Light emiting diode (LED) tube lamp compatible with different ballasts providing external driving signal

Patent metadata

Field	Value
Publication number	US-9913336-B2
Application number	US-201715454228-A
Country	US
Kind code	B2
Filing date	Mar 9, 2017
Priority date	Apr 3, 2015
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

A light emitting diode (LED) tube lamp includes: a lamp tube, for receiving an external driving signal, a rectifying circuit, a filtering circuit, and an LED module coupled to the filtering circuit and configured to receive a filtered signal for emitting light, wherein the LED module comprises an LED unit, a current-limiting element for receiving the external driving signal, the current-limiting element coupled to one or more of the external connection terminals, and coupled to or in the rectifying circuit, and a ballast interface circuit coupled to the current-limiting element and having a first terminal and a second terminal, for the LED tube lamp to be compatible with a ballast providing the external driving signal, wherein the ballast interface circuit comprises a detection circuit and a switching circuit coupled to the detection circuit, and the ballast interface circuit is configured to detect whether the external driving signal comes from a ballast, and to conduct or cut off the switching circuit based on a result of the detection. The detection circuit is configured such that, when the external driving signal is from a ballast and is being input to the LED tube lamp, the detection circuit conducts the switching circuit according to a state of a property of a detection signal transmitted through the first terminal and the second terminal.

First claim

What is claimed is:

1. A light emitting diode (LED) tube lamp, comprising:
a lamp tube, having a first external connection terminal at a first end of the lamp tube and a second external connection terminal at a second end of the lamp tube, for receiving an external driving signal;
a rectifying circuit configured to rectify the external driving signal to produce a rectified signal;
a filtering circuit coupled to the rectifying circuit and configured to filter the rectified signal to produce a filtered signal;
an LED module coupled to the filtering circuit and configured to receive the filtered signal for emitting light, wherein the LED module comprises an LED unit;
a current-limiting element for receiving the external driving signal, the current-limiting element coupled to one or more of the external connection terminals, and coupled to or in the rectifying circuit; and
a ballast interface circuit coupled to the current-limiting element and having a first terminal and a second terminal, for the LED tube lamp to be compatible with a ballast providing the external driving signal, wherein the ballast interface circuit comprises a detection circuit and a switching circuit coupled to the detection circuit, and the ballast interface circuit is configured to detect whether the external driving signal comes from a ballast, and to conduct or cut off the switching circuit based on a result of the detection, and
wherein the detection circuit is configured such that, when the external driving signal is from a ballast and is being input to the LED tube lamp, the detection circuit conducts the switching circuit according to a state of a property of a detection signal transmitted through the first terminal and the second terminal,
wherein the ballast interface circuit comprises a sampling element connected to the switching circuit and the detection circuit comprises a control circuit connected to the sampling element, and the sampling element is configured to reflect a state of a property of, or produce, the detection signal upon the external driving signal being input to the LED tube lamp, which detection signal then results in the control circuit being turned on or off.

2. The LED tube lamp according to claim 1 , wherein the detection circuit comprises a switch and an RC circuit connected to each other and coupled to the control circuit and the sampling element, and the RC circuit is configured to be charged by the detection signal to eventually conduct the switch, causing the control circuit to be turned off.

3. The LED tube lamp according to claim 1 , wherein the control circuit is configured to be turned off through the detection signal reflected or produced by the sampling element, so as to cut off the switching circuit, which cutoff results in the external driving signal flowing through the current-limiting element to eventually turn on the control circuit, which control circuit as turned on eventually causes the switching circuit to conduct current.

4. The LED tube lamp of claim 1 , wherein the current-limiting element comprises a fuse connected to one or more of the external connection terminals.

5. The LED tube lamp of claim 1 , wherein the current-limiting element comprises a capacitor coupled between the first terminal and the second terminal.

6. The LED tube lamp of claim 1 , wherein the current-limiting element comprises at least two capacitors connected in series between the first external connection terminal and the second external connection terminal.

