Abstract: A lamp ballast for operating a high intensity discharge lamp includes an electronic ballast circuit to supply an operating voltage to the discharge lamp, and an igniter circuit to supply starting pulses to the discharge lamp in a cold state and to supply hot restrike pulses to the discharge lamp when the discharge lamp is in a hot state following turn-off. The hot restrike pulses are sufficient to maintain ionization in the discharge lamp but do not cause the discharge lamp to generate substantial light output.

Abstract: An arc discharge metal halide lamp for use in selected lighting fixtures comprising a discharge chamber having light permeable walls of a selected shape including therein a pair of end region wall portions through each of which a corresponding one of a pair of electrodes are supported separated from one another by a separation length. The ratio of the separation length to the effective operation inner diameter of the chamber is greater than two. The lengths of the wall sides between the end wall portions is greater than the effective operation inner diameter. The end wall portions have inner surfaces of constant or smaller varying radii of curvature and they are separated from the interior ends of the electrodes by more than one millimeter. The discharge chamber can be constructed of polycrystalline alumina and contain metal halides.

Abstract: An arc tube is provided for use in a high intensity discharge lamp. The arc tube is generally comprised of an elongated outer envelope defining two opposed ends and a cavity therebetween; an electrode sleeve protruding outwardly from each end of the outer envelope, such that each electrode sleeve has a passageway; and an electrical feedthrough member inserted into the passageway of the electrode sleeve, where the feedthrough member includes an inner rod that extends into the cavity of the arc tube and a ceramic sleeve encircling a portion of the inner rod disposed within the passageway. A sealing compound is disposed at an outwardly facing end of the passageway for sealing the feedthrough member to the electrode sleeve, such that the sealing compound extends into the passageway of the electrode sleeve but is spatially separated from the ceramic sleeve.

Abstract: A lamp ballast for operating a high intensity discharge lamp includes an electronic ballast circuit to supply an operating voltage to the discharge lamp, and an igniter circuit to supply starting pulses to the discharge lamp in a cold state and to supply hot restrike pulses to the discharge lamp when the discharge lamp is in a hot state following turn-off. The hot restrike pulses are sufficient to maintain ionization in the discharge lamp but do not cause the discharge lamp to generate substantial light output.

Abstract: An arc discharge metal halide lamp having a discharge chamber having visible light permeable walls bounding a discharge region supported electrodes in a discharge region spaced apart by a distance Le with an average interior diameter equal to D so they have a selected ratio. Ionizable materials are provided in this chamber involving a noble gas, one or more halides, and mercury in an amount sufficiently small so as to result in a relatively low maximum voltage drop between the electrodes during lamp operation.

Abstract: An arc discharge metal halide lamp having a discharge chamber having visible light permeable walls bounding a discharge region supported electrodes in a discharge region spaced apart by a distance Le with an average interior diameter equal to D so they have a selected ratio. Ionizable materials are provided in this chamber involving a noble gas, one or more halides, and mercury in an amount sufficiently small so as to result in a relatively low maximum voltage drop between the electrodes during lamp operation.

Abstract: An arc discharge metal halide lamp for use in selected lighting fixtures comprising a discharge chamber having light permeable walls of a selected shape including therein a pair of end region wall portions through each of which a corresponding one of a pair of electrodes are supported separated from one another by a separation length. The ratio of the separation length to the effective operation inner diameter of the chamber is greater than two. The lengths of the wall sides between the end wall portions is greater than the effective operation inner diameter. The end wall portions have inner surfaces of constant or smaller varying radii of curvature and they are separated from the interior ends of the electrodes by more than one millimeter. The discharge chamber can be constructed of polycrystalline alumina and contain metal halides.

Abstract: An electrodeless low pressure discharge lamp comprises an envelope made from a straight tube and a reentry cavity sealed to one of tube's ends. The cavity has several hollow ferrite cores separated from each other with a few mm distance. Each ferrite core has an induction coil of few turns wound around the core. Each cavity has a cooling copper tube or rod located inside the ferrite core that removes heat from the cores and dumps the heat into a heat sink welded to the cooling tube/rod thereby keep the temperature of the ferrite cores below their Curie point. Each induction coil is electrically connected to the matching network while all matching networks are connected in parallel to the high frequency power source (driver). Inductively coupled plasmas generated in the envelope by several core/coil assemblies produce axially uniform UV and visible radiation.

Abstract: An electrodeless low pressure discharge lamp comprises an envelope made from a straight tube and a reentry cavity sealed to one of tube's ends. The cavity has several hollow ferrite cores separated from each other with a few mm distance. Each ferrite core has an induction coil of few turns wound around the core. Each cavity has a cooling copper tube or rod located inside the ferrite core that removes heat from the cores and dumps the heat into a heat sink welded to the cooling tube/rod thereby keep the temperature of the ferrite cores below their Curie point. Each induction coil is electrically connected to the matching network while all matching networks are connected in parallel to the high frequency power source (driver). Inductively coupled plasmas generated in the envelope by several core/coil assemblies produce axially uniform UV and visible radiation.