Abstract: A line voltage control circuit for use with a multi-string LED drive system which provides a common line voltage for multiple LED strings that are connected to respective current sink circuits at respective junctions. An error amplifier receives the minimum junction voltage and a reference ‘desired junction voltage’ at respective inputs, and a voltage regulator outputs the line voltage in response to a voltage applied to a feedback input. A comparator toggles an output when the maximum junction voltage (Vmax) exceeds a reference limit (Vlimit). A multiplexer receives the error amplifier output and a fixed voltage at respective inputs and provides one of the signals to the regulator's feedback input in response to the comparator output. When Vmax>Vlimit, the fixed voltage is provided to the feedback input and the line voltage is reduced, thereby protecting low voltage current sinks from potentially damaging high voltages.

Abstract: A plasma display device includes a plasma display panel having discharge cells formed between a plurality of first electrodes and a plurality of second electrodes and a driving circuit dividing one frame into a plurality of subfields, each subfield including a reset period, an address period, and a sustain period, and applying a driving voltage to the first electrodes and the second electrodes. During a sustain period of each subfield, a sustain discharge pulse is alternately applied to the first and second electrodes for triggering a sustain discharge. A width of a last sustain discharge pulse applied to the second electrode is set to be greater than a width of other sustain discharge pulses for selected subfields. The subfields may be selected based on whether a total number of the sustain discharge pulses during the sustain period is less than a critical number of sustain discharge pulses.

Abstract: An electric bulb structure includes a housing, a base post extended into an inside of the housing from one end of the housing, a shade mounted on an opening of the housing, a first conductive wire and a second conductive wire each extended into the inside of the housing from an outside of the housing and each extended through the base post, a first filament having a first end connected to the first conductive wire, a second filament having a first end connected to the second conductive wire, and a third conductive wire having a first end connected to a second end of the first filament, and a second end connected to a second end of the second filament.

Abstract: A fluorescent lamp lighting apparatus includes a fluorescent light emitting tube; and an electronic lighting circuit for applying an electric current to the fluorescent light emitting tube. The electronic lighting circuit includes a pair of electrode filaments provided in the fluorescent light emitting tube, a pair of capacitors each connected in series to a respective one of the pair of electrode filaments and connected parallel to the fluorescent light emitting tube, and an inductor connected in series to one of the pair of electrode filaments.

Abstract: A glow discharge lamp includes a sealed lamp envelope containing a noble gas and mercury, a cathode and an anode disposed in the lamp envelope and an incandescent filament for emitting visible light for illumination immediately upon application of power and for emitting little or no visible light after a glow discharge is formed between the cathode and the anode. The filament, the cathode and the anode are electrically connected in series. The lamp envelope typically includes a phosphor coating for emission of visible light upon absorption of ultraviolet radiation from the glow discharge. An optional switch can be used for disconnecting the filament during steady state operation of the glow discharge lamp.

Abstract: There is provided a luminaire primarily for use with exit signs and other emergency-type lighting comprising a series string of low-voltage, extremely long-life bulbs positioned within an enclosure for protection and electrically connected to a standard base whereby luminaires having lives of 10 to 30 years may replace standard bulbs without the requirement of retrofitting.

Abstract: An extended life incandescent lamp which employs thermal, voltage, or radiation activated differential switching to substitute a series-connected reserve filament for an inoperative primary filament without increasing the normal in-rush current.

Abstract: In order to prolong the life of incandescent electric light bulbs, an arrangement is provided which consists of two bulbs, one of which constitutes a resistance for the second one.The lamp holder which accommodates the two bulbs comprises two sockets into each of which the base of one bulb is inserted, the two sockets being interconnected in series.

Abstract: A lamp is described having an internal switch for keeping at least one filament incandescent for a predetermined time after an external switch indicates the user wishes to turn the lamp off.

Abstract: A motor vehicle rear lighting system comprises first and second lamp filaments in a single bulb envelope, the first lamp filament having a greater resistance than that of the second lamp filament. One or more electrical switches are operable, in one position, to connect the lamp filaments in series with a battery, and, in another position, to complete the circuit from the battery to the second lamp filament without the first lamp filament in series therewith. The arrangement is such that, in said one position of the one or more switches, the first lamp filament becomes luminous and, in said another position of the switch means, the second lamp filament becomes luminous. In one embodiment, a first lamp filament by-pass is provided and, in said another position of the electrical switch, the circuit to the second lamp filament is completed via the by-pass. In another embodiment, the electrical switches are arranged to connect the lamp filaments in parallel when the switches are in their said another position.

Abstract: The invention consists of an electrical circuit for a vehicle headlight system whereby the conventional parallel circuit connection of headlights is automatically converted into a series circuit connection under conditions appropriate for daytime running lights, whereby the light output of the headlights is reduced as compared to that in conventional headlight circuit mode, and a method for interconnecting such circuit with conventional headlight systems.