Light tube and power supply circuit

• US 9,006,990 B1
• Filed: 06/09/2014
• Issued: 04/14/2015
• Est. Priority Date: 02/11/2000
• Status: Expired due to Term

• Current Assignee: Ilumisys Incorporated (Altair Engineering Incorporated)
• Original Assignee: Ilumisys Incorporated (Altair Engineering Incorporated)
• Inventors: Timmermans, Jos, Raymond, Jean C., Ivey, John
• Primary Examiner(s): A, Minh D
• Application Number:
  US14/299,909
• Time in Patent Office: 309 Days
• Field of Search: 315307-308, 315/312, 315/185.R, 315/224, 315/246, 315/247, 340/240, 340/249.02, 340/543, 340/544, 340/548, 340/249.03
• US Class Current: 315/224
• CPC Class Codes: B60Q 3/80 Circuits; Control arrangements for dashboards B60Q3/16; for mass transit vehicles B60Q3/47
• CPC Class Codes: F21K 9/272 Details of end parts, i.e. the parts that connect the light source to a fitting; Arrangement of components within end parts F21K9/278 takes precedence
• CPC Class Codes: F21K 9/275 Details of bases or housings, i.e. the parts between the light-generating element and the end caps; Arrangement of components within bases or housings F21K9/278 takes precedence
• CPC Class Codes: F21K 9/278 Arrangement or mounting of circuit elements integrated in the light source
• CPC Class Codes: F21K 9/60 Optical arrangements integrated in the light source, e.g. for improving the colour rendering index or the light extraction
• CPC Class Codes: F21K 9/66 Details of globes or covers forming part of the light source
• CPC Class Codes: F21K 9/90 Methods of manufacture
• CPC Class Codes: F21S 4/28 rigid, e.g. LED bars
• CPC Class Codes: F21V 15/015 Devices for covering joints between adjacent lighting devices; End coverings
• CPC Class Codes: F21V 19/003 Fastening of light source holders, e.g. of circuit boards or substrates holding light sources
• CPC Class Codes: F21V 19/008 of straight tubular light sources, e.g. straight fluorescent tubes, soffit lamps
• CPC Class Codes: F21V 23/00 Arrangement of electric circuit elements in or on lighting devices characterised by cooling arrangements F21V29/508
• CPC Class Codes: F21V 23/009 the casing being inside the housing of the lighting device
• CPC Class Codes: F21V 23/02 the elements being transformers, impedances or power supply units, e.g. a transformer with a rectifier
• CPC Class Codes: F21V 23/023 Power supplies in a casing F21V23/003 takes precedence
• CPC Class Codes: F21V 23/06 the elements being coupling devices , e.g. connectors
• CPC Class Codes: F21V 3/02 characterised by the shape
• CPC Class Codes: F21Y 2103/10 comprising a linear array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 25/13 the devices being of a type provided for in group H01L33/00
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 : Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05B 45/10 : Controlling the intensity of the light
• CPC Class Codes: H05B 45/14 : using electrical feedback from LEDs or from LED modules
• CPC Class Codes: H05B 45/325 : Pulse-width modulation [PWM]
• CPC Class Codes: H05B 45/3578 : Emulating the electrical or functional characteristics of discharge lamps
• CPC Class Codes: H05B 45/3725 : Switched mode power supply [SMPS]
• CPC Class Codes: H05B 47/10 : Controlling the light source
• CPC Class Codes: Y02B 20/30 : Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

A replacement light tube for replacing a fluorescent light tube includes a bulb portion having a first end and a second end, a first end cap and a second end cap disposed at the first end and the second end, respectively, each configured to fit with a socket for the fluorescent light tube, a plurality of light emitting diodes disposed inside and extending between the first and second ends of the bulb portion, a pulse width modulator configured to receive power from a power source and modulate the received power to one of a first brightness level and a second brightness level, the second brightness level being different than the first brightness level and a current limiter comprising an inductive element coupled between the pulse width modulator and at least some of the plurality of light emitting diodes.

Claims

1. A replacement light tube for replacing a fluorescent light tube, comprising:

a bulb portion having a first end and a second end;

a first end cap and a second end cap disposed at the first end and the second end, respectively, each configured to fit with a socket for the fluorescent light tube;

a plurality of light emitting diodes disposed inside and extending between the first and second ends of the bulb portion, wherein the plurality of light emitting diodes are arranged to provide light through at least a portion of the bulb portion;

a pulse width modulator configured to receive power from a power source and modulate the received power to one of a first brightness level and a second brightness level, the second brightness level being different than the first brightness level; and

a current limiter comprising an inductive element coupled between the pulse width modulator and at least some of the plurality of light emitting diodes.

2. The replacement light tube of claim 1, wherein the first and second brightness levels correspond to different brightness or intensity levels of white light emitted from the replacement light tube.

3. The replacement light tube of claim 1, wherein the pulse width modulator is configured to modulate the received power to one of the first and second brightness levels based on an adjustment made by a user.

4. The replacement light tube of claim 1, wherein the first brightness level corresponds to an off state and the second brightness level corresponds to an on state.

5. The replacement light tube of claim 1, wherein the pulse width modulator is configured to supply the modulated power at the first brightness level to the plurality of light emitting diodes.

6. The replacement light tube of claim 5, wherein the pulse width modulator is configured to supply the modulated power at the second brightness level to the plurality of light emitting diodes.

7. The replacement light tube of claim 1, wherein the pulse width modulator is configured to modulate the received power to one of the first and second brightness levels without an adjustment made by a user.

