Patent ID: 7086758

Claim:
A filament shunted light string comprising the combination of: a plurality of electrical bulb supporting sockets connected in an electrical series circuit arrangement with each other, each of said sockets being adapted to have an electrically operable miniature incandescent bulb for Christmas tree lighting and decoration inserted therein and illuminated whenever an electrical potential having an A.C. cycle is applied to input terminals of said electrical series circuit arrangement wherein said miniature incandescent bulbs draw a current up to approximately 200 milliamperes each, resulting in a power dissipation per bulb equal to or less than approximately one watt; voltage responsive switching means formed of at least one Zener diode connected in parallel across each of said sockets, wherein half of said Zener diodes in said light string conduct in one direction during a first half of the A.C. cycle, and half of said Zener diodes in said light string conduct in a direction opposite to said first direction during a second half of the A.C. cycle, whereby all illuminated bulbs in said string continue to receive current therethrough and continue to be illuminated and the voltage drop across each bulb and the brightness of each bulb remains substantially unchanged even though multiple bulbs in the string are not illuminated for whatever reason, or are actually missing from their respective sockets.