Light tube and power supply circuit

• US 9,739,428 B1
• Filed: 06/20/2016
• Issued: 08/22/2017
• Est. Priority Date: 02/11/2000
• Status: Expired due to Fees

• 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): Ton, Anabel
• Application Number:
  US15/187,456
• Time in Patent Office: 428 Days
• Field of Search: 362222
• 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 extending between a first end and a second end, the bulb portion comprising a support structure, a plurality of white light emitting diodes (LEDs) and an elongate light-transmissive cover. The support structure has a first surface extending between the first end and the second end. The plurality of LEDs are supported by the first surface and arranged between the first end and the second end. The elongate light-transmissive cover extends between the first end and the second end and over the first surface of the support structure. A first end cap and a second end cap are disposed on the first end and the second end, respectively, each configured to fit with a socket for a fluorescent light tube. A power supply circuit is configured to provide power to the plurality of LEDs. The plurality of LEDs are arranged to emit light through the elongate light-transmissive cover and at least a portion of the power supply circuit is packaged inside at least one of the end caps.

Claims

1. A method, comprising:

replacing a fluorescent light tube with an LED light tube in a socket for the fluorescent light tube,

the LED light tube comprising;

a pair of end caps each having a connector for connecting to the socket;

a bulb portion extending between the end caps, the bulb portion comprising a support, a light-transmissive cover, and a plurality of light emitting diodes (LEDs) disposed on the support at different locations between the end caps and arranged so that light emitted by the LEDs is emitted by the bulb portion through the light-transmissive cover; and

a power supply circuit; and

delivering power to the LED light tube in the socket via a ballast for the fluorescent light tube to provide area lighting using the LED light tube,

wherein one or more components of the power supply circuit are packaged in one of the end caps.

2. The method of claim 1, wherein the power supply circuit comprises a rectifier circuit that receives AC power from the ballast and converts the AC power to DC power.

3. The method of claim 2, wherein the power supply circuit comprises a current-limiting circuit that limits current from the rectifier to the LEDs.

4. The method of claim 3, wherein the current-limiting circuit comprises a resistor.

5. The method of claim 3, wherein the current-limiting circuit comprises an inductor.

6. The method of claim 3, wherein the current-limiting circuit comprises a current-limiting semiconductor circuit.

7. The method of claim 2, wherein the power supply circuit further comprises a pulse width modulator (PWM) circuit that modulates power from the rectifier circuit to the LEDs.

8. The method of claim 1, wherein power from the ballast is modulated using a pulse width modulator (PWM) circuit.

9. The method of claim 8, wherein the power supply circuit comprises the PWM circuit.

10. The method of claim 8, wherein the power is modulated to adjust an intensity of the light from the light tube.

11. The method of claim 10, wherein the intensity of the light from the light tube is adjusted by a user.

12. The method of claim 8, wherein the power is modulated to improve an efficiency of the LED light tube relative to providing unmodulated power to the LED light tube.

13. The method of claim 8, wherein the power is modulated to regulate an intensity of light emitted from the LED light tube.

14. The method of claim 13, wherein the intensity is regulated to compensate for voltage fluctuations in the power delivered to the LED light tube.

15. The method of claim 13, wherein the intensity is regulated to compensate for temperature changes of the LED light tube.

16. The method of claim 8, wherein the power is modulated to increase a pulse frequency to the LEDs to a higher frequency than an AC frequency of power delivered to the ballast.

17. The method of claim 1, wherein the LEDs are white-light emitting LEDs.

18. The method of claim 1, wherein the support comprises a pair of sidewalls on opposing sides of a surface of the support supporting the LEDs, the sidewalls each extending between the end caps.

19. The method of claim 18, wherein the sidewalls extend from the surface of the support higher than at least some of the LEDs.

20. The method of claim 18, wherein the sidewalls and surface form a channel extending between the end caps.

21. The method of claim 1, wherein the ballast is an electronic ballast.

22. The method of claim 1, wherein the ballast is a magnetic ballast.

23. The method of claim 1, wherein the connectors are bi-pin connectors.

24. The method of claim 1, wherein the tube provides area lighting in a building.

25. The method of claim 1, wherein the tube provides area lighting in a vehicle.

47. The method of claim 1, wherein the support comprises a circuit board.

48. The method of claim 18, wherein the sidewalls extend perpendicularly to the surface of the support supporting the LEDs.

26. A method, comprising:

replacing a fluorescent light tube with an LED light tube in a socket for the fluorescent light tube,

the LED light tube comprising;

a pair of end caps each having a connector for connecting to the socket;

a bulb portion extending between the end caps, the bulb portion comprising a support, a light-transmissive cover, and a plurality of light emitting diodes (LEDs) disposed on the support at different locations between the end caps and arranged so that light emitted by the LEDs is emitted by the bulb portion through the light-transmissive cover; and

a power supply circuit; and

delivering power to the LED light tube in the socket via a ballast for the fluorescent light tube to provide area lighting using the LED light tube,

wherein the support comprises a pair of sidewalls on opposing sides of a surface of the support supporting the LEDs, the sidewalls each extending between the end caps.

27. The method of claim 26, wherein the sidewalls extend above the surface of the support higher than at least some of the LEDs.

28. The method of claim 26, wherein the sidewalls and the surface form a channel extending between the end caps.

29. The method of claim 26, wherein the power supply circuit comprises a rectifier circuit that receives AC power from the ballast and converts the AC power to DC power.

30. The method of claim 29, wherein the power supply circuit comprises a current-limiting circuit that limits current from the rectifier to the LEDs.

31. The method of claim 30, wherein the current-limiting circuit comprises a component selected from the group consisting of a resistor and an inductor.

32. The method of claim 30, wherein the current-limiting circuit comprises a current-limiting semiconductor circuit.

33. The method of claim 29, wherein the power supply circuit further comprises a pulse width modulator (PWM) circuit that modulates power from the rectifier circuit to the LEDs.

34. The method of claim 26, wherein power from the ballast is modulated using a pulse width modulator (PWM) circuit.

35. The method of claim 34, wherein the power supply circuit comprises the PWM circuit.

36. The method of claim 34, wherein the power is modulated to adjust an intensity of the light from the light tube.

37. The method of claim 36, wherein the intensity of the light from the light tube is adjusted by a user.

38. The method of claim 34, wherein the power is modulated to improve an efficiency of the LED light tube relative to providing unmodulated power to the LED light tube.

39. The method of claim 34, wherein the power is modulated to regulate an intensity of light emitted from the LED light tube.

40. The method of claim 39, wherein the intensity is regulated to compensate for voltage fluctuations in the power delivered to the LED light tube.

41. The method of claim 39, wherein the intensity is regulated to compensate for temperature changes of the LED light tube.

42. The method of claim 34, wherein the power is modulated to increase a pulse frequency to the LEDs to a higher frequency than an AC frequency of power delivered to the ballast.

43. The method of claim 26, wherein the LEDs are white-light emitting LEDs.

44. The method of claim 26, wherein the connectors are bi-pin connectors.

45. The method of claim 26, wherein the support comprises a circuit board.

46. The method of claim 26, wherein the sidewalls extend perpendicularly to the surface of the support supporting the LEDs.