Series Connected Cathodes Or Heaters Patents (Class 315/99)
  • Patent number: 8456407
    Abstract: A display controlling system utilized in a display, such as an LCD, includes a plurality of data lines and a plurality of source drivers. The source drivers receive a plurality of transfer pulse signals, each of which corresponds to one of the source drivers, and drive the corresponding data lines upon receiving the corresponding transfer pulse signal, wherein the transfer pulse signals are not all identical. The transfer pulse signal can be produced by the timing controller of the display, or the transfer pulse information required for generating the transfer pulse signals can be embedded in the source data to be delivered to the source drivers that generate the transfer pulse signals after obtaining the transfer pulse information. The transfer pulse signal lines between the timing controller and the source drivers can therefore be removed.
    Type: Grant
    Filed: April 6, 2009
    Date of Patent: June 4, 2013
    Assignee: Himax Technologies Limited
    Inventors: Meng-Tse Weng, Chien-Ru Chen
  • Patent number: 6417642
    Abstract: A motor-controlling circuit for an optical-axis-adjusting unit of an illuminating device. The motor-controlling circuit ensures smooth control of a motor, which adjusts an optical axis, and ensures accurate repetition of a motor-stop position by way of PID and PWM control. The motor-controlling circuit 9 includes a motor 7 and a position detecting portion 6b. Feedback control is performed whereby an error between the motor's present position information, and the target value of position control, becomes zero. The motor-controlling circuit also includes a calculation portion 14 including a proportional-calculation portion 11, an integration-calculation portion 12, a differential-calculation portion 13, and a PID-calculation-processing portion 15 that calculates control by adding weighted respective outputs of the calculation portion 14.
    Type: Grant
    Filed: May 9, 2001
    Date of Patent: July 9, 2002
    Assignee: Koito Manufacturing Co., Ltd.
    Inventor: Tomoyuki Ichikawa
  • Publication number: 20020067142
    Abstract: An electromagnetic ballast for sequentially starting and simultaneously operating first and second gaseous discharge lamps includes a transformer having a magnetic core, a primary winding for connection to an AC voltage source and first and second secondary windings, all wound around the core. The first and second secondary windings are wound in opposite directions to produce voltages in opposition to each other. The ballast includes first and second series circuits, each including one of the lamps. The magnetic core has an elongated slot formed under the second secondary winding. The slot width relative to the core width, and to the slot length, are dimensioned to provide improved operating performance.
    Type: Application
    Filed: July 25, 2001
    Publication date: June 6, 2002
    Applicant: Koninklijke Philips Electronics N.V.
    Inventor: Luis Alfonso Padilla
  • Publication number: 20020067132
    Abstract: A metal halide lamp including a discharge tube of a transparent ceramic in which a discharge metal and a buffer gas are sealed, the discharge tube having electrodes at both ends thereof, including a discharge portion, slender tube portions provided at both ends of the discharge portion, into which feedthroughs including the electrodes and lead-in wires are inserted, and slender tube sealing portions in which gaps between the slender tube portions and the feedthroughs are sealed with a sealing material, an outer tube containing the discharge tube, and a transparent protecting cylinder provided inside the outer tube so as to surround the discharge tube is provided. At least one of the slender tube sealing portions is exposed beyond the protecting cylinder. This provides a metal halide lamp that suppresses leaks in a discharge tube sealing portion while maintaining high efficiency and high color rendition by using a ceramic discharge tube, and that is tolerant of an external shock.
    Type: Application
    Filed: July 25, 2001
    Publication date: June 6, 2002
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kazuo Takeda, Yoshiharu Nishiura, Takashi Maniwa
  • Publication number: 20020047618
    Abstract: Apparatus for sequentially igniting and serially operating a pair of high output rapid start fluorescent lamps from a source of AC voltage. The apparatus includes a transformer with a primary winding that may be subdivided in two sections, a principal secondary winding connected in series aiding with one section of the primary and in opposition with the other primary section. This arrangement provides the advantage of developing a comparatively high open circuit voltage for starting the lamps without exceeding lamp holder voltage ratings.
