General Electric Company

Other

John M Anderson

Peter D Johnson

Victor D Roberts

Homer H Glascock, Ii

James T Dakin

George A Farrall

John P Cocoma

Sayed Amr El-Hamamsy

Virgil L Stout

A series resonant starting circuit for providing a starting voltage to a starting probe for initiating an arc discharge in an electrodeless HID lamp includes an electrically variable inductance. The HID lamp is of a type having an excitation coil situated around an arc tube containing an ionizable fill in which the arc discharge is ignited. The electrically variable inductance includes a magnetic core having a main winding wound thereon that is coupled in series with a resonant capacitance. A bias winding is also wound on the magnetic core. Either the bias winding is coupled in series with a bias inductor, or, alternatively, the main and bias windings are configured on the magnetic core as a cross-field inductor. A bias circuit supply provides dc or relatively low-frequency ac current to the bias winding in order to vary the permeability of the magnetic core, and hence the inductance of the main winding, thereby tuning the starting circuit.

Magnetically tunable starting circuit for an electrodeless high

A luminaire for an electrodeless high intensity discharge (HID) lamp includes passive and/or active electromagnetic interference (EMI) shielding apparatus. One embodiment of passive EMI shielding apparatus comprises at least one section of a conductive conical surface oriented so that its longitudinal axis is coincident with the envelope of the HID lamp. Currents are induced in the outer surface of the conductive cone-section, establishing a radio frequency magnetic field tending to eliminate the radio frequency magnetic field induced by current through the excitation coil of the lamp. Alternative or additional types of passive EMI shielding apparatus include a conductive disk having an opening for surrounding the envelope in the vicinity of the arc tube, and nested conductive cylinders. Active EMI shielding apparatus comprises a loop of wire for carrying a current in order to establish another magnetic field tending to reduce or eliminate EMI. A luminaire for directing light radiated by the HID lamp includes a parabolic reflector which functions as passive EMI shielding apparatus and, in one embodiment, comprises a waveguide beyond cutoff for preventing electromagnetic radiation from propagating through the lamp.

Luminaire for an electrodeless high intensity discharge lamp with

A luminaire for an electrodeless high intensity discharge lamp houses a replaceable lamp. The lamp is insertable into the socket of the luminaire which has an excitation coil attached thereto. The lamp may include light-reflecting cones for maximizing light output from the arc tube and starting electrodes for initiating the arc discharge in the plasma of the arc tube.

Luminaire for an electrodeless high intensity discharge lamp

An electrodeless high-intensity-discharge lamp, having an envelope situated within the bore of an excitation coil and in the interior of which envelope is to be provided a discharge plasma driven by the excitation coil, is provided with a pair of starting electrodes each of which is either adjacent to, or entering the envelope through, the associated one of an opposed pair of envelope end surfaces. Coupling of a high voltage pulse between the pair of starting electrodes causes an electric field to be produced, between each electrode and the other one of the electrodes or the excitation coil, of magnitude and position sufficient to cause the material within the lamp envelope to create at least one spark channel in which the plasma can then be formed responsive to the normal field provided by the excitation coil.

Starting electrodes for HID lamps

A high intensity discharge electrodeless lamp having a segmented excitation coil and capacitor configuration offers minimum light obstruction and RF losses while providing maximum impedance matching and heat transfer from the coil to a heat sink. The excitation coil includes at least two pairs of interconnected windings, each pair disposed concentrically in its own plane. The windings are clustered in a toroidal shape, the center of which is positioned to surround the arc envelope of a high intensity discharge lamp containing an ionizable gas activatable by RF energy. The coil windings are of large cross-sectional area and the capacitors have short leads, so as to minimize EMI and power losses and facilitate heat condition to heat sink means. The windings are configured to follow the contours of the magnetic field lines created by current flow through the total coil.

Luminaire configuration for electrodeless high intensity discharge lamp

Improved efficacy and color rendition at white color temperatures is achieved in an electrodeless metal halide arc discharge lamp with a novel combination of arc tube fill materials, including sodium halide, cerium halide, and xenon. A preferred lamp structural configuration imparts further efficacy improvement at higher lamp operating temperatures and isothermal lamp operation.

High efficacy electrodeless high intensity discharge lamp

An envelope, containing a torus-shaped arc of a high-intensity-discharge electrodeless arc lamp has a shape, in a vertical plane, with a sidewall formed of a truncated conical portion, with apex located in a downward position with respect to the cone portion utilized. The upper and lower enclosing surfaces are of convex form and are smoothly joined to the truncated conical side wall of the envelope. In one presently preferred embodiment, the sidewall has a dual truncated conical form, with each truncated cone section having an apex located outside of the arc envelope and with the larger diameter section ends joined together, to allow the lamp to operate either with a base-down or a base-up disposition.

