Abstract:
A fill composition for a high intensity discharge device including mercury, niobium oxytrihalide, and a molecular stabilization agent is provided. The molar ratio of niobium oxytrihalide to the molecular stabilization agent in the fill is in the range of from about 5:1 to about 7.5:1. Niobium oxytrihalide is present in the fill in sufficient amount to produce, by dissociation in the discharge, atomic niobium, niobium oxide, NbO, and niobium dioxide, NbO.sub.2, with the molar ratio of niobium-containing vapor species to mercury in the fill being in the range of from about 0.01:1 to about 0.50:1; and mercury pressure of about 1 to about 50 atmospheres at lamp operating temperature. There is also provided a high intensity discharge device comprising a sealed light-transmissive arc tube; the arc tube including the above-described fill; and an energizing means for producing an electric discharge within the arc tube.
Abstract:
A method of forming a sealed capsule containing a submilligram quantity of mercury or the like, the capsule being constructed from a hollow glass tube, by placing a globule or droplet of the mercury in the tube. The tube is then evacuated and sealed and is subsequently heated so as to vaporize the mercury and fill the tube therewith. The tube is then separated into separate sealed capsules by heating spaced locations along the tube with a coiled heating wire means to cause collapse spaced locations therealong and thus enable separation of the tube into said capsules.
Abstract:
Glass encapsulated, metal arc directors for compact fluorescent lamps. The metal parts are coated with an aqueous suspension of glass frit and fired to form the glass coating. Such parts reduce discharge contamination by reducing the outgassing of the metal parts.
Abstract:
An arc discharge lamp comprises a source of UV emission and a chamber external thereto. The chamber contains gaseous molecules which absorb the UV emission and are raised to a highly excited state, from which they relax to the ground state through an intermediate energy state. The transition from either the highly excited state to the intermediate state, or from the intermediate state to the ground state, is accompanied by emission of visible light.
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 electrodeless lamp includes a bulbous lamp envelope enclosing an inert gas and a vaporizable metal fill, the lamp envelope having a reentrant cavity; an electromagnetic coupler positioned within the reentrant cavity; and a cold spot structure configured for low temperature, low duty cycle operation and for room temperature, 100% duty cycle operation. In some embodiments, the cold spot structure includes a dimple in the lamp envelope, the dimple having a thinned sidewall. In further embodiments, a shield is positioned near the dimple to control cold spot temperature. In additional embodiments, the cold spot structure includes a heat sink attached to the exhaust tube of the lamp envelope and thermally isolated from the lamp base.
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 discharge metal halide lamp for use in selected lighting fixtures having a discharge chamber with light permeable walls of a selected shape bounding a discharge region of a selected volume through which walls a pair of electrodes are supported with ionizable materials being provided in the discharge region of the discharge chamber comprising at least one member selected from a group consisting of halides of cerium, dysprosium, holmium, lithium, sodium, praseodymium, thallium and thulium, and further comprising a halide of calcium in a selected fraction of that weight total of all halides present in the discharge chamber with this selection depending also on the addition or not of a halide of aluminum. Others of the foregoing halides that are present are provided in amounts with certain limits.
Abstract:
A lighting system includes a high intensity discharge metal halide lamp having an arc discharge chamber with electrodes at each end and containing a fill of mercury, rare gas and metal halides, and a ballast circuit configured to supply pulsed electrical power to the lamp. The ballast circuit includes a controller configured to adjust the pulsed lamp power between a first relatively high power level at a relatively high duty cycle and a second relatively low power level at a relatively low duty cycle. The controller may be configured to adjust the pulsed lamp power between 90% duty cycle at rated lamp power and 10% duty cycle at 30% of the rated lamp power. The duty cycle of the pulsed lamp power may be controlled to maintain a substantially constant correlated color temperature (CCT) as the power level is adjusted.
Abstract:
An electrodeless lamp includes a bulbous lamp envelope enclosing an inert gas and a vaporizable metal fill, the lamp envelope having a reentrant cavity, a magnetic core positioned within the reentrant cavity, an induction coil disposed on the magnetic core, a cooling structure disposed inside the magnetic core, and a spacer structure between the magnetic core and an inside wall of the reentrant cavity. The spacer structure defines a thermally insulating gap between the magnetic core and the inside wall of the reentrant cavity to control coil/core temperature.