Abstract: A highly efficient tuned oscillator ballast circuit especially suitable for a flourescent lamp load includes an oscillator circuit coupled to a pulsed DC potential source and having a tuned output circuit coupled to a load circuit, to a drive circuit for the oscillator which is dependent upon current flow in the load circuit and to a rectifier and charge storage and isolation and applying network coupled to the pulsed DC potential source and providing energy thereto whenever the potential decreases below a given reference level. A transient compensating circuit to protect the oscillator components from initial or "start-up" transients is also included.

Abstract: A highly efficient tuned oscillator ballast circuit especially suitable for a fluorescent lamp load includes an oscillator circuit coupled to a pulsed DC potential source and having a tuned output circuit coupled to a load circuit, to a drive circuit for the oscillator which is dependent upon current flow in the load circuit and to a rectifier and charge storage and isolation and applying network coupled to the pulsed DC potential source and providing energy thereto whenever the potential decreases below a given reference level. A transient compensating circuit to protect the oscillator components from initial or "start up" transients is also included.

Abstract: A circuit for the operation of fluorescent lamps which allows the current through the lamps to be raised above the manufacturer recommended limit without adversely effecting the lamps. Two oppositely poled diodes are connected to the two contact pins at each end of the lamps, and an AC voltage is applied thereto. The arrangement results in current through two properly poled diodes during one half cycle of the applied voltage, and through the two oppositely poled diodes during the second half cycle of the voltage. As a result of this alternate loading, the thermal stress on the lamp electrodes is substantially lowered, and the current through the lamp may be raised above the recommended limit. The AC voltage is preferably at a high frequency, for example twenty kilohertz, which results in illumination from the lamps originating along the glass walls due to the skin effect, and increases the illumination efficiency of the lamps.

Abstract: A circuit for the operation of fluorescent lamps which allows the current through the lamps to be raised above the manufacturer recommended limit without adversely effecting the lamps. Two oppositely poled diodes are connected to the two contact pins at each end of the lamps, and an AC voltage is applied thereto. The arrangement results in current through two properly poled diodes during one half cycle of the applied voltage, and through the two oppositely poled diodes during the second half cycle of the voltage. As a result of this alternate loading, the thermal stress in the lamp electrodes is substantially lowered, and the current through the lamp may be raised above the recommended limit. The AC voltage is preferably at a high frequency, for example twenty kilohertz, which results in illumination from the lamps originating along the glass walls due to the skin effect, and increases the illumination efficiency of the lamps.

Abstract: A multiple filament lamp has one set of ends of all filaments connected to a common conductor and the end of another set individually connected to separate conductors. The conductors are mounted in a non-conducting lamp base with the common conductor projecting centrally beyond the bottom of the base, and the separate conductors recessed into the side of the base and equally spaced around its circumference. The base is slidable into a socket-adapter having an outer conducting shell defining standard electric socket screw threads fixed to an inner non-conducting cylinder that is recessed interiorly at the top to receive a retainer ring for engaging a similar recess around the top of the lamp base, and recessed exteriorly to receive a conductor contact spring for biasing a spring end extending through the non-conducting cylinder inwardly into separate engagement with the respective conductors recessed in the lamp base as the lamp and its base are turned in the socket-adapter.

Abstract: Apparatus for feeding a discharge lamp such as a mercury vapor lamp mounted in series with a choke from a direct current source comprising a chopper of direct current including an electronic switch and a detector of current intensity mounted in series with the choke. A first comparator compares the intensity of the current to a maximum level for opening the switch when the maximum level is reached and a second comparator compares the intensity of the current to a minimum value for closing the switch when the minimum value is reached. The lamp choke and current detector are connected in series with one another and a diode is mounted in parallel therewith and is oriented in the direction to pass current from the negative terminal towards the positive terminal of the direct current source.

Abstract: A graphite disc assembly for a rotating x-ray tube embodying a graphite substrate and an anode target of either tungsten or tungsten rhenium joined thereto by a layer of rhodium, osmium, ruthenium, platinum, platinum-chromium, or palladium.

Abstract: One of a pair of electrodes forming a spark gap is connected to a flexible coupling link and the other is extended to form an electrode terminal pin. A molding piece for fixing the spark gap is mounted by molding on at least one pair of electrodes. A common terminal is formed as a unitary structure with the coupling link. The coupling link is bent to conform to a cathode ray tube socket and incorporated therein.

Abstract: Electrodes for high current electric discharges in low pressure gases comprise a heated filament, coated with emissive material and surrounded by a hollow emitting surface in the shape of a truncated cone. The electric discharge initially starts from a spot on the filament and transfers to a diffuse mode at the small end of the cone structure.High current fluorescent lamps which include the electrodes of the present invention are characterized by rapid transition from the spot mode to the diffuse mode discharge and by low cathode fall voltage.

