High Frequency Starting Operation For Fluorescent Lamp Patents (Class 315/DIG2)
  • Patent number: 6118227
    Abstract: A high-frequency power supply system for a plurality of fluorescent tubes includes an inverter type power supply connected to the primary side of the high-voltage transformer. The secondary side of the high-voltage transformer includes two high-voltage coils arranged to provide power to four hot cathode fluorescent tubes, wherein each of said high-voltage coils is connected to two of said hot cathode fluorescent tubes connected in parallel. The secondary side of the high-voltage transformer also includes supplemental coils arranged to heat filaments of the hot cathode fluorescent tubes. The power supply also includes at least one capacitor and at least one inductor connected to the secondary side and arranged in a manner that the secondary side provides power to a substantially resistive load.
    Type: Grant
    Filed: May 29, 1998
    Date of Patent: September 12, 2000
    Assignee: Transfotec International LTEE
    Inventor: Robert Beland
  • Patent number: 6118223
    Abstract: The invention relates to a lamp arrangement having a resonant circuit arrangement that is balanced and has two LC series circuits each connected between a respective inverter output terminal and a lamp terminal. The two inductive elements being coupled together via a single core.
    Type: Grant
    Filed: January 22, 1998
    Date of Patent: September 12, 2000
    Assignee: MagneTek, Inc.
    Inventor: Antonio Canova
  • Patent number: 6100648
    Abstract: A circuit, such as a ballast circuit, includes a resonant feedback signal from an inverter that provides substantially linear operation of rectifying diodes. In one embodiment, capacitors coupled in series with respective lamps resonate with a first winding of a feedback transformer so as to generate a feedback signal on a second winding of the transformer. The feedback signal is effective to produce substantially linear operation of the rectifying diodes.
    Type: Grant
    Filed: April 30, 1999
    Date of Patent: August 8, 2000
    Assignee: Electro-Mag International, Inc.
    Inventor: Mihail S. Moisin
  • Patent number: 6049179
    Abstract: To provide a high-pressure discharge lamp lighting apparatus which is adapted to be used in common for several kinds of AC voltages such as 100 V and 200 V, which is small in size, and which can secure good starting property with less circuit loss in use at any of the AC voltages, the apparatus is provided with a diode bridge for rectifying an AC voltage, an active filter for converting, with a high power factor, an AC voltage into a DC voltage, a current limiting circuit for controlling the current to be made to flow in the high-pressure discharge lamp, an inverter for converting a DC voltage into a low-frequency AC voltage, a high-voltage pulse circuit for generating a high-voltage pulse for starting the high-pressure discharge lamp, and a control circuit for controlling the active filter, the current limiting circuit, the inverter, a discharge-lamp voltage detecting circuit, a discharge-lamp current detecting circuit and the high-voltage pulse circuit.
    Type: Grant
    Filed: March 23, 1998
    Date of Patent: April 11, 2000
    Assignees: Mitsubishi Denki Kabushiki Kaisha, Mitsubishi Electric Lighting Corporation, Osram-Melco Limited
    Inventors: Hiroyasu Kisaichi, Masatomi Asayama, Fumitake Oowada
  • Patent number: 6037598
    Abstract: An arrangement for an ultraviolet sterilization system disposed on a packaging machine for processing a series of cartons is disclosed herein. The system may have an ignitor for expediting the commencement of the ultraviolet lamp. Additionally, the system may have an ultraviolet monitor for monitoring the intensity of the ultraviolet radiation being directed to a series of cartons being processed on the packaging machine. The monitor will alert an operator to a change in the intensity of the ultraviolet radiation thereby ensuring properly sterilized cartons.
    Type: Grant
    Filed: January 28, 1998
    Date of Patent: March 14, 2000
    Assignee: Tetra Laval Holdings & Finance, SA
    Inventor: John Cicha
  • Patent number: 6028401
    Abstract: A circuit arrangement for igniting a high pressure discharge lamp includes a secondary winding of a pulse transformer which is at least partially capacitively shunted forming a tuned filter. The tuned filter preferably forms a band pass filter for passing the second harmonic of the signal produced by a pulse generator. An increase in the supply of current during take-over results thereby minimizing the time required for ignition.
    Type: Grant
    Filed: March 3, 1998
    Date of Patent: February 22, 2000
    Assignee: U.S. Philips Corporation
    Inventors: Frans Slegers, Hendrik J. Blankers
  • Patent number: 6018221
    Abstract: The present invention provides an improved power factor and lower harmonic distortion in the power supply circuit of a high frequency discharge lamp. An "extra" circuit path is provided so that the driving power to the lamp will "see" a load that significantly reduces the harmonic distortion and tends to cause the power factor to approach "1". In a preferred embodiment of the invention this is accomplished by providing a third capacitor with which the load circuit forms an in-series resonance circuit with the discharge lamp and its associated current-limiting inductance. The new circuit arrangement provides a high frequency current passage not provided in known lighting circuits of this type that raises the power factor and lowers harmonic distortion.
