Abstract: A high intensity discharge lamp includes, within the outer envelope, a strip of niobium foil serially connected between a power source and one of the electrodes of the arc tube of the lamp. The foil is not a power consuming element but will oxidize and open the circuit, thus extinguishing the lamp, in the event the outer envelope is ruptured.

Abstract: In a blended lamp, an incandescent filament and a high-pressure discharge tube are arranged electrically in series. The filament forms part of a halogen incandescent lamp and the discharge tube contains a sodium amalgam which is very high in mercury. A relatively high lumen per Watt-value is thereby combined with an acceptable color of the light.

Abstract: A tungsten filament lamp incorporates arc discharge electrodes for an arc discharge in a gas fill enclosed in the lamp envelope. The tungsten filament is utilized as a ballast resistance for the arc discharge. A method for mounting the filament and electrodes in an embodiment according to the invention is shown.

Abstract: A lamp assembly includes a lamp and a lamp package. The lamp includes a light-emitting portion with a flange at its base and electrically conducting leads extending from the base. The flange has a flat portion. The lamp package includes a cylindrical housing and a cylindrical cover. The housing has a base and a side wall, the base having holes for the electrical leads to pass therethrough, the bore in the housing being ssmaller than the flange of the lamp. A portion of the side wall of the housing has a flat key for engaging the flat portion of the flange. The cover has a side wall and an inwardly extending flange such that when the cover is slid over the lamp and the housing, the inwardly extending flange engages the outwardly extending flange of the lamp thereby holding it in place against the top of the housing and against the flat key of the housing.

Abstract: A solid-state electronic ballast circuit for supplying direct-current power to an electric discharge vapor lamp is disclosed. The source-drain channel of a Vertical Metal Oxide Semiconductor (VMOS) Field Effect Transistor (FET) is connected in parallel with a fixed ballast resistor, the parallel combination being connected in series with the lamp across a DC source. A resistance network controls the conductivity of a bipolar transistor, which in turn controls the conductivity of the VMOS channel, in response to variations in both lamp voltage and current. The ballast circuit may be manufactured as a part of the lamp bulb assembly, the ballast resistor taking the form of an incandescent lamp filament mounted in the same outer bulb with the vapor lamp arc tube. A variable resistance may be employed to manually adjust the level of illumination delivered by the lamp, or a light-sensitive phototransistor may be employed to deliver constant illumination.

Abstract: A fluorescent lighting device which includes a preheating type fluorescent discharge tube and as the ballast thereof an incandescent bulb. The fluorescent lighting device is ignited by the use of a pulse transformer and a neon tube. A semiconductor element may be used in place of the neon tube.

Abstract: A lighting unit is described utilizing an energy efficient metal vapor arc lamp as the main source of light supplemented by a standby filamentary light source producing light when the arc lamp is being started, the filament thereof serving as a resistive ballast for the arc lamp under normal operation. The lighting unit is designed as a more efficient replacement for the incandescent lamp. The lighting unit includes a rectifier for conversion of 60 hertz ac to dc, and a dc energized operating network, including a ferrite transformer and a transistor switch. The operating network produces an output adapted to each operating state of the arc lamp, including the provision of a high ignition potential, a power boost for the lamp during the glow to arc transition, warm-up and ballasting provisions, and means for sustaining the arc during transients which reduce the line voltage.

Abstract: A metal vapor discharge lamp comprises main electrodes and an auxiliary electrode in an arc tube to initiate the discharge between the main electrode and the auxiliary electrode at the initiation of the operation and then to result the discharge between the main electrodes by disconnection of the auxiliary electrode by a bimetallic switch means. A second bimetallic switch means which delays the operation from that of the first bimetal, is connected in series to the first bimetallic switch means so as to discharge in a circuit formed in an outer bulb to break a part of the circuit and to prevent a ballast from overheating.

Abstract: A high pressure metal vapor discharge lamp according to the present invention comprises the following first and second starting aid circuits mounted within an outer envelope. The first starting aid circuit includes a starting aid and a first thermal switch, and the second starting aid circuit includes a resistive element and a second thermal switch. These two thermal switches are arranged so that at the time of re-starting after a certain period of stopping, the first thermal switch is reset earlier than the second thermal switch. In this high pressure metal vapor discharge lamp having this specific structure, the starting characteristic is improved, and a high voltage pulse generated by the second starting aid circuit and a ballast is assuredly absorbed by an arc tube and occurrence of dielectric breakdown in the respective elements can be completely prevented.

