Discharge Device Loads Patents (Class 315/189)
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Patent number: 11191137Abstract: An LED driving system with a master-slave architecture. The LED driving system has at least two LED driving circuits which both have a first status detecting circuit, a second status detecting circuit and a first feedback control circuit. The first status detecting circuit receives a plurality of headroom detecting voltages provided by a plurality of LED strings and generates at least one self-status signal. The second status detecting circuit receives a downstream feedback signal and generates at least one downstream status signal. The first feedback control circuit generates a first feedback control signal based on the at least one self-status signal and the at least one downstream status signal. The second status detecting circuit of one LED driving circuit is coupled to the first feedback control circuit of the other LED driving circuit.Type: GrantFiled: March 31, 2021Date of Patent: November 30, 2021Assignee: Monolithic Power Systems, Inc.Inventors: Junjian Zhao, Chia-Lung Ni, Zheng Luo, Yu-Huei Lee, Huan Liu
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Patent number: 10009972Abstract: Multiphase lighting fixtures having one or more light emitting diode (LED) light sources are provided. In one example implementation, a light fixture includes one or more light sources, such as LED light sources and a power conversion circuit. The power conversion circuit includes a phase shifting transformer for implementing a phase shift between output phases of secondary windings thereof, a multi-phase rectifier having a first rectifier and a second rectifier connected in parallel for converting a multiphase input power to a rectified output or a six-pulse configuration, a zero sequence blocking transformer for reducing harmonic distortion, an interphase transformer for further reducing harmonic distortion, and a current regulator for providing a constant DC current output to the one or more light sources. In some example implementations, the DC rectified output has a voltage ripple of less than about 7%, or less than about 3%.Type: GrantFiled: February 8, 2017Date of Patent: June 26, 2018Assignee: Hubbell IncorporatedInventors: Thomas N. Clawson, Jr., T. Warren Weeks, Jr., Chris Bailey, Douglas M. Hamilton
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Patent number: 9549445Abstract: A driver circuit is configured for connection to a power source and includes a plurality of light emitting diodes (LEDs) having at least one performance characteristic that varies according to different performance categories ranging between higher performance and lower performance. The driver circuit also includes a plurality of LED sections each populated with at least one LED of a different one of the different performance categories. Circuitry is coupled to the LED sections and configured to activate and deactivate the LED sections based on LED performance.Type: GrantFiled: October 31, 2013Date of Patent: January 17, 2017Assignee: 3M INNOVATIVE PROPERTIES COMPANYInventors: Martin J. Vos, Michael J. Meis, James F. Poch
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Patent number: 9237609Abstract: A light emitting diode (LED) backlight driving circuit includes a rectifier module, a voltage reduction module coupled to the rectifier module, and an LED lightbar coupled to the voltage reduction module. A city voltage is inputted to the rectifier module, and a pulse-width modulation (PWM) controls the voltage reduction module.Type: GrantFiled: June 27, 2013Date of Patent: January 12, 2016Inventor: Hua Zhang
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Patent number: 9131574Abstract: A dual-purpose lamp includes a power-converting module, a light-emitting module and a control unit. The power-converting module is used for generating a direct current. The light-emitting module is electrically connected with the power-converting module. The light-emitting module includes an illuminative light-emitting body and a scenario light-emitting body, and the illuminative light-emitting body and the scenario light-emitting body are connected with each other in parallel. The control unit is electrically connected with the power-converting module and is used for controlling the power-converting module to adjust the brightness of the illuminative light-emitting body when light is emitted, or to adjust the color, the brightness or the chroma of the scenario light-emitting body when light is emitted.Type: GrantFiled: September 4, 2013Date of Patent: September 8, 2015Assignee: Gunitech Cop.Inventors: Wen-Hsin Chang, Jiun-Hua Yang, Chien-Ju Hung, Enoch Zhao, Po-Kuei Chou
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Patent number: 9058777Abstract: A LED backlight driving circuit is disclosed. The driving circuit includes a boost circuit for converting an input voltage to a needed output voltage and for providing the output voltage to at least one LED strings, a follower circuit connecting to a negative end of the LED string, and a reference voltage module connecting to a reference voltage and the follower circuit. The follower circuit is for detecting a negative end voltage of the LED string and for generating a follower voltage according to the negative end voltage. The follower voltage couples with a reference voltage module. The reference voltage module adjusts the output voltage according to the follower voltage generated by the follower circuit. The output voltage is adjusted in accordance with the voltage drop of the LED string. In addition, a liquid crystal device including the LED backlight driving circuit is also disclosed.Type: GrantFiled: August 1, 2013Date of Patent: June 16, 2015Assignee: Shenzhen China Star Optoelectronics Technology Co., LtdInventor: Dan Cao
