Pulsating Or A.c. Supply To The Cathode Or Heater Circuit Patents (Class 315/97)
  • Patent number: 11637288
    Abstract: Provided are a thermally crosslinkable binder aqueous solution for a lithium-ion battery, a thermally crosslinkable slurry for a lithium-ion battery negative electrode, a negative electrode for a lithium-ion battery, a lithium-ion battery negative electrode material, as well as a lithium-ion battery and a method for producing the same.
    Type: Grant
    Filed: June 16, 2020
    Date of Patent: April 25, 2023
    Inventors: Hideki Goda, Naoki Sasagawa, Shinji Ozaki, Satoru Aoyama, Katsuya Okubo, Katsuhiko Ikeyatsu
  • Patent number: 10704727
    Abstract: An electrical installation for an electrical system for trace heating a fluid transport pipe (8) made of metal, at least one polyphase circuit having three main electric cables (6-1, 6-4, and 6-7) in a star connection, and one additional electric cable (6-2, 6-3, 6-5, 6-6, 6-8, and 6-9), the main cables and the additional cable positioned around the pipe and connected at the pipeline end to a common connection ring (10) forming a point of zero electric potential, and detector for detecting a failure, if any, of the polyphase circuit to identify a failed main cable in order to replace it with the additional cable.
    Type: Grant
    Filed: February 7, 2017
    Date of Patent: July 7, 2020
    Assignee: Saipem S.A.
    Inventors: François-Régis Pionetti, Jalil Agoumi, Axel Sundermann
  • Patent number: 10501342
    Abstract: Methods and apparatus are provided for ultraviolet (UV) water purification, comprising UV-C LED modules having improved light extraction efficiency. UV-C LED dies (12) are solidly coupled to associated translucent output windows (14), such that light is transmitted directly from light-emitting surface(s) of the dies (12) to output window(s) (14) of the LED package—without propagation across interstitial air gaps. Gas-to-solid (and solid-to-gas) light transition boundaries are thus eliminated, significantly reducing the amount of light lost through inter-medium boundary reflection, and thereby increasing efficiency of light extraction.
    Type: Grant
    Filed: March 10, 2016
    Date of Patent: December 10, 2019
    Assignee: SIGNIFY HOLDING B.V.
    Inventors: Daiyu Hayashi, Jianghong Yu, Paul Dijkstra, Michiel Van Der Meer, Arie Jan Hovestad
  • Patent number: 9718605
    Abstract: The invention relates to a container for containing a living organism, a docking station for docking the container, and a transportation system comprising the container and the docking station. The container comprises a docking for docking the container to a docking station. The docking station comprises a light emitter. The container comprises light-guiding means for guiding at least part of the light emitted by the light emitter to the living organism. The effect of the measures according to the invention is that the light required for illuminating the living organism is generated by the light emitter of the docking station. As a result, no light emitters are necessary in the container according to the invention which reduces the cost of the container.
    Type: Grant
    Filed: January 29, 2009
    Date of Patent: August 1, 2017
    Inventors: Jeroen Snelten, Denis Joseph Carel Van Oers
  • Patent number: 9273858
    Abstract: Methods and systems to provide compatibility between a load and a secondary winding of an electronic transformer driven by a leading-edge dimmer may include: (a) responsive to determining that energy is available from the electronic transformer, drawing a requested amount of power from the electronic transformer thus transferring energy from the electronic transformer to an energy storage device in accordance with the requested amount of power; and (b) transferring energy from the energy storage device to the load at a rate such that a voltage of the energy storage device is regulated within a predetermined voltage range.
    Type: Grant
    Filed: May 28, 2013
    Date of Patent: March 1, 2016
    Assignee: Phillips International, B.V.
    Inventors: Eric Jerome King, Daniel J. Baker, John L. Melanson
  • Patent number: 8716937
    Abstract: A lighting ballast includes a filament drive reduction circuit with a first inductor coupled across a filament drive source, and a second inductor and a capacitor coupled in parallel to define an LC tank between a first end of the first inductor and the filament drive source. The inductance value of the second inductor and the capacitance value of the capacitor are selected such that the natural resonance of the LC tank is substantially equal to the normal operating frequency of the filament drive source, wherein the LC tank acts as an open circuit during normal operation and the first inductor acts to balance the pin currents of series connected lamp filaments. The first and second inductors are further substantially equal in value, wherein excess filament drive current is shunted away in accordance with a normal operating frequency.