    Type: Grant
    Filed: April 16, 1999
    Date of Patent: January 25, 2000
    Assignee: Toshiba Lighting & Technology Corporation
    Inventor: Hirokazu Ohtake
  • Patent number: 6018220
    Abstract: A ballast circuit for a gas discharge lamp includes a rectifier coupled to convert current from an a.c. source to d.c. current provided on bus and reference conductors. A smoothing capacitance, coupled between the bus and reference conductors, smooths current supplied by the rectifier. A resonant load circuit includes a resonant inductance, a resonant capacitance, and means to connect to the lamp. A d.c.-to-a.c. converter circuit, coupled to the resonant load circuit, induces an a.c. current in the resonant load circuit. The converter circuit comprises first and second switches serially connected between the bus and reference conductors, and being connected together at a common node through which the a.c. load current flows. The switches each comprise a reference node and a control node, the voltage between such nodes determining the conduction state of the associated switch. The respective reference nodes of the switches are interconnected at the common node.
    Type: Grant
    Filed: January 20, 1998
    Date of Patent: January 25, 2000
    Assignee: General Electric Company
    Inventor: Louis R. Nerone
  • Patent number: 6011362
    Abstract: A method and apparatus for efficiently driving a load coupled to a ballast is described. A switching element coupled between a pair of ballast terminals converts a low frequency drive signal to a high frequency drive signal which is provided to the load.
    Type: Grant
    Filed: November 19, 1996
    Date of Patent: January 4, 2000
    Assignee: Electro-Mag International, Inc.
    Inventor: Mihail S. Moisin
  • Patent number: 5962985
    Abstract: A circuit arrangement for operating a discharge lamp comprises a self-oscillating DC/AC converter (II) provided with a series arrangement of a first and a second switching element between a first and a second input terminal (2, 2') for connection to a DC voltage source (III). The series arrangement supplies an alternating current Ib to a load branch having output terminals for connection of the discharge lamp during nominal operation. The circuit arrangement is in addition provided with a starter circuit ST for generating a DC voltage component between the control electrode (1c') and the main electrode (1a') of the second switching element (1'). The starter circuit also include apparatus which comprise an auxiliary switch (25) that brings the first switching element (1) into a conducting state if the amplitude of the alternating current Ib is low compared with its amplitude during nominal operation.
    Type: Grant
    Filed: May 4, 1998
    Date of Patent: October 5, 1999
    Assignee: U.S. Philips Corporation
    Inventors: Arnold W. Buij, Hendricus F. P. Michiels
  • Patent number: 5962990
    Abstract: A d.c. voltage source delivers the voltage at its output terminals. This voltage is converted to a higher voltage level by a d.c./d.c. converter. This higher voltage level forms the input voltage to a controlled power-supply circuit. From this, the power-supply circuit forms the supply voltage and supply current for a high-pressure gas-discharge lamp to supply it with burning energy. A control circuit is provided to control the power-supply circuit, and an ignition circuit (9) is provided for the ignition. The power-supply circuit is controlled by the control circuit so that the high-pressure gas-discharge lamp is operated with a defined overload when illumination is started. In this context, the overload is defined so as to prevent flickering or light-saddles. The overload is controlled by the control circuit as a function of the state of the high-pressure gas discharge lamp.
    Type: Grant
    Filed: May 21, 1998
    Date of Patent: October 5, 1999
    Assignee: Robert Bosch GmbH
    Inventor: Robert Kern
  • Patent number: 5959410
    Abstract: An electric power source device includes a power converting circuit and a load circuit (LD) for receiving an output from the power converting circuit. The power converting circuit includes a rectifier element (DB) for rectifying an input from an alternating current source (AC), a smoothing capacitor (Ce) for smoothing an output from the rectifier element (DB) with a direct current, and switching elements (Q1, Q2) for generating high frequency voltage and current in response to receipt of a voltage of the smoothing capacitor (Ce).
    Type: Grant
    Filed: January 29, 1997
    Date of Patent: September 28, 1999
    Assignees: Matsushita Electric Works R&D Laboratory, Inc., Matsushita Electric Works Ltd.