    Type: Application
    Filed: July 25, 2001
    Publication date: April 25, 2002
    Applicant: Koninklijke Philips Electronics N.V.
    Inventor: Luis Alfonso Padilla
  • Publication number: 20020047534
    Abstract: In a display device including a cathode filament containing a coiled portion and a linear portion thereof and a power feeding member, an end of the coiled portion is fixed to either a substrate made of an insulating material or an insulated support, the power feeding member being installed to contact with the linear portion of the cathode filament.
    Type: Application
    Filed: September 18, 2001
    Publication date: April 25, 2002
    Inventors: Yoshihisa Yonezawa, Yukio Ogawa, Kazuyoshi Ishikawa, Katsutoshi Kogo, Satoshi Yoshimura
  • Patent number: 6252357
    Abstract: The present invention provides self destruct arrangements for self ballasted fluorescent lamps and lighting fixtures using them. The ballast power supply includes at least one element that breaks down at high temperature. The lamp arrangements are constructed such that there is close proximity between at least one electrode of the lamp and the breakdown element of the ballast power supply. In one embodiment the breakdown element is a FET switch. In another embodiment, the breakdown element is a capacitor.
    Type: Grant
    Filed: March 31, 1999
    Date of Patent: June 26, 2001
    Assignee: Toshiba Lighting & Technology Corporation
    Inventors: Toshiya Tanaka, Tsutomu Araki, Hajime Osaki, Shinya Hakuta, Kazuyuki Uratani, Fuminori Nakaya
  • Patent number: 6169369
    Abstract: Provided is a lighting circuit (10, 100, 160) which includes a line voltage source 12 used to supply a full wave signal 72 to circuit 10. A ballast 14 is connected to the line voltage source 12, and a lamp 16. Further included in the circuit (10, 100, 160) is an electronic starter (18, 102, 159) which is connected across the lamp 16. Electronic starter (18, 102, 159) includes a pulse generating circuit ((60, 62, 64) (108, 110, 112, 152, 154)), a switch (30, 120) which is connected to provide a cathode current pulse 74 to first and second cathodes (22, 26) of the lamp 16, generated by the pulse generating circuit. The pulse generating circuit and switch operate in such a manner that the pulse generating circuit limits the duration of the cathode current pulse 74 which is delivered to cathodes 22 and 26. A feedback or pulse timeout circuit (116, 118, 120, 121, 128, 130) may also be used to sense a current delivered to cathodes 122, 126 by cathode current pulse 74.
    Type: Grant
    Filed: September 29, 1999
    Date of Patent: January 2, 2001
    Assignee: General Electric Company
    Inventors: Louis R. Nerone, Mircea Voskerician, Laszlo S. Ilyes
  • Patent number: 5498930
    Abstract: In a method of dimensioning and operating by A.C. or D.C. at a predetermined external heater power a low pressure discharge lamp, particularly a fluorescent lamp having two electrodes between which the discharge is formed, at least one of the electrodes being alkaline earth oxide coated and adapted to form a permanently heated cathode, particularly for use in video matrix board, and external heater current is used which is approximately 1.5 to 5 times higher than the discharge current, the heater volt is approximately 33.33% to 80% lower than that of a conventionally operated cathode or electrode, respectively, and the wattage of the heater circuit is maintained. By this accuracy of optimum cathode temperature control is improved, enhanced lamp life and reduced discoloration are obtained and the formation of hot spots avoided.
    Type: Grant
    Filed: June 10, 1993
    Date of Patent: March 12, 1996
    Assignee: GTE Products Corporation
    Inventors: Helmut M. Loy, Sigurd Kohler, Armin Eich
  • Patent number: 5448136
    Abstract: A regulated and constrained current source is used to drive the cathodes of a hot cathode gas discharge lamp to provide heating during lamp operation. In one embodiment, the regulated current source is time shared between the lamp cathodes and the lamp arc.