    Type: Grant
    Filed: September 19, 2011
    Date of Patent: May 6, 2014
    Assignee: Universal Lighting Technologies, Inc.
    Inventor: Stephen D. Mays, II
  • Patent number: 8324813
    Abstract: An electronic ballast includes a filament voltage control block having first and second switches and configured to receive a filament voltage control signal. An inverter includes an inverter driver having first and second gate drive output terminals for driving first and second inverter switches, and a gate drive transformer having a primary side coupled to the inverter driver. A first secondary side is coupled to the first inverter switch and a second secondary side is arranged to drive the first switch in the control block. The control block is effective in response to a first control signal state to drive the switches in the control block and generate a lamp filament heating voltage, and is further effective in response to a second control signal state to disable the second secondary side of the gate drive transformer and thereby disable the lamp filament heating voltage.
    Type: Grant
    Filed: July 30, 2010
    Date of Patent: December 4, 2012
    Assignee: Universal Lighting Technologies, Inc.
    Inventor: Wei Xiong
  • Publication number: 20120274213
    Abstract: A driving apparatus for fluorescent tubes and a method thereof are provided. The provided driving apparatus changes a sinusoidal driving signal used for driving a fluorescent tube by detecting a current flowing through the fluorescent tube. Accordingly, the current flowing through the fluorescent tube can be conformed to specifications/regulations. Under the condition of being capable of detecting current(s) flowing through fluorescent tube(s), the provided driving apparatus can be suitable for driving fluorescent tubes with different specifications, categories and brands, and would not affect the lifetime of the fluorescent tubes and would not cause the problem of insufficient luminance.
    Type: Application
    Filed: January 18, 2012
    Publication date: November 1, 2012
    Inventors: Chiu-Yuan Lin, Chien-Pang Hung, Chen-Lung Kao
  • Patent number: 8203273
    Abstract: A ballast circuit includes a filament cutback circuit to reduce a pre-heat voltage after the lamp filaments have been pre-heated. The filament cutback circuit includes a filament cut-back inductive component magnetically coupled to the resonant inductive component in the inverter to receive a filament cutback control voltage associated with an AC voltage for powering the lamps. During the pre-heating period, the filament cutback control voltage is not high enough to charge a chargeable component to a switch threshold level. However, during lamp ignition, the filament cutback control voltage is increased and charges the chargeable component to the switch threshold level. This causes a switch device to operate in a conductive switch state and the filament cutback circuit suppresses the pre-heat voltage.
    Type: Grant
    Filed: May 12, 2009
    Date of Patent: June 19, 2012
    Assignee: Universal Lighting Technologies, Inc.
    Inventors: Wei Xiong, Christopher Radzinski
  • Patent number: 8111223
    Abstract: In order to perform local dimming, a driving dimming duty cycle is generated using a target gamma curve (TGV), wherein the driving dimming duty cycle corresponds to a representative grayscale value (RGV) of each of a plurality of dimming unit areas. Each of a plurality of light unit blocks of a light source is driven based on the driving dimming duty cycle, wherein the light unit blocks correspond to the dimming unit areas, respectively. Therefore, a display apparatus may display an image having a higher contrast ratio than normal.
    Type: Grant
    Filed: December 16, 2008
    Date of Patent: February 7, 2012
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Dong-Min Yeo, Gi-Cherl Kim, Byung-Choon Yang, Yong-Hoon Kwon
  • Publication number: 20110260620
    Abstract: A lighting device has: a lighting circuit for lighting a plurality of hot-cathode lamps having filaments at both ends; preheating circuits for preheating the individual filaments of the hot-cathode lamps; at least one first circuit substrate arranged near filaments on one side of the hot-cathode lamps; and at least one second circuit substrate arranged near filaments on the other side of the hot-cathode lamps. The lighting circuit is packaged in either the first circuit substrate or the second circuit substrate, and the preheating circuits are packaged or wired by being divided in the first circuit substrate and the second circuit substrate.
