Series connected light string with filament shunting

• US 7,342,327 B2
• Filed: 10/04/2006
• Issued: 03/11/2008
• Est. Priority Date: 06/26/1995
• Status: Expired due to Fees

• Current Assignee: JLJ, Inc.
• Original Assignee: JLJ, Inc.
• Inventors: Janning, John L.
• Primary Examiner(s): Deberadinis; Robert L.
• Application Number:
  US11/542,184
• Publication Number:
  US 20070029937A1
• Time in Patent Office: 524 Days
• Field of Search: 307/36
• US Class Current: 307/36
• CPC Class Codes: H01K 1/625 Flashing incandescent lamps
• CPC Class Codes: H01K 1/70 with built-in short-circuiting device, e.g. for serially connected lamps
• CPC Class Codes: H05B 39/105 with a spare lamp in the circuit, and a possibility of shunting a failed lamp lamp changing devices H01R33/00, H01R43/00; incandescent lamps with a reserve body H01K
• CPC Class Codes: H05B 47/23 of two or more light sources connected in series

Abstract

A string set of series-connected incandescent bulbs in which substantially all of the bulb filaments in the set are individually provided with a shunt circuit which includes a voltage responsive switch which is inoperative during normal operation of the string set when connected to a source of operating potential and which becomes operative only in response to an increase in the voltage thereacross which exceeds its rating, and in which the remaining bulbs of the circuit continue to receive substantially rated current therethrough and substantially rated voltage thereacross and further continue to be illuminated at substantially constant illumination even though other or substantially all of the other bulbs in the string are either inoperative or are missing from their respective sockets. If flasher bulbs are used in the string, they will twinkle off and on when the operating potential is applied.

Claims

1. A series-wired light string, comprising:

a plurality of light bulbs including a plurality of flasher light bulbs that do not include an internal shunt;

a plurality of light sockets, each light socket of said plurality of light sockets adapted to receive at least one of said plurality of light bulbs; and

a plurality of shunts, each shunt being electrically connected in parallel across a respective light socket to maintain the current passing through the light socket in both directions in the event that a light bulb is inoperative or is missing from the light socket;

wherein, during operation of said light string, said flasher light bulbs flash on and off at different rates and at different times to cause the light string to exhibit a twinkling effect.

2. A method of operating a series-wired light string comprising a plurality of light bulbs including a plurality of flasher light bulbs that do not include an internal shunt, a plurality of light sockets, each light socket adapted to receive at least one of said plurality of light bulbs, and a plurality of shunts, each shunt being electrically connected in parallel across a respective light socket to maintain the current passing through the light socket in both directions in the event that a light bulb becomes inoperative or is missing from the light socket, the method comprising coupling a supply voltage to said series-wired light string, whereby the shunts allow the series-wired light string to remain operative at all times regardless of whether any of said light bulbs are inoperative or missing;

wherein, during operation of said light string, said flasher light bulbs flash on and off at different rates and at different times to cause the light string to exhibit a twinkling effect.