    Inventors: Tokushi Yamauchi, Tsutomu Shiomi
  • Patent number: 5945787
    Abstract: A power control of an AC-operated, high-pressure gas discharge lamp, particularly in a motor vehicle, including a bridge circuit in which two controlled switching transistors are disposed in at least one branch, and in which the high-pressure gas discharge lamp is supplied with ignition and/or burning energy by way of the bridge branch provides that the switching transistors switch the current in the form of pulse packets, with the individual pulse packets respectively containing a certain number of high-frequency pulses; switching is effected with as little loss as possible in the zero crossings of the current; and regulation for maintaining a certain power of the high-pressure gas discharge lamp is effected through continuous averaging over a predetermined interval (44, 45) of the supplied power packets.
    Type: Grant
    Filed: November 6, 1997
    Date of Patent: August 31, 1999
    Assignee: Robert Bosch GmbH
    Inventors: Ingo Gorille, Bernd Mueller
  • Patent number: 5910711
    Abstract: A circuit arrangement for operating a discharge lamp comprising an oscillator for generating a high frequency input voltage and a piezo-electric transformer with input terminals coupled to the oscillator and output terminals. A load circuit is coupled to the output terminals of the piezo-electric transformer and includes terminals for lamp connection. The load circuit comprises an adjustable capacitor which forms a very simple device for controlling the light output of the discharge lamp over a wide range.
    Type: Grant
    Filed: November 24, 1997
    Date of Patent: June 8, 1999
    Assignee: U.S. Philips Corporation
    Inventors: Rebekka Porath, Achim Hilgers
  • Patent number: 5909089
    Abstract: The invention relates to a circuit arrangement for igniting and operating a high-pressure discharge lamp provided with a control circuit which limits the voltage to a value Vb across the output terminals of the circuit arrangement such that:Vla<Vb<Vi.wherein Vla is the nominal lamp voltage and Vi is the threshold voltage across the output terminals at which the ignitor starts.
    Type: Grant
    Filed: April 16, 1997
    Date of Patent: June 1, 1999
    Assignee: U.S. Philips Corporation
    Inventors: Oscar J. Deurloo, Franciscus H. T. Lammers
  • Patent number: 5894202
    Abstract: An ignition device for gas discharge lamps is proposed, in particular for motor vehicle lights. The ignition device contains a first transformer (17) which is supplied on its primary side with an alternating current produced from a direct current supply voltage. To generate this alternating current, a capacitor (14), which is acted upon by a charging current, constitutes a closed circuit together with the primary winding of the first transformer and a spark gap (16), wherein the spark gap (16) arcs at a predetermined charge state of the capacitor (14). This device makes a simple, inexpensive, and space-saving device possible for generating the required operating voltage for the transformer (17), wherein the spark gap can be reliably used, even at higher temperatures.
    Type: Grant
    Filed: January 3, 1997
    Date of Patent: April 13, 1999
    Assignee: Robert Bosch GmbH
    Inventors: Dieter Betz, Ulrich Drews, Thomas Gross, Bernd Rothfuss, Thomas Kienzler
  • Patent number: 5828186
    Abstract: A circuit arrangement for igniting a high pressure discharge lamp includes a secondary winding of a pulse transformer which is at least partially capacitively shunted forming a tuned filter. The tuned filter preferably forms a band pass filter for passing the second harmonic of the signal produced by a pulse generator. An increase in the supply of current during take-over results thereby minimizing the time required for ignition.
    Type: Grant
    Filed: February 29, 1996
    Date of Patent: October 27, 1998
    Assignee: U.S. Philips Corporation
    Inventors: Frans Slegers, Hendrik J. Blankers, Nicolaas J. De Jong
  • Patent number: 5821696
    Abstract: Start and operation of high pressure discharge lamps, in which a high-frequency starting voltage U.sub.HF and an operating voltage U.sub.B are furnished to the lamp electrodes includes the steps of: 1) turning on the high-frequency starting voltage U.sub.HF at a starting time t.sub.0 to ionize the lamp filling and preheat the electrodes; 2) turning on the operating voltage U.sub.B after a preheating interval .DELTA.t.sub.H, that is, at time t.sub.1 =t.sub.0 +.DELTA.t.sub.H ; and 3) turning off the starting voltage U.sub.HF at time t.sub.2 .gtoreq.t.sub.1, as a result of which the lamp is then operated solely by means of the operating voltage U.sub.B. As a result, the transfer phase for the development of the arc is shortened. Advantageously, the frequency of the starting voltage is selected such that the product of the frequency f of the starting voltage U.sub.HF and the spacing d between the electrodes meets the condition f.multidot.d.gtoreq.50 kHz.multidot.cm.