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Patent number: 9024532Abstract: The present invention discloses a direct type LED backlight and a liquid crystal display thereof. The direct type LED backlight comprises a power converting circuit, which transfers an alternating current voltage generated from an external liquid crystal display into direct an current voltage and outputs it; multiple LED strings connected in parallel, wherein each LED string comprises a predetermined amount of LED connected in parallel, which receives a direct current from the power converting circuit; wherein, the predetermined amount is limited to that the direct current of the LED string emitting light normally is smaller than or equal to the direct current output from the power converting circuit. According to the direct type LED backlight of the present invention, it can avoid using a boost circuit in order to decrease circuit complexity and save costs.Type: GrantFiled: December 21, 2012Date of Patent: May 5, 2015Assignee: Shenzhen China Star Optoelectronics Technology Co., Ltd.Inventors: Wei Chen, Xinhong Chen, Hua Zhang
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Patent number: 8933635Abstract: Circuits and methods prevent ringing of white LED drivers by adding a high voltage coil switch (CS) circuit, a high voltage edge detector circuit, and a boot strap circuit. The coil switch (CS) circuit to short the coil of a boost converter, when the current in it reaches zero during DCM, comprises a series of 2 identical HV enhancement NMOS with bulk switch system. An Edge Detector circuit senses the fast falling edge of an LX node. A Boost Strap circuit lifts the gate of coil switch circuit above the battery voltage level and turns on the coil switch. A Boost Strap (BS) system lifts the gate of CS above the VBAT level and turns on CS, wherein minimum current is required to minimize impact on efficiency.Type: GrantFiled: April 11, 2012Date of Patent: January 13, 2015Assignee: Dialog Semiconductor GmbHInventor: Pier Cavallini
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Patent number: 8912727Abstract: In a wagering game environment, a light engine can determine a number of lighting devices that constitute a light chain, and a chaining configuration. The light chain is associated with a wagering game machine. The light engine can determine attributes of the constituent lighting devices and compute timing to produce the light effect. In accordance with the determined attributes and computed timing, the light engine generates output lighting device commands for controlling the lighting devices and/or light source elements of the constituent lighting devices. The light engine can dynamically handle a variation in the number or chaining configuration of the lighting devices that constitute the light at runtime. Accordingly, the light engine can generate appropriate output lighting device commands to display the appropriate light effects.Type: GrantFiled: May 17, 2011Date of Patent: December 16, 2014Assignee: WMS Gaming, Inc.Inventors: Edward G. Brunell, Paul J. Radek
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Publication number: 20140346961Abstract: Aspects of the disclosure include a ceramic metal halide lamp in which two arc tubes are arranged electrically in series inside the same outer globe. By arranging the two arc tubes in such a way that light-emitting parts thereof do not overlap, decline in lifespan due to the heat of one arc tube causing the temperature of the other arc tube to increase and lighting failure due to an increase in lamp voltage do not occur. And by setting the distance from an electrode tip at a base side of the first arc tube to an electrode tip at a lamp-top side of the second arc tube to be equal to or less than 3.5 times the average inter-electrode distance of both arc tubes, a preferable distribution of light is implemented.Type: ApplicationFiled: November 2, 2012Publication date: November 27, 2014Applicant: IWASAKI ELECTRIC CO., LTD.Inventors: Masashi Iida, Akiyoshi Maehara, Makoto Ohkahara
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Patent number: 8624511Abstract: Circuits and methods to achieve a most efficient driver for white LEDs are disclosed. Switching Losses associated with the switching activity of a boost converter and mainly depending on clock frequency and total capacitance at the switching nodes and conduction losses associated with the current flowing in the boost converter and mainly depending on the series resistance of the elements in the regulation loop are minimized by using a size programmable NFET power switch with constant current limit, a very low voltage and accurate programmable current source, a programmable reference voltage for the error amplifier, and a PWM generator with programmable clock frequency. A limited number of configuration windows corresponding to a set of programmable values (OTP registers) for specific ranges of the current fed to the WLEDs.Type: GrantFiled: April 6, 2012Date of Patent: January 7, 2014Assignee: Dialog Semiconductor GmbHInventors: Pier Cavallini, Louis DeMarco, Adil Sabihi
