GB2554904A

GB2554904A - Lighting apparatus

Info

Publication number: GB2554904A
Application number: GB1617361.9A
Authority: GB
Inventors: Chang Hsiutseng
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-10-13
Filing date: 2016-10-13
Publication date: 2018-04-18
Also published as: GB201617361D0

Abstract

A lighting apparatus 10 comprises a lighting string 30 comprising a plurality of light emitting diode (LED) sources 31 connected in series. The lighting apparatus comprises a low voltage power input VIN, which may be supplied by a battery pack 50, and a power output VOUT connected to, or connectable to, the lighting string. A power conversion circuitry 20, such as a boost converter, is connected between the power input and the power output. A controller 60 is configured to control operation of the power conversion circuitry. The controller is configured to cause the power conversion circuitry to provide an output voltage at the power output which is higher than an input voltage at the power input. The power conversion circuitry comprises an inductor L1 and a power switching device Q3. The controller outputs a pulse width modulated waveform to control the power switching device.

Description

(71) Applicant(s):

HsiuTseng Chang

Kwang TA Electric Co. Ltd, Long Xi Industrial Park, DuYuan Town , PengJian Area, JiangMen, Guangdong, China (72) Inventor(s):

HsiuTseng Chang (56) Documents Cited:

US 7276861 B1 US 20120326632 A1 US 20100117562 A1 US 20050068459 A1 US 20030117088 A1 (58) Field of Search:

US 20130264953 A1 US 20120299488 A1 US 20060186830 A1 US 20040208011 A1

INT CL H05B

Other: Online: WPI, EPODOC (74) Agent and/or Address for Service:

Handsome I.P. Ltd

27-28 Monmouth Street, BATH, BA1 2AP, United Kingdom (54) Title of the Invention: Lighting apparatus Abstract Title: Lighting apparatus (57) A lighting apparatus 10 comprises a lighting string 30 comprising a plurality of light emitting diode (LED) sources 31 connected in series. The lighting apparatus comprises a low voltage power input VIN, which may be supplied by a battery pack 50, and a power output VOUT connected to, or connectable to, the lighting string. A power conversion circuitry 20, such as a boost converter, is connected between the power input and the power output. A controller 60 is configured to control operation of the power conversion circuitry. The controller is configured to cause the power conversion circuitry to provide an output voltage at the power output which is higher than an input voltage at the power input. The power conversion circuitry comprises an inductor L1 and a power switching device Q3. The controller outputs a pulse width modulated waveform to control the power switching device.

At least one drawing originally filed was informal and the print reproduced here is taken from a later filed formal copy.

11 16 /1 ο

LIGHTING APPARATUS

The present invention relates generally to a lighting apparatus.

Lighting strings may be used for decorative lighting, such as festive lighting displays at Christmas or other occasions. A lighting string comprises a plurality of light sources which are physically arranged in a string. There is increasing use of low power consumption light sources, such as Light Emitting Diodes (LED), in lighting strings. A lighting string may be powered by a mains power supply with appropriate voltage down conversion, or by a battery pack.

According to an aspect of the present invention, there is provided a lighting apparatus comprising: a lighting string comprising a plurality of light emitting diode (LED) sources connected in series; a low voltage power input; a power output connected to, or connectable to, the lighting string; power conversion circuitry connected between the power input and the power output; a controller configured to control operation of the power conversion circuitry; wherein the controller is configured to cause the power conversion circuitry to provide an output voltage at the power output which is higher than an input voltage at the power input.

The power conversion circuitry may comprise an inductor and a power switching device, and the controller outputs a pulse width modulated waveform to control the power switching device.

A duty cycle of the pulse width modulated (PWM) waveform may be fixed, or may be variable.

The input voltage may be in the range 2.4V to 6.6V and the output voltage may be in the range 6V to 27V.

The lighting apparatus may comprise a plurality of lighting strings, each light string comprising a plurality of light emitting diode (LED) light sources connected in series.

