LED LIGHTING SYSTEM AND POWER SYSTEM THEREOF

• US 20110121740A1
• Filed: 02/01/2010
• Published: 05/26/2011
• Est. Priority Date: 11/24/2009
• Status: Abandoned Application

• Current Assignee: Darfon Electronics Corporation
• Original Assignee: Darfon Electronics Corporation
• Inventors: Shih, Cheng Te
• Application Number:
  US12/697,634
• Publication Number:
  US 20110121740A1
• Time in Patent Office: Days
• US Class Current: 315/185.R
• CPC Class Codes: H05B 45/46 having LEDs disposed in parallel lines

Abstract

An LED lighting system including an LED device, a current-balancing device, a comparing device, a power device, and a control device is provided. The current-balancing device generates a feedback voltage based on the operation condition of the LED device. The comparing device compares the feedback voltage with a reference voltage and accordingly generates a compared result. The power device is used for providing a DC voltage to the LED device. The control device generates a control signal based on the compared result. The power device adjusts the DC voltage according to the control signal.

Claims

1. An LED lighting system, comprising:

an LED device;

a current balancing device coupled to the LED device, for generating a feedback voltage based on an operation condition of the LED device;

a comparing device coupled to the current balancing device, for comparing the feedback voltage with a reference voltage and generating a comparing result;

a power device for providing a DC voltage to the LED device; and

a control device coupled between the comparing device and the power device, for generating a control signal based on the comparing result, the power device optionally adjusting the DC voltage according to the control signal.

2. The LED lighting system of claim 1, wherein the LED device comprises one set or plural sets of LEDs connected in series.

3. The LED lighting system of claim 1, wherein when the feedback voltage is lower than the reference voltage, the control device requests the power device to raise the DC voltage;

when the feedback voltage is higher than the reference voltage, the control device requests the power device to reduce the DC voltage.

4. The LED lighting system of claim 1, wherein the power device comprises a DC-to-DC converter and the power device optionally adjusts the DC voltage outputted by the DC-to-DC converter according to the control signal.

5. The LED lighting system of claim 4, wherein the DC-to-DC converter is a push-pull converter, a full-bridge converter, a half-bridge converter, a DC boost converter, a DC buck converter, or a flyback converter.

6. The LED lighting system of claim 4, wherein the power device further comprises a power factor correction circuit coupled between the DC-to-DC converter and an AC power port for providing an AC voltage, and the power factor correction circuit is used for providing a power factor correction function.

7. The LED lighting system of claim 1, further comprising an isolation device coupled between the comparing device and the control device.

8. The LED lighting system of claim 7, wherein the isolation device comprises an opto-coupler or an isolating transformer.

9. The LED lighting system of claim 1, wherein the control signal is a pulse-width modulation signal or a frequency modulation signal.

10. A power system for driving an LED device, comprising:

a current balancing device coupled to the LED device, for generating a feedback voltage based on an operation condition of the LED device;

a comparing device coupled to the current balancing device, for comparing the feedback voltage with a reference voltage and generating a comparing result;

a power device for providing a DC voltage to the LED device; and

a control device coupled between the comparing device and the power device, for generating a control signal based on the comparing result, the power device optionally adjusting the DC voltage according to the control signal.

11. The power system of claim 10, wherein the LED device comprises one set or plural sets of LEDs connected in series.

12. The power system of claim 10, wherein when the feedback voltage is lower than the reference voltage, the control device requests the power device to raise the DC voltage;

when the feedback voltage is higher than the reference voltage, the control device requests the power device to reduce the DC voltage.

13. The power system of claim 10, wherein the power device comprises a DC-to-DC converter and the power device optionally adjusts the DC voltage outputted by the DC-to-DC converter according to the control signal.

14. The power system of claim 13, wherein the DC-to-DC converter is a push-pull converter, a full-bridge converter, a half-bridge converter, a DC boost converter, a DC buck converter, or a flyback converter.

15. The power system of claim 13, wherein the power device further comprises a power factor correction circuit coupled between the DC-to-DC converter and an AC power port for providing an AC voltage, and the power factor correction circuit is used for providing a power factor correction function.

16. The power system of claim 10, further comprising an isolation device coupled between the comparing device and the control device.

17. The power system of claim 16, wherein the isolation device comprises an opto-coupler or an isolating transformer.

18. The power system of claim 10, wherein the control signal is a pulse-width modulation signal or a frequency modulation signal.