    Type: Grant
    Filed: April 13, 1993
    Date of Patent: September 5, 1995
    Assignee: Rockwell International Corporation
    Inventor: Gregory M. Fischer
  • Patent number: 5432406
    Abstract: A simple and compact magnetic ballast for powering a wide range of fluorescent lamp load Wattage such as 14 Watt to 60 Watt without need for modification to the ballast unit. Arc current to the lamp load is supplied through a saturable reactor including a power winding on a magnetic core. Arc current delivered to the lamp load is a function of magnetic saturation of the core determined by a control current through a control winding on the core. In one application, multiple fluorescent lighting fixtures of different wattages illuminating the interior of an aircraft cabin are each powered by essentially identical ballast units for easier installation and maintenance of the cabin lighting.
    Type: Grant
    Filed: September 14, 1993
    Date of Patent: July 11, 1995
    Assignee: Bruce Industries, Inc.
    Inventor: Douglas W. Brooks
  • Patent number: 5387849
    Abstract: A ballast circuit for a fluorescent lamp including a magnetic choke electrically connected between the lamp and a power supply and an electronic starter circuit electrically coupled across said lamp, which ballast circuit is configured to provide a power factor of at least 90%. To this end, for certain lamps a power factor correcting capacitance is electrically connected across the power supply. For other lamps, a power factor correcting resistance is coupled between the ballasting capacitance and inductor so that the inductor and ballasting capacitance close to resonance.
    Type: Grant
    Filed: December 14, 1992
    Date of Patent: February 7, 1995
    Assignee: Radionic Technology Incorporated
    Inventor: Sri Sridharan
  • Patent number: 5216334
    Abstract: An improved display bias arrangement is provided using a DC filament voltage in conjunction with stepped grid voltages to maintain even illumination. In a VF display there is a directly heated cathode (filament), an anode and a grid. If a DC filament voltage is used, one end of the cathode will be at different potential than the other, thus resulting in a variation in anode-to-cathode potential across the display. This varying potential causes electrons to hit the anode with varying speed, causing a variation in display intensity. In this invention, the cathode (filament) is supplied with a DC voltage and the grid of each segment is supplied with a different voltage, thereby equalizing the anode-to-cathode potential for each display digit. In a first embodiment, resistor networks are used to equalize the anode-to-cathode voltages. In a second embodiment, diode networks are used to equalize the anode-to-cathode voltages.
    Type: Grant
    Filed: February 20, 1991
    Date of Patent: June 1, 1993
    Assignee: Motorola, Inc.
    Inventor: Christopher R. Bach
  • Patent number: 5010274
    Abstract: A starter circuit for a discharge lamp includes a current control circuit which initially has a low impedance so as to produce an initial cathode heating current for the lamp. The current control circuit is switched into a high impedance condition by means of a control voltage applied to its gate thereby causing a high voltage striking pulse to be applied across the lamp. A field effect transistor is effective to modify the control voltage to the gate such that the starting circuit is effective to produce a succession of starting pulses across the lamp during each half cycle of a rectified AC supply.
    Type: Grant
    Filed: March 16, 1989
    Date of Patent: April 23, 1991
    Assignee: Thorn EMI plc
    Inventors: Geoffrey J. Phillips, Kevin F. George
  • Patent number: 4879493
    Abstract: Disclosed is a low-pressure discharge lamp comprising a discharge vessel defining an airtight space therein, at least one pair of electrodes disposed in the discharge vessel, and discharge gases enclosed in the discharge vessel, one of the electrodes which acts as an anode being located in a zone of negative glow.