Abstract: A circuit for starting and ballasting a compact high intensity arc discharge lamp, and for preventing failure of the arc discharge. A filament connected in series with the arc lamp provides illumination during arc start-up and functions as a ballast during normal arc operation. An oscillatory starting circuit supplies starting voltage to the arc lamp until an operating arc is established. The circuit includes a "keep-alive" feature which prevents the arc from extinguishing during power fluctuations.

Abstract: A low pressure gas discharge lamp is provided with a pair of high power incandescent electrodes to increase output illumination at the lamp ends. In an alternate construction, the electrodes are of high power, low emissivity and are electrically connected to a second pair of high emissivity electrodes which provide the means for enabling the mercury discharge. With this second construction, the low emissivity electrodes can act as ballast for the circuit.

Abstract: The invention relates to a mixed light lamp arrangement intended to be connected to an a.c. power supply. The lamp arrangement comprises a rectifier bridge having output terminals interconnected by the mixed light combination consisting of a series arrangement of an incandescent filament and a discharge tube. The series arrangement is shunted by a branch comprising a capacitor and an anti-parallel arrangement of a diode and a thyristor with the thyristor being rendered conductive just prior to the end of each half cycle of the a.c. power supply. This results in a mixed light lamp wherein the capacitance of the capacitor can have a relatively low value and the luminous efficacy can be relatively high.

Abstract: The present invention relates to a lighting unit utilizing an energy efficient arc lamp as the main source of light supplemented by a standby filamentary lamp, the filament serving as a resistive ballast for the arc lamp during normal operation. The lighting unit is designed for functional similarity to an incandescent lamp, the filament providing immediate illumination when the lighting unit is first energized and continuing illumination until the arc lamp itself produces light. In accordance with the invention, if the arc lamp does not start within a predetermined period, the application of starting potentials produced through operation of a solid state switch and a high frequency step-up transformer is discontinued and the lighting unit rendered inactive. Exemplary means includes a positive temperature coefficient thermistor responsive to the temperature rise of the solid state switch.

Abstract: A jacketed metal halide discharge lamp combining a miniature arc tube containing sodium iodide and a standby filament within an outer envelope, is provided with a glass sleeve around the arc tube. The glass sleeve is preferably connected to a point of potential which is positive relative to the arc tube, suitably the anode when the arc is operated on d.c. The glass sleeve prevents sodium loss from the arc by trapping ultraviolet light and by shielding the arc from photoelectrons. The sleeve serves also to reduce color shift when the arc tube is switched over from "high" to "low", and to protect the outer bulb in the event of arc tube rupture.

Abstract: A light source includes a high pressure discharge lamp and incandescent filaments which provide illumination during the warm-up and hot restart periods associated with the discharge lamp. A current regulator, which provides dc power to the discharge lamp, draws sufficient current through one filament to energize the filament only during discharge lamp warm-up. A second filament provides illumination during the period after the occurrence of a momentary power failure or power transient which is required by the discharge lamp to cool down to its maximum starting temperature. A bimetal switch permits current flow through the second filament when the discharge lamp is above the maximum starting temperature. An electronic switch permits current flow through the second filament when a current sensing resistor senses a lack of current through the discharge lamp.

Abstract: A lamp assembly (10) comprises a base plate (12) having both an incandescent bulb (18) and a fluorescent bulb (16) affixed thereto. The incandescent bulb (18) acts as ballast and light source. A glow switch (26) and capacitor (27) act as starter and are contained within the base plate (12) or socket means (14). A starting aid (24) is impedance coupled into the series filament network.

Abstract: Mixed light lamps require a complicated construction so as to be able to suspend the filament and the discharge lamp. In a mixed light lamp according to the invention a bipartite filament of coiled-coil wire is used, the parts of which are each stretched between one pole wire and a current supply conductor of the discharge lamp.

