Light emitting diode replacement lamp
View Patent ↗Thermal management and control techniques for light emitting diode and other incandescent replacement light technologies using a current controller are disclosed.
1. A method of thermal management of an illumination device comprising a light-emitting diode (LED), the method comprising:
(a) generating a regulated current from a source voltage;
(b) supplying the regulated current to the LED;
(c) generating a sense voltage based on (i) the regulated current and (ii) an LED temperature resulting from heat produced by the LED; and
(d) modifying the regulated current supplied to the LED based on the sense voltage, whereby the LED temperature is maintained within a non-destructive range of LED temperatures,
wherein generating the sense voltage comprises flowing at least a portion of the regulated current through a temperature-dependent resistance responsive to the LED temperature resulting from heat produced by the LED.
2. The method of claim 1 , further comprising repeating steps (b)-(d) at least once.
3. The method of claim 1 , wherein the temperature-dependent resistance has a positive temperature coefficient.
4. The method of claim 1 , wherein the temperature-dependent resistance has a negative temperature coefficient.
5. The method of claim 1 , wherein the temperature-dependent resistance comprises a thermistor.
6. The method of claim 1 , wherein the temperature-dependent resistance is disposed in contact with the LED.
7. The method of claim 1 , wherein the temperature-dependent resistance is spaced away from the LED by a thermal pathway comprising air.
8. The method of claim 1 , wherein the temperature-dependent resistance is spaced away from the LED by a thermal pathway comprising a non-air fluid medium.
9. The method of claim 1 , wherein generating the sense voltage comprises flowing a second portion of the regulated current through a resistor connected in parallel to the temperature-dependent resistance.
10. The method of claim 1 , wherein generating the sense voltage comprises amplifying at least a portion of the regulated current, an amplitude of the amplification being based on the LED temperature resulting from heat produced by the LED.
11. The method of claim 1 , wherein the temperature-dependent resistance is (i) disposed on a printed circuit board and (ii) proximate the LED.
12. The method of claim 11 , wherein the LED is disposed on the printed circuit board.
13. A method of thermal management of an illumination device comprising a light-emitting diode (LED), the method comprising:
(a) generating a regulated current from a source voltage;
(b) supplying the regulated current to the LED;
(c) generating a sense voltage based on (i) the regulated current and (ii) an LED temperature resulting from heat produced by the LED; and
(d) modifying the regulated current supplied to the LED based on the sense voltage, whereby the LED temperature is maintained within a non-destructive range of LED temperatures,
wherein modifying the regulated current comprises decreasing the regulated current when the LED temperature resulting from heat produced by the LED decreases.
14. The method of claim 13 , further comprising repeating steps (b)-(d) at least once.
15. The method of claim 13 , wherein generating the sense voltage comprises amplifying at least a portion of the regulated current, an amplitude of the amplification being based on the LED temperature resulting from heat produced by the LED.
16. The method of claim 13 , wherein generating the sense voltage comprises flowing at least a portion of the regulated current through a temperature-dependent resistance responsive to the LED temperature resulting from heat produced by the LED.
17. The method of claim 16 , wherein the temperature-dependent resistance has a positive temperature coefficient.
18. The method of claim 16 , wherein the temperature-dependent resistance has a negative temperature coefficient.
19. The method of claim 16 , wherein the temperature-dependent resistance comprises a thermistor.
20. The method of claim 16 , wherein the temperature-dependent resistance is disposed in contact with the LED.
21. The method of claim 16 , wherein the temperature-dependent resistance is spaced away from the LED by a thermal pathway comprising air.
22. The method of claim 16 , wherein the temperature-dependent resistance is spaced away from the LED by a thermal pathway comprising a non-air fluid medium.
23. The method of claim 16 , wherein generating the sense voltage comprises flowing a second portion of the regulated current through a resistor connected in parallel to the temperature-dependent resistance.
24. The method of claim 16 , wherein the temperature-dependent resistance is (i) disposed on a printed circuit board and (ii) proximate the LED.
