Limited flicker light emitting diode string

• US 20080116816A1
• Filed: 11/08/2007
• Published: 05/22/2008
• Est. Priority Date: 11/08/2006
• Status: Active Grant

• Current Assignee: Seasonal Specialties LLC (Seasonal Specialties)
• Original Assignee: Seasonal Specialties LLC (Seasonal Specialties)
• Inventors: Altamura, Steven J., Neuman, Robert C.
• Granted Patent: US 7,649,322 B2
• Time in Patent Office: Days
• US Class Current: 315/185S
• CPC Class Codes: F21S 4/10 with light sources attached to loose electric cables, e.g. Christmas tree lights
• CPC Class Codes: H05B 45/30 Driver circuits
• CPC Class Codes: H05B 45/40 Details of LED load circuits
• CPC Class Codes: Y10S 362/806 Ornamental or decorative

Abstract

A limited flicker decorative light-emitting diode (LED) string includes a power plug adapted to connect to an alternating current (AC) power source and supply AC power to the LED string, a first pair of LEDs and a second pair of LEDs, a plurality of LEDs electrically connected in series to form an LED series, and a plurality of rectifying diodes. The plurality of rectifying diodes provides full-wave rectification of the AC power to the LED series and half-wave rectification of the AC power to the first and second pair of LEDs.

Claims

1. A limited flicker decorative light-emitting diode (LED) string, comprising:

a power plug adapted to connect to an alternating current (AC) power source and supply AC power to the LED string;

a first pair of LEDs and a second pair of LEDs;

a plurality of LEDs electrically connected in series to form an LED series;

a plurality of rectifying diodes, wherein the plurality of rectifying diodes provide full-wave rectification of the AC power to the LED series and half-wave rectification of the AC power to the first and second pair of LEDs.

2. The LED string of claim 1, wherein each rectifying diode is located in a bulb assembly socket.

3. The LED string of claim 2, wherein the bulb assembly sockets are three-wire sockets.

4. The LED string of claim 1, further comprising a current-limiting device electrically connected in series with at least one LED.

5. The LED string of claim 4, wherein the current-limiting device is a surface-mount current-limiting device encased in an LED lens.

6. The LED string of claim 4, wherein the current-limiting device is located in a socket of an LED assembly.

7. The LED string of claim 4, wherein the current-limiting device is a resistor.

8. The LED string of claim 1, wherein the power plug includes a current tap.

9. The LED string of claim 1, wherein the rectifying diodes are LEDs.

10. The LED string of claim 1, wherein two of the rectifying diodes of the two pairs are electrically connected to the first power terminal, and two of the rectifying diodes of the two pairs are electrically connected to the second power terminal.

11. The LED string of claim 1, wherein multiple LEDs are housed within a single LED bulb assembly.

12. The LED string of claim 1, wherein the LEDs emit more than one color of light.

13. The LED string of claim 1, further comprising an end connect power terminal.

14. The LED string of claim 1, further comprising:

a plurality of bulb assemblies, wherein each bulb assembly includes a socket and at least one LED, wherein each socket is adapted to receive either two or three wires;

a wire set electrically connecting the power plug, rectifying diodes, and LEDs; and

a plurality of splice compartments, wherein the splice compartment is adapted to receive two wires of the wire set, output a single wire of the wire set, and electrically connect all three wires such that the number of wires entering the socket is reduced.

15. The LED string of claim 14, wherein at least one rectifying diode is located within at least one of the plurality of splice compartments.

16. A decorative LED string, comprising:

a first power terminal and a second power terminal;

a first diode and a second diode electrically connected in series to form a first diode pair, wherein at least one of the first or second diodes is a rectifying diode and the first pair is electrically connected to the first power terminal;

a third diode and a fourth diode electrically connected in series to form a second diode pair, wherein at least one of the third or fourth diodes is a rectifying diode and the second pair is electrically connected to the first power terminal;

a fifth diode and a sixth diode electrically connected in series to form a third diode pair, wherein at least one of the fifth or sixth diodes is a rectifying diode and the third pair is electrically connected to the second power terminal;

a seventh diode and an eighth diode electrically connected in series to form a fourth diode pair, wherein at least one of the seventh or eighth diodes is a rectifying diode and the fourth pair is electrically connected to the second power terminal;

a plurality of LEDs electrically connected in series to form an LED series, wherein a first LED of the LED series is electrically connected to the first and second diode pairs, and a last LED of the LED series is electrically connected to the third and fourth diode pairs.