Abstract: High-pressure discharge lamps, having a sealed discharge vessel surrounded by a sealed glass envelope, are known in which an oxidizable metal foil (e.g. of molybdenum) is located, in the space between the vessel and the envelope substantial on the axis of the vessel and is electrically in series with the discharge path. If the envelope is fractured for any reason and the lamp is subsequently ignited, the temperature of the foil is increased due to the discharge current passing through it. The foil is oxidized, and hence fractured, by the air which has permeated said space and the lamp is, extinguished. Such oxidation and fracture normally takes about ten minutes. In accordance with the invention, the foil (14) in the space between the envelope (1) and vessel (2) is arranged close to the wall of the vessel adjacent to an electrode (6) so as to be heated mainly by heat generated in the vessel. This reduces the fracturing time to about one minute.

Abstract: A high pressure sodium vapor lamp having an elongated light-transmitting refractory arc tube with closure members sealing each end of the arc tube. An elongated hollow refractory metal member of predetermined length and surface area projects from the arc tube and is sealed through one of the closure members. The interior of the hollow metal member opens into the interior of the arc tube and the projecting end of the hollow metal member is sealed. During the operation of the lamp, the hollow metal member acts as a condensing repository for excess discharge sustaining filling which is not vaporized since the coolest spot of the hollow metal member is at a temperature less than the arc tube. The hollow metal member is provided on the outer surface with a radiation-emissive and electrical-insulating means, and a resistive-heater member is affixed to the exterior of the hollow metal member and in thermal contact with the radiation-emissive and electrical-insulating means.

Abstract: Safety devices for high intensity discharge lamps, having an outer envelope and an inner arc tube in which the arc discharge is produced, for extinguishing the arc in a relatively short period of time. A switching element is placed in series with the current supply to the arc tube and the element opens when the outer envelope is broken. In one embodiment, the switching element is a normally closed thermostatic switch in series with a second filament which is connected in parallel with a first filament. During starting the switching element is closed and both of the filaments are in series with the arc tube and both receive a part of the high starting lamp current. The thermostatic switch opens when the lamp reaches operating temperature so that all of the current passes through the first filament if the envelope breaks causing the first filament to burn out. The switch then closes so that all of the current passes through the second filament causing it to burn out.

Abstract: There is provided in combination with a rapid-start series-sequence type ballast for two low-pressure mercury discharge lamps, apparatus for reducing the power consumption of both lamps. The apparatus utilizes switch means in conjunction with a capacitor to limit the current supply to the lamps after the lamps are energized. The switch means has two members in series circuit arrangement with one of the electrodes of one of the lamps. Each member is connected on opposite sides of the electrode. The capacitor is connected in parallel circuit arrangement with one of the members. Initially upon energization the switch means has a low impedance state to permit current flow and then switches to a high impedance state. The switch means permits preheating of the electrode and thereafter upon response to current flow switches and causes the lamp current to pass through the capacitor and thereby decrease by a predetermined amount the current through the normally operating lamps.

Abstract: The inner arc tube of some jacketed discharge lamps transmits ultraviolet radiation which is normally absorbed without harm by the glass outer envelope but may be released should the outer envelope be broken off. This is prevented by a fuse heater and shunting thermal switch connected in series with the arc tube and located within the outer envelope. Should the outer envelope be broken, air cools the switch so that it opens. Current flow through the heater now raises its temperature and causes it to oxidize, thereby opening the circuit and disabling the lamp.

Abstract: A filament coil is connected in series with an arc tube to form a self ballasted lamp. An internal starting coil is connected across the arc tube through a bimetal switch, which is normally closed, for energizing the starting coil. When an arc is struck and the tube temperature rises, the bimetal switch opens to cut out the starting coil. A fuse wire is connected across the bimetal switch to facilitate flashing of the filament coil by application of less than rated voltage during evacuation of the lamp envelope when the bimetal switch is normally open because of the elevated temperatures required for glass working and sealing. Upon subsequent application of rated voltage, the fuse wire melts and the lamp operates in its normal manner.

Abstract: In a sodium vapor lamp, a means for rapid warm-up and/or maintaining the temperature of the discharge tube in order to quickly achieve and maintain the sodium vapor pressure at a desired level is disclosed. The discharge tube is surrounded with a resistive conductor so as to ohmically heat the tube to a desired temperature, e.g. 270.degree.C. The heating element is a resistive tube coating.