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Patent number: 8354797Abstract: In various embodiments, a circuit arrangement for operating a series circuit of a first and a second low-pressure gas-discharge lamp is provided, which may include an input with a first and a second input connection for application of a supply voltage; an output with a first arrangement, which has a first and a second connection pair for connection of the first lamp, and a second arrangement, which has a first and a second connection pair for connection of the second lamp, wherein a first connection of the second pair of the first arrangement is coupled to a first connection of the first pair of the second arrangement; a resonant circuit; and a capacitive voltage divider, which has a first capacitor, which is coupled in parallel with the first arrangement, and a second capacitor, which is coupled in parallel with the second arrangement.Type: GrantFiled: May 19, 2010Date of Patent: January 15, 2013Assignee: OSRAM Gesellschaft mit beschraenkter HaftungInventor: Bernd Rudolph
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Patent number: 8247975Abstract: A backlight assembly for a liquid crystal display device including an LED backlight unit including a plurality of light emitting diode strings coupled to a plurality of current balancing circuits, a backlight driver including a light emitting diode driver that supplies current to the light emitting diode strings, and a connector electrically connecting the plurality of current balancing circuits to the light emitting diode driver.Type: GrantFiled: September 18, 2009Date of Patent: August 21, 2012Assignee: LG Display Co., Ltd.Inventors: Yeon-Taek Yoo, Ki-Ho Lee
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Publication number: 20120074855Abstract: A lamp assembly adapted to operate as one of a total number of lamp assemblies that are connected together in series and connected to a ballast. The lamp assembly comprises an electrodeless, closed-loop, tubular lamp envelope enclosing mercury vapor and a buffer gas, and a transformer core disposed around a portion of the lamp envelope. An input winding is disposed on the transformer core so that it has a particular number of turns, Ninput. An auxiliary winding is disposed on the transformer core so that it has a particular number of turns, Nauxiliary. The auxiliary winding is adapted to connect to the ballast and to couple with the input winding. The ratio of the particular number of turns Ninput to the particular number of turns Nauxiliary is substantially proportional to the total number of lamp assemblies that are adapted to operate in series together.Type: ApplicationFiled: September 29, 2010Publication date: March 29, 2012Applicant: OSRAM SYLVANIA Inc.Inventors: Valery Godyak, Benjamin Alexandrovich, Robert Martin
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Publication number: 20100264837Abstract: A peak detection/digitization circuit includes a plurality of level detect units, each having a comparator and a flip-flop with a clock input responsive to the output of the comparator. For a detection period, each level detect unit configures a data output signal of the flip-flop to a first data state responsive to a start of the detection period. Further, each level detect unit is configured to enable the comparator responsive to the data output signal having the first data state or a second data state, respectively. While the comparator is enabled during the detection period, the level detect unit configures the data output signal of the flip-flop responsive to a comparison of an input signal to a corresponding reference voltage level by the comparator. The data output signals of the flip-flops of the level detect units at the end of the detection period are used to determine a digital value representative of a peak voltage level of the input signal.Type: ApplicationFiled: April 15, 2009Publication date: October 21, 2010Applicant: FREESCALE SEMICONDUCTOR, INC.Inventor: Bin Zhao
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Publication number: 20100195024Abstract: A backlight assembly for a liquid crystal display device including an LED backlight unit including a plurality of light emitting diode strings coupled to a plurality of current balancing circuits, a backlight driver including a light emitting diode driver that supplies current to the light emitting diode strings, and a connector electrically connecting the plurality of current balancing circuits to the light emitting diode driver.Type: ApplicationFiled: September 18, 2009Publication date: August 5, 2010Inventors: Yeon-Taek Yoo, Ki-Ho Lee