    Type: Grant
    Filed: November 30, 1995
    Date of Patent: October 13, 1998
    Assignee: Patent-Treuhand Gesellschaft F. Elektrische Gluehlampen mbH
    Inventors: Dietrich Fromm, Joachim Arlt
  • Patent number: 5710487
    Abstract: An improved energizing circuit for starting and regulating a gaseous discharge lamp. The circuit is 100% solid state and does not require the use of any inductive components or any filaments for its proper operation. The circuit is made up of several sub-circuits including a rectifying and voltage-doubling circuit, a second multiplying circuit, a low power oscillating circuit and a high voltage amplifier circuit. A high frequency AC signal is used to ionize the gas and ignite the lamp, while a DC signal is generated by the circuit to keep the lamp illuminated once it is ignited. The size and weight of the integrated circuit ballast are such that it could be incorporated into the fluorescent lamp package itself.
    Type: Grant
    Filed: August 24, 1994
    Date of Patent: January 20, 1998
    Inventor: Francisco Javier Velasco Valcke
  • Patent number: 5642016
    Abstract: A solar lamp drive circuit is arranged to delay start-up while a current is supplied to the lamp filament to warm up the filament. During operation, the back e.m.f. induced in the lamp is sampled, and, if operating conditions deteriorate, the current to the filament is reapplied automatically and the power supply to the lamp increased.
    Type: Grant
    Filed: July 26, 1995
    Date of Patent: June 24, 1997
    Inventor: Ram Shalvi
  • Patent number: 5589739
    Abstract: A circuit for operating a discharge lamp includes input terminals for connection to a supply voltage source and a first apparatus coupled to the input terminals for generating a low-frequency alternating current from a supply voltage delivered by the supply voltage source. A second apparatus is coupled to the input terminals for generating from the supply voltage a further current which is superimposed on the low-frequency alternating current. The polarity of the further current is the same as that of the low-frequency alternating current. As a result, instabilities do not arise in the discharge arc of a high-pressure discharge lamp operated by the circuit.
    Type: Grant
    Filed: August 18, 1995
    Date of Patent: December 31, 1996
    Assignee: U.S. Philips Corporation
    Inventor: Hendrikus M. W. Goossens
  • Patent number: 5523655
    Abstract: A nearly pure neon is described along with a method of operating the lamp. A phosphor is coated on the lamp wall. By properly stimulating the neon, ultraviolet light may be emitted, that can stimulate the phosphor to a first light emission. The lamp may then be operated to produce a visible light emission that is the result of neon emission or of intermediate combinations of the neon and phosphor emissions. A single neon lamp may then produce in one instance, an amber color, or in other instance, a red color without the cold environment problems typical of a mercury based lamp. The output efficiency is enhanced when the lamp is formed as an aperture lamp. The narrow source is also useful as a source in reflector and lens systems. High pressure neon lamps offer a small source size, direct color with no filtering, good tolerance of impact and jarring, moderate cost, and increased vehicle styling potential.
    Type: Grant
    Filed: August 31, 1994
    Date of Patent: June 4, 1996
    Assignee: Osram Sylvania Inc.
    Inventors: Scott D. Jennato, Harold L. Rothwell, Jr., George J. English
  • Patent number: 5504399
    Abstract: In an electrical circuit for feeding a fluorescent lamp, a serial resonant circuit is comprised of a first coil of a feedback-transformer, a resonant inductor, a coupling condenser, a first lamp cathode, a resonant condenser, and a first coil of an isolating transformer, this serial resonant circuit being connected between the output of an inverted rectifier, connected to a voltage supply source and one terminal of said voltage supply source, with a second coil of the isolating transformer being connected in parallel with the second lamp cathode. If the coils of the isolating transformer have the same number of loops, this connection of the second lamp cathode ensures that the same heating current will flow through both lamp cathodes, so that these will be heated equally. The parallel circuit of the second lamp cathode with the second coil of the isolating transformer is connected through a resistance with a terminal of the supply voltage.
    Type: Grant
    Filed: September 23, 1993
    Date of Patent: April 2, 1996
    Assignee: Knobel AG Lichttechnische Komponenten
    Inventor: Felix Tobler
  • Patent number: 5479326
    Abstract: A grid is suspended some distance below a permanent ceiling. The grid has plural grid openings. Each grid opening is covered by a regular ceiling panel or by a special light-weight lighting panel. Both the ceiling panels and the lighting panels are readily installable and movable, without requiring the making or breaking of hard-wire electrical connections. Each one of the lighting panels is powered by way of an individual flexible cord-and-plug means. This cord-and-plug means is plugged into a male receptacle on the lighting panel and into a female receptacle on a special power supply mounted on the permanent ceiling above this one ceiling panel. This special power supply has several such female receptacle means and can accommodate several ceiling panels. To power all the lighting panels of a complete ceiling, several of the special power supplies are used.
