Abstract: An LED driving circuit that is directly activated by an AC power supply is disclosed. A driving circuit has a first and second pair of opposite branches. The first pair of opposite branches operates in a positive half cycle of the AC power supply and the second pair of branches operates in a negative half cycle of the AC power supply, so the lighting time for each LED is less than a half cycle time, in other words, the time for heat dissipation is prolonged.

Abstract: A warning light that comprises at least one circuit board with a multiplicity of LEDs which has a low current draw as compared to an equivalent incandescent bulb, and fits a standard incandescent light socket.

Abstract: A lampholder for use with cold cathode lamps intended to be wired in a parallel configuration includes an insulating bulb-end receptacle mounted in a conductor housing. The receptacle is divided into a pair of individual bulb-end receiving portions, each of which is provided with a conductive clip which establishes electrical contact with an inserted bulb. At least one of the clips is in two sections which are configured as switch contacts in series with the mains side of a ballast for the lamps. Insertion of a lamp into the clip closes the switch contacts, establishing the mains circuit and allowing high-voltage to be generated and applied to the lamps. The lampholder insures that high-voltage is not produced unless a lamp is in place.

Abstract: A traffic signalling apparatus wherein LEDs are employed to present various displays and the LEDs are secured with their sidewalls in a tubular holding device such that a good heat discharge from the LEDs to the holding device is guaranteed. The holding device is securely fixated in a front plate of the signalling apparatus, preferably detachably. An optical imaging device is additionally provided in order to achieve an emission characteristic which is optimized for traffic participants.

Abstract: A lampholder for use with cold cathode lamps intended to be wired in a parallel configuration includes an insulating bulb-end receptacle mounted in a conductor housing. The receptacle is divided into a pair of individual bulb-end receiving portions, each of which is provided with a conductive clip which establishes electrical contact with an inserted bulb. At least one of the clips is in two sections which are configured as switch contacts in series with the mains side of a ballast for the lamps. Insertion of a lamp into the clip closes the switch contacts, establishing the mains circuit and allowing high-voltage to be generated and applied to the lamps. The lampholder insures that high-voltage is not produced unless a lamp is in place.

Abstract: A retrofit lamp having light emissive diodes, and more particularly, to a retrofittable lamp configured as a standard incandescent lamp which can be used effectively in illuminated signs, such as an exit sign, for operation on each cycle of A/C voltage applied. The newly designed solid-state lamp features a base that can be rotated, approximately 160 degrees, to allow for the optimal positioning of the LED array to maximize the light intensity directed toward the illuminated area.

Abstract: A retrofittable lamp using light emitting diodes as the illumination source, the lamp is fitted with any one of the common lamp bases and is intended as a retrofit for incandescent lamps having such bases in illuminated signs such as exit signs and the like. The invention contemplates the packaging of a number of light emitting diodes in a circuit usually having a current limiting device to allow LED operation at a desired current level. The light emitting diodes are placed within a standard glass or plastic bulb envelope in arrangements capable of providing even illumination from the lamp.

Abstract: A ballast for a gas discharge lamp circuit has a d-c output which contains three series-connected diodes connected across the output terminals, a pair of capacitors connected from different respective nodes of the diodes to respective ones of the output terminals, and a resistor connected between two of the diodes. The resistor increases the circuit power factor to greater than 0.95.

Abstract: A starting capacitor disconnect scheme for a fluorescent lamp system in which each starting capacitor shunts one or more series connected fluorescent lamps until all of the fluorescent lamps are ignited. Following ignition of all fluorescent lamps, each starting capacitor is effectively removed from the ballast. Preconditioning of the fluorescent lamp filaments can be limited to the period of time that one or more lamp loads are shunted by the starting capacitor.

Abstract: An adaptor circuit used to enable stable, flicker-free operation of T8-type fluorescent lamps in a lighting fixture which already has a standard two-lamp, series-sequence, 40 watt, rapid-start type ballast installed therein. The adaptor circuit contains an isolation transformer for controlling the voltage supplied by the ballast to the T8-type fluorescent lamps and a frequency selective impedance modifier circuit for controlling the operating current supplied by the ballast to the T8-type fluorescent lamps at preselected frequencies. In one embodiment, the frequency selective impedance modifier circuit substantially eliminates the third harmonic component of the fundamental frequency of the operating current.

Abstract: A field lighting network providing for individual control of the light fittings while reducing overall cable costs. A converter unit converts a supply voltage obtained from an A.C. main to a substantially constant current in a Boucherot circuit with a series resonance circuit, tuned to the main frequency. The converter unit includes a Boucherot circuit having a series resonance circuit, substantially tuned on the main frequency, and an additional inductance in series with a load connected to the converter unit. A regulator unit supplied with current couples to each fitting or group of fittings for individual regulation of the current passing through the respective lamp or lamps. Each regulator unit is disposed to receive control information on the power cable.