The lighting apparatus may comprise a switch connected in series with the lighting string, wherein the controller is configured to turn the switch on for an on period and to turn the switch off for an off period to implement a lighting effect.

The controller may be configured to cause the power conversion circuitry to provide an output voltage at the power output which is matched to a number of LED sources in the lighting string.

The controller may be configured to vary operation of the power conversion circuitry to maintain an output voltage at the power output with variation in the input voltage. For example, the controller may be configured to receive a signal indicative of one or more of: the output voltage; output current; the input voltage; input current; and to use the signal to vary the duty cycle of the pulse width modulated waveform.

The controller may be configured to operate the apparatus for a first time period and to turn the switch off for a second time period to implement a daily on/off operational cycle.

The first time period may be selectable from a range of different values. For example, the first time period may be selected from the values 4hrs, 6hrs, 8hrs, lOhrs.

The lighting apparatus may comprise an input device which is sequentially operable to cycle through the range of different values of the first time period.

The controller may be configured to indicate the selected value of the first time period by flashing the lighting string, or lighting strings, a number of times.

The controller may be configured to indicate the selected value of the first time period by flashing the lighting string a number of times equal to a number of hours of the first time period.

The lighting apparatus may comprise a battery pack connected to, or connectable to, the power input. The battery pack may hold one battery, or a plurality of batteries. Powering the lighting apparatus by a battery pack allows the lighting apparatus to be deployed without the need for a connection to a mains electricity outlet. This can allow the lighting apparatus to be deployed in a wider range of locations.

The above and other characteristics, features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. This description is given for the sake of example only, without limiting the scope of the invention. The reference figures quoted below refer to the attached drawings.

Figure 1 is a schematic drawing of a lighting apparatus.

The present invention will be described with respect to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are nondimiting. Each drawing may not include all of the features of the invention and therefore should not necessarily be considered to be an embodiment of the invention. In the drawings, the size of some of the elements may be exaggerated and not drawn to scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that operation is capable in other sequences than described or illustrated herein.

Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that operation is capable in other orientations than described or illustrated herein.

It is to be noticed that the term “comprising”, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a device comprising means A and B” should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

Similarly, it is to be noticed that the term “connected”, used in the description, should not be interpreted as being restricted to direct connections only. Thus, the scope of the expression “a device A connected to a device B” should not be limited to devices or systems wherein an output of device A is directly connected to an input of device B. It means that there exists a path between an output of A and an input of B which may be a path including other devices or means. “Connected” may mean that two or more elements are either in direct physical or electrical contact, or that two or more elements are not in direct contact with each other but yet still co-operate or interact with each other. For instance, wireless connectivity is contemplated.

Reference throughout this specification to “an embodiment” or “an aspect” means that a particular feature, structure or characteristic described in connection with the embodiment or aspect is included in at least one embodiment or aspect of the present invention. Thus, appearances of the phrases “in one embodiment”, “in an embodiment”, or “in an aspect” in various places throughout this specification are not necessarily all referring to the same embodiment or aspect, but may refer to different embodiments or aspects. Furthermore, the particular features, structures or characteristics of any embodiment or aspect of the invention may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments or aspects.

Similarly, it should be appreciated that in the description various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Moreover, the description of any individual drawing or aspect should not necessarily be considered to be an embodiment of the invention. Rather, as the following claims reflect, inventive aspects lie in fewer than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

Furthermore, while some embodiments described herein include some features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form yet further embodiments, as will be understood by those skilled in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practised without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

In the discussion of the invention, unless stated to the contrary, the disclosure of alternative values for the upper or lower limit of the permitted range of a parameter, coupled with an indication that one of said values is more highly preferred than the other, is to be construed as an implied statement that each intermediate value of said parameter, lying between the more preferred and the less preferred of said alternatives, is itself preferred to said less preferred value and also to each value lying between said less preferred value and said intermediate value.

The use of the term “at least one” may mean only one in certain circumstances.

