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

• US 8,237,582 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 L
• Application Number:
  US12/359,090
• Publication Number:
  US 20090128052A1
• 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 distributed 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. An LED driver, comprising:

circuitry for driving a subset of LEDs within at least one multi-chip LED package; and

a controller for activating and deactivating the circuitry, wherein the controller monitors an operating parameter of the LED driver and once the operating parameter of the LED driver satisfies a predetermined value, then the controller deactivates the circuitry and sends a signal to a second LED driver that causes the second LED driver to activate a second subset of LEDs within the at least one multi-chip LED package associated with the second LED driver,

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

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

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

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

4. The LED driver of claim 1, wherein the operating parameter corresponds to an output of the LED driver and is selected from the group consisting of:

output current, output voltage, output power.

5. The LED driver of claim 1, wherein the signal is a power signal.

6. A single light fixture, comprising:

a plurality of LED drivers, wherein each LED driver includes a controller and at least one of the LED drivers is connected to at least one other LED driver; and

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

wherein each of the controllers of the at least one LED driver is operable to;

in response to a received signal, activate its corresponding LED driver so that the subset of LEDs associated with the LED driver is activated;

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

once the LED driver satisfies the predetermined value, deactivate the LED driver so that the subset of LEDs associated with the LED driver is deactivated and transmit a signal to the other LED driver.

7. The light fixture of claim 6, further comprising:

a multi-chip LED driver, wherein the multi-chip LED driver is connected to at least two of the subsets of LEDs and to a selected one of the LED drivers and wherein the multi-chip LED driver includes a multi-chip controller,

wherein the controller of the selected LED driver is operable to;

in response to a received signal, activate its corresponding LED driver so that the subset of LEDs associated with the selected LED driver is activated;

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

once the selected LED driver satisfies the predetermined value, deactivate the LED driver so that the subset of LEDs associated with the selected LED driver is deactivated and transmit a selected signal to the multi-chip LED driver, and

wherein the multi-chip controller is operable to;

in response to the signal received from the selected LED driver, concurrently activate the subsets of LEDs connected to the multi-chip LED driver.

8. The light fixture of claim 6, wherein the signal is a power signal.

9. A method for controlling a plurality of LED drivers within a single light fixture, comprising:

activating, by a first LED driver, a first subset of LEDs within at least one multi-chip LED package;

monitoring, by a first controller associated with the first LED driver, an operating parameter of the first LED driver;

once the operating parameter satisfies a predetermined value, deactivating the first LED driver and the first subset of LEDs and transmitting, by the first controller, a signal to a second LED controller associated with a second LED driver;

in response to receiving the signal, activating, by the second LED driver, 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, the first subset of LEDs is distinct from the second subset of LEDs, and the first controller is distinct from the second controller; 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.

10. The method of claim 9, 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 subset of LEDs, and expected lumen depreciation of the first subset of LEDs.

11. The method of claim 9, 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.

12. The method of claim 9, further comprising:

monitoring, by the second controller, a second operating parameter of the second LED driver;

once the second operating parameter satisfies a second predetermined value, deactivating the second LED driver and the second subset of LEDs and transmitting, by the second controller, a second signal to a multi-chip LED controller associated with a multi-chip LED driver, wherein the multi-chip LED driver is connected to the first subset of LEDs and the second subset of LEDs; and

concurrently activating, by the multi-chip LED driver, the first subset of LEDs and the second subset of LEDs.

13. The method of claim 12, 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.

14. The method of claim 12, 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.

15. The method of claim 9, wherein the signal is a power signal.

20. The method of claim 15, wherein the signal is a power signal.

16. A method for controlling a plurality of LED drivers within a single light fixture, comprising:

activating, by a first LED driver, a first subset of LEDs within at least one multi-chip LED package;

monitoring, by a first controller associated with the first LED driver, light intensity output by the first subset of LEDs;

once the light intensity satisfies a predetermined value, deactivating the first LED driver and the first subset of LEDs and transmitting, by the first controller, a signal to a second LED controller associated with a second LED driver;

in response to receiving the signal, activating, by the second LED driver, 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, the first subset of LEDs is distinct from the second subset of LEDs, and the first controller is distinct from the second controller; 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.

17. The method of claim 16, further comprising:

monitoring, by the second controller, 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 transmitting, by the second controller, a second signal to a multi-chip LED controller associated with a multi-chip LED driver, wherein the multi-chip LED driver is connected to the first subset of LEDs and the second subset of LEDs; and

concurrently activating, by the multi-chip LED driver, the first subset of LEDs and the second subset of LEDs.

18. The method of claim 17, 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.

19. The method of claim 17, 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.