Control system for fluorescent light fixture

• US 20060238145A1
• Filed: 04/22/2005
• Published: 10/26/2006
• Est. Priority Date: 04/18/2005
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell World Trade Limited (Marvell Technology Group Limited)
• Inventors: Sutardja, Sehat
• Granted Patent: US 7,560,866 B2
• Time in Patent Office: Days
• US Class Current: 315/309
• CPC Class Codes: H05B 41/2856 against internal abnormal circuit conditions
• CPC Class Codes: H05B 41/2986 against internal abnormal circuit conditions

Abstract

A ballast module for a fluorescent light comprises an electrolytic capacitance element. A temperature sensor senses a temperature of the electrolytic capacitance element. A control module communicates the temperature sensor and adjusts power output to the fluorescent light when the sensed temperature exceeds a predetermined threshold.

Claims

1. A ballast module for a fluorescent light, comprising:

an electrolytic capacitance element;

a temperature sensor that senses a temperature of said electrolytic capacitance element; and

a control module that communicates said temperature sensor and that adjusts power output to the fluorescent light when said sensed temperature exceeds a predetermined threshold.

2. The ballast module of claim 1 wherein said control module reduces said power output to the fluorescent light.

3. The ballast module of claim 1 wherein said control module reduces said power output for a predetermined period.

4. The ballast module of claim 3 wherein said control module increases power output to the fluorescent light after said predetermined period.

5. The ballast module of claim 1 wherein said control module turns off said power output to the fluorescent light.

6. The ballast module of claim 1 wherein said control module turns off said power output for a predetermined period.

7. The ballast module of claim 6 wherein said control module increases power output to the fluorescent light after said predetermined period.

8. The ballast module of claim 1 wherein said control module modulates said power output based on said sensed temperature.

9. A system comprising the ballast module of claim 1 and further comprising a switch that selectively provides power to said control module.

10. The system of claim 9 wherein said switch is a three-way switch.

11. The ballast module of claim 1 further comprising a rectifier module having an input that selectively communicates with a voltage source, wherein said electrolytic capacitance element and said control module communicate with an output of said rectifier module.

12. The ballast module of claim 11 further comprising:

a first power transistor having a first terminal that communicates with a first output terminal of said rectifier and a control terminal that communicates with said control module; and

a second power transistor having a first terminal that communicates with a second terminal of said first power transistor, and a control terminal that communicates with said control module.

13. The ballast module of claim 12 further comprising a second capacitance element that communicates with said first and second terminals of said first power transistor.

14. The ballast module of claim 13 further comprising an inductance element having one end that communicates with said second terminal of said first power transistor and an opposite end that communicates with an electrode of the fluorescent light.

15. A system comprising the ballast module of claim 1 and further comprising:

the fluorescent light having first and second pairs of electrodes; and

a third capacitance element that communicates with one of said first pair of electrodes and one of said second pair of electrodes.

16. A system comprising the ballast module of claim 13 and further comprising:

the fluorescent light having first and second pairs of electrodes; and

a fourth capacitance element that communicates with one of said first pair of electrodes and said second capacitance element.

17. A ballast module for a fluorescent light, comprising:

electrolytic capacitance means for providing capacitance;

temperature sensing means for sensing a temperature of said electrolytic capacitance means; and

control means that communicates said temperature sensing means for adjusting power output to the fluorescent light when said sensed temperature exceeds a predetermined threshold.

18. The ballast module of claim 17 wherein said control means reduces said power output to the fluorescent light.

19. The ballast module of claim 17 wherein said control means reduces said power output for a predetermined period.

20. The ballast module of claim 19 wherein said control means increases power output to the fluorescent light after said predetermined period.

21. The ballast module of claim 17 wherein said control means turns off said power output to the fluorescent light.

22. The ballast module of claim 17 wherein said control means turns off said power output for a predetermined period.

23. The ballast module of claim 22 wherein said control means increases power output to the fluorescent light after said predetermined period.

24. The ballast module of claim 17 wherein said control means modulates said power output based on said sensed temperature.

25. A system comprising the ballast module of claim 17 and further comprising switching means for selectively providing power to said control means.

26. The system of claim 25 wherein said switching means is a three-way switching means.

27. The ballast module of claim 17 further comprising rectifier means for rectifying and having an input that selectively communicates with a voltage source, wherein said electrolytic capacitance means and said control means communicate with an output of said rectifier means.

28. The ballast module of claim 27 further comprising:

first power switching means for switching and having a first terminal that communicates with a first output terminal of said rectifier and a control terminal that communicates with said control means; and

second power switching means for switching and having a first terminal that communicates with a second terminal of said first power switching means, and a control terminal that communicates with said control means.

29. The ballast module of claim 28 further comprising second capacitance means for providing capacitance and that communicates with said first and second terminals of said first power switching means.

30. The ballast module of claim 29 further comprising inductance means for providing inductance and having one end that communicates with said second terminal of said first power switching means and an opposite end that communicates with an electrode of the fluorescent light.

31. A system comprising the ballast module of claim 17 and further comprising:

the fluorescent light having first and second pairs of electrodes;

third capacitance means for providing capacitance and that communicates with one of said first pair of electrodes and one of said second pair of electrodes.

32. A system comprising the ballast module of claim 29 and further comprising:

the fluorescent light having first and second pairs of electrodes;

fourth capacitance means for providing capacitance and that communicates with one of said first pair of electrodes and said second capacitance means.

33. A method for operating a ballast module for a fluorescent light, comprising:

providing an electrolytic capacitance element in the ballast module;

sensing a temperature of said electrolytic capacitance element; and

adjusting power output to the fluorescent light when said sensed temperature exceeds a predetermined threshold.

34. The method of claim 33 further comprising reducing said power output to the fluorescent light.

35. The method of claim 33 further comprising reducing said power output for a predetermined period.

36. The method of claim 35 further comprising increasing power output to the fluorescent light after said predetermined period.

37. The method of claim 33 further comprising turning off said power output to the fluorescent light.

38. The method of claim 33 further comprising turning off said power output for a predetermined period.

39. The method of claim 38 further comprising increasing power output to the fluorescent light after said predetermined period.

40. The method of claim 33 further comprising modulating said power output based on said sensed temperature.

41. The method of claim 33 further comprising selectively provides power to said control module.