Abstract: A circuit (500) for driving two or more series-connected gas discharge lamps, having: an oscillator (518, 520, 522); and a transformer (524) with a primary winding (526) and a secondary winding (528). The transformer secondary winding has first (129A) and second (129B) points connected respectively to first (508) and second (514) output terminals across the series-connected lamps. A capacitor (532) couples the first point of the transformer secondary winding to an intermediate output terminal (112). The voltage produced by the secondary winding thus drives the lamps in series, while the pre-strike voltage produced across the secondary winding is applied across a single lamp (106) to cause it to strike. After striking, current to the intermediate output terminal (512) is limited by the capacitor (532). In this way, the voltage which needs to be produced across the secondary winding to ensure striking of all of the lamps is reduced.

Abstract: A rapid start fluorescent system which has its starting capacitance connected to a tap on the secondary of the ballast transformer which tap is located at a predetermined number of turns of the secondary.

Abstract: An attachment is provided for connection in fluorescent lamp circuits for reducing power consumption. The attachment is particularly designed for use with fluorescent lamp circuits having an encapsulated ballast including a transformer and capacitance. The attachment includes an isolation transformer with a capacitor and a resistor connected across the transformer, and an inductance connected in line with the primary of the ballast transformer with a resettable thermal switch connected to shut down the ballast transformer in response to high current overload conditions, and a surge voltage protection circuit connected through the thermal switch to shut down the ballast in response to a ballast power factor capacitor failure. The ballast and power reducer cooperate to produce a substantially square wave output resulting in increased system efficacy, reduced lamp lumen depreciation, and increased lamp life.

Abstract: A low pressure gas discharge lamp ballast circuit is provided for three series-connected low energy gas discharge lamps, in which a first starting capacitor provides a starting voltage to one of the lamps, and a second starting capacitor provides a starting voltage to a second one of the lamps in sequence, so that the ballast losses can be minimized by reducing the ratio of the voltage applied across the three lamp system to the total lamp voltage, while still maintaining the light output and not having to use expensive lamp bases and lampholders.

Abstract: Apparatus and method for evaporation arc stabilization including a target having a surface of material of non-permeable material to be evaporated; circuitry for establishing an arc on the target surface for evaporating the target material, the arc being characterized by the presence of charged particles and a cathode spot which randomly migrates over the target surface; and a confinement ring surrounding the target surface, the ring being composed of a magnetically permeable material to thereby confine the cathode spot to the target surface.

Abstract: A pair of 48-inch long preheat fluorescent lamps, each one and a half inches diameter and consuming less than 10 watts power per foot of length, are connected in series with each other and with a ballast, for operation from 50 or 60 hertz a-c line voltage in the range of 200 to 300 volts. A starter switch is connected in parallel across each lamp. The lamp designs are specified such that they will start and operate in the circuit from the a-c line voltage.

Abstract: A device and a method for reducing power consumption and correspondingly reducing lumen output of a phosphor excitable lamp, such as a fluorescent lamp, connected to a source of power for operation of the same, without any appreciable loss of operating efficiency. A load limiting arrangement, often referred to as a load limiting control device, and which generally includes a capacitive element is electrically connectable to one terminal of the phosphor excitable lamp. This device, when connected, is effectively electrically interposed between the lamp and the source of power in a series connection. The capacitive element is selected with a capacitive value so that the lumen output is reduced but with substantially uniform lumen output at the reduced level and the power consumption is reduced without substantially changing the voltage to the lamp and without any appreciable effects on the efficiency of operation of the lamp or the source of power.

Abstract: An electric device comprising at least one low-pressure mercury vapor discharge tube intended to be connected to an AC voltage source at a frequency of 50 to 60 Hz. The discharge tube is of a type which produces a comparatively large current distortion and has a proportionally low required reignition voltage. The electric device produces relatively small electric losses. The discharge tube remains operative even for small deviations of the nominal AC supply voltage.

Abstract: A device and a method for reducing power consumption and correspondingly reducing lumen output of a phosphor excitable lamp, such as a fluorescent lamp, connected to a source of power for operation of the same, without any appreciable loss of operating efficiency. A capacitive element is electrically connectable to one terminal of the phosphor excitable lamp and is effectively electrically interposed between the lamp and the source of power in a series connection. The capacitive element is selected with a capacitive value so that the lumen output is reduced but with substantially uniform lumen output at the reduced level and the power consumption is reduced without substantially changing the voltage to the lamp and without any appreciable effects on the efficiency of operation of the lamp or the source of power.