    Type: Grant
    Filed: November 30, 1987
    Date of Patent: November 7, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Hiromistu Mastuno, Seiichi Murayama, Tetsuo Ono, Yoshio Watanabe
  • Patent number: 4695768
    Abstract: A fluorescent lamp electrode heat cutout switch is provided for placement within a fluorescent lamp stem and outside the discharge envelope and is configured such that a resistive heater wire is connected to one electrode lead-in and a bimetallic switch element is connected to the other electrode lead-in and configured upon an insulating support in such fashion that the heat cutout switch receives heat from the resistive heater to activate the switch so that the electrode heat is cut off when the lamp starts and is kept off during normal lamp operation.
    Type: Grant
    Filed: December 19, 1985
    Date of Patent: September 22, 1987
    Assignee: General Electric Company
    Inventors: Edward J. Covington, John E. Cridland, John P. Gorman
  • Patent number: 4689524
    Abstract: An electronic fluorescent lamp ballast having at least an energy storing component, a controlling component which has two states, and two socket elements which enables the filaments of the fluorescent lamp to be connected in series with the energy storing component. A constant current flows through a portion of the energy storing component when the controlling component is in one state producing an "energy latching" effect which will enable the ballast to achieve a very high efficiency of energy transfer. The ballast also has a self adjustable frequency of operation as a function of lamp impedance variation due to age and enables constant ionization within the fluorescent lamp.
    Type: Grant
    Filed: October 4, 1985
    Date of Patent: August 25, 1987
    Inventor: Alexander Ureche
  • Patent number: 4649319
    Abstract: A starter circuit for use with a fluorescent lamp includes an inductor coupled in series with the lamp electrodes and a semiconductor bilateral trigger, such as a Sidac, connected between the lamp electrodes. The semiconductor bilateral switch is selected to conduct electricity at a value below the instantaneous peak voltage applied and to cease conduction at a level above the operating voltage of the lamp. When the voltage reaches the predetermined level at which the semiconductor switch turns on, current is conducted through the electrode and the bilateral trigger. When the bilateral switch turns off, a large voltage pulse is generated in the inductor which voltage pulse appears at one of the lamp electrodes. A voltage potential is therefore set up across the electrodes to the lamp fixture which is grounded ionizing ionizable material, for example, mercury, within the lamp.
    Type: Grant
    Filed: October 3, 1984
    Date of Patent: March 10, 1987
    Assignee: Duro-Test Corporation
    Inventor: Joel Shurgan
  • Patent number: 4647817
    Abstract: To provide for reliable ignition of low-pressure discharge lamps, particularly compact fluorescent lamps, operated at high frequency, for example in the order of about 45 kHz, an ignition circuit is connected in parallel to the lamp and serially with the electrodes (16, 17) thereof, which comprises a limiting capacitor (19) and the parallel circuit of a positive temperature coefficient (PTC) resistor (20) and a starting capacitor (18). The two capacitors (18, 19), together with an inductance (13, 14) in the operating circuit of the lamp, and a further capacity formed by a blocking capacitor (15), after preheating of the lamp electrodes by current flowing through the initially cold PTC resistor, will cause voltage rise across the resonance capacitors (18, 19) which will cause ignition of the lamp.
    Type: Grant
    Filed: November 7, 1985
    Date of Patent: March 3, 1987
    Assignee: Patent-Truehand Gesellschaft m.b.H.
    Inventors: Hans-Jurgen Fahnrich, Ulrich Roll, Eugen Statnic
  • Patent number: 4588925
    Abstract: To provide for reliable starting of compact-type fluorescent lamps, or ot discharge lamps difficult to start, a voltage divider which is formed only by serially connected capacitors (C1, C2) is connected across the lamp (L), the junction point (5) of the voltage divider being connected to a charging circuit formed by a resistor (R1) and a capacitor (C3). The junction (4) between the charging resistor and capacitor (R1, C3) is connected through a diac (D) to the trigger or gate electrode (3) of a triac (T) connected across the lamp. Preferably, the capacity relationship of each one of the capacitors (C1, C2) of the voltage divider to the trigger capacitor (C3) is between about 1:1 and 1:5, desirably about 1:3. The time constant formed by the charge circuit (R1, C3), preferably, is between about 4 to 6 milliseconds, so that the charge time of the trigger capacitor (C3) is sufficiently long to provide multiple starting pulses to the triac (T) at peak values. A circuit to provide for polarity independence (FIG.
