Light emitting diode (LED) tube lamp

• US 9,801,240 B2
• Filed: 03/10/2016
• Issued: 10/24/2017
• Est. Priority Date: 03/10/2015
• Status: Active Grant

• Current Assignee: Jiaxing Super Lighting Electric Appliance Co., Ltd.
• Original Assignee: Jiaxing Super Lighting Electric Appliance Co., Ltd.
• Inventors: Xiong, Aiming, Hu, Hechen, Ye, Qifeng
• Primary Examiner(s): Richardson, Jany
• Application Number:
  US15/065,886
• Publication Number:
  US 20160270164A1
• Time in Patent Office: 593 Days
• Field of Search: None
• CPC Class Codes: F21K 9/278 Arrangement or mounting of circuit elements integrated in the light source
• CPC Class Codes: F21Y 2103/10 comprising a linear array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 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 47/24 Circuit arrangements for protecting against overvoltage
• CPC Class Codes: H05B 47/25 Circuit arrangements for protecting against overcurrent

Abstract

A light emitting diode (LED) tube lamp includes a lamp tube having four pins for receiving an external driving signal; a first rectifying circuit coupled to two of the four pins to rectify the external driving signal; a second rectifying circuit coupled to another two of the four pins to rectify the external driving signal; a filtering circuit coupled to the first and the second rectifying circuits to filter rectified signal; and an LED lighting module coupled to the filtering circuit to receive filtered signal to emit light. The first rectifying circuit further includes a terminal adapter circuit for providing four terminals correspondingly coupled to the four pins. With function of the terminal adapter circuit, the LED tub lamp is compatible with an AC driving mode and a ballast driving mode. The LED lighting module further includes a driving circuit having a controller and a converter circuit. The controller receives a current detection signal for controlling or stabilizing the driving signal output by the converter circuit to be above an objective current value. The controller is further coupled to the filtering circuit for setting the objective current value according to the voltage output by the filtering circuit.

Claims

1. A light emitting diode (LED) tube lamp, comprising:

a lamp tube;

four pins coupled to the lamp tube for receiving an external driving signal;

a first rectifying circuit, coupled to two of the four pins to rectify the external driving signal;

a second rectifying circuit, coupled to another two of the four pins to rectify the external driving signal;

a filtering circuit, coupled to the first and the second rectifying circuits to filter rectified signal; and

an LED lighting module, coupled to the filtering circuit to receive filtered signal to emit light,

wherein, the first rectifying circuit further includes a terminal adapter circuit for providing four terminals correspondingly coupled to the four pins to make the LED tube lamp be compatible with an AC driving mode and a ballast driving mode, and the terminal adapter circuit includes a first capacitor, a second capacitor, and a third capacitor, the first capacitor has one end coupled to at least one of two of the four pins and the other end coupled to one end of the second capacitor and one end of the third capacitor, and the other end of the second capacitor and the other end of the third capacitor are correspondingly coupled to the other two of the four pins;

wherein, the LED lighting module further includes a driving circuit having a controller and a converter circuit, the controller is configured to receive a current detection signal for controlling a driving signal output by the converter circuit to be above an objective current value, and the controller is further coupled to the filtering circuit for setting the objective current value according to a voltage output by the filtering circuit; and

wherein, the LED tube lamp further includes an over voltage protection circuit coupled to the filtering circuit for detecting a filtered signal, and the over voltage protection circuit is configured to clamp the filtered signal when determining the filtered signal is higher than a defined over voltage protection value.

2. The LED tube lamp in claim 1, wherein the capacitance values of the first capacitor, the second capacitor, and the third capacitor are about 100 pF-100 nF.

3. The LED tube lamp in claim 1, wherein the terminal adapter circuit further includes a fourth capacitor;

one end of the fourth capacitor is coupled to the end of the first capacitor coupled to the second capacitor and the third capacitor; and

the other end of the first capacitor and the other end of the fourth capacitor are coupled to two of the four pins disposed at one end of the lamp tube, respectively.

4. The LED tube lamp in claim 3, wherein the capacitance value of the first capacitor, the second capacitor, the third capacitor, and the fourth capacitor is about 100 pF-100 nF.

5. The LED tube lamp in claim 1, wherein the terminal adapter circuit further includes a fourth capacitor and a fifth capacitor connected to each other;

a connection node between the fourth and fifth capacitors is connected to the end of the first capacitor coupled to at least one of two of the four pins disposed at one end of the lamp tube; and

the other end of the fourth capacitor and the other end of the fifth capacitor are coupled to the two pins disposed at the one end of the lamp tube, respectively.

6. The LED tube lamp in claim 5, wherein the capacitance values of the fourth capacitor and the fifth capacitor are about 100 pF-100 nF.

7. The LED tube lamp in claim 1, wherein the first and the second rectifying circuits, the filtering circuit, and the LED lighting module include surface mount components so as to reduce circuit volume and increase the efficiency of heat dissipation.

8. The LED tube lamp of claim 1, wherein the first or second rectifying circuit is a full-wave rectifying circuit.

9. The LED tube lamp of claim 1, wherein the over voltage protection circuit includes a voltage clamping diode.

10. A light emitting diode (LED) tube lamp, comprising:

a lamp tube;

four pins coupled to the lamp tube for receiving an external driving signal;

a first rectifying circuit, coupled to two of the four pins disposed at one end of the lamp tube, to rectify the external driving signal;

a second rectifying circuit, coupled to the other two of the four pins disposed at the other end of the lamp tube, to rectify the external driving signal;

a filtering circuit, coupled to the first and the second rectifying circuits to filter rectified signal;

an LED lighting module, coupled to the filtering circuit to receive filtered signal to emit light; and

a current-limiting circuit coupled to the first rectifying circuit and coupled between at least one of the two pins disposed at one end of the lamp tube and at least one of the other two pins disposed at the other end of the lamp tube, wherein the current-limiting circuit includes a first capacitor and a second capacitor, the first capacitor has one end coupled to at least one of the two pins at one end of the lamp tube and has the other end coupled to one end of the second capacitor, and the other end of the second capacitor is coupled to at least one of the other two pins at the other end of the lamp tube;

wherein, the LED lighting module further includes a driving circuit having a controller and a converter circuit, the controller is configured to receive a current detection signal for controlling a driving signal output by the converter circuit to be above an objective current value, and the controller is further coupled to the filtering circuit for setting the objective current value according to a voltage output by the filtering circuit; and

wherein, the LED tube lamp further includes an over voltage protection circuit coupled to the filtering circuit for detecting a filtered signal, and the over voltage protection circuit is configured to clamp the filtered signal when determining the filtered signal is higher than a defined over voltage protection value.

11. The LED tube lamp in claim 10, wherein the current-limiting circuit further includes a reactive element, one end of the reactive element is coupled to the connection node between the first and second capacitors;

and the other end of the second capacitor and the other end of the reactive element are coupled to the two pins disposed at the other end of the lamp tube, respectively.

12. The LED tube lamp in claim 11, wherein the reactive element comprises an inductor.

13. The LED tube lamp in claim 11, wherein the reactive element comprises a third capacitor.

14. The LED tube lamp of claim 10, wherein the over voltage protection circuit includes a voltage clamping diode.

15. The LED tube lamp in claim 10, wherein the first and the second rectifying circuits, the filtering circuit, and the LED lighting module include surface mount components so as to reduce circuit volume and increase the efficiency of heat dissipation.