LED tube lamp
An LED tube lamp comprises a glass tube; a diffusive layer covered on the glass tube; two end caps coupled to the glass tube; a light strip attached inside the glass tube and comprises a first set of connecting pads; a plurality of light sources; and a power supply module comprises a circuit board, a rectifying circuit, and a filtering circuit. The circuit board comprises a first surface, a second surface opposite to and substantially parallel to the first surface and the axial direction of the glass tube, and a second set of connecting pads arranged on one of the surfaces. The light strip, a portion of the circuit board being stacked with the light strip, and at least one set of the connecting pads is disposed between the light strip and the portion of the circuit board are stacked sequentially in a radial direction of the glass tube.
1. An LED tube lamp, comprising:
a glass lamp tube;
a diffusive layer covered on a surface of the glass lamp tube;
two end caps, each of the two end caps coupled to a respective end of the glass lamp tube;
a light strip, attached to an inner circumferential surface of the glass lamp tube by a glue, the light strip comprising a first set of connecting pads arranged at one end thereof;
a plurality of LED light sources mounted on a surface of the light strip; and
a power supply module comprising a circuit board separate from the light strip and electrically connected to the light strip, the circuit board comprising a first surface and a second surface opposite to and substantially parallel to the first surface, and the first surface and the second surface being substantially parallel with the axial direction of the glass lamp tube, the circuit board further comprising a second set of connecting pads arranged on one of the first surface and the second surface, wherein a portion of the circuit board being stacked with the end of the light strip,
wherein the power supply module further comprises a rectifying circuit and a filtering circuit electrically connected to the rectifying circuit, the rectifying circuit has at least two input terminals and is configured to rectify a signal received from the two input terminals;
wherein at least one set of the first set and the second set of connecting pads is disposed between the end of the light strip and the portion of the circuit board;
wherein the end of the light strip, the set of connecting pads disposed between the end of the light strip and the portion of the circuit board and the portion of the circuit board are stacked sequentially in a radial direction of the glass lamp tube, the light strip being electrical connecting to the circuit board by the first set and the second set of connecting pads.
2. The LED tube lamp according to claim 1 , wherein at least a portion of the printed circuit board is disposed in one of the two end caps.
3. The LED tube lamp according to claim 2 , the light strip further comprising a protective layer disposed on the surface of the light strip the plurality of LED light sources is mounted on, and the other surface of the light strip is attached to the inner circumferential surface of the glass tube by the glue.
4. The LED tube lamp according to claim 3 , wherein the first set of connecting pads is arranged on the surface of the light strip the plurality of LED light sources is mounted on.
5. The LED tube lamp according to claim 4 , wherein the first set of connecting pads comprises at least one connecting pad and the second set of connecting pads comprises at least one connecting pad, the number of connecting pads of the first set is equal to the number of connecting pads of the second set.
6. The LED tube lamp according to claim 5 , wherein the second set of connecting pads is disposed between the end of the light strip and the portion of the circuit board, the end of the light strip, the second set of connecting pads and the portion of the circuit board are stacked sequentially in a radial direction of the glass lamp tube.
7. The LED tube lamp according to claim 6 , wherein the protective layer comprises a plurality of first openings and at least one second opening, the first openings for disposing the plurality of LED light sources, and the second opening for disposing the first set of connecting pads.
8. The LED tube lamp according to claim 7 , wherein the first set of connecting pads, the end of the light strip, the second set of connecting pads and the portion of the circuit board are stacked sequentially in a radial direction of the glass lamp tube.
9. The LED tube lamp according to claim 8 , wherein the second set of connecting pads is arranged at one end of one of the first surface and the second surface of the circuit board.
10. The LED tube lamp according to claim 7 , wherein the filtering circuit comprises:
a first capacitor, having an end coupled to a first output terminal of the rectifying circuit, and the other end coupled to a second output terminal of the rectifying circuit.
11. The LED tube lamp as claimed in claim 10 , wherein the filtering circuit further comprises:
an EMI-reducing capacitor, coupled between the input terminals of the rectifying circuit.
12. The LED tube lamp as claimed in claim 10 , wherein the filtering circuit further comprises:
a first resistor, having an end coupled to a pin on one of the end caps; and
a second capacitor, having an end coupled to the other end of the first resistor, and the other end of the second capacitor coupled to one of input terminals of the rectifying circuit.
13. The LED tube lamp as claimed in claim 12 , wherein the filtering circuit further comprises:
a passive component, coupled to the second capacitor in parallel.
14. The LED tube lamp as claimed in claim 13 , wherein the passive component is an inductor.
15. The LED tube lamp as claimed in claim 10 , wherein the rectifying circuit comprises:
a first diode, having an anode connected to the second output terminal, and a cathode connected to a pin on one of the end caps;
a second diode, having an anode connected to the second output terminal, and a cathode connected to a pin on the other one of the end caps;
a third diode, having an anode connected to the pin on the one of the end caps, and a cathode connected to the first output terminal; and
a fourth diode, having an anode connected to the pin on the other one of the end caps, and a cathode connected to the first output terminal.
16. The LED tube lamp as claimed in claim 15 , wherein the rectifying circuit further comprises:
a terminal adapter circuit, coupled to the cathode of the first diode, the anode of the second diode, and the pins on both of the end caps, and configured to transmit signal received from at least one of the pins to the cathode of the first diode and the anode of the second diode.
17. The LED tube lamp as claimed in claim 16 , wherein the terminal adapter circuit comprises:
a third capacitor, having an end connected to a pin on one of the end caps, and the other end of the third capacitor connected to the cathode of the first diode and the anode of the second diode; and
a fourth capacitor, having an end connected to a pin on one of the end caps, and the other end of the fourth capacitor connected to the other end of the third capacitor.
18. The LED tube lamp as claimed in claim 16 , wherein the terminal adapter circuit comprises:
a first fuse, having an end connected to a pin on one of the end caps, and the other end of the first fuse connected to the cathode of the first diode and the anode of the second diode; and
a second fuse, having an end connected to a pin on one of the end caps, and the other end of the second fuse connected to the other end of the first fuse.
19. The LED tube lamp according to claim 7 , wherein the power supply module further comprises a first circuit electrically connected between the rectifying circuit and the filtering circuit to cause a delay before the LED tube lamp lights up.
20. The LED tube lamp according to claim 19 , wherein the first circuit comprises a capacitor configured to be charged when an AC driving signal is provided to the LED tube lamp to cause the LED tube lamp to conduct when a voltage of the capacitor exceeds a threshold trigger voltage.