    Type: Grant
    Filed: March 19, 1984
    Date of Patent: May 13, 1986
    Assignee: Patent Treuhand Gesellschaft fur elektrische Gluhlampen GmbH
    Inventors: Hans-Jurgen Fahnrich, Ulrich Roll
  • Patent number: 4568860
    Abstract: A two-lamp rapid start fluorescent lamp circuit in which the lamps are ignited in sequence and then operated in series. The circuit being energized from a low voltage a.c. source through the use of a substantially conventional ballast which utilizes a transformer having a primary winding and a secondary winding connected in autotransformer relationship. The circuit includes a disconnect socket and a conventional two contact socket for mounting each lamp. The disconnect sockets in one circuit are arranged in one example to open the connections between the filament windings and a filament of each lamp. In another circuit one disconnect socket is arranged to open a connection to a filament winding and the other disconnect socket is arranged to open one of the connections to the line.
    Type: Grant
    Filed: August 17, 1983
    Date of Patent: February 4, 1986
    Assignee: Advance Transformer Co.
    Inventors: Albert E. Feinberg, Robert W. Wisbey
  • Patent number: 4562381
    Abstract: Two or more fluorescent lamps having a total length of about 96 inches and each having a diameter of one and a half inches and consuming less than 10 watts power per foot of length are connected in electrical series combination, one cathode of each lamp being connected to that of another lamp. An end of each remaining cathode of the combination is respectively connected to one of a pair of input electrical power terminals for a 50 or 60 hertz a-c line voltage in the range of 200 to 300 volts, one of the latter connections being via a ballast inductor. A starter switch is connected across the other ends of the remaining cathodes, and a secondary winding on the ballast inductor is connected across the interconnected cathodes. The lamp designs are specified such that they will start and operate in the circuit from the a-c line voltage.
    Type: Grant
    Filed: September 13, 1984
    Date of Patent: December 31, 1985
    Assignee: General Electric Company
    Inventors: Edward E. Hammer, Eugene Lemmers
  • Patent number: 4521718
    Abstract: A beam mode lamp has two discharge electrodes which alternately function as anode and cathode. One or more modifying electrodes are located between the discharge electrodes. Each modifying electrode is kept equal to or negative with respect to the cathode, raising the operating voltage of the lamp from a normal 20 volts to line voltage.
    Type: Grant
    Filed: February 1, 1983
    Date of Patent: June 4, 1985
    Assignee: GTE Laboratories Incorporated
    Inventors: Wojciech W. Byszewski, A. Bowman Budinger, Joseph M. Proud
  • Patent number: 4473777
    Abstract: Disclosed herein is an electron emitter assembly for an electron gun which includes a first emitter ring, a second emitter ring, a power supply, connectors for connecting the power supply to the two electron emitter rings so that heating current flows from the power supply through the rings, and said rings being mounted so that a magnetic field formed by the second ring counteracts the magnetic field formed by the first ring.
    Type: Grant
    Filed: September 29, 1982
    Date of Patent: September 25, 1984
    Assignee: The Perkin-Elmer Corporation
    Inventors: George N. Steinberg, W. Derek Buckley
  • Patent number: 4413209
    Abstract: A ballast apparatus for series-sequenced gaseous discharge devices having series-connected filaments wherein a transformer is connected to a potential source and to a pair of series-sequenced gaseous discharge devices with a starting capacitor shunting one of the gaseous discharge devices and a circuit means series-connects a filament of each of the gaseous discharge devices to the transformer by way of a rectifier means.
