ambient light source into electrical power.

Preferably the control system is arranged to vary the intensity of the light source. For example, a switch on the transmitter may turn the light source on at full intensity if manuallyoperated momentarily, but then causes the light to be progressively dimmed whilst the switch is kept operated for a longer period.

An embodiment of this invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a block diagram of a remotelyoperated light control system in accordance with the invention, and showing the main units of the system; Figure 2 is a block circuit diagram of the transmitter unit; Figure 3 is a block circuit diagram of the receiver unit; and Figure 4 is a block diagram of the light source controller.

Figure 1, the light control system which is shown comprises three main units, namely a wall mounted transmitter unit T with rechargeable batteries B and a light cell L, a receiving unit R and a controller unit C for control ling the light source S. These three units may be placed in the most convenient locations. A more detailed description of the individual units now follows:- Referring to Figure 2, the transmitting unit T comprises rechargeable batteries B, a light sensitive cell L, a switch Sw, a binary code selector Bs, a pulse position modulator M, a power amplifier A and one or more infra red transmitting diodes D. Operation of the switch Sw causes a five bit binary pulse position modulated code determined by Bs to be produced by M. The signal is amplified by A to energise the infra red transmitting diode(s).

The signal continues to be repeated until switch Sw is released. Power for the circuit is derived from the batteries B which are in turn recharged with current generated by light cells L: diode dd prevents reverse current flow into the light cell when low light levels prevail.

The receiving unit R shown in Figure 3 comprises one or more infra red receiving diodes Id, a preamplifier P, a filter F, a pulse position demodulator X, and binary decoder Y. The diode(s) Id convert the received infra red into a correspondingly coded signal which is amplified by P and then filtered by F to remove noise and background signals. The signal is then demodulated by X to produce a five bit parallel binary bit pattern. If this bit pattern corresponds to the pattern set in the binary decoder Y then an output O/P is generated and fed to the light source controller.

The light source controller C shown in Fig.

4 comprises a triac controller Z, a triac driver Td and a triac Tr. An input I/P to the controller, being the output O/P from the receiver, will initially switch the triac Tr on thus energizing the light source S from the mains. Should this input persist for a predetermined time (i.e.

the switch Sw in the transmitting unit remains closed), then the triac controller Z will progressively vary the firing angle of the triac until the input is removed, thus providing a light dimming capability. Removal of the input and then its subsequent replacement, for a second time, will cause the triac to be turned off, deenergizing the light source.

It should be appreciated that various other signal transmission techniques could be imple mented in accordance with this invention.

Thus ultra sonic, radio waves, microwaves or ultra violet could be used as the signal carrier.

These could then be modulated by using pulse width modulation, pulse amplitude modulation or any other digital modulation system. The bit pattern of the coded signal need not in any event be restricted to a five bit length but could be any number of bits.

The signal coding could be achieved by using analogue techniques, for example expressing the codes as a number of differing frequencies, either of the carrier medium or imposing them upon the carrier using amplitude or frequency modulation methods.

The placing of the remote operating points can also be expanded allowing a more flexible approach to lighting systems then presently possible. For example control could be achieved from not only wall mounted points but portable hand held transmitter units of the same electronic design.

Claims

1. A remotely-operated light control system comprising a transmitter for use at a remote control point, and a receiver for responding to signals which it receives from the transmitter and serving to control the light source.

2. A light control system as claimed in claim 1, in which the transmitter includes a rechargeable battery from which it derives its electrical power, and a light-sensitive transducer serving to convert light from the light source and/or ambient light into electrical power which recharges the battery.

3. A light control system as claimed in claim 1 or 2, comprising a switch operable to energise the transmitter, the receiver being responsive to energisation of the transmitter a first time to energise the light source, and further responsive to energisation of the transmitter subsequently to de-energise the light source.

4. A light control system as claimed in claim 3, in which the receiver is responsive to continuing energisation of the transmitter said first time, to progressively vary the energisation of the light source until this energisation of the transmitter is terminated.

5. A light control system as claimed in any preceding claim, in which the transmitter is arranged to transmit a coded signal and the receiver is arranged to respond only to signals of predetermined coding.

6. A light control system as claimed in any preceding claim, in which the transmitter comprises a portable hand-held unit.

7. A remotely-operated light control system substantially as herein described with reference to the accompanying drawings.