    Type: Application
    Filed: September 16, 2008
    Publication date: October 27, 2011
    Inventors: Kazuhiro Kumada, Shigeru Ido
  • Patent number: 7909473
    Abstract: There is described a method for operating a high-intensity discharge lamp (2), in which the high-intensity discharge lamp (2) is acted upon by an AC current (I) which commutates between positive pulses (Ip) and negative pulses (In) with a predefined current amplitude (IA), wherein a pulse width ratio between the pulse width of a positive pulse (Ip) and the pulse width of an adjacent negative pulse (In) is modulated in such a way that the mean current value (I) of two successive positive and negative pulses (Ip, In) fluctuates periodically between positive and negative values. In addition, the value of the current amplitude (IA) is modulated in accordance with a predefined modulation function (M). A description is also given of a corresponding lamp driver (10) for a high-intensity discharge lamp (2) and of a projection system (1) comprising such a lamp driver (10).
    Type: Grant
    Filed: September 1, 2006
    Date of Patent: March 22, 2011
    Assignee: Koninklijke Philips Electronics N.V.
    Inventor: Carsten Deppe
  • Patent number: 7683547
    Abstract: A method for lighting a flat fluorescent lamp for a large-sized backlight unit is disclosed, to prevent a discharge interference (scattering in fluorescent discharge) when lighting a plurality of groups of cylindrical electrodes being adjacent, in which an A.C. voltage is applied to one or two groups of cylindrical electrodes through introduction wires for lighting lamp in state of being not applied to adjacent one or two groups of cylindrical electrodes, so the plurality of groups of cylindrical electrodes are sequentially switched on and off in a time-division method at a speed not to generate the flicker of lamp.
    Type: Grant
    Filed: January 26, 2005
    Date of Patent: March 23, 2010
    Assignee: LG Display Co., Ltd.
    Inventor: Masanobu Aizawa
  • Patent number: 7183714
    Abstract: An apparatus for detecting the reconnection of a lamp filament to an electronic ballast driving a fluorescent lamp. A control circuit controls an inverter circuit to providing power to a filament control circuit. The filament control circuit preheats and powers the lamp filament of the one or more lamps. A pulse generator generates an input signal as a function of the number of lamp filament connected to the filament control circuit. A current sensor generates a first voltage indicative of whether a lamp filament has been reconnected to the circuit. A peak detector generates a peak voltage signal when the first voltage indicates a reconnection of a lamp filament has occurred. A sensing circuit generates a command signal to provide to the control circuit to supply power to the filament control circuit to preheat and power the lamp when the peak detector generates the peak voltage signal.
    Type: Grant
    Filed: June 30, 2005
    Date of Patent: February 27, 2007
    Assignee: Osram Sylvania, Inc.
    Inventor: Ayan Kumar Choudhury
  • Publication number: 20040189212
    Abstract: A high-intensity discharge lamp connected to a lighting device has various superior emission properties such as efficiency. The discharge lamp includes a translucent ceramic discharge vessel, in which a pair of electrodes and a discharge medium are inserted. The lamp further includes an outer jacket, in which the arc tube is disposed, and a pair of feeder members. The discharge medium has metal halides including those of Na, Tl and Tm or Na, Tl, In and Tm, and the ratio (MTm/M) of the weight of the gross sealed mass M of the metal halides to the filled mass MTm of the Tm halide is about 0.4≦MTm/M≦0.9. The deviation in chromaticity (d.u.v.) on the x-y chromaticity coordinates (CIE 1931) for the overall operating position during the life of the lamp is within the range of about −0.006 to +0.010.
    Type: Application
    Filed: March 2, 2004
    Publication date: September 30, 2004
    Applicant: OSRAM-MELCO TOSHIBA Lighting Ltd.
    Inventors: Seiji Ashida, Hisashi Honda, Shinji Atago, Satoshi Iwasawa
  • Publication number: 20040183450
    Abstract: The invention intends to improve the determination of the resonant frequency of a resonant circuit, in particular of a heating circuit for a discharge lamp. For this purpose, the frequency of a supply voltage for the resonant circuit is varied within a predetermined frequency range. The voltage or the current across/in the resonant circuit are measured as a function of the varied frequency. The predetermined frequency range is run through in both directions, in each case a maximum for the measured voltage or the measured current being established. The resonant frequency is preferably calculated from the two maxima by averaging.
    Type: Application
    Filed: February 23, 2004
    Publication date: September 23, 2004
    Inventors: Olaf Busse, Bernhard Schemmel
  • Publication number: 20040183447
    Abstract: An electric gas lighting device including an ignition circuit for generating sparks at at least one burner and connected to a supply line, supplying a supply voltage, via enabling means for alternatively enabling/disabling spark generation when connected/disconnected to/from a reference potential line; the enabling means are defined by a secondary winding of an isolation transformer interposed between the supply line and the ignition circuit; a first terminal of the secondary winding of the isolation transformer is connected to a first terminal of hand-operated switch means, a second terminal of which is connected to the reference potential line; and the ignition circuit also includes a discharge generating circuit, a first node of which is connected to the reference potential line, and a second node of which is connected to a second terminal of the secondary winding of the isolation transformer.