Abstract: Apparatus for indicating and displaying the focus of an optical objective and particularly a photographic camera. An image of the object is projected by means of the objective onto a scanning disk or plate where the light rays are divided into two separate light beams originating from two different areas of the exit pupil of the objective. Two photoelectric detectors are provided behind said scanning disk with one of said light beams impinging on one detector. Each detector delivers an electrical signal, the phase difference between these signals being a measure of the degree of focus of the objective.

Abstract: A high-pressure sodium vapor discharge lamp which is provided with a discharge tube and an outer envelope which envelopes this tube.In accordance with the improvement there are disposed in the space between the discharge tube and the outer envelope both a capacitor and a glow discharge starter which are both in parallel with the discharge tube. Consequently an external lamp starter is superfluous. In addition the lamp base may be relatively small.

Abstract: A hollow cylindrical member composed of a high-voltage potting material is secured adjacent the photocathode to the high-voltage potting material encircling the image-tube. The hollow member is concentric with the axis of the tube and extends away from the photocathode. A plurality of equally spaced metallic discs are embedded in the potting material of the corona-shield interconnected by a plurality of resistors. A high-voltage is coupled to one of the metallic discs adjacent the photocathode and a ground is coupled to another of the metallic discs most remote from the photocathode.

Abstract: A subminiature incandescent lamp having a tubular bulb with a flattened ps portion effecting closure of the bulb having a pair of lead-in wires sealed therethrough. The lead-in wires extend exteriorly of the bulb and are re-entrant into the press portion of the bulb to form two U-shaped loops, the sides of each of which touch throughout their length, and with the loops bent back about opposite sides of the flattened press portion.

Abstract: A spark plug for an internal combustion engine, the spark plug comprising a casing, a center electrode, a connector pin for the center electrode, and a plunger adapted to be axially displaced within the spark plug by the compression pressure as pressure builds in the cylinder, the plunger first closes a set of contacts in the spark plug causing current to flow in the primary side of an ignition coil, then closes a second set of contacts in the spark plug connecting the center electrode to the secondary side of the ignition coil, and finally opens the first set of contacts causing a large voltage to be induced in the secondary side which voltage is applied to the center electrode.

Abstract: A low-pressure sodium vapor discharge lamp and a current stabilizing ballast element are connected in series to an energy source so that the lamp is operated by means of a non-sinusoidal current. The temperature of the wall of the discharge tube is maintained in an accurately defined interval and the instantaneous current density in the tube is kept below a first given value and the effective current density is kept above a second given value. This results in a relatively high luminous efficacy.

Abstract: The specification discloses an igniter circuit for extending the lifetime of a gas filled electric lamp. The igniter circuit includes a D.C. boost converter for generating an open circuit D.C. voltage for application to the lamp prior to ignition of the lamp. A resistance is initially connected between the converter and the lamp in order to limit the current applied to the lamp to a first predetermined level. A timer is connected to be energized concurrently with the D.C. boost converter in order to generate a timing signal after a predetermined time interval. A relay is responsive to the timing signal in order to establish a short circuit across the resistance in order to increase the current applied to the lamp to a second predetermined level higher than the first level. Current is not increased to the second predetermined level if the lamp ignites prior to generation of the timing signal.

Abstract: A lead-in seal of the type having a metal foil seal member sealed into an envelope, comprising a relatively narrow intermediate foil tab member connected between the foil seal member and a conductor. The result is reduced stress in the seal and less likelihood of cracking.

Abstract: A high power factor conversion circuit suitable as a ballast circuit for lamps includes a full-wave rectifier coupled to an AC potential source and providing a pulsating DC potential. A high frequency inverter is coupled to a load circuit and to a feedback rectifier circuit supplying a rectified high frequency potential to an energy storage feedback circuit which provides energy in a manner to inhibit a decline in the pulsating DC potential thereby providing a substantially uniform DC potential to the high frequency inverter.

Abstract: The ballast circuit comprises a transistor having its collector and emitter and an emitter resistor in series with an alternating current operated current-controlled power supply and a gas discharge load device, such as a He-Ne gas laser. The transistor base is biased by a resistance voltage divider between the collector and the other end of the emitter resistor. A decoupling capacitor is connected between that end of the emitter resistor and the base.

Abstract: The HID lamp starting and operating apparatus of the invention includes inductive ballast means containing a winding and a core of magnetic material which may form a reactor or a transformer, and such winding is adapted for connection in circuit with an HID lamp; source means for supplying a cyclically varying AC voltage to said ballast means so as to provide AC voltage across said winding; first semiconductor switch means and a first capacitor means are coupled in circuit to said winding, responsive to said voltage across said lamp attaining a first predetermined instantaneous AC level, possible only during the time period before the lamp starts, for discharging the capacitor means through at least a portion of said winding at least once in each cycle of AC voltage to thereby generate high voltage pulses across said lamp and further responsive to said lamp being in the operating condition for terminating such capacitor discharging function; and second semiconductor switching means, including timing means ass