Abstract: A light source to be powered by microwave energy, having a dielectric body or fabrication of material lucent for exit of light therefrom, a receptacle within the dielectric body or fabrication, and a lucent microwave-enclosing Faraday cage surrounding the dielectric body or fabrication. The dielectric body or fabrication within the Faraday cage forms at least part of a microwave resonant cavity. A sealed plasma enclosure of lucent material within the receptacle has a means for locating the plasma enclosure within the receptacle with respect to the dielectric body or fabrication.

Abstract: A power supply for a magnetron has a high voltage converter, a microprocessor and a resistor. The high voltage converter comprises an integrated circuit oscillator, switching transistors, an inductance L1, a transformer and a rectifier. A voltage source supplies an augmented DC voltage to the converter. An operational amplifier, arranged as an error signal magnifier with an integrating capacitor and a resistor, compares a control signal from the microprocessor and the resistor and supplies an output signal to the oscillator. The oscillator controls the switching transistors, the output of which is connected to the inductance and the primary winding of the transformer. The secondary winding of the transformer is connected to half bridge diodes and capacitors, which provide DC current from the transformer to the magnetron.

Abstract: An electrodeless, microwave lamp has a magnetron as a microwave source and an excitable material lucent crucible in whose excitable material a plasma is established. For coupling microwaves from the magnetron into the crucible, an air wave guide coupling circuit is provided, with an output of the magnetron as an input at one quarter lambda from one end and an output at one quarter from the other end as an input to a connection to the crucible.

Abstract: A power supply for a magnetron has a PFC DC voltage source and an HV (High Voltage) converter. The voltage source is mains driven and supplies DC voltage above mains voltage on line, smoothed by capacitor to the HV converter. The latter supplies switched alternating current to transformer. This supplies higher voltage alternating current to a rectifier, in turn supplying the magnetron with high, magnetron powering, anode voltage on line. The DC voltage source has an PFC inductor, which is switched by a transistor switch under control of an integrated circuit. It is the inductor which enables the voltage source to provide a variable DC voltage. An input rectifier is provided for rectifying mains voltage. The output voltage of the voltage source is monitored and fed back to the integrated circuit by a voltage divider.

Abstract: A Lucent Waveguide Electromagnetic Wave Plasma Light Source has a fabrication (1) of quartz with an inner closed void enclosure (2) is formed of 8 mm OD, 4 mm ID drawn tube. It is sealed at its inner and outer ends (3,4). Microwave excitable plasma material is sealed inside the enclosure. Its outer end (4) protrudes through an end plate (5) by approximately 10.5 mm and the overall length of the enclosure is approximately 20.5 mm. The tube (71) from which the void is formed is continued backwards from the inner end of the void enclosure as an antenna sheath (72). The 2 mm thick end plate (5) is circular and has the enclosure (2) sealed in a central bore in it.

Abstract: To the common point (C) of two transistors of a magnetron, switched converter power circuit is connected a coupling capacitor which provides input to a starter circuit. A transistor switch id in series with a capacitor and a diode. When the switch is off no current flows in (D11). When the switch is made, (D11) conducts during alternate halves of cycles present a (C). A second diode also conducts and allows current to pass through discharge capacitor. This progressively charges until the voltage across it reaches the breakdown voltage of a gas discharge tube (GTD). Whereupon the capacitor discharges through the primary winding of transformer (TR2). The second winding has many more turns and a started voltage is induced in the starter electrode. This is isolated from the Faraday cage and terminates adjacent to the crucible, close to the void.

Abstract: A LUWPL luminaire has a housing with a lower transparent closure and a heat dissipating top of cast aluminum. This has a suspension eye. The housing has an upper flange via which it is bolted with the interposition of a seal to a underside rim of the top. Within the rim, the underside is substantially flat, with a magnetron attachment boss and other attachment points. A magnetron is supported by being clamped by a saddle to the attachment boss at the magnetron's anode. The magnetron is fast with a transition box and a crucible support block. A bracket fixed to certain of the attachment points extends down from the top is screwed to the transition box. Thus the LUWPL parts are securely supported below the top.

Abstract: A method of applying a Faraday cage to a lucent resonator, the resonator having a void containing microwave-excitable material and being adapted for microwave resonance in the resonator and within the Faraday cage for driving a light emitting plasma in the void, the method consisting in the steps of: deposition of a conductive material onto the lucent resonator; applying, patterning and developing a photoresist material over the conductive material to leave the conductive material exposed where it is not required; removing the conductive material where not required and the photoresist material from the required conductive material, leaving a reticular network of conductive material providing a Faraday cage and depositing a layer of protective material over the cage of conductive material.

Abstract: A band pass filter comprises an air filled aluminum chamber, having a lid and a cuboid resonant cavity having a central iris. At opposite end nodes of the cavity, perfect electric conductors (PECs) are provided. One is connected to a feed wire from an input at one end of the cavity. The other PEC is connected via a further feed wire to a radiator in a fabrication of solid-dielectric, lucent material. Threaded tuning projections opposite the PECs and in the iris are provided, whereby the pass band and the transmission characteristics of the filter in the pass band can be tuned to match the input impedance of the band pass filter and the wave guide to the output impedance of a microwave drive circuit (not shown). Typically the impedance will be 50?.