Abstract: A generator for the starting and thereafter maintaining energization and operation of a load which has a relatively high impedance during starting and a substantially lower impedance after starting and during operation thereof. The load may be an ionic conduction lamp including a phosphor excitable lamp in the nature of a fluorescent lamp, or electroluminescent lamp, or vapor lamp. The generator includes a mechanism for generating electrical power with a relatively high voltage and impedance so as to match the relatively high impedance of the load before starting and generization of electrical power of a substantially lower voltage and impedance so as to match the lower impedance of the load during the energizing and operation of the load. The mechanism for generating the electrical power may be an inductive member, such as a coil, and a solid state element, such as a transistor, to develop a voltage over the coil. The coil may be coupled to the lamp through some agent developing a capacitance, e.g.

Abstract: An electronic ballast-inverter for multiple fluorescent lamps employs a push-pull inverter and a series resonant circuit for driving the lamps. The inverter operates at the resonant frequency of the series resonant circuit. Current in the resonant circuit is limited, for low-load conditions, in response to a sensing voltage which is used to lower the frequency of operation of the inverter, to make the load more reactive.

Abstract: A lamp simulator for use as a replacement for a phosphor excitable lamp, such as a fluorescent lamp in a plural lamp fixture. The fixture is typically one with socket-type connectors adapted to have at least two or more phosphor excitable lamps mounted therein. The lamp simulator replaces one or more of the illuminatable lamps in the fixture. The simulator comprises a lamp body or housing having end caps on each of the transverse ends and generally has a size approximately equal to a lamp it replaces. In one embodiment, a capacitor may be physically mounted on one of the end caps and is electrically connected to one of the terminals on the end cap and electrically connected to a terminal on the other of the end caps. Further, the caps may have a diametral size at least slightly greater than the lamp tube such that a plurality of lamps can be packed in a single container without a separate jacket for each lamp.

Abstract: Electronic ballast apparatus includes a transformer having an "E"-shaped core member with a primary winding wrapped on a center leg member and coupled to a potential source and first and second secondary windings each wrapped on a first and second outer leg member of the core member and coupled to gaseous discharge lamps such that flux developed in the primary winding is differentially divided between the first and second secondary windings in inverse relation to energization of the gaseous discharge lamps.

Abstract: A device which is designed to save electrical energy expended by a regular rapid start fluorescent lighting fixture having a plurality of lamps, or tubes, and a conventional ballast. The device comprises the combination of a step-up transformer, a resistor and two capacitors, all of which are mounted externally of the ballast. The device is wired in series with the ballast and one of the lamps to allow normal ballast voltages to be delivered to the lamp circuit, thereby eliminating any detrimental effects to the lamps or ballast. At the same time, the current to the lamps and consequent consumption of power by the lamps is substantially reduced to save electrical energy while providing a reduced, but uniform level of illumination.

Abstract: A circuit arrangement for igniting at least one gas discharge flash tube having two main electrodes includes a chargeable flash capacitor connected in parallel with the flash tube and an electronic switch. These elements are connected to a voltage generator which supplies ignition voltage pulses and the electronic switch constitutes a gas discharge path for the flash tube. The voltage generator has such a low impedance, in particular a low inductance, that the ignition voltage pulses supplied thereby at least approximately adiabatically heat the gas discharge paths.

Abstract: A device for replacing a fluorescent lamp in a two lamp serially connected fluorescent fixture either of the type which includes a rapid-start type transformer for every two rapid-start fluorescent lamps or an instant start fixture for every two instant start lamps. By placing the device in the fixture in place of one of the two lamps the remaining lamp is energizable to provide illumination, whereas without the device the remaining lamp is inactive.

Abstract: An attachment is provided for inclusion in a two-lamp rapid-start type fluorescent lamp and encapsulated ballast transformer combination to reduce the electrical power consumption thereof, comprising an isolation transformer and a capacitor. The isolation transformer is connected in circuit between the secondary heater winding at the electrical leads that extend from the encapsulated ballast and the first heater terminals of the first lamp, and the capacitor is connected in circuit between the primary and secondary of the isolation transformer.

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: Electrical lamp ballast system for starting and operating fluorescent lamps with improved efficiency. System includes high leakage reactance autotransformer having primary and secondary windings, and a ballast capacitor connected in series with the secondary winding and two serially connected fluorescent lamps of low starting and operating voltage, the secondary circuit being connected to a tap on the primary winding for reducing the ratio of the ballast power input to the lamp light output. The system provides for reduced lamp current crest factor, thereby improving life and operating characteristics of the lamps.