US 2010/0045186 A1 · DUAL BRIGHTNESS TWINKLE IN A MINIATURE LIGHT BULB

Abstract

A circuit for high-low flashing in a series-wired light string circuit. The series-wired light string includes miniature incandescent bulbs disposed in respective light sockets. A resistive element connected in series with a bi-metallic thermal switching element is mounted—as a shunt—either inside the light socket or inside the bulb, so as to be connected in parallel with the bulb filament. The bi-metallic thermal switching element, in series with the resistive element, electrically switches the resistive element off and on across the bulb filament. The bi-metallic thermal switching electrical contacts are in the normally closed position. Because the resistive element is in parallel with the bulb filament when the bi-metallic switching element is in its normally closed position, the bulb filament brightness is at its low state. As current flows through the resistive element and the bi-metallic thermal switching element, the bi-metallic switching element is warmed and activated and moves from its normally closed position to an open position. The shunt is now removed from across the bulb filament and the bulb illuminates brighter. Since the resistive element no longer passes current through it when it opens, it cools. When it cools sufficiently, the bi-metallic switching element moves back to its normally closed position. The cycle is repeated.

Claims18

Dependent claims

A series-wired light string, comprising:

a plurality of light bulbs, including at least one bulb having a voltage rating higher than the other bulbs of the series-wired string;
a plurality of light sockets, each light socket of the plurality of light sockets adapted to receive at least one of the plurality of light bulbs;
and
a shunt circuit disposed across the filament of the bulb having a higher voltage, the shunt circuit comprising a resistive element and a thermal element that moves alternately between an open position and a closed position as the thermal element heats when current is passing therethrough and cools when current is not passing therethrough,
wherein, when the thermal element is in the closed position with current passing therethrough, the filament of the bulb having a higher voltage is shunted by the resistive element, such that the filament carries less current and produces light of a low brightness, and
wherein, when the thermal element heats up as current passes therethrough and moves to an open position, the filament is no longer shunted by the resistive element and carries full current, whereby the filament produces light of a high brightness,
thereby causing the light bulbs having a higher voltage rating to produce illumination of a high and low brightness at different times to cause the light string to exhibit a twinkling effect.

4 more elements

A method of operating a series-wired light string comprising a plurality of light bulbs including a plurality of light bulbs having a voltage rating higher than the other bulbs of the series-wired light string, a plurality of light sockets, each light socket of the plurality of light sockets adapted to receive at least one of the plurality of light bulbs, and a shunt circuit disposed across the filament of the bulb having a higher voltage, the shunt circuit comprising a resistive element and a thermal element that moves alternately between an open position and a closed position as the thermal element heats when current is passing therethrough and cools when current is not passing therethrough,

wherein, when the thermal element is in the closed position with current passing therethrough, the filament of the bulb having a higher voltage is shunted by the resistive element, such that the filament carries less current and produces light of a low brightness, and
wherein, when the thermal element heats up as current passes therethrough and moves to an open position, the filament is no longer shunted by the resistive element and carries full current, whereby the filament produces light of a high brightness, thereby causing the light bulbs having a higher voltage rating to produce illumination of a high and low brightness at different times to cause the light string to exhibit a twinkling effect.

Dependencies are inferred from the claim text.

Dual brightness twinkle in a miniature light bulb

Life of this patent

Dual brightness twinkle in a miniature light bulb

Life of this patent

Abstract

Claims18