    Type: Grant
    Filed: September 2, 1993
    Date of Patent: December 26, 1995
    Inventor: Ole K. Nilssen
  • Patent number: 5453667
    Abstract: This invention suppresses the occurrence of interference in a very short period to prevent device destruction. An inverter circuit of this invention includes a crystal oscillator, which oscillates at a fixed frequency, a load-status detector, which receives a voltage and current to be applied to a load including an inductive or capacitive component and detects the status of the load, a voltage-controlled oscillator, which oscillates at a frequency corresponding to the load status detected by the load-status detector, and a switch, which selects the output of the crystal oscillator or the output of the voltage-controlled oscillator and supplies the selected output to the load. An electrodeless discharge lamp lighting device according to this invention uses an inverter circuit having the above structure.
    Type: Grant
    Filed: June 30, 1993
    Date of Patent: September 26, 1995
    Assignee: Toshiba Lighting & Technology Corporation
    Inventors: Mitsuhiro Matsuda, Keiichi Shimizu, Kenji Araki, Ichiro Yokozeki, Fumio Hirano
  • Patent number: 5440205
    Abstract: A fluorescent lamp starter which includes: a series circuit to be connected to a power source for supplying an AC voltage, including a ballast and a fluorescent lamp equipped with electrodes; a transistor having a collector and an emitter connected through a diode between the electrodes on an opposite side of the fluorescent lamp in which the power source is not connected; a control voltage supply means having a resistance means and a capacitor, which are operated by a voltage between the collector and the emitter of the transistor; and a transistor base control means for switching the transistor by a total voltage of a part of a voltage generated in the resistance means of the control voltage supply means and a voltage generated in the capacitor thereof.
    Type: Grant
    Filed: September 28, 1993
    Date of Patent: August 8, 1995
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tetsuya Tahara, Kazushige Sugita, Kazuhiko Ito, Nobuhisa Yoshikawa
  • Patent number: 5434480
    Abstract: An electronic device for powering a gas discharge load (FL1) from a low frequency alternating voltage source (AVS). This device is drawing a current proportional to a voltage of the source (AVS) and is constituted by a resonant boosting circuit integrated into a power line voltage rectifier (BI,BRB) which performs boost switching and rectifying functions developed by and synchronized with a pulsating current drawn from the rectifier by a resonant oscillator circuit (RO1) equipped with a switching transistors (Q1,Q2) and adapted to energize the gas discharge load (FL1).
    Type: Grant
    Filed: October 12, 1993
    Date of Patent: July 18, 1995
    Inventor: Andrzej A. Bobel
  • Patent number: 5426350
    Abstract: A novel high frequency LCLC double resonant electronic ballast has been developed for gas discharge lamp applications. The ballast consists of a half-bridge inverter which switches at zero voltage crossing and an LCLC resonant circuit which converts a low ac voltage to a high ac voltage. The LCLC resonant circuit has two LC stages. The first LC stage produces a high voltage before the lamp is ignited. The second LC stage limits lamp current with the circuit inductance after the lamp is ignited. In another embodiment a filament power supply is provided for soft start up and for dimming the lamp. The filament power supply is a secondary of the second resonant inductor.
    Type: Grant
    Filed: November 18, 1993
    Date of Patent: June 20, 1995
    Assignee: Electric Power Research Institute, Inc.
    Inventor: Jih-Sheng Lai
  • Patent number: 5424616
    Abstract: A circuit arrangement for operating a discharge lamp by means of a high-frequency current includes a switching device for generating the high-frequency current from a supply voltage, a modulator for the substantially square-wave modulation of the amplitude of the high-frequency current at a modulation frequency f, and an apparatus (M) for limiting the interference with infrared systems caused by the discharge lamp. The limiting apparatus (M) comprise a circuit N for providing a gradual increase in the rate at which the amplitude of the high-frequency current decreases at the end of a square wave of the square-wave modulation. This provides a considerable reduction in the interference with infrared systems caused by a lamp operated by the circuit arrangement.
    Type: Grant
    Filed: September 22, 1994
    Date of Patent: June 13, 1995
    Assignee: U.S. Philips Corporation
    Inventor: Jozef H. Reijnaerts
  • Patent number: 5416384
    Abstract: This is an emergency lighting system that provides an emergency driving voltage to drive at least one lamp when the AC power input to the lamp is detected as absent. A rechargeable battery pack and recharging circuit are contained in a first modular housing, and driving circuitry is contained in a second modular housing. An easily accessible, manually-operable service switch disables the provision of battery power to the driving circuitry (when the switch is in the open state), thereby allowing substantial reduction in installation time and cost. A test switch is included to emulate power failures. A transmitter and receiver mechanism allow a user to remotely disable the provision of battery power to the driving circuitry, thereby offering battery power conservation, if the emeregency lamplight is not needed. Likewise, a photo-sensing mechanism disables the provision of battery power to the driving circuitry, if there is sufficient ambient light.