25. The method of claim 24 , wherein the LED is disposed on the printed circuit board.
26. A thermal-management system for an illumination device comprising a light-emitting diode (LED), the system comprising:
means for generating a regulated current from a source voltage;
means for supplying the regulated current to the LED;
means for generating a sense voltage based on (i) the regulated current and (ii) an LED temperature resulting from heat produced by the LED;
means for modifying the regulated current supplied to the LED based on the sense voltage, whereby the LED temperature is maintained within a non-destructive range of LED temperatures; and
means for measuring the LED temperature resulting from heat produced by the LED.
27. The system of claim 26 , wherein the means for measuring the LED temperature resulting from heat produced by the LED comprises a temperature-dependent resistance.
28. The system of claim 26 , wherein the means for measuring the LED temperature resulting from heat produced by the LED has a positive temperature coefficient.
29. The system of claim 26 , wherein the means for measuring the LED temperature resulting from heat produced by the LED has a negative temperature coefficient.
30. The system of claim 26 , wherein the means for measuring the LED temperature resulting from heat produced by the LED comprises a thermistor.
31. The system of claim 26 , wherein the means for measuring the LED temperature resulting from heat produced by the LED is disposed in contact with the LED.
32. The system of claim 26 , wherein the means for measuring the LED temperature resulting from heat produced by the LED is spaced away from the LED by a thermal pathway comprising air.
33. The system of claim 26 , wherein the means for measuring the LED temperature resulting from heat produced by the LED is spaced away from the LED by a thermal pathway comprising a non-air fluid medium.
34. The system of claim 26 , further comprising resistive means connected in parallel to the means for measuring the LED temperature resulting from heat produced by the LED.
35. The system of claim 26 , further comprising a printed circuit board on which the means for measuring the LED temperature resulting from heat produced by the LED is disposed.
36. The system of claim 35 , wherein the LED is disposed on the printed circuit board.
37. The system of claim 26 , further comprising means for amplifying at least a portion of the regulated current.
38. The system of claim 37 , wherein a gain of the amplifying means depends at least in part on the LED temperature resulting from heat produced by the LED.
39. A thermal-management system for an illumination device comprising a light-emitting diode (LED), the system comprising:
means for generating a regulated current from a source voltage;
means for supplying the regulated current to the LED;
means for generating a sense voltage based on (i) the regulated current and (ii) an LED temperature resulting from heat produced by the LED; and
means for modifying the regulated current supplied to the LED based on the sense voltage, whereby the LED temperature is maintained within a non-destructive range of LED temperatures,
wherein the means for modifying the regulated current supplied to the LED based on the sense voltage is configured to decrease the regulated current when the LED temperature resulting from heat produced by the LED decreases.
40. The system of claim 39 , further comprising means for measuring the LED temperature resulting from heat produced by the LED.
41. The system of claim 40 , wherein the means for measuring the LED temperature resulting from heat produced by the LED comprises a temperature-dependent resistance.
42. The system of claim 40 , wherein the means for measuring the LED temperature resulting from heat produced by the LED has a positive temperature coefficient.
43. The system of claim 40 , wherein the means for measuring the LED temperature resulting from heat produced by the LED has a negative temperature coefficient.
44. The system of claim 40 , wherein the means for measuring the LED temperature resulting from heat produced by the LED comprises a thermistor.
45. The system of claim 40 , wherein the means for measuring the LED temperature resulting from heat produced by the LED is disposed in contact with the LED.
46. The system of claim 40 , wherein the means for measuring the LED temperature resulting from heat produced by the LED is spaced away from the LED by a thermal pathway comprising air.
47. The system of claim 40 , wherein the means for measuring the LED temperature resulting from heat produced by the LED is spaced away from the LED by a thermal pathway comprising a non-air fluid medium.
48. The system of claim 40 , further comprising resistive means connected in parallel to the means for measuring the LED temperature resulting from heat produced by the LED.
49. The system of claim 40 , further comprising a printed circuit board on which the means for measuring the LED temperature resulting from heat produced by the LED is disposed.
50. The system of claim 49 , wherein the LED is disposed on the printed circuit board.
51. The system of claim 39 , further comprising means for amplifying at least a portion of the regulated current.
52. The system of claim 51 , wherein a gain of the amplifying means depends at least in part on the LED temperature resulting from heat produced by the LED.