Thermal Management of LED Lighting Systems

• US 20100124058A1
• Filed: 11/18/2009
• Published: 05/20/2010
• Est. Priority Date: 11/18/2008
• Status: Active Grant

• Current Assignee: ABL IP Holding LLC (Acuity Brands, Inc.)
• Original Assignee: ABL IP Holding LLC (Acuity Brands, Inc.)
• Inventors: Miller, Michael R.
• Granted Patent: US 8,240,885 B2
• Time in Patent Office: Days
• US Class Current: 362/249.20
• CPC Class Codes: F21S 8/038 intended to be mounted on a light track suspended from a light track F21S8/066; details of supporting elements displaceable along a guiding element F21V21/34
• CPC Class Codes: F21S 8/088 with lighting device mounted on top of the standard, e.g. for pedestrian zones
• CPC Class Codes: F21V 21/30 Pivoted housings or frames
• CPC Class Codes: F21V 29/63 using electrically-powered vibrating means; using ionic wind
• CPC Class Codes: F21V 29/67 characterised by the arrangement of fans
• CPC Class Codes: F21V 29/773 the planes containing the fins or blades having the direction of the light emitting axis
• CPC Class Codes: F21V 29/83 the elements having apertures, ducts or channels, e.g. heat radiation holes
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

Embodiments of the invention provide thermal management systems for LED light fixtures. In one embodiment, an LED track light fixture includes a lighting assembly, a fixture housing mounted to the lighting assembly and having a plurality of apertures, and a mounting structure that affixes the fixture housing to a track. In this embodiment, the lighting assembly includes a heat sink, a reflector, at least one light emitting diode, and a synthetic jet actuator. In a second exemplary embodiment, a sealed, enclosed LED light fixture includes a lighting assembly, along with an enclosure and a fixture housing surrounding the lighting assembly. In this embodiment, the lighting assembly includes at least one light emitting diode, a thermoelectric cooler, and at least one heat sink. In some embodiments, a forced air cooling device may be located between the printed circuit board and the thermoelectric cooler.

Claims

1. An LED track light fixture comprising:

a. a fixture housing comprising a plurality of apertures;

b. a lighting assembly positioned at least partially within the fixture housing and comprising;

i. a heat sink with a plurality of fins;

ii. a reflector mounted on the heat sink;

iii. at least one light emitting diode supported on the heat sink, wherein the at least one light emitting diode is supported to emit light towards the reflector; and

iv. a synthetic jet actuator positioned adjacent the heat sink; and

c. a mounting structure for mounting the fixture housing to a track.

2. The LED track light fixture of claim 1, wherein the at least one light emitting diode is mounted on a printed circuit board and wherein the printed circuit board is mounted to the heat sink.

3. The LED track light fixture of claim 2, further comprising a thermal interface material positioned between the printed circuit board and the heat sink.

4. The LED track light fixture of claim 1, wherein the synthetic jet actuator comprises a plurality of rectangular nozzles that direct air flow across the plurality of fins.

5. The LED track light fixture of claim 4, wherein the plurality of rectangular nozzles direct air flow along a plurality of inner heat sink channels formed between the plurality of fins.

6. The LED track light fixture of claim 4, wherein the plurality of rectangular nozzles receive air flow along a plurality of outer heat sink channels formed between the plurality of fins.

7. An enclosed LED light fixture comprising:

a. a lighting assembly comprising;

i. at least one light emitting diode positioned on a first side of a printed circuit board;

ii. a thermoelectric cooler comprising a cold side and a hot side, wherein the cold side of the thermoelectric cooler is adjacent a second side of the printed circuit board; and

iii. a heat sink comprising a first side and a second side, wherein the heat sink is mounted to the thermoelectric cooler so that the first side of the heat sink is adjacent the hot side of the thermoelectric cooler and wherein a plurality of fins extend from the second side of the heat sink; and

b. an at least partially transparent enclosure and a fixture housing that surround the lighting assembly.

8. The enclosed LED light fixture of claim 7, further comprising a forced air cooling device that is located between the second side of the printed circuit board and the cold side of the thermoelectric cooler.

9. The enclosed LED light fixture of claim 8, wherein the forced air cooling device comprises a synthetic jet actuator.

10. The enclosed LED light fixture of claim 7, wherein the heat sink is mounted to the fixture housing.

11. The enclosed LED light fixture of claim 7, further comprising an external air movement device positioned in the fixture housing adjacent the plurality of fins of the heat sink.

12. The enclosed LED light fixture of claim 11, wherein the external air movement device comprises a fan or a synthetic jet actuator.

13. The enclosed LED light fixture of claim 7, wherein the enclosure is mounted to the first side of the heat sink to form a sealed, enclosed environment.

14. An enclosed LED light fixture comprising:

a. a lighting assembly comprising;

i. at least one light emitting diode positioned on a first side of a printed circuit board;

ii. a synthetic jet actuator comprising a nozzle surface and a mounting surface, wherein the nozzle surface of the synthetic jet actuator is adjacent a second side of a printed circuit board;

iii. a thermoelectric cooler comprising a cold side and a hot side, wherein the cold side of the thermoelectric cooler is affixed to the mounting surface of the synthetic jet actuator; and

iv. a heat sink comprising a first side and a second side, wherein the heat sink is mounted to the thermoelectric cooler so that the first side of the heat sink is adjacent the hot side of the thermoelectric cooler and wherein a plurality of fins extend from the second side of the heat sink; and

b. an at least partially transparent enclosure and a fixture housing that surround the lighting assembly.

15. The enclosed LED light fixture of claim 14, further comprising a plurality of nozzles on the nozzle surface of the synthetic jet actuator that direct air flow away from the second side of the printed circuit board.

16. The enclosed LED light fixture of claim 14, further comprising an external air movement device positioned in the fixture housing adjacent the plurality of fins of the heat sink.

17. The enclosed LED light fixture of claim 16, wherein the external air movement device comprises a fan or a synthetic jet actuator.

18. The enclosed LED light fixture of claim 14, wherein the enclosure is mounted to the first side of the heat sink to form a sealed, enclosed environment.