White light-emitting-diode lamp driver based on multiple output converter with output current mode control

• US 6,369,525 B1
• Filed: 11/21/2000
• Issued: 04/09/2002
• Est. Priority Date: 11/21/2000
• Status: Expired due to Fees

• Current Assignee: Philips Electronics North America Corporation (Koninklijke Philips N.V.)
• Original Assignee: Philips Electronics North America Corporation (Koninklijke Philips N.V.)
• Inventors: Muthu, Subramanian, Chang, Chin, Bruning, Gert W.
• Primary Examiner(s): Philogene, Haissa
• Application Number:
  US09/717,969
• Time in Patent Office: 504 Days
• Field of Search: 315/209.R, 315/276, 315/224, 315/278, 315/291, 315/297, 315/300, 315/302, 315/307, 315/312, 315/309, 315/362, 363/17, 363/21, 363/23, 363/126, 363/132, 362/800, 362/236
• US Class Current: 315/300
• CPC Class Codes: H02M 1/342 Active non-dissipative snubbers
• CPC Class Codes: H02M 3/33561 having more than one ouput with independent control
• CPC Class Codes: H02M 3/33569 having several active switching elements H02M3/3353 takes precedence
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/385 using flyback topology
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A white light-emitting-diode array driver circuit with a multiple output flyback (or forward) converter with output current mode control. The circuit comprises a power supply source and a transformer. The transformer has a primary winding coupled to, and configured to receive current from, the power supply, and a plurality of secondary windings coupled to the primary winding. The circuit also comprises a plurality of light-emitting-diode arrays, wherein each light-emitting-diode array is coupled to one of the secondary windings. A main controller is coupled to a first of the light-emitting-diode arrays and is configured to control a flow of current to the primary transformer winding. The circuit also comprises a plurality of secondary controllers, each of which are coupled to another of the light-emitting-diode arrays. In addition, each of the secondary controllers are configured to control a flow of current to its corresponding light-emitting-diode array. According to one embodiment of the invention, each of the light-emitting diodes has a resistor coupled to its cathode terminal. An output signal of each resistor is transmitted to the respective controller and is employed to determine the appropriate current flow to the light-emitting-diode array. The circuit may be configured as either a flyback converter, wherein the primary transformer winding is wound in the opposite direction of the secondary transformer windings, or as a forward converter, wherein the primary transformer winding is wound in the same direction as secondary transformer windings.

Claims

1. A driver circuit comprising:

a power supply source;

a transformer having a primary winding coupled to, and configured to receive current from, said power supply, and a plurality of secondary windings coupled to said primary winding;

a plurality of light-emitting-diode arrays, each said light-emitting-diode array coupled to one of said plurality of secondary windings;

a main controller coupled to a first of said light-emitting-diode arrays and configured to control a flow of current to said primary transformer winding;

a plurality of secondary controllers, each of said secondary controllers coupled to a second and third of said plurality of light-emitting diodes, wherein said secondary controllers are configured to control a flow of current to a corresponding light-emitting-diode array.

2. The circuit according to claim 1, wherein each one of said plurality of light-emitting diodes has coupled thereto a resistor.

3. The circuit according to claim 2, wherein an output signal of each said resistor is transmitted to a respective said controller.

4. The circuit according to claim 1, wherein said transformer comprises a flyback converter.

5. The circuit according to claim 4, wherein said flyback converter comprises said primary transformer winding having a direction of said winding opposite to a direction of said secondary transformer windings.

6. The circuit according to claim 1, wherein said transformer comprises a forward converter.

7. The circuit according to claim 6, wherein said forward converter comprises said primary transformer winding having a direction of said winding the same as a direction of said secondary transformer windings.

8. The circuit according to claim 1, wherein said circuit is a white light-emitting-diode array driver circuit.

9. The circuit according to claim 8, wherein said plurality of light-emitting-diode arrays is three.

10. The circuit according to claim 9, wherein said light- emitting-diode arrays are red, green and blue.

11. The circuit according to claim 10, wherein said first light-emitting-diode array is red.

12. The circuit according to claim 10, wherein said first light-emitting-diode array is green.

13. The circuit according to claim 10, wherein said first light-emitting-diode array is blue.

14. A driver circuit comprising:

a power supply source;

a transformer having a primary winding coupled to, and configured to receive current from, said power supply, and a plurality of secondary windings coupled to said primary winding;

a plurality of light-emitting-diode arrays, each said light-emitting-diode array coupled to one of said plurality of secondary windings;

a plurality of secondary controllers, each one of said secondary controllers coupled to a corresponding one of said plurality of light-emitting-diode arrays, wherein said secondary controllers are configured to control a flow of current to said corresponding light-emitting-diode array.

15. The circuit according to claim 14, wherein each one of said plurality of light-emitting diodes has coupled thereto a resistor.

16. The circuit according to claim 15, wherein an output signal of each said resistor is transmitted to said corresponding controller.

17. The circuit according to claim 14, wherein said transformer comprises a flyback converter.

18. The circuit according to claim 17, wherein said flyback converter comprises said primary transformer winding having a direction of said winding opposite to a direction of said secondary transformer windings.

19. The circuit according to claim 14, wherein said transformer comprises a forward converter.

20. The circuit according to claim 19, wherein said forward converter comprises said primary transformer winding having a direction of said winding the same as a direction of said secondary transformer windings.

21. The circuit according to claim 14, wherein said circuit is a white light-emitting-diode array driver circuit.

22. The circuit according to claim 21, wherein said plurality of light-emitting-diode arrays is three.

23. The circuit according to claim 22, wherein said light-emitting-diode arrays are red, green and blue.

24. The circuit according to claim 23, wherein said first light-emitting-diode array is red.

25. The circuit according to claim 23, wherein said first light-emitting-diode array is green.

26. The circuit according to claim 23, wherein said first light-emitting-diode array is blue.