    Type: Application
    Filed: October 21, 2003
    Publication date: September 23, 2004
    Inventor: Massimo Aleardi
  • Patent number: 6114809
    Abstract: A planar fluorescent lamp having a resistive trace and optically transmissive cover electrodes is described. In one embodiment, the lamp includes an insulative lamp body with the transparent cover electrodes supported by the lamp cover. The resistive trace is supported by the base, either as an exterior resistive trace or within the lamp. The resistive trace acts as a heating element by producing heat in response to an electric current passed through the resistive trace. Because the resistive trace is in thermal contact with the lamp body, heat produced by the resistive trace heats the lamp, improving cold starting. The cover electrodes and, in some embodiments, the resistive trace, are used to control electric fields within the lamp body by applying voltage potentials between discrete cover electrodes or between the cover electrodes and the resistive trace. The controllable electric fields improve cold starting and uniformity of light during low light operation.
    Type: Grant
    Filed: February 2, 1998
    Date of Patent: September 5, 2000
    Assignee: Winsor Corporation
    Inventor: Mark D. Winsor
  • Patent number: 5907222
    Abstract: A fluorescent cavity backlight system that provides a high efficiency light source suitable for rear illumination of transmissive electronic display devices. The inventive fluorescent cavity backlight system can be adapted to a wide variety of flat panel display applications. The invention takes a complete system approach towards designing a high efficiency backlight source. The backlight system comprises three major subassemblies: a phosphor illuminator, a fluorescent cavity, and improved control/driver electronics. Each of the subassemblies has been optimized internally, and with respect to each of the other subassemblies.
    Type: Grant
    Filed: November 11, 1997
    Date of Patent: May 25, 1999
    Assignee: Litton Systems, Inc.
    Inventors: J. Michael Lengyel, Loy L. Spears
  • Patent number: 5726534
    Abstract: A feedback control system of ballast which has function to detect the number of lamp and is applied to an integrated circuit to control the ballast for a fluorescent lamp etc, and provides the ballast with the feedback control system which can detect the number of lamp, control ballast continuously by means of the n-lamp detector and soft start controller which produce the compensated current from the feedback current and direct link voltage. Therefore, the feedback control system can control the ballast accurately according to the load change such as the change of input voltage, number of lamp.
    Type: Grant
    Filed: April 24, 1996
    Date of Patent: March 10, 1998
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Maeng-ho Seo
  • Patent number: 5604409
    Abstract: An electronic circuit for converting AC or DC input current to pulsating DC, then to high frequency AC. The DC input is used for aircraft applications, or in emergency situations. The circuit operates over a wide range of input voltages and frequencies, including aircraft 115 volts, 400 Hertz. The circuit has a multivibrator that receives a smooth DC operating potential. The multivibrator is operably connected to a differentiator that produces substantially square waveform outputs. Dual wave shape filters are operably connected to the differentiator to shape the square wave outputs into a sine wave and a cosine wave respectively. A transistor switch is operably connected to each wave shape filter. The circuit has a transformer operably connected between the transistor switches and a load. In a specific embodiment the loads are either hot or cold fluorescent lamps, or the like.
    Type: Grant
    Filed: July 12, 1993
    Date of Patent: February 18, 1997
    Inventor: Dalziel L. Fisher
  • Patent number: 5517082
    Abstract: A power supply for supplying the heating coils of a tube (WR), in particular a traveling-wave tube, wherein a transformer (Tr) and an inverter (S1, S2) are provided in the heating circuit of the tube (WR), and the frequency of the AC current is reduced from a high initial value to a lower value during the heat-up time of the tube (WR) in such a way that the change of the inductive voltage drop caused by this frequency change limits the heating current at the leakage inductance (LS) of the transformer (Tr).
