GB2358094A - Lighting system circuit with photoelectric cell - Google Patents

Abstract

A circuit for a lighting system includes a mains power supply, a light emitting element 15 and at least one photoelectric cell 14. Electrical energy from the photoelectric cell is supplied to an input of the light emitting device and at least part of the electrical energy from the photoelectric cell is derived from the light output of the light emitting element, thereby reducing the current drawn from the mains supply. The circuit may include a rectifier to convert the AC from the mains to supply DC to the lamp (12, fig. 4), or may include an inverter (12, fig. 5) to convert DC from the photocell to supply AC to the lamp. The photocell may be attached to the housing of the lamp, preferably a removable collar 10 with the photocell located on an interior face. The light emitting element may be a light bulb, and/or a light emitting diode.

Description

2358094 A CIRCUIT FOR A LIGHTING SYSTEM This invention relates to a

circuit for a lighting system.

Light bulbs, be they standard incandescent type, halogen, low energy or in other forms all have a common characteristic, namely the production of artificial light.

In order to operate such light bulbs an electrical power source is required. The traditional methods of producing such a power source coupled with the varying lo degrees of energy usage by the differing light bulb types are costly to both the consumer and to the environment.

Disadvantages arise with traditional methods of powering a light bulb, because of the inefficiencies involved.

is it is an object of the present invention to address the above mentioned disadvantages.

According to one aspect of the present invention a circuit for a light system includes a mains power supply, a light emitting element and at least one photoelectric cell electrically connected together, wherein the circuit is operable to supply electrical energy converted from light energy derived at least partially from the light emitting element by the at least one photoelectric cell to an input of the light-emitting element to thereby reduce the current drawn from the mains supply by the light emitting element.

The light emitting element may be a light bulb and/or a light emitting diode.

The mains supply may be a supply from a generator.

The circuit may include an alternating current to direct current (AC/DC) converter, for converting alternating current from the mains power supply to direct current. The circuit may include a direct current to alternating current converter (DC/AC), for 2 converting direct current from the or each photoelectric cell to alternating current. The converter may be a rectifier.

The or each photoelectric cell may be located within an open housing, which may be a s collar, from which the light emitting element may project. The housing may have at least one face which faces the light emitting element, the or each photoelectric cell is preferably located on that face.

The housing may include electrical contacts for electrically coupling the or each photoelectric cell to the remainder of the circuit.

The housing may have attachment means, which may be a screw threading, for attachment of the housing to a support portion of the light-emitting element. Said support portion may be a socket for the light emitting element. The support portion is may be electrically connected to the mains power supply. The housing may be electrically connected to the support portion to complete the electrical circuit.

Preferably, the housing is a collar, which may include the attachment means at a first end thereof. The light emitting means may be receivable at a second end of the housing. The housing is preferably fi-usto-conical in shape, with the or each photoelectric cells being received on an interior face thereof. The housing may have a circular cross-section, which may not be continuous. The housing may be a cuboid shape, for instance if the light emitting element is a fluorescent-type light bulb.

The housing may be removable by means of the attachment means, the housing may be replaceable.

Preferably, the circuit comprises a plurality of photoelectric cells, which are preferably distributed about an interior face of the housing. The photoelectric cells may be substantially parallel to an outer surface of the light-emitting element.

The total output of the or each photoelectric cell may be limited to be less than the output of the light emitting element, to allow the circuit to be turned off.

3 The or each photoelectric cell may provide a substantially continuous feed of power to the light emitting element.

s According to another aspect of the present invention a housing for a light-fitting comprises at least one photoelectric cell, wherein the housing is arranged to be received by a light fitting, and wherein the or each photoelectric cell is located on a face of the housing which, in use, faces a light emitting element of the light fitting, the or each photoelectric cell being operable to receive light from the light emitting lo element, to convert that light to electrical energy, and to supply the electrical energy to an electrical input of the light fitting.

The housing may be a housing as described in the first aspect. The housing may be a, preferably removeable, collar.

is The housing may include an A/D converter and/or a D/A converter.

The housing may be arranged to fit into a standard light bulb holder.

According to another aspect of the invention a method of at least partially powering a light emitting element comprises placing at least one photoelectric cell to receive light from a light emitting element, which light emitting element is powered by a mains supply, wherein light from the light emitting element is converted to electrical energy by the or each photoelectric cell, said electrical energy being supplied to an electrical input of the light emitting element, to thereby at least partially power the light emitting element.

All of the features described herein can be combined with any of the above aspects, in any combination.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which:- 4 Figure 1 shows in perspective a collar lined with photoelectric cells in relation to a light bulb and a mains electrical connector; Figure 2 shows in section the combination of the collar with the existing electrical 5 connector and light bulb components; Figure 3 shows in exploded isometric view the constituent parts of the collar; Figure 4 illustrates a wiring diagram showing the collar in its position within an lo electrical circuit which is a Direct Current (DC) variant; Figure 5 illustrates a wiring diagram showing the position of the collar within an alternative electrical circuit which is an Alternating Circuit (AC) variant; is Figure 6 illustrates a wiring diagram showing a switching arrangement causing initial illumination of light bulb; Figure 7 illustrates a wiring diagram showing the balance of mains electrical power and collar generated electricity during operation of the collar.

A photo-electric light bulb collar 10 has a splayed cross-section, and an interior face which is lined with photo-electric cells 14. The collar 10 has live and neutral connector pads 11 a and 1 lb for connection to a mains supply (not shown) and to a rectifier circuit 12. Spring loaded electrical peg connectors 13 provide an electrical connection to a light bulb 15. Light from the light bulb 15 received by the photoelectric cells 14 is converted into electrical energy which is supplied to the peg connectors 13 to partially power the light bulb 15.

