Christmas light string with single Zener shunts

• US 20060082223A1
• Filed: 11/22/2005
• Published: 04/20/2006
• Est. Priority Date: 06/26/1995
• Status: Active Grant

• Current Assignee: JLJ, Inc.
• Original Assignee: JLJ, Inc.
• Inventors: Janning, John L.
• Granted Patent: US 7,279,809 B2
• Time in Patent Office: Days
• US Class Current: 307/36
• 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.

Claims

1. A series-wired incandescent miniature light string, comprising:

at least 20 miniature light bulbs wired in electrical series connection;

at least one silicon rectifier diode in series with said series-wired miniature light bulbs for half-wave rectification of standard alternating house current;

at least one Zener diode connected across each filament of said miniature light bulbs in said miniature light sting; and

an electrolytic filter capacitor between 5 and 100 microfarads coupled across said light string for filtering the half-wave rectifier voltage output from the silicon rectifier diode.

2. The light string of claim 1, comprising 50 miniature electrical light bulbs.

3. The light string of claim 1, further comprising a current limiting resistor in series with the silicon rectifier diode.