Envelope for small high-intensity-discharge electrodeless arc lamp

A fluorescent lamp has an envelope tube forming a gas-tight enclosure about a pair of externally-energizable filaments which generate a plasma discharge for conversion to visible light; a keep-alive electrode is located adjacent to at least one filament. A dimming control circuit individually externally energizes each keep-alive electrode to generate an auxiliary discharge, between that keep-alive electrode and the adjacent filament, at a magnitude sufficient to maintain the adjacent filament in the spot mode of operation even if the main plasma discharge current is varied over a range sufficient to change the visible light output of the lamp over at least a 10:1 range.

Fluorescent lamp dimming over large light output range

A lead-tin-bismuth alloy is disposed within a solenoidal electric field lamp to control the mercury vapor pressure. In accordance with one embodiment of the present invention, the alloy is placed within the tip-off region of the lamp envelope. The alloy is fixed within the tip-off region by a means of wetting the alloy to a metal wire structure such as a helix or a cylindrical screen. Alternatively, the alloy may be placed on an interior surface of the envelope by first wetting the glass with a layer of indium or other metallic wetting agent. Additionally, methods for wetting the lead-tin-bismuth alloy to the metal wire include firing the alloy in contact with the wire in a hydrogen atmosphere at a sufficiently high temperature to wet the alloy to the wire. The present invention permits the control of mercury vapor pressure in solenoidal electric field discharge lamps.

Use of amalgams in solenoidal electric field lamps

A novel electrode structure for a fluorescent lamp, particularly one employing a low discharge gas pressure, comprises a directly heated hollow cathode interiorly coated with an emissive mixture. In accordance with one embodiment of the present invention, a flat metal ribbon is wound to form a helix which is heated resistively. In accordance with another embodiment of the present invention, a flat metal ribbon is wound in a flat spiral configuration and likewise heated resistively. In yet another embodiment of the present invention, a fluorescent lamp electrode comprises a metal cylinder heated directly by a filamentary coil disposed about the circumference of the cylinder and electrically insulated therefrom.

Fluorescent lamp electrodes

It is known that electrical discharges in capillary tubing shows a positive volt-ampere characteristic even for low pressure gas fills. In contrast, conventional fluorescent lamps exhibit a negative volt-ampere characteristic and, accordingly, require special ballast circuits for operation. In the present invention, a fluorescent lamp comprises a plurality of discharge tube sections which are connected by capillary tube sections to provide the necessary ballasting action to prevent lamp current runaway. In one embodiment of the present invention, the ballastless lamp is configured in a compact configuration which may include much simpler ballast components configured in a package similar to a conventional screw-in incandescent lamp.

Fluorescent lamp without ballast

A hollow cathode electrode, particularly useful in fluorescent lamps, comprises an outer metal sleeve, an inner metal sleeve disposed within the outer sleeve and an emissive mix disposed on the inner sleeve. In one embodiment, the inner sleeve is a folded cylinder having a square cross section disposed within a circular cylinder. The object of the present invention is to prevent heat loss from the inner sleeve and to minimize sputtering. The electrode of the present invention may also include a third exterior sleeve surrounding but not contacting the interior sleeve or sleeves.

Shielded hollow cathode electrode for fluorescent lamp

A lead-tin-bismuth alloy is disposed within a solenoidal electric field lamp to control the mercury vapor pressure. In accordance with one embodiment of the present invention, the alloy is placed within the tip-off region of the lamp envelope. The alloy is fixed within the tip-off region by a means of wetting the alloy to a metal wire structure such as a helix or a cylindrical screen. Alternatively, the alloy may be placed on an interior surface of the envelope by first wetting the glass with a layer of indium. Additionally, methods for wetting the lead-tin-bismuth alloy to the metal wire include firing the alloy in contact with the wire in a hydrogen atmosphere at a sufficiently high temperature to wet the alloy to the wire. The present invention permits the control of mercury vapor pressure in solenoidal electric field discharge lamps.

A balanced hydraulic well pumping unit for actuating an underground pump in which the weight of the downstroke is utilized to store energy in an accumulator which is then used to assist in the upward stroke of the pump. A working rod passes through first and second vertically positioned cylinders and is connected to first and second pistons in the cylinders, respectively. Hydraulic power means are connected to the first cylinder for alternately supplying hydraulic fluid to opposite sides of the first piston for moving the working rod upwardly and downwardly. An accumulator is connected to opposite ends of the second cylinder whereby downward movement of the working rod causes the second piston to store energy in the accumulator which is then used to assist movement of the working rod upwardly on the upward stroke of the pumping unit. Preferably, the sucker rod of the well pump extends into the working rod thereby allowing the pumping unit to be positioned close to the well surface. Various controls are provided for admitting and replenishing air and hydraulic fluid to the accumulator and second cylinder, but limiting the amount of air and hydraulic fluid.

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Scotia, NY, United States of America

John M Anderson