LED lighting system

• US 8,791,638 B2
• Filed: 08/23/2012
• Issued: 07/29/2014
• Est. Priority Date: 09/02/2011
• Status: Active Grant

• Current Assignee: Delta Electronics Incorporated
• Original Assignee: Delta Electronics Incorporated
• Inventors: Huang, Chung-Tsai, Yan, Shang-Jin, Wu, Hsiang-Chen
• Primary Examiner(s): Hammond, Crystal L
• Application Number:
  US13/592,815
• Publication Number:
  US 20130057152A1
• Time in Patent Office: 705 Days
• Field of Search: None
• US Class Current: 315/113
• CPC Class Codes: H05B 45/48 having LEDs organised in strings and incorporating parallel shunting devices

Abstract

Provided is a LED lighting system, including a lighting device driver having a power converter for converting an input voltage into a first DC voltage and outputting a first current having a substantially constant current value; and a LED lighting device assembly connected to the lighting device driver through two contacts. The LED lighting device assembly includes a plurality of light-emitting diode lighting devices having a plurality of lighting device connection bases and a plurality of LED units. The lighting device connection bases are connected in series with each other to allow the LED lighting devices to be connected in series with each other, and the lamp voltage is applied across the positive terminal and the negative terminal of the lighting device connection base and is generated by dividing the first DC voltage, thereby allowing the lamp currents outputted by the lighting device connection bases are substantially equal.

Claims

1. A light-emitting diode lighting system, comprising:

a lighting device driver having a power converter for converting an input voltage into a first DC voltage and outputting a first current having a substantially constant current value; and

a light-emitting diode lighting device assembly connected to the lighting device driver through two contacts, comprising;

a plurality of light-emitting diode lighting devices having a plurality of lighting device connection bases and a plurality of light-emitting diode units, each lighting device connection base having a positive terminal and a negative terminal and is connected to a corresponding light-emitting diode unit for transmitting a lamp voltage and a lamp current to the corresponding light-emitting diode unit;

wherein the lighting device connection bases are connected in series with each other to allow the light-emitting diode lighting devices to be connected in series with each other, and the lamp voltage is applied across the positive terminal and the negative terminal of the lighting device connection base and is generated by dividing the first DC voltage, thereby allowing the lamp currents outputted by the lighting device connection bases are substantially equal.

2. The light-emitting diode lighting system according to claim 1 wherein the power converter is a single-stage flyback converter, an active-clamp converter, or a resonant converter.

3. The light-emitting diode lighting system according to claim 1 wherein the power converter is a constant-current power converter for outputting the first current having a substantially constant current value, and the first DC voltage is the sum of the lamp voltages of the lighting device connection bases.

4. The light-emitting diode lighting system according to claim 1 further comprising an over-current protection circuit connected between the power converter and an output end of the lighting device driver for preventing the first current outputted by the power converter from being excessive.

5. The light-emitting diode lighting system according to claim 4 wherein the over-current protection circuit includes:

a switch circuit connected to a current loop of the first current;

a current detector connected to an output end of the power converter and the switch circuit for generating a first control voltage according to the first current flowing therethrough and outputting the first control voltage to a control terminal of the switch circuit, thereby driving switch circuit to turn on or off according to the first control voltage.

6. The light-emitting diode lighting system according to claim 5 wherein the switch circuit includes:

a first switch element connected to the current loop; and

a body diode connected between a current terminal of the first switch element and another current terminal of the first switch element.

7. The light-emitting diode lighting system according to claim 6 wherein the current detector includes:

a first resistor having one end connected to a first output terminal of the power converter and the other end connected to a first node connecting to the switch circuit;

a second resistor connected in series with the switch circuit for generating a second control voltage when the first current flows therethrough;

a second switch element having a control terminal connected to a second node, a first current terminal connected to the first node, and a second current terminal connected to a second output terminal of the power converter; and

a first zener diode connected between the first node and the second node for clamping the first control voltage generated between the first node and the second node.

8. The light-emitting diode lighting system according to claim 1 wherein a positive terminal of a first light-emitting diode lighting device connection base set of the lighting device connection bases is connected to a first output terminal of the lighting device driver, and a negative terminal of a last light-emitting diode lighting device connection base set of the lighting device connection bases is connected to a second output terminal of the lighting device driver, such that the a negative terminal of the present light-emitting diode lighting device connection base set of the lighting device connection bases is connected to a positive terminal of the next light-emitting diode lighting device connection base set of the lighting device connection bases.

9. The light-emitting diode lighting system according to claim 1 wherein each light-emitting diode device includes one light-emitting diode module or a plurality of light-emitting modules connected in series between a positive terminal and a negative terminal of a corresponding lighting device connection base.

10. The light-emitting diode lighting system according to claim 9 wherein each light-emitting diode module further includes an output protection circuit connected in parallel between a first conductive terminal and a second conductive terminal of the light-emitting diode module for bypassing the light-emitting diode module when the light-emitting diode module is malfunctioned.

11. The light-emitting diode lighting system according to claim 10 wherein the output protection circuit includes:

a third switch element connected between the first conductive terminal and the second conductive terminal of the light-emitting diode module; and

a triggering circuit connected to the first conductive terminal and the second conductive terminal of the light-emitting diode module and a control terminal of the third switch element for controlling switching operations of the third switch element according to a module voltage of the light-emitting diode module;

wherein when the module voltage of the light-emitting diode module exceeds a rated voltage range of the module voltage, the triggering circuit sends a triggering signal to a control terminal of the third switch element to drive the third switch element to turn on, thereby allowing the output protection circuit to activate to bypass the light-emitting diode module.

12. The light-emitting diode lighting system according to claim 11 wherein the triggering circuit includes a third resistor, a fourth resistor, and a second zener diode connected in series between the first conductive terminal and the second conductive terminal of the light-emitting diode module for performing a current limiting function and a voltage dividing function.

13. The light-emitting diode lighting system according to claim 12 wherein the triggering circuit further includes a delay circuit comprising a fifth resistor and a capacitor.

14. The light-emitting diode lighting system according to claim 9 wherein each light-emitting diode lighting device includes a mechanical structure, comprising:

a housing having a receiving space for mounting a light-emitting diode module or a plurality of light-emitting diode modules and having one side for mounting the positive terminal and the negative terminal of the light-emitting diode connection base set with a waterproof structure; and

a lamp cover linked with an opening of the housing, wherein lights generated by the light-emitting diode module or the light-emitting diode modules penetrates a transparent portion of the lamp cover to reach a lighting space.

15. The light-emitting diode lighting system according to claim 14 wherein the mechanical structure of the light-emitting diode lighting device further includes:

a heat-dissipating structure mounted on an external surface of the housing for lowering a temperature of the light-emitting diode module or the light-emitting diode modules; and

a light homogenizing plate mounted between the opening of the housing and the lamp cover for homogenizing lights generated by the light-emitting diode lighting device.

16. The light-emitting diode lighting system according to claim 1 wherein a rated operating voltage value of the lighting device connection bases is lower than a minimum voltage value for allowing a human body to conduct electricity.