Abstract: A uniform voltage is applied to loads even to other than a multiple of three loads made of heating lamps connected in parallel to each other, without causing any burden on a primary side. The number of loads is divided into a multiple of three and a multiple of two. A three-phase AC voltage is applied to three primary windings, which are connected as a Y-connection or a ?-connection. Secondary windings, which are each magnetically coupled to a primary winding of a plurality of three-phase transformers and have the same number of turns, are connected with the multiple of three loads.

Abstract: For providing a lamp lighting device and a filament lamp wherein a wire breakage of the filament lamp can be detected without an excessive consumption of power while the device as a whole is not enlarged, a filament lamp is provided comprising a light emission tube having at least one sealing portion and in the interior of which at least one filament is arranged, internal leads connected to both ends of said filament, metal foils for power supply provided in said at least one sealing portion of the light emission tube and connected to said internal leads, and external leads connected to said metal foils for power supply; wherein a metal foil for detection is provided in said sealing portion and is connected to one of a said internal lead and a said metal foil for power supply, and an external detection lead is provided at said metal foil for detection.

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 bridge switch consists of a fusible link between two balanced electrical loads connected in parallel. This fusible link stops a movable member from completing a secondary circuit. When that fusible link is destroyed the movable member is allowed to close the electrical contact(s) that will cause power to go to a secondary circuit. When one side of the parallel circuit to which the bridge switch is connected fails causing current to flow through the fusible link at a rate high enough to destroy that link allowing the movable member to activate the secondary circuit and/ or removing power from the primary circuit. More than one bridge switch may be employed in the total circuit where the second bridge switch is connected across two elements of the secondary circuit with the movable member restoring power to the primary parallel circuit without removing it from the secondary parallel circuit. This would then create a third parallel circuit.

Abstract: An improved incandescent light bulb which is capable of affording increased light efficiency without a resultant increase in either cost or energy consumption. In one embodiment of the bulb, said bulb includes a refractory stiff supporting element, at least one elongated helical resistive filament, two terminals which are each capable of being physically and electrically connected to a different socket and an elongated light transmissive envelope. In another embodiment the bulb additionally includes a reflector bonded to the envelope which reflects light and conducts heat away from said envelope. The stiff supporting element is formed to have a hollow interior. In said hollow interior a magnetizable elongated slug and two holding magnets may be contained. The slug and holding magnets cooperate with a switching means in the interior of the envelope to allow the bulb to selectively emit either a bright or a dim light.

Abstract: A status indicating and current limiting circuit includes a pair of lamp filaments connected in parallel to provide a high reliability for status indication of a monitored switch. The circuit indicates the status of the lamps as well as the open or closed status of the switch. In one embodiment, the pair of lamp filaments are serially connected in parallel between a source of current and the switch so that both the lamp filaments emit bright light when the switch is closed. The lamps are also connected to ground potential through a resistive element to maintain current flow through the lamp filaments when the switch is open, the current being at a level just below the current flow necessary to dimly light the filaments. In the event of a failure of one of the filaments, the other filament will begin to emit a dim but visible light even though the monitored switch is open indicating the failure of the one lamp filament.

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 switch, and a dual lamp and switch combination comprising two conductive strips spaced from each other and each having a contact point adjacent an upper end. The conductive strips contacting filament wires of the lamp or electrical conductors of a power line. A handle including a base is pivotably mounted relative to the contact points, and a conductive member operated by the handle, selectively contacts at least one of the contact points. The conductive member is integral with at least a portion of the conductive member and engages a metallic screw-on section of the lamp or electrical conductors of the power line.

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.