Abstract: A Lucent Waveguide Electromagnetic wave Plasma Light Source has a fabrication of fused quartz sheet and drawn tube. An inner closed void enclosure is formed of 8 mm outside diameter, 4 mm inside diameter drawn tube. Electromagnetic wave excitable plasma material is sealed inside the enclosure. The end plate is circular and has the enclosure sealed in a central bore in it, the bore not being numbered as such. A similar plate is positioned to leave a small gap between the inner end of the enclosure and itself. The two tubes are concentric with the two plates extending at right angles to their central axis. The outer tube extends back from the back surface of the inner plate as a skirt.

Abstract: Operation to produce an intermediate product for a crucible for a LUWPL is as follows: a) a body 2 is preheated and placed on a support, with its bore concentric with a tube 4 supported in a chuck and connected to a inflation means; b) the tube is heated with the chuck being rotated for evenness of heating; c) when the temperature of the tube is detected to be the softening point of the quartz of the tube, its rotation is stopped and it is advanced into a bore 3 in the body 2; d) advance is stopped when the distal, sealed end is detected to have reached a determined protrusion 18; e) simultaneously with the advance being stopped, inflation gas is admitted into the tube, to inflate it albeit it marginally, and bring its outer surface 5 into intimate contact with the surface 6 of the bore 4.

Abstract: The manufacture of an electrodeless bulb involves one end of a tube closed off, and a first neck is formed in the tube close to the closed end. A second neck is formed in the tube, close to the still open end; a metal halide pellet of known size is dropped into the tube and the tube is evacuated. With the vacuum being maintained heat is applied to the closed end, causing the metal halide pellet to sublime and with it the impurities. The impurities are drawn off, the vacuum being maintained and the metal halide condenses in the tube between the necks. Once the tube is cool, the evacuation is discontinued and the tube is refilled with noble gas and the quartz tube is sealed off at the second neck.

Abstract: A plasma crucible has a through bore and two tubes butt scaled on to the end faces of the crucible. One of the tubes is closed prior to the filling of the crucible. The tube is tipped off and worked in a glass lathe to form it to have a flat end. After evacuation, dosing and gas fill, the other tube is tipped off in the similar manner.

Abstract: A discharge tube of glass, filled with a halogen/noble-gas mix, which passes through a ½ lambda wave guide of alumina at an aperture ¼ lambda from one end. The wave guide is silver plated to establish resonance between its opposed ends. An antenna/probe is provided in another aperture, driven via a matching circuit from an amplifier. The discharge tube has a length greater than twice the thickness of the wave guide, extending from the wave guide on at least one side thereof.

Abstract: A method of making an electrodeless incandescent bulb comprises the steps of: providing a bulb tube of quartz glass, closing one end of the bulb tube, forming a neck having a bore less than the internal diameter of the bulb tube, inserting a pellet of excitable material into the bulb tube through the adjacent neck, evacuating the bulb tube through the neck and sealing the bulb.

Abstract: A lamp with a quartz electrodeless bulb has a ceramic wave guide with a central void, in which the bulb is accommodated. The wave guide is rectangular. The central void is centered on a central longitudinal plane of the wave guide, normal to front and back faces of the wave guide and equally spaced from end faces. Parallel with the central void and also on the central plane are two further voids for respective antennae. The central void is open through the front face for egress of light, but the antenna voids are not open in this face. The latter is metalized to inhibit egress of microwave energy from the wave guide.

Abstract: An electrodeless bulb has a hollow quartz tube, with a solid stem extending from one end and a short hollow tip extending from the other end. The hollow interior of the tube extends into the tip with the same diameter as in the tube, but the wall thickness of the tip is reduced from that of the tube. The bulb is charged with an amount of indium bromide and traces of other metal halides to adjust light spectrum and a filling of xenon gas.

Abstract: A bandpass filter comprises an air filled aluminum chamber having a lid and a cuboid resonant cavity having a central iris. At opposite end nodes of the cavity, perfect electric conductors (PECs) are provided. Threaded tuning projections opposite the PECs and in the iris are provided, whereby the pass band and the transmission characteristics of the filter in the pass band can be tuned to match the input impedance of the band pass filter and the wave guide to the output impedance of a microwave drive circuit. It is mounted on one end of the filter chamber, with an electrodeless bulb in a central cavity directed axially away from the chamber and the radiator in a further cavity set to one side of the central cavity. When the filter is driven, the wave guide resonates driving the bulb.

Abstract: A plasma lamp is provided having an integrated dielectric waveguide structure having a body, a gas housing formed within the body and having an aperture formed at a first outer surface of the body, a fill mixture disposed within the gas housing, and a probe operatively coupled to the body so that microwave energy supplied to the fill mixture forms a plasma that emits high intensity light.