Extended life LED fixture with central controller and multi-chip LEDs

• US 8,237,581 B2
• Filed: 01/23/2009
• Issued: 08/07/2012
• Est. Priority Date: 10/09/2007
• Status: Active Grant

• Current Assignee: ABL IP Holding LLC (Acuity Brands, Inc.)
• Original Assignee: ABL IP Holding LLC (Acuity Brands, Inc.)
• Inventors: Ries, Jack Leighton II
• Primary Examiner(s): Crosland, Donnie
• Application Number:
  US12/359,069
• Publication Number:
  US 20090128060A1
• Time in Patent Office: 1,292 Days
• Field of Search: 340/815.45
• US Class Current: 340/815.45
• CPC Class Codes: H05B 45/30 Driver circuits
• CPC Class Codes: H05B 47/155 Coordinated control of two or more light sources
• CPC Class Codes: H05B 47/29 Circuits providing for substitution of the light source in case of its failure
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

An LED fixture includes multiple LED drivers and a multi-chip LED package so that the lifetime of the fixture is a multiple of the lifetime of a conventional fixture that uses only a single LED driver. A central controller activates and deactivates the LED drivers so that different subsets of LEDs within the LED package are driven sequentially. An optional multi-chip LED driver concurrently drives multiple subsets of LEDs that were previously driven by the LED drivers.

Claims

1. A method for controlling a plurality of LED drivers within a single light fixture using a central controller, comprising:

activating a first LED driver so that it drives a first subset of LEDs within at least one multi-chip LED package;

monitoring the first LED driver;

once an operating parameter of the first LED driver satisfies a predetermined value, deactivating the first LED driver and the first subset of LEDs; and

activating a second LED driver so that it drives a second subset of LEDs within the at least one multi-chip LED package,

wherein the first LED driver is distinct from the second LED driver and the first subset of LEDs is distinct from the second subset of LEDs, and

wherein the first LED driver, the second LED driver, and the at least one multi-chip LED package are within the single light fixture.

2. The method of claim 1, wherein the operating parameter is operating time and the predetermined value is based on a selection from the group consisting of:

expected operating life of the first LED driver, expected operating life of the first LED lamp, and expected lumen depreciation of the first LED lamp.

3. The method of claim 1, wherein the operating parameter corresponds to an output of the first LED driver and the predetermined value is based on a selection from the group consisting of:

a value that indicates a failure of the first LED driver and a value that indicates a performance degradation of the first LED driver.

4. The method of claim 1, further comprising:

monitoring the second LED driver;

once a second operating parameter of the second LED driver satisfies a second predetermined value, deactivating the second LED driver and the second subset of LEDs; and

activating a multi-chip LED driver that concurrently drives the first subset of LEDs and the second subset of LEDs.

5. The method of claim 4, wherein the first LED driver drives the first subset of LEDs at a first level and the second LED driver drives the second subset of LEDs at a second level and wherein the multi-chip LED driver drives the first subset of LEDs at approximately the first level and drives the second subset of LEDs at approximately the second level.

6. The method of claim 4, wherein the first LED driver drives the first subset of LEDs at a first level and the second LED driver drives the second subset of LEDs at a second level and wherein the multi-chip LED driver drives the first subset of LEDs at a level that is distinct from the first level and drives the second subset of LEDs at a level that is distinct from the second level.

7. A single light fixture, comprising:

a plurality of LED drivers;

a plurality of subsets of LEDs, wherein each subset of LEDs includes a plurality of LEDs within at least one multi-chip LED package and each subset of LEDs is connected to a distinct LED driver; and

a central controller, connected to each of the LED drivers, wherein the controller is operable to;

activate a first one of the LED drivers so that a first subset of LEDs associated with the first LED driver is activated;

monitor the first LED driver to determine when an operating parameter of the first LED driver satisfies a predetermined value; and

once the first LED driver satisfies the predetermined value, deactivate the first LED driver and activate a second one of the LED drivers so that the first subset of LEDs is deactivated and a second subset of LEDs associated with the second LED driver is activated.

8. The light fixture of claim 7, further comprising:

a multi-chip LED driver, wherein the multi-chip LED driver is connected to each of the subsets of LEDs and is connected to the central controller;

wherein for each of the LED drivers, other than the first LED driver, the central controller is further operable to;

monitor the LED driver to determine when an operating parameter of the LED driver satisfies the predetermined value;

once the LED driver satisfies the predetermined value, deactivate the LED driver;

if at least one of the LED drivers has not been activated, then activate one of the LED drivers that has not been activated; and

if all of the LED drivers have been activated, then activate the multi-chip LED driver so that all of the subsets of LEDs are activated concurrently.

