Light tube and power supply circuit

• US 8,247,985 B2
• Filed: 03/21/2005
• Issued: 08/21/2012
• Est. Priority Date: 02/11/2000
• Status: Active Grant

• Current Assignee: Ilumisys Incorporated (Altair Engineering Incorporated)
• Original Assignee: Ilumisys Incorporated (Altair Engineering Incorporated)
• Inventors: Timmermans, Jos, Raymond, Jean C.
• Primary Examiner(s): Owens, Douglas W
• Assistant Examiner(s): A, Minh D
• Application Number:
  US11/085,744
• Publication Number:
  US 20050162093A1
• Time in Patent Office: 2,710 Days
• Field of Search: 315/200.R, 315/291, 315/246, 315/185.R, 315/209.R, 315/268, 315/269, 315271-272, 315/312, 362/221, 362/225, 362/249, 362/659
• US Class Current: 315/246
• 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

The present invention provides a light tube for illumination by a power supply circuit including a bulb portion and a pair of end caps disposed at opposite ends of the bulb portion. A plurality of light emitting diodes are disposed inside the bulb portion and in electrical communication with the pair of end caps for illuminating in response to electrical current to be received from the power supply circuit.

Claims

1. An LED lighting unit for replacing a conventional fluorescent tube between the opposed electrical receptacles of a fluorescent lighting fixture, comprising:

an elongate support structure having a first end and a second end opposite said first end;

a first end cap disposed upon said first end of said elongate support structure;

a second end cap disposed upon said second end of said elongate support structure;

wherein each of said first end cap and said second end cap includes a fluorescent light fixture receptacle connector extending from each said end cap and configured for installing within the opposed electrical receptacles of the fluorescent lighting fixture;

a plurality of LEDs disposed along said elongate support structure in an electrical circuit with one another;

a cover overlying the elongate support structure and forming a housing enclosing the plurality of LEDs;

a battery supplying power to the plurality of LEDs;

a pulse-width modulating circuit receiving DC power from said battery and supplying modulated power to said plurality of LEDs; and

one or more current-limiting circuits coupled between said pulse-width modulating circuit and said plurality of LEDs;

wherein said one or more current-limiting circuits comprises an inductor electrically connected in series between said pulse-width modulating circuit and said plurality of LEDs and a power diode electrically connected between ground and a node between said pulse-width modulating circuit and said inductor.

2. The LED lighting unit according to claim 1 wherein at least certain of said plurality of LEDs are electrically connected in series with one another.

3. The LED lighting unit according to claim 1 wherein at least certain of said plurality of LEDs are electrically connected in parallel.

4. The LED lighting unit according to claim 1 wherein said elongate support structure is a circuit board.

5. The LED lighting unit according to claim 1 wherein said plurality of LEDs are arranged in spaced-apart groups along one surface of said elongate support structure.

6. An LED lighting unit for replacing a conventional fluorescent tube between the opposed electrical receptacles of a fluorescent lighting fixture, comprising:

an elongate support structure having a first end and a second end opposite said first end;

a first end cap disposed upon said first end of said elongate support structure;

a second end cap disposed upon said second end of said elongate support structure;

wherein each of said first end cap and said second end cap includes a fluorescent light fixture receptacle connector extending from each said end cap and configured for installing within the opposed electrical receptacles of the fluorescent lighting fixture;

a plurality of LEDs disposed along said elongate support structure in an electrical circuit with one another;

a cover overlying the elongate support structure and forming a housing enclosing the plurality of LEDs; and

one or more current-limiting circuits coupled between said battery and said plurality of LEDs;

wherein said one or more current-limiting circuits comprises an inductor electrically connected in series between said battery and said plurality of LEDs and a power diode electrically connected between ground and a node between said battery and said inductor;

a battery supplying power to the plurality of LEDs;

wherein said elongate support structure is a circuit board and said circuit board has an H-shaped cross-section.

7. The LED lighting unit according to claim 6, further comprising:

a pulse-width modulating circuit receiving DC power from said battery and supplying modulated power to said plurality of LEDs.

8. The LED lighting unit according to claim 7, further comprising:

one or more current-limiting circuits coupled between said pulse-width modulating circuit and said plurality of LEDs.

9. The LED lighting unit according to claim 8 wherein said one or more current-limiting circuits comprises one of a resistor, a current-limiting semiconductor circuit or a switching power supply type current limiter.

10. The LED lighting unit according to claim 8 wherein said one or more current-limiting circuits comprises an inductor electrically connected in series between said pulse-width modulating circuit and said plurality of LEDs and a power diode electrically connected between ground and a node between said pulse-width modulating circuit and said inductor.

11. The LED lighting unit according to claim 7 wherein said pulse-width modulating circuit is configured to modulate the plurality of LEDs to emit light at a frequency higher than 120 Hz.

12. The LED lighting unit according to claim 7 wherein said pulse-width modulating circuit is configured to modulate the plurality of LEDs to cyclically flash light from the LED lighting unit on and off.

13. The LED lighting unit according to claim 6 wherein said plurality of LEDs are arranged in spaced-apart groups along one surface of said elongate support structure.

14. An LED lighting unit for replacing a conventional fluorescent tube between the opposed electrical receptacles of a fluorescent lighting fixture, comprising:

an elongate support structure having a first end and a second end opposite said first end;

a first end cap disposed upon said first end of said elongate support structure;

a second end cap disposed upon said second end of said elongate support structure;

wherein each of said first end cap and said second end cap includes a fluorescent light fixture receptacle connector extending from each said end cap and configured for installing within the opposed electrical receptacles of the fluorescent lighting fixture;

a plurality of LEDs disposed along said elongate support structure in an electrical circuit with one another;

a cover overlying the elongate support structure and forming a housing enclosing the plurality of LEDs; and

one or more current-limiting circuits coupled between said battery and said plurality of LEDs;

wherein said one or more current-limiting circuits comprises an inductor electrically connected in series between said battery and said plurality of LEDs and a power diode electrically connected between ground and a node between said battery and said inductor;

a battery supplying power to the plurality of LEDs;

wherein said plurality of LEDs are arranged in spaced-apart groups along one surface of said elongate support structure.

15. The LED lighting unit according to claim 14 wherein said cover is a hollow tube surrounding said elongate support structure.

16. The LED lighting unit according to claim 14 wherein said battery generates DC power for a power supply coupled to said plurality of LEDs and providing regulated power to said plurality of LEDs using said DC power.

17. The LED lighting unit according to claim 16 wherein said power supply is of a switching type.

18. The LED lighting unit according to claim 16 wherein said power supply is packaged at least in part within said cover or in either one of said first end cap or said second end cap.