    Type: Grant
    Filed: February 23, 1993
    Date of Patent: May 16, 1995
    Inventor: Joseph Bavaro
  • Patent number: 5394064
    Abstract: An electronic ballast circuit for multiple fluorescent lamps. Control is achieved by varying the voltage and the frequency of operation of an inverter utilized to drive the fluorescent lamps. A separate voltage boost converter provides regulated voltage to the converter. Dimming is accomplished by varying the voltage either manually or in response to sensor circuitry.
    Type: Grant
    Filed: October 15, 1993
    Date of Patent: February 28, 1995
    Assignee: Micro-Technology Inc.-Wisconsin
    Inventors: Krishnappa Ranganath, Alexander Kurnia
  • Patent number: 5311102
    Abstract: The present invention relates to a power supply unit for discharge lamps, comprising a rectifier (3); an oscillator output portion (5); an inductor (1); capacitor (2, 4, 7, 8). And further comprising a sampling resistor (9) and a module (10). It is used to reduce the capacitive impedance at the input end of the circuit, minimizing the components of high-order harmonics produced in the circuit, weakening the high-order harmonics of source current to the degree that they no longer impact the power network.
    Type: Grant
    Filed: May 12, 1992
    Date of Patent: May 10, 1994
    Assignee: Wei Hai Bei Yang Electric Group Corp.
    Inventor: Rong Jiu Du
  • Patent number: 5309066
    Abstract: A device to produce alternating electric current of high frequency for power consumers such as fluorescent lamps, which includes the means of supplying a DC voltage nearly twice the size of the peak voltage of the alternating voltage input--with negligible loss of power--to the remainder of the circuit and thus reducing the intrinsic power consumption of the device as well as making it possible to supply the said power consumer such as the fluorescent lamp with a higher start voltage as well as a higher voltage in operation.
    Type: Grant
    Filed: May 29, 1992
    Date of Patent: May 3, 1994
    Assignee: Jorck & Larsen A/S
    Inventor: Claes Ditlevsen
  • Patent number: 5289083
    Abstract: The invention relates to an inverter powering a lamp that uses a switch to vary the resonance of the resonance circuit for starting and for operating.
    Type: Grant
    Filed: June 18, 1991
    Date of Patent: February 22, 1994
    Assignee: Etta Industries, Inc.
    Inventor: Fazle S. Quazi
  • Patent number: 5262700
    Abstract: A special fluorescent lamp is provided with its own built-in cathode heating means and is operable to be properly ballasted by way of a light-weight two-wire power cord coming from a special power plug that comprises a built-in high-frequency ballasting means. This special power plug is suitable for being plugged into, held by, and powered by any ordinary household electric power receptacle. The combination of the special fluorescent lamp and the special power plug constitutes a product similar to the so-called bright-stick marketed by General Electric.
    Type: Grant
    Filed: December 30, 1991
    Date of Patent: November 16, 1993
    Inventor: Ole K. Nilssen
  • Patent number: 5243261
    Abstract: A circuit arrangement suitable for operating low-pressure mercury discharge lamp by means of a high-frequency current includes circuitry (I) for generating the high-frequency current from a supply voltage, and a modulator (II) for the substantially square-wave modulation of the amplitude of the high-frequency current at a modulation frequency f. The circuit arrangement is further provided with circuitry (V) for limiting the amplitude of the re-ignition voltage across the low-pressure mercury discharge lamp to a voltage Vi. As a result, interference with infrared systems caused by a discharge lamp operated by the circuit arrangement is substantially fully suppressed.
    Type: Grant
    Filed: January 15, 1992
    Date of Patent: September 7, 1993
    Assignee: U.S. Philips Corporation
    Inventors: Jozef R. M. Bergervoet, Leonardus U. E. Konings, Jacob Schlejen, Andrianus M. J. De Bijl, Johannes H. Wessels
  • Patent number: 5235254
    Abstract: A power circuit for a fluorescent discharge lamp comprising a converter for producing a DC output. A voltage controlled oscillator is driven by the output from the converter, the oscillator providing a high voltage output for driving the lamp. The frequency of the output increases and decreases with increases and decreases in the powering voltage from the converter. A current detector detects the current passing through the lamp and controls the output voltage of the converter according to that current to increase the the voltage to strike the lamp and then control the voltage to give the required running current.
    Type: Grant
    Filed: March 26, 1991
    Date of Patent: August 10, 1993
    Assignee: PI Electronics Pte. Ltd.