    Type: Grant
    Filed: May 9, 1994
    Date of Patent: May 14, 1996
    Assignee: Ant Nachrichtentechnik GmbH
    Inventor: Franz Ohms
  • 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: 5463278
    Abstract: Radiated emission is reduced in a vacuum fluorescent tube having a pulsed filament current in a variable frequency range above audible frequencies. A driver circuit produces a fixed width pulse of filament current when triggered by a random frequency generator. The frequency generator comprises a shift register and XOR gates intercoupled to generate a random series of logic outputs, a filter to produce a randomly varying voltage from the logic outputs, and a voltage-to-frequency converter responsive to the filter voltage to yield a random frequency in the required range. The random frequency triggers the driver and clocks the shift register.
    Type: Grant
    Filed: August 1, 1994
    Date of Patent: October 31, 1995
    Assignee: Delco Electronics Corporation
    Inventor: Craig S. Gray
  • Patent number: 5451841
    Abstract: A method is provided in which a relatively cold lamp filament may be turned on for a brief period of time, then turned off, then turned on again, then off again, and this process repeated for successively longer periods of on time, until eventually the filament power is left on continuously. This "pulse starting" may be controlled by a programmable microcontroller in association with a power supply to the lamp filament. The result is a longer lasting lamp filament.
    Type: Grant
    Filed: January 28, 1994
    Date of Patent: September 19, 1995
    Assignee: Avionic Displays Corporation
    Inventors: William R. Dunn, James E. Strickling, III, Joseph W. Goode, III
  • Patent number: 5436527
    Abstract: In a circuit for operating a fluorescent lamp with controllable luminance, with the fluorescent lamp comprising a discharge path and heater coils, the discharge path is connected through a transformer to a controllable alternating current source. The current through the heater coils is preferably controllable in such fashion that the sum of the current through the discharge path and through the heater coils remains essentially constant.
    Type: Grant
    Filed: January 11, 1994
    Date of Patent: July 25, 1995
    Assignee: Robert Bosch GmbH
    Inventors: Winfried Koenig, Florian Schwabe, Reinhold Fiess, Peter Scharlach
  • Patent number: 5367223
    Abstract: A method and apparatus for automatically adjusting the light intensity output of a fluorescent lamp of a document scanner. The fluorescent lamp current level control apparatus comprises preheating circuitry for applying low voltage pulses of alternating polarity across filaments of the lamp, the low voltage pulses sufficient to preheat the filaments but insufficient to cause the lamp to fluoresce; high voltage circuitry for applying high voltage pulses of alternating polarity across the lamp, the high voltage pulses sufficient to cause the lamp to fluoresce; and control circuitry for receiving a first signal (PWM (D)) indicative of a desired level of current in the filaments, sensing a current indicative of the actual level of current in the filaments, and controlling the high voltage circuitry to cause the actual level of current to tend toward the desired level of current.
    Type: Grant
    Filed: October 14, 1993
    Date of Patent: November 22, 1994
    Assignee: Hewlett-Packard Company
    Inventor: Joseph A. Eccher
  • Patent number: 5347197
    Abstract: A display device having a display tube including a cold cathode, for example a PN emitter (PNE), has the terminals of the PN emitter (PNE) coupled between first terminals of a first (CR1) and a second (CR2) current mirror. The first current repeater (CR1) is connected to an output of an amplifier (AMP) whose feedback input (FI) is connected to second terminals of the first (CR1) and second (CR2) current mirrors.
    Type: Grant
    Filed: March 19, 1993
    Date of Patent: September 13, 1994
    Assignee: U.S. Philips Corporation
    Inventors: Terence Doyle, Matheus J. G. Lammers
  • Patent number: 5256939
    Abstract: A magnetic-type ballast powers an F40/T12 four foot fluorescent lamp from a regular 120 Volt/60 Hz power line by way of a main inductor. A power factor correction capacitor is connected in series with an auxiliary inductor of relatively small inductance value, thereby forming a series-combination; which series-combination is connected across the power line. A 30 Volt/60 Hz voltage is established across this auxiliary inductor. The phasing of this 30 Volt/60 Hz voltage is opposite that of the 120 Volt/60 Hz power line voltage. Thus, by adding the 30 Volt/.alpha.Hz voltage to the 120 Volt/60 Hz voltage, a 150 Volt/60 Hz voltage is obtained; which 150 Volt/60 Hz voltage is of magnitude adequate to properly power the F40/T12 four foot fluorescent lamp, although it is not of magnitude adequate to provide proper lamp ignition in a rapid-start mode.