The principles of the invention will now be described by a detailed description of at least one drawing relating to exemplary features of the invention. It is clear that other arrangements can be configured according to the knowledge of persons skilled in the art without departing from the underlying concept or technical teaching of the invention, the invention being limited only by the terms of the appended claims.

Figure 1 shows a lighting apparatus 10 according to an embodiment of the present invention. The lighting apparatus 10 comprises at least one lighting string 30,

40. In this example, the lighting apparatus 10 comprises a first lighting string 30 and a second lighting string 40. In other examples, there may be a different number of lighting strings, such as one, or more than two. Each lighting string 30, 40 comprises a series connected arrangement of light emitting diode (LED) sources 31, 41 connected by a suitable electrical cable 32, 42 and electrical fittings connecting between the cable 32 and the individual LEDs 31, 41. For example, the number of LEDs in each string may range between 10 and 200. The lighting string may have a length of 1-20 metres or more. The lighting strings 30, 40 may be physically intertwined into a single overall string. Along the length of the overall string, there may alternately be an LED 31 of the first lighting string and an LED 41 of the second lighting string. Other arrangements are possible.

The lighting apparatus 10 is powered by a low voltage supply, such as a battery pack.

Power conversion circuitry 20 comprises a power input VIN and a power output VOUT. The power input VIN is connectable to a low voltage power source, such as a battery pack 50 which is capable of holding one or more batteries 51. The power output VOUT is connected to, or connectable to, the lighting string(s) 30, 40. For example, the power output VOUT may comprise a connector which allows the lighting string(s) to be connected and disconnected from the power output. A controller 60 is configured to control operation of the power conversion circuitry 20.

The controller 20 is configured to cause the power conversion circuitry 20 to provide an output voltage at the power output VOUT which is higher than an input voltage at the power input VIN. For example, a battery pack 50 may provide a voltage of between 2.4V and 6.6V, or any other input voltage.

A lighting string may require a voltage of 15V, 30V or some other value which is higher than the voltage supplied by the battery pack.

The controller 60 may be configured to adapt to a voltage demand of a particular lighting string, or lighting strings, connected to the power output VOUT.

The controller 60 may be configured to vary operation of the power conversion circuitry 20 to maintain an output voltage VOUT at the power output with variation in the input voltage VIN.

The power conversion circuitry 20 comprises an inductor LI, a power switching device Q3, a diode D2 and a capacitor El. The power switching device Q3 may be a transistor or any other suitable semiconductor device. The controller 20 is configured to output a pulse width modulated (PWM) signal to control the power switching device Q3. The PWM signal is applied to the base input of switching device Q3. The PWM signal comprises ON and OFF periods. The ratio of ON to OFF is called a duty cycle. The power conversion circuitry 20 operates as a boost converter. During an ON period of the PWM signal, the input voltage VIN is applied across LI and Q3. Energy is stored in the magnetic field of the inductor LI during the ON period. During an OFF period of the PWM signal, the current flow path through the switching device Q3 is turned off and current flow through the inductor LI is interrupted. This causes a voltage to appear across inductor LI, due to the stored energy in the magnetic field of the inductor LI. This voltage attempts to maintain current flow in the same flow direction as during the ON period. This voltage across the inductor LI has an opposite polarity to the voltage during the ON period and causes the inductor to appear as another voltage source. During the ON period the capacitor El is charged by a combination of the input voltage VIN and the voltage across the inductor LI, since both now act as voltage sources. This causes the capacitor El to be charged to a voltage which is higher than VIN. An output voltage VOUT is taken across El. Diode D2 only allows current flow from the capacitor El through the lighting string(s). Current will flow through the lighting string(s) 30, 40 during the ON and OFF periods of the PWM signal. With a suitably sized inductor LI, capacitor El and ON/OFF duty ratio, the lighting string(s) 30, 40 can be powered at any voltage required by the lighting string(s).

An oscillator Y1 and capacitors C3, C4 provide a timing reference to the controller 60.