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Publication number: 20100141163Abstract: A method of driving a light source includes; driving a plurality of light source strings in response to a plurality of driving signals, when a light source module having the plurality of light source strings connected in parallel with each other receives a driving voltage, detecting a detection voltage from channel input terminals of a multichannel current control part, wherein the multichannel current control part controls a resistance difference of the plurality of light source strings based on the plurality of driving signals, and controlling a level of the driving voltage via adjusting a current applied to a feedback terminal of a driving voltage generating part, wherein the driving voltage generating part generates the driving voltage.Type: ApplicationFiled: May 20, 2009Publication date: June 10, 2010Applicant: Samsung Electronics Co., Ltd.Inventors: Byoung-Dae YE, Gi-Cherl KIM, Byung-Choon YANG, Sang-Chul BYUN
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Publication number: 20090284160Abstract: The invention provides a current balancing circuit for powering a first load with a negative dynamic resistance and a second load with an essentially different negative dynamic resistance, and a transformer with such turns ratio that at least at an operating frequency impedances of the first and second windings complement the resistances of the first and the second loads, respectively, to a common value.Type: ApplicationFiled: July 4, 2007Publication date: November 19, 2009Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.Inventors: Arnold Willem Buij, Alexander Abraham Cornelius Van Der Zande
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Publication number: 20090161381Abstract: A light-emitting-diode (LED) lamp includes a control circuit board having a control circuit and a plurality of insertion holes provided thereon; a plurality of LED units, each of which including a circuit board, a plurality of LEDs mounted on the circuit board, and terminals provided at an end of the circuit board for plugging into the insertion holes on the control circuit board to thereby electrically assemble the LED unit to the control circuit board; and a glass bulb or tube for receiving the assembled control circuit board and LED units to complete the LED lamp that can be mounted to a general lamp holder. When electricity is supplied to the LED lamp, the LEDs are driven by the control circuit to emit light for illumination. The number of LED units and of the LEDs may be adjusted according to desired illuminance.Type: ApplicationFiled: December 21, 2007Publication date: June 25, 2009Inventor: Tsu Yao Wu
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Publication number: 20090085488Abstract: Techniques are described to enhance a backlight design for electronic devices. A circuit is described to provide backlight for a display of an electronic device. In an implementation, the circuit includes a collection of light elements arranged electrically in a series and includes one said light element of the series which is operable both with the collection and independently of the collection. In another implementation, the one said light element is arranged to be in a last position of the series electrically and physically is arranged to correspond to a center portion of the display of the electronic device.Type: ApplicationFiled: October 1, 2007Publication date: April 2, 2009Inventors: Jason D. Bridges, Curtis E. Tabb
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Publication number: 20090033234Abstract: An illuminating lamp for a display device is capable of minimizing a luminance difference between a high-voltage driving side and a low-voltage driving side. The illuminating lamp is arranged behind a display panel via optical sheets and driven in a high-voltage driving method. The illuminating lamp includes discharge lamps connected in series, wherein gas pressures of the discharge lamps at a high-voltage driving side are set to be higher than those of the discharge lamps at a low-voltage driving side.Type: ApplicationFiled: July 18, 2006Publication date: February 5, 2009Applicant: SHARP KABUSHIKI KAISHAInventor: Kenichi Iwamoto
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Publication number: 20080203932Abstract: In one embodiment, an LED system is controlled to have a substantially unity power factor.Type: ApplicationFiled: February 26, 2007Publication date: August 28, 2008Inventor: Alan R. Ball
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Publication number: 20080116817Abstract: A controlling apparatus for controlling a plurality of LED strings and related light modules is disclosed, wherein each of the plurality of LED strings has a first terminal being electrically connected to an operating voltage. The controlling apparatus includes: a plurality of transistors, each having a control terminal, a first terminal, and a second terminal, wherein the first terminal of each transistor is electrically connected to a second terminal of a corresponding string of the plurality of LED strings, and the second terminals of the plurality of transistors are respectively grounded through a plurality of impedance elements; and a transistor controller, electrically connected to the control terminals of the plurality of transistors, for controlling a current of the first terminal of each transistor by adjusting an input signal of the control terminal of the transistor according to a voltage at the second terminal of the transistor.Type: ApplicationFiled: February 7, 2007Publication date: May 22, 2008Inventors: Han-Yu Chao, Bi-Hsien Chen, Shin-Chang Lin