    Type: Grant
    Filed: March 18, 1992
    Date of Patent: October 26, 1993
    Inventor: Ole K. Nilssen
  • Patent number: 5247228
    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.
    Type: Grant
    Filed: January 2, 1992
    Date of Patent: September 21, 1993
    Assignee: GTE Products Corporation
    Inventor: William J. Roche
  • Patent number: 5243258
    Abstract: A fluorescent lamp system including a ballast with primary and secondary windings and a switch for each of the plurality of electrodes of the lamp system. Each switch is operable in response to the voltage across its associated lamp after its associated lamp turns on to interrupt the connection of an associated electrode to its associated heater winding, and wherein at least two of the plurality of switches conduct current which flows through a semiconductor conducting device before the lamps turn on.
    Type: Grant
    Filed: August 30, 1991
    Date of Patent: September 7, 1993
    Assignee: North American Philips Corporation
    Inventor: Glenn D. Garbowicz
  • Patent number: 5208511
    Abstract: A fluorescent lamp system including a ballast with primary and secondary windings and a switch for each electrode of the lamp system. Each switch is operable in response to the voltage across its associated lamp after its associated lamp turns on to interrupt the connection of an associated electrode to its associated heater winding and wherein at least one of said heater windings is a portion of the secondary winding.
    Type: Grant
    Filed: March 21, 1991
    Date of Patent: May 4, 1993
    Assignee: North American Philips Corporation
    Inventor: Glenn D. Garbowicz
  • Patent number: 5175470
    Abstract: A fluorescent lamp system including a switch for each electrode of the lamp system wherein each switch is operable in response to the voltage across its associated lamp after its associated lamp turns on to interrupt the connection of an associated electrode to its associated heater winding.
    Type: Grant
    Filed: December 19, 1990
    Date of Patent: December 29, 1992
    Assignee: North American Philips Corporation
    Inventor: Glenn D. Garbowicz
  • Patent number: 5099178
    Abstract: A method and system for providing a wide range of variable brightness levels for a vacuum fluorescent (VF) display by changing the duty cycle of the driving signal beyond the limits of normal driving techniques by varying the frequency as well as the on-time of the driving signal. The driving signal is multiplexed by a programmed driver microcomputer to drive a plurality of grids. Consequently, by varying the frequency, the multiplex period is also varied. The driver microcomputer communicates with a host microcomputer as well as drivers and grids of the VF display to control the VF display. In addition, the driver microcomputer samples a VF filament signal to synchronize the VF display multiplex frequency with the frequency of the VF filament signal to reduce flicker at low display brightness levels. The method and system achieve a continuously variable appearance of the VF display from full bright to barely discernable.
    Type: Grant
    Filed: August 20, 1990
    Date of Patent: March 24, 1992
    Assignee: Ford Motor Company
    Inventors: Erich Bozzer, James M. Raffa, Thomas G. Burke
  • Patent number: 5066929
    Abstract: A circuit for producing four indications on a bicolor light emitting diode (LED) includes a ring oscillator, with two inputs controlling inverters of opposite phase. By enabling or disabling these inverters, either, both, or neither dies of the LED are energized, causing it to emit light of either of its two primary colors, a secondary color formed by the combination of its two primaries, or no light, respectively. Nonlinear resistances are used to equalize the brightness of the two primaries and set the hue of the secondary.
    Type: Grant
    Filed: January 2, 1991
    Date of Patent: November 19, 1991
    Inventor: Keith R. Frantz
  • Patent number: 5063328
    Abstract: Circuits for increasing the efficiency of fluorescent tubes by openings one side of all of the filament circuits of the tubes in response to flow of plasma current. The circuits may be employed in conjunction with the circuits of Lucetta U.S. Pat. No. 3,954,316. It should be noted that solid state relays could also be employed so that filament current, although not completely terminated, would be substantially terminated and filament losses would be inconsequential.
