Systems and methods for active thermal management

• US 9,967,940 B2
• Filed: 05/04/2012
• Issued: 05/08/2018
• Est. Priority Date: 05/05/2011
• Status: Active Grant

• Current Assignee: Integrated Illumination Systems, Inc.
• Original Assignee: Integrated Illumination Systems, Inc.
• Inventors: Zampini, II, Thomas Lawrence, Valois, Charles Bernard
• Primary Examiner(s): Owens, Douglas W
• Assistant Examiner(s): LUONG, HENRY T
• Application Number:
  US13/464,747
• Publication Number:
  US 20120280625A1
• Time in Patent Office: 2,195 Days
• CPC Class Codes: H05B 45/18 using temperature feedback
• CPC Class Codes: H05B 45/20 Controlling the colour of the light

Abstract

The present disclosure is directed to a solution providing active thermal management that has multiple innovations and advantages. In some aspects, the design of the active thermal management (ATM) device is not a threshold clamp and instead, is a non-linear equation that proportionally changes relative to the dimming input. In some aspects, the innovation of the ATM design is how ATM works while the light is being dimmed. The design anticipates overheating by reducing power before the product gets to the maximum temperature threshold. The design also may include an equation that predicts the LED die temperature as a function of product case temperature. The ATM may operate responsive to one or more of a plurality of profile or power curves.

Claims

1. A method for managing intensity to a light source responsive to temperature of the light source, the method comprising:

(a) intercepting, by an active thermal management device, prior to input to the light source of a lighting fixture, an incoming signal from a dimmer, the incoming signal comprising a plurality of portions, each of the plurality of portions comprising a duration of a duty cycle identifying a first intensity for the light source, a first portion of the plurality of portions comprising an instruction for assigning a status of one of a master or a slave to the light source;

(b) measuring, by the active thermal management device, a temperature of an enclosure of the lighting fixture to determine the temperature of the light source;

(c) determining, by the active thermal management device, a second intensity less than the first intensity identified by the incoming signal from the dimmer, the second intensity determined from a function of both the first intensity identified by the incoming signal from the dimmer and the temperature of the light source determined from the measured temperature of the enclosure of the lighting fixture;

(d) modifying, by the active thermal management device responsive to the determination and prior to input to the light source, the duty cycle of the each of the plurality of portions of the incoming signal to provide a second signal identifying the second intensity at which to emit light, the second intensity less than the first intensity, while maintaining the first portion comprising the instruction for assigning the status of one of the master or the slave to the light source; and

(e) outputting, by the active thermal management device responsive to the determination, the second signal as input to the light source, the second signal identifying both the second intensity less than the first intensity and assigning the status of one of the master or the slave to the light source based on the first portion of the incoming signal that is maintained in the second signal.

2. The method of claim 1, wherein step (a) further comprise receiving, by the active thermal management device, the incoming signal comprising a dimming signal.

3. The method of claim 1, wherein step (b) further comprises measuring, by the active thermal management device, a temperature of air within the enclosure of the lighting fixture.

4. The method of claim 1, wherein step (b) further comprises predicting a temperature of a LED of the light source based on the measured temperature of the enclosure of the lighting fixture and using the predicted LED temperature as the temperature of the light source.

5. The method of claim 1, wherein step (c) further comprises determining the second intensity from the function comprising an intensity curve comprising a curve of a selection of second intensity values based on values of the first intensity and the temperature of the light source.

6. The method of claim 1, wherein step (c) further comprises determining the second intensity from the function comprising a non-linear relationship between a first signal and the second signal.

7. The method of claim 1, wherein step (c) further comprises determining the second intensity from the function comprising a temperature compensation factor applied to a dimming level of the first intensity.

8. The method of claim 1, wherein step (e) further comprises outputting the second intensity to reduce power to the light source prior to reaching a predetermined threshold of a maximum temperature.

9. The method of claim 1, wherein step (e) further comprises outputting the second intensity to reduce power to the light source while dimming the light source.

10. The method of claim 1, wherein the active thermal management device is enclosed within the lighting fixture.

11. The method of claim 1, wherein the active thermal management device comprises a diode for measuring the temperature of the enclosure of the lighting fixture.

12. A system for managing intensity to a light source responsive to temperature of the light source, the system comprising:

an active thermal management device that intercepts, prior to input to the light source of a lighting fixture, an incoming signal from a dimmer, the incoming signal comprising a plurality of portions, each of the plurality of portions comprising a duration of a duty cycle identifying a first intensity for the light source, a first portion of the plurality of portions comprising an instruction for assigning a status of one of a master or a slave to the light source;

a temperature measuring component of the active thermal management device that measures a temperature of an enclosure of the lighting fixture to determine the temperature of the light source;

a processor of the active thermal management device that;

determines a second intensity less than the first intensity identified by the incoming signal from the dimmer, the second intensity determined from a function of both the first intensity identified by the incoming signal from the dimmer and the temperature of the light source determined from the measured temperature of the enclosure of the lighting fixture; and

modifies, responsive to the determination and prior to input to the light source, the duty cycle of each of the plurality of portions of the incoming signal to provide a second signal identifying the second intensity at which to emit light, the second intensity less than the first intensity, while maintaining the first portion comprising the instruction for assigning the status of one of the master or the slave to the light source,

wherein the active thermal management device responsive to the determination, outputs the second signal as input to the light source, the second signal identifying both the second intensity less than the first intensity and assigning the status of one of the master or the slave to the light source based on the first portion of the incoming signal that is maintained in the second signal.

13. The system of claim 12, wherein the active thermal management device receives the incoming signal comprising a dimming signal.

14. The system of claim 12, wherein the temperature measuring component measures a temperature of air within the enclosure of the lighting fixture.

15. The system of claim 12, wherein the processor predicts a temperature of a LED of the lighting fixture based on the measured temperature of the light fixture and uses the predicted LED temperature as the temperature.

16. The system of claim 12, wherein the processor determines the second intensity from the function comprising an intensity curve comprising a curve of a selection of second intensity values based on values of the first intensity and the temperature of the enclosure of the lighting fixture.

17. The system of claim 12, wherein the processor determines the second intensity from the function comprising a non-linear relationship between a first signal and the second signal.

18. The system of claim 12, wherein the processor determines the second intensity from the function comprising a temperature compensation factor applied to a dimming level of the first intensity.

19. The system of claim 12, wherein the active thermal management device outputs the second intensity to reduce power to the light source prior to reaching a predetermined threshold of a maximum temperature.

20. The system of claim 12, wherein the active thermal management device outputs the second intensity to reduce power to the light source while dimming the light.

21. The system of claim 12, wherein the temperature measurement component comprises a diode.

22. The system of claim 12, wherein the active thermal management device is enclosed within the lighting fixture.