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Patent number: 7148632Abstract: A lighting device that can generate light of variable color and intensity under processor control. Multiple lighting devices of a modular design can be incorporated into a lighting system to illuminate larger areas. A lighting module includes three groups of LEDs each of which generates light of a different color whose intensity can be controlled. A lighting system can be formed by coupling multiple lighting devices to a central controller comprising an operator interface panel and an interface to an external computer. The external computer can be provided with programming tools that allow the creation of lighting programs for controlling the operation of the lighting system. A user can select programs or modify the operation of the lighting system from the operator interface panel provided at the central controller or from the external computer. Procedures are provided for calibrating the color and power output of each lighting device.Type: GrantFiled: January 15, 2003Date of Patent: December 12, 2006Assignee: Luminator Holding, L.P.Inventors: George Berman, Jerry Haden Graves, John Bartholomew Gunter
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Patent number: 6759810Abstract: A transmission structure for animated ornamental lighting comprising an ornamental body, at least one transmission device mounted within said ornamental body, at least one illumination element mounted with the ornamental body 11; and at least one transmission structure connecting the transmission device to the ornamental body, whereby the transmission structure to transmit smooth motions to the ornamental body in order to adjust the moving direction, reducing or eliminating torque, causing high efficiency and extending the life-span of the transmission device.Type: GrantFiled: December 23, 2002Date of Patent: July 6, 2004Inventor: Wen-Hua Pan
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Publication number: 20040119422Abstract: A transmission structure for animated ornamental lighting comprising an ornamental body, at least one transmission device mounted within said ornamental body, at least one illumination element mounted with the ornamental body 11; and at least one transmission structure connecting the transmission device to the ornamental body, whereby the transmission structure to transmit smooth motions to the ornamental body in order to adjust the moving direction, reducing or eliminating torque, causing high efficiency and extending the life-span of the transmission device.Type: ApplicationFiled: December 23, 2002Publication date: June 24, 2004Inventor: Wen-Hua Pan
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Patent number: 6534929Abstract: 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: GrantFiled: July 25, 2001Date of Patent: March 18, 2003Assignee: Koninklijke Philips Electronics N.V.Inventor: Luis Alfonso Padilla
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Patent number: 6459216Abstract: The multiple lamp circuit for minimizing lamp current imbalance comprises at least one transformer comprising primary windings and secondary windings. Multiple lamps are coupled in serial to the secondary windings of the transformer. Multiple separated lamp drive circuits are spliced from the transformer's secondary windings. A current balancing resistance is connected at a common node of the multiple lamps and other terminal of the current balancing resistance is connected to ground. The impedance of the current balancing resistance is relatively high compared to the ones of the multiple lamps to generate a balancing current for one of the multiple lamps, thereby resulting a current that flows through the multiple lamps is approximately equal.Type: GrantFiled: April 16, 2001Date of Patent: October 1, 2002Assignee: Monolithic Power Systems, Inc.Inventor: Ying Hsien Tsai
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Patent number: 6300878Abstract: A constant current regulator that receives an AC input current from a source provides a constant AC current to a load. The regulator includes first, second, third, and fourth electronically controllable switches, a transformer coupled to the switches, and a controller connected to the switches. An output of the first switch is electrically connected to an input of the second switch and one input of the transformer primary winding. An output of the third switch is electrically connected to an input of the fourth switch and another input of the transformer primary winding. The controller provides a trigger signal to each of the switches. The controller adjusts a duty cycle of the trigger signals based on a comparison between an actual current value and a reference current value to provide a constant AC current to the load.Type: GrantFiled: August 23, 2000Date of Patent: October 9, 2001Assignee: Cooper Industries, Inc.Inventors: James H. Galloway, Douglas M. Giardini