    Type: Grant
    Filed: October 5, 1981
    Date of Patent: November 1, 1983
    Assignee: GTE Products Corporation
    Inventor: William J. Roche
  • Patent number: 4358709
    Abstract: A screw-in fluorescent light unit having two light levels, for use in a 3-way socket. A reactor ballasts the lamp for high light output, and a resistor is added to ballast the lamp for low light output. A bilateral switch device is connected across the resistor to facilitate lamp starting at the low light output.
    Type: Grant
    Filed: December 19, 1980
    Date of Patent: November 9, 1982
    Assignee: General Electric Company
    Inventor: Donald E. Magai
  • Patent number: 4327308
    Abstract: A simplified power source for fluorescent lamps is characterized as that the filaments of the fluorescent lamps are connected in series with the primary winding of a transformer, an oscillator circuit and the power source so that the oscillating current will exert high voltage across the primary winding to start and drive the fluorescent lamps and when the fluorescent lamps are removed from their sockets, the oscillator circuit will be opened to prevent from occurring high tension for safety measure.
    Type: Grant
    Filed: November 13, 1980
    Date of Patent: April 27, 1982
    Inventors: Top-Ping Hwang, Chin-Liang Feng
  • Patent number: 4288725
    Abstract: A lightweight starting and operating ballasting means for starting and operating a fluorescent lamp means from a household source of AC energy. The ballasting means has elements which perform with the lamp means in a starting mode and an operating mode. In the operating mode with a low-pressure mercury discharge existing between the lamp electrodes, the lamp means is ballasted solely by a series-connected resistor means and capacitor means.
    Type: Grant
    Filed: November 26, 1979
    Date of Patent: September 8, 1981
    Assignee: Westinghouse Electric Corp.
    Inventor: Edward W. Morton
  • Patent number: 4165475
    Abstract: A starter circuit for a hot cathode discharge lamp which has a switching element which is connected across the lamp to permit a cathode heating current to flow and then opens to permit the lamp to strike. The starter circuit has a thyristor as the switch element, and a control circuit for rendering the thyristor conductive at a desired point during each cycle of the applied voltage. The control circuit includes means for increasing the instantaneous applied voltage which is required to trigger the thyristor with successive cycles of the applied voltage after switch-on of the circuit. This means preferably includes a capacitor which is progressively charged to provide an increasing bias which must be overcome by the applied voltage. If the lamp fails to strike, the required voltage for triggering goes on increasing until it is too high for the thyristor to trigger at all. No damage can then occur to the starter circuit or the lamp ballast.
    Type: Grant
    Filed: April 17, 1978
    Date of Patent: August 21, 1979
    Assignee: Thorn Electrical Industries Limited
    Inventors: John C. Pegg, Clive R. Walker
  • Patent number: 4158792
    Abstract: A light control device for a high frequency lighted fluorescent lamp includes a high frequency variable voltage power source. A first impedance element (a capacitor and inductor in series) is provided between the terminals of the lamp on the side opposite to the power source. A second impedance element (an inductor) is connected between the power source and the terminals of the lamp, and a third impedance element (a capacitor) is connected across the lamp on the power source side. A constant power source circuit supplies, upon starting of the lamp, constant power to the first impedance element to thereby apply substantially constant cathode pre-heating current and starting voltage and applies, during the lighting of the lamp, substantially constant cathode heating current. The control circuit is capable of pre-set light control. The light control device suppresses beat interference and fluorescent lamp noises due to the electric field radiated from the lamp. Rapid and instant starting is enabled.