17. The decorative LED string of claim 16, wherein the first, third, fifth, and seventh diodes are rectifying diodes.

18. The decorative LED string of claim 16, wherein the second, fourth, sixth, and eighth diodes are LEDs.

19. The decorative LED string of claim 16, wherein the first, second, third, fourth, fifth, sixth, seventh and eighth diodes are LEDs, and at least one LED in each of the diode pairs acts as a rectifying diode.

20. A decorative LED string, comprising:

a first power terminal and a second power terminal;

a first diode, wherein an anode of the first diode is electrically connected to the first power terminal;

a second diode, wherein an anode of the second diode is electrically connected to a cathode of the first diode;

a third diode, wherein an anode of the third diode is electrically connected to the second power terminal;

a fourth diode, wherein an anode of the fourth diode is electrically connected to a cathode of the third diode, and a cathode of the fourth diode is electrically connected to a cathode of the second diode;

a fifth diode, wherein a cathode of the fifth diode is electrically connected to the first power terminal;

a sixth diode, wherein a cathode of the sixth diode is electrically connected to an anode of the fifth diode;

a seventh diode, wherein a cathode of the sixth diode is electrically connected to the second power terminal;

an eighth diode, wherein a cathode of the eighth diode is electrically connected to an anode of the seventh diode, and an anode of the eighth diode is electrically connected to an anode of the sixth diode;

a plurality of LEDs electrically connected in series to form an LED series, wherein a first LED of the LED series is electrically connected to the second diode and to the fourth diode, and a last LED of the LED series is electrically connected to the sixth diode and the eighth diode.

21. The decorative LED string of claim 20, wherein the first, third, fifth, and seventh diodes are rectifying diodes.

22. The decorative LED string of claim 20, wherein the first, third, fifth, and seventh diodes are LEDs.

23. A limited flicker decorative light-emitting diode (LED) string, comprising:

a power plug adapted to connect to an alternating current (AC) power source and supply AC power to the LED string;

a first plurality of LEDs electrically connected in series to form an LED series;

a second plurality of LEDs acting as rectifying diodes, wherein the second plurality of LEDs provides full-wave rectification of the AC power to the LED series and half-wave rectification of the AC power to the second plurality of LEDs.

24. The LED string of claim 23 further comprising a current-limiting device located inside a socket of the LED string.

25. The LED string of claim 23 further comprising a current-limiting device located inside an LED lens of the LED light string.

26. A method of reducing flicker in a decorative LED string, comprising:

providing AC power to a set of terminals of the LED string;

full-wave rectifying the AC power delivered to a first portion of LEDs of the LED string, wherein the first portion LEDs are electrically connected in series;

half-wave rectifying the AC power delivered to a second portion of LEDs of the LED string.

27. A reduced flicker LED lighting system, comprising:

an AC power source;

a power plug adapted to connect to the AC power source and receive AC power;

a plurality of LEDs with a first portion of LEDs and a second portion of LEDs, wherein the first portion of LEDs are electrically connected to form an LED series;

a full-wave rectifier adapted to provide full-wave rectified AC power to the LED series;

a half-wave rectifier adapted to provide half-wave rectified AC power to the second portion of LEDs; and

a wire set electrically connecting the power plug, plurality of LEDs, full-wave rectifier, and half-wave rectifier.

28. The reduced flicker LED lighting system of claim 27, wherein the full-wave rectifier comprises four diodes.

29. The reduced flicker LED lighting system of claim 28, wherein the four diodes are located in four separate sockets.

30. The reduced flicker LED lighting system of claim 29, wherein the half-wave rectifier comprises two of the four diodes of the full-waver rectifier.