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Patent number: 6184628Abstract: A multicolor LED lamp bulb includes a hollow lamp body which has a substantially tapered intermediate portion, a longitudinal portion and a stem portion, a lens sealingly engaged with the longitudinal portion, a plurality of different colored LED bulbs mounted in a predetermined spaced-apart arrangement on a circuit board wafer mounted inside the lamp body in an orientation normal to the central axis of the lamp body, a controller circuit electrically connected wherein predetermined arrays of the plurality of different colored LED bulbs activate at predetermined sequences for predetermined time intervals, and a screw-type base affixed to the stem portion and adapted to engage a conventional lamp socket. The controller circuit includes a rectifier circuit for converting a 12 volt-ac source applied to the LED lamp bulb to a 12 volt-dc circuit for supplying electrical power to the arrays of the plurality of different colored LED bulbs.Type: GrantFiled: November 30, 1999Date of Patent: February 6, 2001Inventor: Douglas Ruthenberg
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Patent number: 6127787Abstract: A series of arc lamps is ignited sequentially while maintaining a specified voltage on one side of each lamp with dielectric insulation on the high voltage side.Type: GrantFiled: January 21, 1999Date of Patent: October 3, 2000Assignee: Northrop Grumman CorporationInventors: Maurice LeRoy Strong, III, James Robert Guzak, Michael A. Mast
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Patent number: 5955845Abstract: A high pressure sodium discharge lamp includes first and second discharge devices electrically connected in series within an outer envelope. The discharge devices each include a discharge vessel enclosing a discharge space with an ionizable fill and first and second discharge electrode assemblies. The first discharge electrode assemblies of the discharge devices are connected so as to receive a starting pulse and lamp operating voltage. Each discharge vessel includes a first wall portion spaced from the first discharge electrode assembly and defining an ionizable gap therebetween. A conductive element bridges the discharge devices at the first wall portions and capacitively couples the first discharge electrode assemblies to induce ionization in one of the discharge devices in the ionizable gap between the first wall portion and first discharge electrode assembly.Type: GrantFiled: April 7, 1997Date of Patent: September 21, 1999Assignee: Philips Electronics North America CorporationInventor: Mark W. Fellows
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Patent number: 5898274Abstract: A control and starting device for fluorescent tubes powered by an electrical circuit via two electrodes, the device includes a loaded polymer part provided adjacent to the tube and used as a ballast providing starting and proper operation control functions for the tube.Type: GrantFiled: August 22, 1997Date of Patent: April 27, 1999Inventor: Alexandre Ferrero
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Patent number: 5561346Abstract: An improved LED lamp construction is disclosed having a plurality of LEDs electrically interconnected and mounted upon opposed rounded surfaces formed at one end of the lamp body. The opposed rounded surfaces comprise a substantially semi-spherical lamp head concavely open at the upper end of the lamp and a cover similar in curvature to the head and fixed across the open end thereof in a convex position relative thereto. The LEDs are arranged in multiple series groups connected in parallel and disposed circumferentially along the rounded surfaces so as to project radially therefrom in substantially all directions. The LEDs are electrically and mechanically connected to a conventional screw-type base at the opposite end of the lamp body through an intermediate stem. Depending upon the nature and level of the power source being provided to the screw-type base, the stem may-house a conventional regulator circuit intended to convert an applied level of A.C. voltage to a relatively low D.C.Type: GrantFiled: August 10, 1994Date of Patent: October 1, 1996Inventor: David J. Byrne
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Patent number: 5345164Abstract: An improved power factor DC power supply in accordance with the present invention (100 or 200) employs a power factor correcting network ( 120), a full-wave rectifier means (122), a pair of filter capacitors (124 and 126 ) , and three current steering diodes (128, 130 and 132). The power factor correcting network ( 120) includes both an inductor means (136 and 240) and a capacitor (138), the combination configured to improve the power factor DC power supply (100 or 200) presents to the AC power-line (102) by reducing the level of harmonic currents the DC power supply generates on the AC power-line. The filter capacitors (124 and 126) are configured with the current steering diodes (128, 130 and 132) such that the filter capacitors are charged in series and discharged in parallel.Type: GrantFiled: April 27, 1993Date of Patent: September 6, 1994Assignee: Metcal, Inc.Inventor: Ronald A. Lesea
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Patent number: 5220247Abstract: For driving gas discharge lamps (102, 104) having heatable filaments (102A, 102B, 104A, 104B), a circuit (100) has an inverter (132, 134) and a series-resonant LC oscillator (150, 158, 170) forming a self-oscillating inverter. The oscillator output provides filament-heating current through the filaments in series, and drives arc current serially through the lamps. A feedback transformer (174) with a winding (172) connected serially in the filament-heating current path controls the operation of the inverter. A voltage clamp (180, 182) limits the voltage applied to the lamps. The circuit does not require an output-coupling transformer to couple the output of the self-oscillating inverter to lamps, thus avoiding the added cost that the use of such a transformer would bring, while providing efficient, substantially fixed frequency operation of a wide variety of lamp loads, together with the ability to address a number of lamp fault modes. Alternatively, the lamps may be driven in parallel.Type: GrantFiled: March 31, 1992Date of Patent: June 15, 1993Inventor: Mihail S. Moisin