    Inventor: Joseph K. P. Ho
  • Patent number: 5233273
    Abstract: When a discharge lamp is started, high voltage pulses which superpose the voltage due to LC resonance of a resonance circuit are supplied to the discharge lamp, and breakdown occurs in the discharge lamp. The pulse energy needed for the high voltage pulses is small and the output power of the resonance circuit can be decreased. After the breakdown, the energy needed for the transfer from glow discharge to arc discharge is supplied by the resonance, and the high voltage pulses used to supply the starting energy are allowed to be stopped. Thus, the starting and restriking of a discharge lamp is sure, and the starting circuit for a discharge lamp can be made more compact.
    Type: Grant
    Filed: September 9, 1991
    Date of Patent: August 3, 1993
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Atsuo Waki, Koji Miyazaki, Masataka Ozawa, Takayuki Kamitani, Shigeru Horii
  • Patent number: 5191263
    Abstract: A driver circuit for one or more gas discharge lamps (102, 104, 106) includes: a self-oscillating, series-resonant oscillator (196, 198, 178, 180) for producing a constant-frequency, high-frequency output voltage for application to the lamps; an inductive voltage boost IC (144) for causing the oscillator to produce a temporary excessive boosted output voltage (300 V) when the voltage boost IC is initially activated and a steady-state boosted output voltage (250 V) thereafter, ensuring striking of the lamps and prolonging their life.
    Type: Grant
    Filed: March 4, 1992
    Date of Patent: March 2, 1993
    Assignee: Motorola Lighting, Inc.
    Inventor: John G. Konopka
  • Patent number: 5187414
    Abstract: An electronic controller for fluorescent lamps includes a DC to AC converter which supplies high frequency current to the lamps and a preconditioner stage which includes a switched mode power supply connected to accept line power and produce a DC input for the DC to AC converter. The switched mode power supply and the DC to AC converter are synchronized to operate in a fixed phase relationship and/or at the same frequency.
    Type: Grant
    Filed: November 25, 1991
    Date of Patent: February 16, 1993
    Assignee: North American Philips Corporation
    Inventors: Mark W. Fellows, John M. Wong, Edmond Toy, Robert A. Erhardt, James A. Thomsen
  • Patent number: 5150014
    Abstract: A circuit arrangement and a method suitable for operating a low-pressure mercury discharge lamp which includes circuitry for adjusting the average amplitude of the current provided to the lamp as well as circuitry for adjusting the modulation of the current provided to the lamp.
    Type: Grant
    Filed: January 9, 1991
    Date of Patent: September 22, 1992
    Assignee: U. S. Philips Corporation
    Inventor: Lukas Kastelein
  • Patent number: 5144205
    Abstract: A dimming system provides power from a switch-controlled power source in series with a leakage auto-transformer to a compact fluorescent lamp. The system incorporates a high-frequency resonant converter that provides high voltages to strike and maintain an electric discharge in the lamp. The converter is loaded in parallel by the lamp, whose impedance damps the converter to stabilize lamp operation. An inductor, connected between the leakage auto-transformer and the resonant converter, isolates the switch-controlled power source from the high-frequency voltage. The system can be used with a variety of standard leakage reactance auto-transformers to provide full-range dimming of compact fluorescent lamps from 5 to 100 percent light output with minimal flicker.
    Type: Grant
    Filed: December 12, 1989
    Date of Patent: September 1, 1992
    Assignee: Lutron Electronics Co., Inc.
    Inventors: Eric R. Motto, Scott R. Jurell
  • Patent number: 5117161
    Abstract: An improved electronic ballast inverter for a gas discharge lamp includes an oscillator having at least two switching transistors for operating the gas discharge lamp at a high frequency during steady-state operation, a triggering circuit for initiating the operation of the oscillator, and an electrical circuit connected to the oscillator for gradually increasing the base current of at least one of the switching transistors immediately after start-up in order to delay the gas breakdown and thereby to produce preheating of the gas discharge lamp during startup.
    Type: Grant
    Filed: January 29, 1991
    Date of Patent: May 26, 1992
    Assignee: Gaash Lighting Industries
    Inventor: Zohar Avrahami
  • Patent number: 5111118
    Abstract: A controller operates in pre-ignition and ignition phases to obtain stable and reliable control of operation of a half-bridge DC-AC converter in a frequency range which is offset from a resonant frequency of an output circuit which includes a transformer and capacitors and which couples the converter to a fluorescent lamp load. The converter is supplied with a DC voltage from a switched-mode DC-DC supply of a pre-conditioner circuit which responds to a full-wave rectified AC voltage and which is supplied with pulse-width modulated gating pulses from the controller, preferably at a frequency which is the same as that of the converter. The controller monitors signals from the output circuit and pre-conditioner circuits and exercises control to reliable starting and highly efficient lamp operation and to obtain an in-phase proportional relationship of input voltage and current wave forms.