Each of the lighting strings 30, 40 is independently controllable. A switch Ql is connected in series with lighting string 30. Switch Ql is controllable by a signal OUT1. A switch Q2 is connected in series with lighting string 40. Switch Q2 is controllable by a signal OUT2. The controller 60 is configured to turn the switches Ql, Q2 on for an on period and to turn the switches Ql, Q2 off for an off period to implement a lighting effect. For example, if the lighting strings 30, 40 are physically intertwined into a single overall string then along the length of the overall string there may alternately be an LED 31 of the first lighting string and an LED 41 of the second lighting string. When the first lighting string 30 is turned on, LEDs 31 are illuminated. When the second lighting string 30 is turned on, LEDs 41 are illuminated. The controller 60 may implement a plurality of different lighting effects. An input device, such as button or switch, KEYl allows a user to select a required lighting effect. The input device KEYl may be sequentially operated to advance through a plurality of different lighting effects until a required lighting effect is selected.

The controller 60 is configured to operate the apparatus for a first time period and to turn the switch off for a second time period to implement a daily on/off operational cycle. For example, the first time period may be 4 hrs. The first time period may be selectable from a range of different values, e.g. 4hrs, 6hrs, 8hrs, lOhrs. An input device KEY2 allows a user to select a required first time period. The input device KEYl may be sequentially operated to advance through a plurality of different first time periods until a required first time period is selected. The selected duration is confirmed with turning the lighting string(s) on and off, i.e. flashing, for a number of times equal to the number of hours. For example, an operating duration of 4hrs is confirmed by flashing four times. As an alternative to, or in addition to, flashing the lighting string(s), it is possible to provide an indicator near to the input device KEY2 which can indicate which time period has been selected.

Claims

1. A lighting apparatus comprising:

a lighting string comprising a plurality of light emitting diode (LED) sources connected in series;

a low voltage power input;

a power output connected to, or connectable to, the lighting string; power conversion circuitry6 7 connected between the power input and the power output;

a controller configured to control operation of the power conversion circuitry;

wherein the controller is configured to cause the power conversion circuitry to provide an output voltage at the power output which is higher than an input voltage at the power input.

2. A lighting apparatus according to claim 1, wherein the power conversion circuitry comprises an inductor and a power switching device, and the controller outputs a pulse width modulated waveform to control the power switching device.

3. A lighting apparatus according to claim 1 or 2 comprising a capacitor in parallel with the power output.

4. A lighting apparatus according to any one of the preceding claims comprising a battery pack connected to, or connectable to, the power input.

5. A lighting apparatus according to any one of the preceding claims, wherein the input voltage is in the range 2.4V to 6.6V.

6. A lighting apparatus according to any one of the preceding claims, wherein the output voltage is in the range 6V to 27V.

7. A lighting apparatus according to any one of the preceding claims comprising a plurality of lighting strings, each light string comprising a plurality of light emitting diode (LED) light sources connected in series.

8. A lighting apparatus according to any one of the preceding claims comprising a switch connected in series with the lighting string, wherein the controller is configured to turn the switch on for an on period and to turn the switch off for an off period to implement a lighting effect.

9. A lighting apparatus according to any one of the preceding claims, wherein the controller is configured to operate the apparatus for a first time period and to turn the switch off for a second time period to implement a daily on/off operational cycle.

10. A lighting apparatus according to claim 9, wherein the first time period is selectable from a range of different values.

11. A lighting apparatus according to claim 10 comprising an input device which is sequentially operable to cycle through the range of different values of the first time period.

12. A lighting apparatus according to claim 10 or 11, wherein the controller is configured to indicate the selected value of the first time period by flashing the lighting string a number of times.

13. A lighting apparatus according to claim 12, wherein the controller is configured to indicate the selected value of the first time period by flashing the lighting string a number of times equal to a number of hours of the first time period.

Intellectual

Property

Office

Application No: GB1617361.9