CAPACITOR SHUNTED LED LIGHT STRING

• US 20090091263A1
• Filed: 12/12/2008
• Published: 04/09/2009
• Est. Priority Date: 11/24/2008
• Status: Active Grant

• Current Assignee: JLJ, Inc.
• Original Assignee: JLJ, Inc.
• Inventors: Janning, John L.
• Granted Patent: US 8,324,820 B2
• Time in Patent Office: Days
• US Class Current: 315/122
• CPC Class Codes: H05B 45/42 Antiparallel configurations

Abstract

A series connected LED light string using capacitors as shunts. The shunts are implemented by inserting a capacitor—for example a low breakdown voltage chip capacitor—in every light socket, or internally within each LED. The capacitive shunt continues current in the light string in the event an LED fails by opening electrically—the capacitor shorts out, thus, keeping the string of lights illuminated. The shunt capacitor across the LED also helps filter the pulsating DC voltage to the bulbs and reduces annoying flicker.

Claims

1. A series wired light string, comprising:

a plurality of light sockets, each socket adapted to receive at least one light emitting diode (LED), the light sockets connected in electrical series, and being connected to a source of 120 volts AC;

a plurality of LED'"'"'s, at least one of each of said LED'"'"'s being received within each of said sockets; and

a plurality of shunts, each shunt being electrically connected in parallel across a respective socket to maintain the current passing through the socket in the event that an LED is inoperative or is missing from the socket, such that the remaining LED'"'"'s in the light string remain illuminated at substantially unchanged brightness.

2. A series wired light string as recited in claim 1, further comprising a rectifier in series with said source of AC voltage to convert said AC voltage into pulsating DC voltage for powering said light string.

3. A series wired light string as recited in claim 1, wherein each of said shunts comprises a capacitor.

4. A series wired light string as recited in claim 1, wherein each socket contains two of said LED'"'"'s counter connected in parallel.

5. A series wired light string as recited in claim 1, wherein each of said shunts comprises two electrical conductors separated by a thin dielectric film that will break down at a voltage of approximately ten volts or more.

6. A series wired light string as recited in claim 4, wherein the dielectric film is a metal oxide.

7. A series wired light string, comprising:

a plurality of light sockets, each socket adapted to receive at least one light emitting diode (LED), the light sockets connected in electrical series, and being connected to a source of 120 volts AC;

a plurality of LED'"'"'s, at least one LED being received within each of said sockets, each LED including, within its housing, a shunt to maintain the current passing through the light string in the event that the LED becomes open circuited, such that the remaining LED'"'"'s in the light string remain illuminated at substantially unchanged brightness.

8. A series wired light string as recited in claim 7, further comprising a rectifier in series with said light string to convert said AC voltage into pulsating DC voltage for powering said light string.

9. A series wired light string as recited in claim 7, wherein each of said shunts comprises a capacitor.

10. A series wired light string as recited in claim 7, wherein each socket contains two of said LED'"'"'s counter connected in parallel.

11. A series wired light string as recited in claim 7, wherein each of said shunts comprises two electrical conductors separated by a thin dielectric film that will break down at a voltage of approximately ten volts or more.

12. A series wired light string as recited in claim 11, wherein the dielectric film is a metal oxide.