    Type: Grant
    Filed: August 12, 1991
    Date of Patent: May 5, 1992
    Assignee: North American Philips Corporation
    Inventors: Mark W. Fellows, John M. Wong, Edmond Toy, Robert A. Erhardt, James A. Thomsen, Jr.
  • Patent number: 5103143
    Abstract: In a process for starting a high pressure gas discharge lamp (GDL) of a motor vehicle of a type for which an alternating voltage is developed from a direct voltage, the alternating voltage being fed to an ignition device to ignite the high pressure gas discharge lamp, a lamp voltage and/or a lamp current is measured, an actual value based on lamp current and/or lamp voltage is compared with a desired value and after ignition of the high pressure gas discharge lamp for a predetermined time span, or period, an additional power is added to an operational power of the high pressure gas discharge lamp by means of changes in the alternating voltage which, on the one hand, is limited by a maximum permissible lamp current and on the other hand is terminated at the end of the predetermined time span.
    Type: Grant
    Filed: May 13, 1991
    Date of Patent: April 7, 1992
    Assignee: Hella KG Hueck & Co.
    Inventor: Wolfgang Daub
  • Patent number: 5065074
    Abstract: The invention relates to a low voltage, high frequency driver circuit for a fluorescent tube which has high efficiency and low heat output, the invention provides a fluorescent tube driver having first positive and second nominally zero input terminals arranged to be supplied by a low voltage dc source comprising an oscillator circuit consisting of a current source effectively connected through a first capacitor to the second input, a transformer having first and second windings and a transistor, the base of the transistor being connected through the first winding to the junction of the current source and the first capacitor, the collector of the transistor being connected through the second winding to the first input and the emitter of the transistor being connected to the second input, the current source being adjustable such that the power output is in the range 18 to 40 watts, and output means comprising a third winding on the transformer, the third winding having a greater number of turns than the first
    Type: Grant
    Filed: March 13, 1991
    Date of Patent: November 12, 1991
    Assignee: Coolite Limited
    Inventors: John Hesketh, Martin Thornton
  • Patent number: 5059867
    Abstract: A ballast circuit for operating a metal halide lamp by applying DC excitation during its start, glow and run modes is disclosed. The type and values of the circuit components of the ballast circuit are selected to provide automatic, sequential and desired transfer functions as the impedance value of the metal halide lamp transitions from its value occurring during the start, glow and run modes of operation. The ballast circuit has an input stage that is easily adapted to present a high power factor to the AC power source supplying the metal halide lamp. Further, the ballast circuit generates a signal for more easily starting the lamp and having a relatively high DC level upon which are developed pulse signals.
    Type: Grant
    Filed: April 3, 1990
    Date of Patent: October 22, 1991
    Assignee: General Electric Company
    Inventors: Louis R. Nerone, Michael M. Secen, Michael M. Minarczyk
  • Patent number: 5029061
    Abstract: A circuit 10 for supply a fluorescent tube 12 comprises a power supply 14 which modulates the mains supply at 24 to produce a DC supply at 16. A relay J and a switch S2 apply the DC supply to a terminal 38. The power supply 14 also supplies a charging current at 30 to a battery pack 32. The supply at 38 powers an oscillator circuit 18 which incorporates inductors L1, L2 which are windings on a transformer 20. A secondary winding 22 taps the transformer 20 to supply the tube 12. A third winding L3 detects the voltage being applied to the tube 12 and a feedback circuit 40 controls the output amplitude of the oscillator 18 in order to maintain a constant supply voltage to the tube 12.
    Type: Grant
    Filed: August 18, 1989
    Date of Patent: July 2, 1991
    Inventor: Kwei C. Shek
  • Patent number: 5023519
    Abstract: A circuit is disclosed which is capable of positively shifting a gas discharge lamp from its off-state to its on-state without emitting light flashes and further positively maintains the gas discharge lamp in its on-state when first ignited. The circuit contains an oscillator device which generates and supplies an oscillator signal of a specific oscillator frequency from two output terminals of the oscillator device. It also contains a current limiting device an a parallel-resonance circuit comprising a capacitor and an inductor. The parallel resonance circuit has a frequency of resonance substantially identical to the oscillator frequency. The current limiting device and parallel-resonance circuit are connected in a series configuration across the output terminals of the oscillator device. Further, the gas discharge lamp is connected across or in parallel with the parallel-resonance circuit.
    Type: Grant
    Filed: May 16, 1988
    Date of Patent: June 11, 1991
    Inventor: Kaj Jensen
  • 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