The peg connectors 13 may be made of brass or similar highly conductive material for connection to the light bulb 15. The connector pegs 13 may be adapted to flat strip connectors so that the collar can receive a standard screw fitting bulb.

The collar 10 has an attachment section 16 by which it is attached to an existing light bulb socket. The form of the attachment section 16 depends on the type of light fitting to be used. For instance, this fitting could be a standard bayonet fitting, a screw-in fitting or a push-in type fitting. It will be appreciated that many different types of s fitting can be envisaged without altering the usefulness of this device.

The shape, in particular the splay, of the collar 10 is chosen to suit a particular light bulb 15. i.e. a larger light bulb will require a greater degree of splaying of the collar, whereas for a thin light bulb a cylindrical collar may be suitable. An elongate, cuboidal lo collar may provided for a standard fluorescent bulb.

The rectifier 12 is shown in its two variants in Figures 4 and 5.

In Figure 4 the rectifier 12 converts alternating current from the mains supply to direct is current for supply to the light bulb 15. Current from the photo- electric cells 14 is also direct current and is fed into the light bulb supply at points 17a and 17b. Since the power from the mains supply and the photo-electric cells is direct current the light bulb will function.

Figure 5 shows an alternative arrangement of rectifier 12 in which current from the photo-electric cells 14 is converted from direct current to alternating current and is fed to the light bulb supply at the points 17a and 17b. In this embodiment the mains supply is alternating current and after rectification the supply from the photo-electric cells 14 is alternating current. Consequently, the light bulb 15 will function normally, 25 since the currents are of the same type.

In use, the collar is inserted into an existing light bulb socket in the same way as a light bulb is inserted into the socket. The light bulb 15 is then placed in to the connector pads 11 a and 1 lb of the collar 10. The bulb can then be illuminated using a switch, in 3o the usual way.

Light from the bulb 15 will be received by the photo-electric cells 14 and will be converted into electrical power which, as shown by Figures 4 and 5 is supplied to the 6 input for the light bulb 15. Thus, the current from the photo-electric cells 14 is fed into the light bulb circuit, thus reducing the mains power demand from the light bulb 15 by an amount proportionate to the efficiency of the photo-electric cells 14 and the inefficiency of the light bulb 15.

The functioning of the collar is not affected by the choice of rectifying the mains supply from AC to DC or rectifying the current from the photoelectric cells 14 from DC to AC. In either embodiment the amount of mains current used is reduced by the amount of current supplied from the photoelectric cells 14.

The electrical output of the collar 10 is restricted to be less than the total electrical supply required to fully illuminate the inserted bulb, in order to maintain the ability to switch the light bulb off. If one hundred per cent efficiency of the light bulb and photo-electric cells can be achieved, then the collar would provide sufficient electricity is to be equivalent to the electrical demand required by the light bulb. This would create a perpetual operation of the photo-electric light bulb collar without the requirement for mains supply.

Figures 6 and 7 show respectively one hundred per cent of the requirement of the light bulb being supplied by the mains (Figure 6) and a reduced amount of power being supplied by the mains because some of current in the circuit being supplied by the collar 10 (Figure 7).

It will be appreciated that significant advantages arise from this device, because some of the light output from a light bulb which would not otherwise be used (since it is directed upwards/sideways) can be converted into electrical power to reduce the amount of current drawn from the mains supply. Thus, cost savings are made and environmental benefits will be achieved because of the small amount of, current needed.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application

7 and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, s abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, lo abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

is The invention is not restricted to the details of the foregoing embodiment(s). The invention extend to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims (9)

1 A circuit for a lighting system includes a mains power supply, a lightemAting element and at least one photoelectric cell electrically connected together, wherein the circuit is operable to supply electrical energy converted from light energy derived at least partially from the light emitting element by theat least one photoelectric cell to an input of the ligh-l-emitting element to thereby reduce the current drawn from the i.:iains supply by the light emitting-element.

2 A circuit for a lighting system as claimed in claim 1, wherein the circuit may include an electrical converter through which mains supply electricity passes, converting from ing current to Direct current without the use of batten-s.

Iten,.,it' AC/DC) j A circuit for a lighting system as claimed in claim 1 or 2, wherein the circuit may include an electrical converter through which Direct current from one or more photoelectric cells is converted to Alternating current (DC/AC) without the use of batteries, the converter being a rectifier.

4 A circuit for a lighting system as claimed in claim 2 or claim 3, wherein the electrical output from the photoelectric cell or cells may be limited to be less than the output of the light emitting-element, allowing the circuit to be switched off.

A circuit for a lighting system as claimed in any preceding claim, wherein the or each photoelectric cell may be located within an open housing or collar which-is preferably frusto-conical in shape where at least one face of the collar faces the light-emitting element, the photoelectric cell or cells being located on that face.

6 A circuit for a lighting circuit as claimed in claim 5, wherein the housing or collar includes both attachment means via electrical connectors which are compatible to a mains supply connection, whilst forming a continuous connection via electfical connectors to a G\ light-emitting element whose support portion is compatible with the said connectors,which maybe of standard type.

7 A circuit for a lighting system as claimed in claim 6, wherein the or each photoelectric cell may provide a substantially continuous feed of power to the light-emitting element.

8 A circuit for a lighting system as claimed in claim 7, wherein the housing or collar incorporates electrical coupling of each or the photoelectric cells to the remainder of the circuit.

9 A circuit for a lighting system as claimed in claim 8, wherein the housing or collar Is removeable or replaceable.

A circuit for a lighting system as described herein with reference to Figures 1-7 of the accompanying drawings.