9. The light fixture of claim 7, further comprising:

a multi-chip LED driver, wherein the multi-chip LED driver is connected to at least the first subset of LEDs and the second subset of LEDs and is connected to the central controller; and

wherein the central controller is further operable to;

monitor the second LED driver to determine when a second operating parameter of the second LED driver satisfies a second predetermined value; and

once the second LED driver meets the second predetermined value, deactivate the second LED driver and activate the multi-chip LED driver so that the first and the second subsets of LEDs are activated concurrently.

10. The light fixture of claim 9, wherein the first LED driver drives the first subset of LEDs at a first level and the second LED driver drives the second subset of LEDs at a second level and wherein the multi-chip LED driver drives the first subset of LEDs at approximately the first level and drives the second subset of LEDs at approximately the second level.

11. The light fixture of claim 8, wherein the first LED driver drives the first subset of LEDs at a first level and the second LED driver drives the second subset of LEDs at a second level, and wherein the multi-chip LED driver drives the first subset of LEDs at a level distinct from the first level and drives the second subset of LEDs at a level distinct from the second level.

12. The light fixture of claim 7, wherein the operating parameter is operating time and the central controller monitors the operating time of the LED drivers.

13. The light fixture of claim 7, wherein the operating parameter corresponds to an output of the first LED driver and the central controller monitors the output of the first LED driver.

14. A single light fixture, comprising:

a plurality of LED drivers;

a plurality of subsets of LEDs, wherein each subset of LEDs includes a plurality of LEDs within at least one multi-chip LED package and each subset of LEDs is connected to a distinct LED driver;

a multi-chip LED driver, wherein the multi-chip LED driver is connected to at least two of the subsets of LEDs; and

a central controller, connected to each of the LED drivers and the multi-chip LED driver, wherein the controller is operable to;

activate a first one of the LED drivers so that a first subset of LEDs associated with the first LED driver is activated;

monitor the first LED driver to determine when an operating parameter of the first LED driver satisfies a predetermined value;

once the first LED driver satisfies the predetermined value, deactivate the first LED driver and activate a second one of the LED drivers so that the first subset of LEDs is deactivated and a second subset of LEDs associated with the second LED driver is activated;

monitor the second LED driver to determine when a second operating parameter of the second LED driver satisfies a second predetermined value;

once the second LED driver satisfies the second predetermined value, deactivate the second LED driver and activate the multi-chip LED driver so that the multi-chip LED driver concurrently activates the first subset of LEDs and the second subset of LEDs.

15. The light fixture of claim 14, wherein the operating parameter is operating time and the predetermined value is based on a selection from the group consisting of:

expected operating life of the LED drivers, expected operating life of the first LED lamp, and expected lumen depreciation of the first LED lamp.

16. The light fixture of claim 14, wherein the operating parameter corresponds to an output of the first LED driver and the predetermined value is based on a selection from the group consisting of:

a value that indicates a failure of the first LED driver and a value that indicates a degradation of the first LED driver.

17. The light fixture of claim 14, wherein the first LED driver drives the first subset of LEDs at a first level and the second LED driver drives the second subset of LEDs at a second level and wherein the multi-chip LED driver drives the first subset of LEDs at approximately the first level and drives the second subset of LEDs at approximately the second level.

18. The light fixture of claim 14, wherein the first LED driver drives the first subset of LEDs at a first level and the second LED driver drives the second subset of LEDs at a second level and wherein the multi-chip LED driver drives the first subset of LEDs at a level that is distinct from the first level and drives the second subset of LEDs at a level that is distinct from the second level.

19. A method for controlling a plurality of LED drivers within a single light fixture using a central controller, comprising:

activating a first LED driver so that it drives a first subset of LEDs within at least one multi-chip LED package;

monitoring light intensity output by the first subset of LEDs;

once the light intensity output by the first subset of LEDs satisfies a predetermined value, deactivating the first LED driver and the first subset of LEDs; and

activating a second LED driver so that it drives a second subset of LEDs within the at least one multi-chip LED package,

wherein the first LED driver is distinct from the second LED driver and the first subset of LEDs is distinct from the second subset of LEDs, and

wherein the first LED driver, the second LED driver, and the at least one multi-chip LED package are within the single light fixture.

20. The method of claim 19, further comprising:

monitoring light intensity output by the second subset of LEDs;

once the light intensity output by the second subset of LEDs satisfies a second predetermined value, deactivating the second LED driver and the second subset of LEDs; and

activating a multi-chip LED driver that concurrently drives the first subset of LEDs and the second subset of LEDs.

21. The method of claim 20, wherein the first LED driver drives the first subset of LEDs at a first level and the second LED driver drives the second subset of LEDs at a second level and wherein the multi-chip LED driver drives the first subset of LEDs at approximately the first level and drives the second subset of LEDs at approximately the second level.

22. The method of claim 20, wherein the first LED driver drives the first subset of LEDs at a first level and the second LED driver drives the second subset of LEDs at a second level and wherein the multi-chip LED driver drives the first subset of LEDs at a level that is distinct from the first level and drives the second subset of LEDs at a level that is distinct from the second level.