    Type: Grant
    Filed: October 14, 1977
    Date of Patent: June 19, 1979
    Assignee: Kuroi Kosan Kabushiki Kaisha
    Inventors: Hisashi Kuroi, Masamichi Hatada, Kumio Morita, Eiji Tanaka
  • Patent number: 4119887
    Abstract: A starter for a discharge lamp including first and second filaments, comprises an SCR having an anode and a cathode connected in series through the first and second filaments and a ballast transformer to an AC power supply. The gate electrode and the anode of the SCR are connected to each other through a first resistor, while the gate electrode is further connected through a second resistor to the power supply side.
    Type: Grant
    Filed: March 31, 1976
    Date of Patent: October 10, 1978
    Assignee: Hitachi, Ltd.
    Inventors: Hiroyuki Iyama, Mitsuo Akatsuka, Teruichi Tomura
  • Patent number: 4117374
    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.
    Type: Grant
    Filed: February 28, 1978
    Date of Patent: September 26, 1978
    Assignee: General Electric Company
    Inventor: Harald L. Witting
  • Patent number: 4081718
    Abstract: A discharge lamp lighting device combines one or more discharge lamps and a backswing booster including essentially a power source circuit having a power source connected in series with a ballast and a high voltage generating circuit having an oscillation capacitor and a series circuit of a nonlinear inductor and a switching semiconductor. The supply voltage for the discharge lamp from the power source circuit is established to the extent permissible by the lower limit for sustaining an arc discharge of the lamp so that the terminal voltage of the ballast in the lamp operation is maintained as low as possible. The preferred backswing booster is of small size and an impedance circuit having a capacitor either with or without a bias coil is added to the high voltage generating circuit to produce a momentary high voltage.
    Type: Grant
    Filed: May 20, 1975
    Date of Patent: March 28, 1978
    Assignee: NEC Sylvania Corporation
    Inventor: Isao Kaneda
  • Patent number: 4017761
    Abstract: The invention relates to a capacitively stabilized discharge lamp shunted by a coil. During the starting procedure of the lamp the coil is brought into saturation so that, by means of resonance with the capacitive ballast, a high voltage is applied across the lamp to start it.The B-H magnetization curve of the coil has been chosen so that a transition from the unsaturated condition to the saturated condition also occurs during the operating condition of the device, namely just before the lamp is extinguished during each half cycle of the a.c. supply voltage. Consequently the ratio of the r.m.s. voltage of the a.c. voltage source to the operating voltage of the lamp may be relatively small.A resistor having a positive temperature coefficient shunts the lamp and is in series with the coil so as to limit the electric current if the lamp refuses to start.
    Type: Grant
    Filed: November 25, 1975
    Date of Patent: April 12, 1977
    Assignee: U.S. Philips Corporation
    Inventor: Leonard Woldring
  • Patent number: 4015167
    Abstract: A circuit for operating an electric discharge lamp wherein a change in the mode of operation of the circuit is effected in response to a change of phase of a voltage or current in the circuit which occurs during operation e.g. when the lamp strikes or as the lamp runs up to full current.
    Type: Grant
    Filed: June 25, 1975
    Date of Patent: March 29, 1977
    Assignee: The General Electric Company Limited
    Inventor: Philip Rufus Samuels
  • Patent number: 3991340
    Abstract: A discharge lamp (e.g., fluorescent lamp) lighting apparatus using as the starting element a sintered type oxide resistance element having the voltage-current characteristic that the element is rendered conductive when impressed with an inter-electrode voltage applied at the discharge lamp starting time and rendered substantially non-conductive while impressed with an inter-electrode voltage applied during lighting of the discharge lamp. The discharge lamp lighting apparatus using in particular a sintered type oxide resistance element comprising ZnO, MgO and MnO.sub.2 as the starting element presents an excellent performance.
    Type: Grant
    Filed: August 14, 1974
    Date of Patent: November 9, 1976
    Assignee: Tokyo Shibaura Electric Co., Ltd.