    Type: Grant
    Filed: May 26, 1988
    Date of Patent: November 5, 1991
    Inventor: John F. Walton
  • Patent number: 5032765
    Abstract: A lighting arrangement comprises:a) an array of plural pairs of series-connected fluorescent lamps, with each lamp pair: i) adapted to be powered from 30 kHz/240 Volt by way of a high-Q series-resonant L-C circuit, ii) receiving cathode heating by way of transformer connected with the 30 kHz/240 Volt, iii) connected in parallel with the capacitor of the L-C circuits and iv) connected in parallel with a circuit protection means operative to limit the magnitude of the voltage that can develop across the capacitor of the L-C circuit as a result of Q-multiplication, and --in response to a control signal, or in case the lamp pair fails to start within a reasonably short time--to place a short circuit across the capacitor;b) a frequency converter connected with a power line and operable to provide the 30 kHz/240 Volt; andc) programming means connected with each circuit protection means and operable: i) before providing 30 kHz/240 Volt to the array, to provide a signal to all circuit protection means, thereby placin
    Type: Grant
    Filed: August 14, 1989
    Date of Patent: July 16, 1991
    Inventor: Ole K. Nilssen
  • Patent number: 4954749
    Abstract: A fluorescent lamp system including a relay whose coil is connected across the secondary of the transformer of the system and whose contacts interrupt the connection of the electrodes of the lamp system to their associated heater windings after lamp turn on.
    Type: Grant
    Filed: November 15, 1988
    Date of Patent: September 4, 1990
    Assignee: North American Philips Corporation
    Inventor: Joseph A. Crawford
  • Patent number: 4947086
    Abstract: A system for lighting fluorescent lamps, includes a plurality of fluorescent lamps, a transformer for generating filament voltage and a starting voltage for the fluorescent lamps, a switching circuit for sequentially and periodically opening and closing a plurality of its contacts and a driving circuit for electrically biasing the transformer and the switching circuit. A starting voltage is sequentially applied to the fluorescent lamps which are each independently connected to one of the contacts so that the fluorescent lamps may be sequentially turned on.
    Type: Grant
    Filed: February 10, 1988
    Date of Patent: August 7, 1990
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Fumikazu Nagano
  • Patent number: 4914354
    Abstract: An improved, more energy efficient reactor-type ballasting circuit for fluorescent lamps includes an inductive ballasting coil for directly applying an AC line voltage to the cathodes of a lamp without an intermediate autotransformer and also includes a glow type thermal switch in series with a positive temperature coefficient (PTC) resistor for electrical connection across the cathodes of the lamp to conduct pre-heating current to the lamp cathodes. The PTC resistor will effectively remove the glow switch from the ballast circuit if the switch fails to open after an appropriate time delay.
    Type: Grant
    Filed: September 8, 1988
    Date of Patent: April 3, 1990
    Assignee: General Electric Company
    Inventors: Edward E. Hammer, Eugene Lemmers
  • Patent number: 4900986
    Abstract: An improved ballast circuit for fluorescent lamps includes an electronic bilateral triggering device and a capacitor connected in series combination across the secondary winding output terminals of a ballasting transformer and in shunt with the fluorescent lamps. The triggering device and the capacitor operate to produce high frequency oscillations superimposed on the high AC voltage applied across the lamp cathodes to improve the capacitive coupling between the lamps and their mounting fixture during starting. The triggering device becomes nonconductive to effectively remove itself and the capacitor from the starting circuit while the lamps are lit.
    Type: Grant
    Filed: September 6, 1988
    Date of Patent: February 13, 1990
    Assignee: General Electric Company
    Inventors: Edward E. Hammer, Eugene Lemmers
  • Patent number: 4896078
    Abstract: A ballasting system for powering an array of multiple parallel-oriented fluorescent lamps in a sun tanning apparatus comprises and an electronic frequency converter adapted to convert ordinary 60 Hz power line voltage into a 350 Volt/30 Hz sinusoidal voltage provided between a pair of bus conductors and suitable for directly powering each fluorescent lamp by way of a simple capacitive or inductive current-limiting reactance means. The fluorescent lamp cathodes are heated by way of individual transformers, with one transformer for each pair of lamp cathodes. Only two pairs of distribution conductors are required for powering the complete array of mutually parallel-disposed fluorescent lamp pairs regardless of the number of lamps involved, with one pair running along the one side of the array, and the other pair running along the other side of the array. Of each pair of fluorescent lamps, one lamp is powered by way of an inductive reactance means and one lamp is powered by way of a capacitive reactance means.
    Type: Grant
    Filed: May 6, 1985
    Date of Patent: January 23, 1990
    Inventor: Ole K. Nilssen
  • Patent number: 4862035
    Abstract: A fluorescent lamp unit comprising a self-contained assembly intended for use in replacement for a conventional incandescent filament lamp comprises two U-shaped fluorescent tubes (54, 55), each provided with filaments (56, 57) at respective ends of the arc discharge path. Lead-in wires (60, 68, 69, 76) are arranged to connect the separate arc discharge paths of the two fluorescent tubes in series, and remaining lead-in wires (61, 70, 67, 73) of the fluorescent tubes are connected to components of a starter circuit housed within the mounting (20, 22) of the lamp unit. The starter circuit preferably comprises a separate glow bottle switch (62, 71) for each fluorescent tube, and a single capacitor (65).