7. The LED tube lamp of claim 1 , further comprising a conduction-delaying device, wherein the LED module includes an LED unit for emitting light and the conduction-delaying device is connected to the LED unit; and the conduction-delaying device is positioned to switch on when the voltage across the conduction-delaying device exceeds the conduction-delaying device's breakover voltage, upon the external driving signal being input to the LED tube lamp.

8. An LED tube lamp, comprising:
a lamp tube, having a first external connection terminal at a first end of the lamp tube and a second external connection terminal at a second end of the lamp tube, for receiving an external driving signal;
a rectifying circuit configured to rectify the external driving signal to produce a rectified signal;
a filtering circuit coupled to the rectifying circuit and configured to filter the rectified signal to produce a filtered signal;
an LED module coupled to the filtering circuit and configured to receive the filtered signal for emitting light, wherein the LED module comprises an LED unit;
a current-limiting element for receiving the external driving signal, the current-limiting element coupled to one or more of the external connection terminals, and coupled to or in the rectifying circuit; and
a ballast interface circuit coupled to the current-limiting element and having a first terminal and a second terminal, for the LED tube lamp to be compatible with a ballast providing the external driving signal,
wherein the ballast interface circuit comprises a detection circuit and a switching circuit coupled to the detection circuit, and the ballast interface circuit is configured to detect whether the external driving signal comes from a ballast, and to conduct or cut off the switching circuit based on a result of the detection,
wherein the detection circuit is configured such that, when the external driving signal is from a ballast and is being input to the LED tube lamp, the detection circuit conducts the switching circuit according to a state of a property of a detection signal transmitted through the first terminal and the second terminal, and
wherein when the external driving signal is an AC signal from an electronic ballast and being input to the LED tube lamp, states of the property of current or voltage of the detection signal result in the detection circuit alternately conducting and cutting off the switching circuit.

9. An LED tube lamp, comprising:
a lamp tube, having a first external connection terminal at a first end of the lamp tube and a second external connection terminal at a second end of the lamp tube, for receiving an external driving signal;
a rectifying circuit configured to rectify the external driving signal to produce a rectified signal;
a filtering circuit coupled to the rectifying circuit and configured to filter the rectified signal to produce a filtered signal;
an LED module coupled to the filtering circuit and configured to receive the filtered signal for emitting light, wherein the LED module comprises an LED unit;
a current-limiting element for receiving the external driving signal, the current-limiting element coupled to one or more of the external connection terminals, and coupled to or in the rectifying circuit; and
a ballast interface circuit coupled to the current-limiting element and having a first terminal and a second terminal, for the LED tube lamp to be compatible with a ballast providing the external driving signal, wherein the ballast interface circuit comprises a detection circuit and a switching circuit coupled to the detection circuit, and the ballast interface circuit is configured to detect whether the external driving signal comes from a ballast, and to conduct or cut off the switching circuit based on a result of the detection, and wherein the detection circuit is configured such that, when the external driving signal is from a ballast and is being input to the LED tube lamp, the detection circuit conducts the switching circuit according to a state of a property of a detection signal transmitted through the first terminal and the second terminal,
wherein when the external driving signal is a relatively low frequency AC signal or DC signal from an emerge

Assignees

• Jiaxing Super Lighting Electric Appliance Co Ltd
• Jiaxing Super Lighting Electric Appliance Co Ltd

Inventors

• Xiong Aiming
• Liu Xintong
• Zhang Yueqiang
• Wang Caihua

Classifications

• F21K9/27 Primary

  Retrofit light sources for lighting devices with two fittings for each light source, e.g. for substitution of fluorescent tubes · CPC title

• F21V25/02

  coming into action when lighting device is disturbed, dismounted, or broken · CPC title

• F21Y2115/10

  Light-emitting diodes [LED] · CPC title

• F21Y2103/10

  comprising a linear array of point-like light-generating elements · CPC title

• F21K9/278

  Arrangement or mounting of circuit elements integrated in the light source · CPC title