8. A replacement light tube for replacing a fluorescent light tube, comprising:

a housing having a first end and a second end;

a first end cap and a second end cap disposed at the first end and the second end, respectively, each configured to fit with a socket for the fluorescent light tube;

a rigid support structure having a planar portion having a first surface extending within the housing between the first end and the second end and having spaced-apart sidewalls extending away from the first surface and extending within the housing between the first end and the second end, at least a portion of the sidewalls in contact with an interior surface of the housing;

a plurality of light emitting diodes supported by a second surface of the planar portion opposite to the first surface and extending between the first and second ends of the housing, wherein the plurality of light emitting diodes are arranged to provide light through at least a portion of the housing; and

power supply circuitry configured to receive power from a power source and modulate the received power to one of a first brightness level and a second brightness level, the second brightness level being different than the first brightness level.

9. The replacement light tube of claim 8, wherein the first and second brightness levels correspond to different brightness or intensity levels of white light emitted from the replacement light tube.

10. The replacement light tube of claim 8, wherein the pulse width modulator is configured to modulate the received power to one of the first and second brightness levels based on an adjustment made by a user.

11. The replacement light tube of claim 8, wherein the first brightness level corresponds to an off state and the second brightness level corresponds to an on state.

12. The replacement light tube of claim 8, wherein the pulse width modulator is configured to supply the modulated power at the first brightness level to the plurality of light emitting diodes.

13. The replacement light tube of claim 12, wherein the pulse width modulator is configured to supply the modulated power at the second brightness level to the plurality of light emitting diodes.

14. The replacement light tube of claim 8, further comprising:

a current limiter comprising an inductive element coupled between the pulse width modulator and at least some of the plurality of light emitting diodes.

15. The replacement light tube of claim 8, wherein the pulse width modulator is configured to modulate the received power to one of the first and second brightness levels without an adjustment made by a user.

16. The replacement light tube of claim 8, wherein the planar portion is integral with the sidewalls.

17. The replacement light tube of claim 8, wherein the sidewalls each have a substantially uniform cross-section along a length of the housing.

18. A method for operating a replacement light tube for replacing a fluorescent light tube, the replacement light tube including:

a bulb portion having a first end and a second end;

a first end cap and a second end cap disposed at the first end and the second end, respectively, each configured to fit with a socket for the fluorescent light tube;

a plurality of light emitting diodes disposed inside and extending between the first and second ends of the bulb portion; and

power supply circuitry having a pulse-width modulator and a current limiting circuit including an inductive element coupled between pulse-width modulator and at least some of the plurality of light emitting diodes, the method comprising;

receiving power from a power source; and

modulating, using the pulse-width modulator, the received power to one of a first brightness level and a second brightness level, the second brightness level being different than the first brightness level.

19. The method for operating the replacement light tube of claim 18, wherein the first and second brightness levels correspond to different brightness or intensity levels of white light emitted from the replacement light tube.

20. The method for operating the replacement light tube of claim 18, wherein modulating the received power further comprises:

modulating, using the pulse-width modulator, the received power to one of a first brightness level and a second brightness level, the second brightness level being different than the first brightness level based an adjustment made by a user.

21. The method for operating the replacement light tube of claim 18, wherein the first brightness level corresponds to an off state and the second brightness level corresponds to an on state.

22. The method for operating the replacement light tube of claim 18, further comprising:

supplying the modulated power at the first brightness level to the plurality of light emitting diodes.

23. The method for operating the replacement light tube of claim 22, further comprising:

supplying the modulated power at the second brightness level to the plurality of light emitting diodes.

24. The method for operating the replacement light tube of claim 18, wherein modulating the received power further comprises:

modulating, using the pulse-width modulator, the received power to one of a first brightness level and a second brightness level, the second brightness level being different than the first brightness level without an adjustment made by a user.

25. A replacement light tube for replacing a fluorescent light tube, the replacement light tube configured to emit white light at a plurality of brightness levels, comprising:

a housing having a first end and a second end;

a first end cap and a second end cap disposed at the first end and the second end, respectively, each configured to fit with a socket for the fluorescent light tube;

a plurality of light emitting diodes disposed inside and extending between the first and second ends of the housing, wherein the plurality of light emitting diodes are arranged to provide light through at least a portion of the housing;

a pulse width modulator configured to;

receive power from a power source,

in response to a first user adjustment, modulate the received power to a first one of the plurality of brightness levels, and

in response to a second user adjustment, modulate the received power to a second one of the plurality of brightness levels, wherein the second brightness level is different than the first brightness level; and

a current limiter comprising an inductive element coupled between the pulse width modulator and at least some of the plurality of light emitting diodes.

26. The replacement light tube of claim 25, wherein the first and second brightness levels correspond to different brightness or intensity levels of white light emitted from the replacement light tube.

27. The replacement light tube of claim 25, wherein the first brightness level corresponds to an off state and the second brightness level corresponds to an on state.

28. The replacement light tube of claim 25, wherein the pulse width modulator is configured to supply the modulated power at the first brightness level to the plurality of light emitting diodes.

29. The replacement light tube of claim 28, wherein the pulse width modulator is configured to supply the modulated power at the second brightness level to the plurality of light emitting diodes.

30. The replacement light tube of claim 25, further comprising:

a rigid support structure having a planar portion having a first surface extending within the housing between the first end and the second end and having spaced-apart sidewalls extending away from the first surface and extending within the housing between the first end and the second end, at least a portion of the sidewalls in contact with an interior surface of the housing, wherein at least a portion of the sidewalls is in contact with an interior surface of the elongate tubular housing.