    Type: Grant
    Filed: February 23, 1989
    Date of Patent: August 29, 1989
    Assignee: GTE Sylvania Limited
    Inventors: John Cunliffe, Brian J. Grabham
  • Patent number: 4847536
    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.
    Type: Grant
    Filed: November 20, 1986
    Date of Patent: July 11, 1989
    Assignee: Duralux Industries, Inc.
    Inventors: Archie H. Lowe, Addison Gooding, William S. Culwell
  • Patent number: 4740873
    Abstract: A "U" shaped fluorescent lamp includes a housing extending the legs of the lamp, the housing containing means to reduce current flow in the lamp, thereby saving energy.
    Type: Grant
    Filed: August 7, 1987
    Date of Patent: April 26, 1988
    Assignee: GTE Products Corporation
    Inventor: Norman A. Blake
  • 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: 4663566
    Abstract: The preferred embodiment provides such a fluorescent tube ignitor having a plurality of auxiliary electrodes provided in the periphery of the tube wall of each fluorescent tube, while the potentials of these auxiliary electrodes are set at a specific level equal to or lower than those of the low-voltage-applied filament circuits of each fluorescent tube. Integration and simplification of the preheat circuit at one-end of respective fluorescent tubes securely realizes a still smaller size of the ignitor, cost reduction, suppression of noise interference, and easier and faster start of illumination.
    Type: Grant
    Filed: February 1, 1985
    Date of Patent: May 5, 1987
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Fumikazu Nagano
  • Patent number: 4613792
    Abstract: A device to reduce power consumption in a rapid-start fluorescent lighting fixture having one or more lamps and a conventional ballast. The device includes a step-up isolation transformer, a capacitor connected in parallel with a bleed resistor and in series with a protective fuse all across the transformer. The device being mounted external of the ballast and wired in series between the ballast and the filament of a lamp to present a symmetrical load to the ballast circuit. In one embodiment the capacitor of the device is connected between the primary and secondary windings of the transformer by taps intermediate of the windings with an optimum connection at the center taps of the windings. In a second embodiment the capacitor is connected between either lead of the primary winding of the transformer and the center tap of the secondary winding.
    Type: Grant
    Filed: October 10, 1984
    Date of Patent: September 23, 1986
    Inventor: Peter R. Kroessler
  • Patent number: 4525649
    Abstract: The above and other objects, advantages and capabilities are achieved in one aspect of this invention by a drive scheme for a plurality, that is, for N, where N-2, flourescent lamps. The drive circuit comprises (N+1) pairs of output terminals, each comprising associated first and second individual terminals. An output transformer is coupled at one end to the (0,1).sup.1 terminal and at another end to the (0,1).sup.N+1 terminal. N impedance elements, typically capacitors, are coupled across associated pairs of lamp filaments in a fashion whereby each impedance element is coupled at one end to the second terminal of one pair and at another end to the second terminal of the succeeding pair. To wit: The first impedance element is coupled between the second terminal of the first pair, and the N.sup.th element is coupled between the second terminal of the N.sup.th pair and the second terminal of the (N+1).sup.th pair.
    Type: Grant
    Filed: July 23, 1984
    Date of Patent: June 25, 1985
    Assignee: GTE Products Corporation
    Inventors: William C. Knoll, David L. Bay
  • Patent number: 4523795
    Abstract: A process for operating a discharge lamp with an arc drop of not less than about 75% of a given service voltage includes the steps of series connecting a ballast and discharge lamp, coupling the series connected ballast and discharge lamp to a service voltage source and shunting the discharge lamp with a means for developing a pulse potential at or near the beginning of each half-cycle of the service voltage. Also, a series connected inductive ballast and discharge lamp are connected to a service voltage source and a non-linear dielectric element and preheat switching means each shunting the discharge lamp.
    Type: Grant
    Filed: August 10, 1984
    Date of Patent: June 18, 1985
    Assignee: GTE Products Corporation
    Inventors: Stephen G. Johnson, William M. Labadini