LED light fixture with internal power supply

• US 20080310162A1
• Filed: 06/13/2007
• Published: 12/18/2008
• Est. Priority Date: 06/13/2007
• Status: Active Grant

• Current Assignee: Electraled Incorporated
• Original Assignee: Electraled Incorporated
• Inventors: Thomas, James, Warner, Bryan T., Mosier, Jim, Lynd, David, Gatesman, Gary
• Granted Patent: US 7,651,245 B2
• Time in Patent Office: Days
• US Class Current: 362/249
• CPC Class Codes: F21K 9/69 Details of refractors forming part of the light source
• CPC Class Codes: F21S 2/005 of modular construction
• CPC Class Codes: F21V 15/01 Housings, e.g. material or assembling of housing parts F21V15/02 takes precedence housings forming signs or letters G09F13/04
• 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 21/30 Pivoted housings or frames
• 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 23/026 Fastening of transformers or ballasts
• CPC Class Codes: F21V 29/15 Thermal insulation
• CPC Class Codes: F21V 29/74 with fins or blades
• CPC Class Codes: F21V 29/75 with fins or blades having different shapes, thicknesses or spacing
• CPC Class Codes: F21V 29/763 the planes containing the fins or blades having the direction of the light emitting axis
• CPC Class Codes: F21V 29/767 the planes containing the fins or blades having directions perpendicular to the light emitting axis
• 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 31/03 with provision for venting for vehicle head lights F21S45/33; for vehicle rear lights F21S41/192
• CPC Class Codes: F21W 2131/10 Outdoor lighting
• CPC Class Codes: F21W 2131/40 Lighting for industrial, commercial, recreational or military use
• CPC Class Codes: F21W 2131/402 for working places
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

The invention provides a light fixture that includes a light engine, a rugged housing, and an internal power module that is thermally isolated. The light fixture includes several novel heat management features designed to thermally isolate the power supply in order to reduce the risk of failure and thereby increase the reliability of the light fixture. The light engine includes groups of light modules, each having a light emitting diode (LED) and a zener diode. The power module resides within a rear receptacle of the housing and includes a power supply, a box, and a cover that enclose the power supply. The housing also includes an arrangement of external fins that dissipate heat generated by the light engine. During operation, heat is generated by the light modules, namely the LEDs, and then is transferred along a flow path through a main body portion of the housing and the fins for dissipation to ambient without negatively impacting the power supply.

Claims

1. A light fixture comprising:

a housing having a main body portion and a plurality of fins that extend from the main body portion, wherein the fins define a receptacle;

a light engine assembly mounted to the main body portion, the light engine having a plurality of light modules comprising a LED and a zener diode mounted to a printed circuit board, the light engine further having a heat transfer element positioned between the circuit board and the body portion; and

,

a power module residing within the receptacle and connected to the main body portion, the power module including a box, an internal power supply, and an openable cover that encloses the power supply.

2. The light fixture of claim 1, wherein the main body portion has at least one internal passageway that receives supply leads extending between the power supply and the circuit board.

3. The light fixture of claim 1, wherein the housing has a flange that defines an inwardly extending receiver that provides a primary mounting surface for the light engine.

4. The light fixture of claim 3, wherein the flange provides a second mounting surface for a lens.

5. The light fixture of claim 1, wherein the heat transfer element is a thermal pad that contacts the rear surface of the circuit board.

6. The light fixture of claim 1, wherein the light modules are arranged into at least two parallel groups, and wherein the light modules within each group are serially arranged.

7. The light fixture of claim 6, wherein a pair of supply leads extend between the power supply and the circuit board, and wherein a positive supply lead supplies current to the first module of each group.

8. The light fixture of claim 1, wherein the main body portion includes at least one boss for mounting of the power module, and wherein a thermal insulator is utilized between the boss and the power module.

9. The light fixture of claim 1, wherein the cover includes an opening that receives power leads and a ground lead that connect with the power supply.

10. The light fixture of claim 9, further comprising a mounting arm, and wherein the power and ground leads extend through the mounting arm and into the cover.

11. A LED light fixture comprising:

a housing including a body portion and a plurality of fins extending rearward from the body portion, the fins defining a receptacle;

a light engine assembly mounted to the body portion, the light engine having a plurality of light modules comprised of a LED and a zener diode mounted to a printed circuit board; and

,

a power module residing within the receptacle, the power module including a power supply residing within an openable box within the receptacle.

12. The LED light fixture of claim 11, wherein first and second supply leads extend from the power supply through the body portion for connection with the circuit board.

13. The LED light fixture of claim 12, wherein the body portion includes a first passageway extending from the receptacle to the light engine, and wherein the first supply lead extends through the first passageway and is electrically connected to the circuit board.

14. The LED light fixture of claim 13, wherein the body portion includes a second passageway extending from the receptacle to the light engine, and wherein the second supply lead extends through the second passageway and is electrically connected to the circuit board.

15. The LED light fixture of claim 11, wherein first and second supply leads extend from the power supply to the circuit board, and wherein the light modules are divided into at least two parallel groups of serially arranged modules.

16. The LED light fixture of claim 15, wherein current flows along the first supply lead to a primary light module of each group and illuminates the LED therein, and wherein current exits the primary light modules along an interconnect trace.

17. The LED light fixture of claim 16, wherein current flows from the interconnect trace into a secondary light module to illuminate the LED therein, and wherein current exits the second light module along an interconnect trace.

18. The LED light fixture of claim 11, wherein the light engine assembly includes a thermal pad that is positioned between the circuit board and the body portion.

19. The LED light fixture of claim 11, further comprising a mounting arm extending from a cover segment of the box of the power module, wherein electrical leads extend along the mounting arm and through an opening in the cover for connection to the power supply.

20. The LED light fixture of claim 19, wherein the cover is pivotally connected to the box to allow an operator to access the power supply.

21. A LED light fixture comprising:

a housing having a main body and an array of fins extending rearward from the main body;

a light engine assembly mounted to a front receiver of the main body, the light engine having a plurality of light modules comprising a LED and a zener diode mounted to a printed circuit board, wherein the light modules are divided into at least two groups that are parallel to each other, and wherein the light modules in each group are serial to each other;

a power module secured to the main body of the housing, the power module including a power supply embedded within a box; and

,

wherein during operation, heat generated by the LEDs passes through the circuit board and then said heat is dissipated by the main body and the fins.

22. The LED light fixture of claim 21, wherein a first quantity of said heat flows along a first flow path into the main body for dissipation to ambient.

23. The LED light fixture of claim 22, wherein a second quantity of said heat flows along a second flow path into the fins for dissipation to ambient.

24. The LED light fixture of claim 23, wherein the quantity of heat dissipated by the second flow path exceeds the heat dissipated by the fist flow path.

25. The LED light fixture of claim 21, wherein a cavity is defined between the power module and the main body, and wherein the cavity is adapted to thermally isolate the power supply.

26. The LED light fixture of claim 25, wherein the cavity is further defined between the box and an arrangement of inner fins and intermediate fins.

27. The LED light fixture of claim 21, wherein the fins define a receptacle and the power module is positioned within the receptacle.

28. The LED light fixture of claim 21, further comprising a mounting arm extending from a cover segment of the box of the power module, and wherein the cover is pivotally connected to the box to allow an operator to access the power supply.