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Patent number: 5214355Abstract: A half-bridge inverter is powered from a constant-magnitude DC supply voltage and provides at the inverter's output a first AC output voltage that is describable as a modified squarewave voltage. This first AC voltage is applied across a series-combination of a tank inductor and a tank capacitor, the junction between which is clamped to the DC supply voltage. As a result, a second AC voltage gets established across the tank capacitor; which second AC voltage is also describable as a modified squarewave voltage. However, the phasing of the second AC voltage is delayed by roughly 90.degree. degrees with respect to the first AC voltage; which results in the voltage across the tank inductor being of approximately sinusoidal waveform.Type: GrantFiled: December 13, 1991Date of Patent: May 25, 1993Inventor: Ole K. Nilssen
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Patent number: 5173643Abstract: A dimming control circuit provides power from an ac source to a compact fluorescent lamp. The circuit generally includes a resonant half-bridge inverter driven by a pulse-duration-modulated voltage, for providing a high-frequency ac voltage between the lamp electrodes. A combination inductive and capacitive snubber circuit reduces switching losses in the inverter and increases the efficiency of the dimming circuit. A low-voltage transformer connected across the resonant portion of the inverter provides voltage to heat the lamp filaments. The filament voltage is substantially constant over a range of pulse-durations providing a dimming range from about 100% to 1% of full light output. A power supply circuit having a power factor of about 0.95 provides both high-voltage and low-voltage dc power to the dimming circuit with minimal losses. A shutdown circuit is provided to shut off power to the lamp if the dimming circuit is miswired or a ground fault occurs.Type: GrantFiled: June 25, 1990Date of Patent: December 22, 1992Assignee: Lutron Electronics Co., Inc.Inventors: Charles R. Sullivan, Scott R. Jurell, David G. Luchaco
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Patent number: 5150016Abstract: An LED light source with readily adjustable luminous energy including LED chips is disclosed. A resistor device is provided in order to control the current flowing in LED chips for reducing variance of luminous energy. The resistor device includes a plurality of resistors arranged in parallel, and a plurality of fuses connected in series with the respective resistors. In order to obtain the desired resistance value of the resistor device, the fuses connected to unnecessary resistors in series are burnt out by applying an excess current to the fuses thereby omitting a bonding process of the resistors or the like.Type: GrantFiled: September 20, 1991Date of Patent: September 22, 1992Assignee: Rohm Co., Ltd.Inventors: Kensuke Sawase, Hiromi Ogata
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Patent number: 5028845Abstract: A 1000 watt arc discharge arc tube assembly comprises two series connected side-by-side arc discharge tubes whose combined break down voltage in sufficient for a standard 2-5 kv starting pulse to simultaneously start both arc tubes without additional structure. A standard ballast, starter and fixture can be used with the arc tube assembly whose overall length is less than 300 millimeters. The lamps are spaced sufficiently apart to preclude detrimental heat transfer effects on one another and sufficiently close to act as a single source of light in standard fixtures normally employing lamps having a single discharge tube.Type: GrantFiled: December 21, 1989Date of Patent: July 2, 1991Assignee: North American Philips CorporationInventors: Jagannathan Ravi, Kenneth E. Pearson, Jay J. Palmer, Ronald C. Marburger, John P. Dunn, Kent L. Collins, Dale E. Brabham, Kathleen P. Bernard, Herbert Bayne, John Alderman, Kris Aelterman
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Patent number: 4906899Abstract: One of the low voltage output windings of a standard ballast circuit is coupled to one filament of a pair of series connected fluorescent lamps by an external current controller. The current controller acts to restrictively reduce the operating voltage applied to the filaments of one of the lamps to which it is connected, below firing value during start up operation and thereafter maintain a lower running voltage for the lamps without adversely affecting restart.Type: GrantFiled: October 16, 1986Date of Patent: March 6, 1990Inventors: Rodney C. Hope, Gale M. Hope, executrix
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Patent number: 4862035Abstract: 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: GrantFiled: February 23, 1989Date of Patent: August 29, 1989Assignee: GTE Sylvania LimitedInventors: John Cunliffe, Brian J. Grabham
