DRIVING A LIGHTING DEVICE

• US 20100141148A1
• Filed: 02/22/2008
• Published: 06/10/2010
• Est. Priority Date: 02/26/2007
• Status: Active Grant

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Sauerlaender, Georg, Wendt, Matthias, Van Den Bogaart, Patrick
• Granted Patent: US 8,749,158 B2
• Time in Patent Office: Days
• US Class Current: 315/112
• CPC Class Codes: H05B 45/00 Circuit arrangements for operating light-emitting diodes [LED]
• CPC Class Codes: H05B 45/3725 Switched mode power supply [SMPS]
• CPC Class Codes: H05B 45/375 using buck topology
• CPC Class Codes: H05B 45/38 using boost topology
• CPC Class Codes: H05B 45/385 using flyback topology
• CPC Class Codes: H05B 45/395 Linear regulators
• CPC Class Codes: H05B 45/40 Details of LED load circuits
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

Driving a lighting device by a driving circuit for providing driving power for driving a lighting device, and by a decoupling unit for electrically decoupling the driving circuit from a lighting circuit. The driving power is transferred at least partially from the driving circuit to the lighting circuit, and the lighting device is arranged within the lighting circuit such that its anode is at ground potential of the driving circuit.

Claims

1. A system for driving a lighting device comprising:

a driving circuit for providing driving power for driving a lighting device,

the lighting device being arranged within a lighting circuit such that its anode is at ground potential of the driving circuit, and

the lighting device is arranged within the lighting circuit such that its cathode is at a potential negative to the ground potential, wherein the potential at the cathode is electrically decoupled from a positive potential of the driving circuit.

2. The system of claim 1, further comprising a decoupling unit for electrically decoupling the potential at the cathode from the positive potential of the driving circuit.

3. The system of claim 1, wherein the system is arranged in a buck-boost converter topology.

4. The system of claim 2, wherein the decoupling comprises electrically decoupling the driving circuit from the lighting circuit and transferring the driving power at least partially from the driving circuit to the lighting circuit.

5. The system of claim 4, wherein the decoupling unit comprises a transformer.

6. The system of claim 4, wherein the system is arranged in a flyback converter topology.

7. The system of claim 4, wherein the system is arranged in a forward converter topology.

8. The system of claim 1, further comprising a switching unit for operating a driving current which flows through the decoupling unit.

9. The system of claim 1, further comprising a controlling unit for controlling the switching unit such that a current through the lighting device is constant.

10. The system of claim 1, further comprising a shunt resistance arranged in the lighting circuit such that a current through the shunt resistance and the current through the lighting device are equal.

11. The system of claim 9, wherein the controlling unit obtains the current of the lighting device from a measured voltage at the shunt resistance for controlling the switching unit.

12. The system of claim 1, further comprising a cooling unit such that it is directly connected to the lighting device and to ground.

13. The system of claim 12, wherein the anode of the lighting device is connected to the cooling unit.

14. The system of claim 12, wherein the lighting circuit is mounted on the cooling unit, and

wherein the cathode of the lighting device is electrically connected to the lighting circuit at least one of:

A) a mounting screw;

B) a cooling clamp.

15. The system of claim 4, further comprising multiple lighting devices mounted on a common cooling unit with an electrical contact to a common ground.

16. The system of claim 5, wherein the transformer has on its secondary side multiple taps of multiple isolated coils such that between each of two consecutive taps the lighting circuits are connected.

17. A method for driving a lighting device with:

providing within a driving circuit driving power for driving a lighting device,

coupling the lighting device within a lighting circuit with its anode to ground potential of the driving circuit, and

coupling the lighting device within the lighting circuit with its cathode to a potential negative to the ground potential,

electrically decoupling the potential at the cathode from a positive potential of the driving circuit.

18. A method for driving a lighting device with:

receiving driving power from a driving circuit for driving a lighting device,

receiving a ground potential of the driving circuit within the anode of the lighting device being arranged within a lighting circuit, and

receiving a potential negative to the ground potential at the cathode of the lighting device, wherein the potential at the cathode is electrically decoupled from a positive potential of the driving circuit.

19. A module for driving a lighting device with:

receiving means for receiving driving power from a driving circuit for driving a lighting device,

the lighting device being arranged within a lighting circuit such that its anode is at ground potential of the driving circuit, and

the lighting device is arranged within the lighting circuit such that its cathode is at a potential negative to the ground potential, wherein the potential at the cathode is electrically decoupled from a positive potential of the driving circuit.