    Inventors: Noboru Ichinose, Yuhji Yokomizo, Masaki Katsura, Suezo Sugaike
  • Patent number: 3986076
    Abstract: A ballast impedance for an electric discharge lamp comprises an inductor and a capacitor connected in series with the lamp across AC input terminals. The lamp operating voltage is less than 20 percent of the AC supply voltage. The values of L and C are chosen so that the ballast has a net capacitive character and to provide a resonance between 3.5 and 4 times the frequency of the AC supply voltage.
    Type: Grant
    Filed: February 24, 1975
    Date of Patent: October 12, 1976
    Assignee: U.S. Philips Corporation
    Inventor: Jacob Rottier
  • Patent number: 3978369
    Abstract: A solid state starter apparatus for a discharge lamp comprises a current limiter, an AC power supply, a discharge lamp of filament-preheating type and a switching circuit for controlling the turning on and off of the discharge lamp. The switching circuit further includes a lightedstate detector circuit for detecting the turning on or off of the discharge lamp, a current breaker circuit controlled by the lighted-state detector circuit to cause the filament current to be turned on and off, and a preheater circuit for starting to supply a filament preheating current in accordance with the magnitude of the current controlled by the current breaker circuit.
    Type: Grant
    Filed: January 7, 1975
    Date of Patent: August 31, 1976
    Assignee: Hitachi, Ltd.
    Inventors: Ichiro Imaizumi, Teruichi Tomura, Mitsuo Akatsuka, Mineo Katsueda, Toshiaki Okada, Hiroyuki Iyama
  • Patent number: 3978368
    Abstract: A voltage producing device comprises a circuit in which an AC power source, a coil and a first capacitor connected in series. A unidirectional triode semiconductor switching element is connected across both terminals of the capacitor, a voltage limiting semiconductor element is connected to a gate electrode of the switching element, and a charging-and-discharging circuit including a second capacitor is connected to a cathode of the switching element.
    Type: Grant
    Filed: February 21, 1974
    Date of Patent: August 31, 1976
    Assignee: Hitachi, Ltd.
    Inventors: Teruichi Tomura, Hiroyuki Iyama, Mitsuo Akatsuka
  • Patent number: 3956665
    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.
    Type: Grant
    Filed: April 11, 1975
    Date of Patent: May 11, 1976
    Assignee: California Institute of Technology
    Inventor: James A. Westphal
  • Patent number: 3942069
    Abstract: A discharge lamp lighting apparatus includes three oscillation circuits. The first comprises a linear inductor and a capacitor connected in series to a power source. The second oscillation circuit is connected across the capacitor and includes a bounce or backswing booster inductor and a voltage responsive switching element connected in series. The third oscillation circuit comprises the bounce inductor and its distributed capacity. The bounce booster inductor has a magnetic core with a shape and of a material providing an abrupt saturation characteristic. The core factor K of the core is small and may have a ratio of the cross sections of the wound to the unwound parts thereof of less than one half. Alternatively, the ratio of the wound part of the core to the unwound part thereof is less than one fourth and a conventional core material may be employed for the core.
    Type: Grant
    Filed: September 9, 1974
    Date of Patent: March 2, 1976
    Assignee: NEC Sylvania Corporation
    Inventor: Isao Kaneda
  • Patent number: 3942070
    Abstract: An electric discharge lamp lighting circuit in which a discharge lamp is lighted by a circuit comprising a semiconductor switching circuit in which the cathode of a first thyristor is connected to the gate of a second thyristor and the first and second thyristors are commonly connected at the respective anodes, an integration circuit consisting of a capacitor and a resistor and connected between the gate of the first thyristor and the cathode of the second thyristor, a resistor connected between the integration circuit and the anode of the first thyristor, and a resistor connected between the gate and cathode of the second thyristor.
    Type: Grant
    Filed: September 10, 1974
    Date of Patent: March 2, 1976
    Assignee: Hitachi, Ltd.
    Inventors: Teruichi Tomura, Mitsuo Akatsuka, Hiroyuki Iyama