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Patent number: 4754201Abstract: A series ballast circuit for operating a gas discharge tube from a constant current alternating voltage source having a fundamental frequency is disclosed. The primary feature of the ballast circuit comprises a ballast transformer having a magnetic core and at least a primary coil and at least a secondary coil. The ballast transformer has parameters that are selected in accordance with the operational conditions, that is, the extinguished and non-extinguished states of the gas discharge lamp. The primary coil and the area of the core have parameters selected in accordance with the extinguished state of the gas discharge tube. The primary and secondary coils have a selected turn ratio so as to produce a current level sufficient to maintain the ionization condition of the gas discharge tube in its non-extinguished state.Type: GrantFiled: February 26, 1987Date of Patent: June 28, 1988Assignee: General Electric CompanyInventors: David W. Knoble, Joseph W. Sanders
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Patent number: 4751432Abstract: The invention relates to a high-pressure discharge lamp comprising an outer bulb accommodating a first and a second discharge vessel, these discharge vessels being connected electrically in series. According to the invention, the second discharge vessel is electrically shunted by a bimetal switch which is closed at a temperature of at least 300 K. The lamp thus starts in two steps, which facilitates the starting process and renders it more reliable.Type: GrantFiled: March 20, 1986Date of Patent: June 14, 1988Assignee: U.S. Philips CorporationInventor: Marc G. A. M. Van Delm
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Patent number: 4525649Abstract: 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: GrantFiled: July 23, 1984Date of Patent: June 25, 1985Assignee: GTE Products CorporationInventors: William C. Knoll, David L. Bay
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Patent number: 4513225Abstract: A pair of 48-inch long preheat fluorescent lamps, each one and a half inches diameter and consuming less than 10 watts power per foot of length, are connected in series with each other and with a ballast, for operation from 50 or 60 hertz a-c line voltage in the range of 200 to 300 volts. A starter switch is connected in parallel across each lamp. The lamp designs are specified such that they will start and operate in the circuit from the a-c line voltage.Type: GrantFiled: December 13, 1982Date of Patent: April 23, 1985Assignee: General Electric CompanyInventors: Alfred E. Lemmers, Edward E. Hammer
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Patent number: 4467247Abstract: A high frequency fluorescent lamp circuit for operating two or more fluorescent lamps connected in electrical series. A capacitor is connected between one end of the series-connected lamps and electrical ground and/or an electrically conductive fixture for holding the lamps. This causes the lamps to start more reliably and at a lower starting voltage.Type: GrantFiled: October 30, 1981Date of Patent: August 21, 1984Assignee: General Electric CompanyInventor: Edward E. Hammer
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Patent number: 4441055Abstract: A lighting system comprises gaseous discharge lamps (8) connected to a source (1) of regulated alternating current through current transformers (5). The primary windings (6) of the current transformers (5) are connected in series to the source (1). The gaseous discharge lamps (8) are connected to the secondary windings (7) of the transformers (5).The lighting system is designed for lighting industrial buildings, streets, highways, stadiums, mines, etc.Type: GrantFiled: February 4, 1982Date of Patent: April 3, 1984Assignee: Kaunassky Politekhnichesky InstitutInventors: Povilas I. Balchjunas, Ionas J. Martinaitis, Sauljus A. Tulaba, Alfredas B. Pilkauskas
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Patent number: 4413209Abstract: 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: GrantFiled: October 5, 1981Date of Patent: November 1, 1983Assignee: GTE Products CorporationInventor: William J. Roche
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Patent number: RE39856Abstract: A multicolor LED lamp bulb includes a hollow lamp body which has a substantially tapered intermediate portion, a longitudinal portion and a stem portion, a lens sealingly engaged with the longitudinal portion, a plurality of different colored LED bulbs mounted in a predetermined spaced-apart arrangement on a circuit board wafer mounted inside the lamp body in an orientation normal to the central axis of the lamp body, a controller circuit electrically connected wherein predetermined arrays of the plurality of different colored LED bulbs activate at predetermined sequences for predetermined time intervals, and a screw-type base affixed to the stem portion and adapted to engage a conventional lamp socket. The controller circuit includes a rectifier circuit for converting a 12 volt-ac source applied to the LED lamp bulb to a 12 volt-dc circuit for supplying electrical power to the arrays of the plurality of different colored LED bulbs.Type: GrantFiled: May 1, 2002Date of Patent: September 25, 2007Assignee: Zodiac Pool Care, Inc.Inventor: Douglas Ruthenberg