Plural Transformers In The Supply Circuit Patents (Class 315/220)
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Patent number: 11356024Abstract: An ignition exciter high frequency switching converter, ignition assembly, and method of operating the same, include a high frequency switching converter operably by way of a control circuit having a timing mechanism, to operate the high frequency switching converter in discontinuous conduction mode to charge a tank capacitor for igniting an igniter.Type: GrantFiled: December 6, 2018Date of Patent: June 7, 2022Assignee: Unison Industries, LLCInventors: Jay Joseph Carpenter, Michael Joseph Cochran, Robert Wake Cook
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Patent number: 10591453Abstract: A test bench for a control system for controlling a wideband lambda sensor, which is configured to calculate an actual value, which represents an oxygen concentration in a measuring gap of a wideband lambda sensor or an indicator value from which the oxygen concentration can be derived, with consideration of a current generated by a pump voltage in an electrical circuit. In order to simulate the electrical response of a pump cell of the wideband lambda sensor, a first diode and a second diode are connected in parallel in the electrical circuit such that a current flows through the first diode at a first polarity of the pump voltage and a current flows through the second diode at a second polarity of the pump voltage.Type: GrantFiled: December 14, 2017Date of Patent: March 17, 2020Assignee: dSPACE digital signal processing and control engineering GmbHInventors: Dirk Hasse, Michael Wartig
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Patent number: 9874194Abstract: A method is described for operating an ignition system for an internal combustion engine, including a primary voltage generator and a bypass, in particular, a boost converter for maintaining a spark generated with the aid of the primary voltage generator, the method includes an ascertainment of a modified energy requirement for an ignition spark, which is to be maintained with the aid of the bypass and a modification of the working mode of the bypass in response thereto.Type: GrantFiled: October 16, 2014Date of Patent: January 23, 2018Assignee: ROBERT BOSCH GMBHInventors: Tim Skowronek, Thomas Pawlak, Wolfgang Sinz
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Patent number: 9771919Abstract: An ignition system for use with an engine is disclosed. The ignition system may have a pre-combustion chamber in fluid communication with a combustion chamber associated with the engine, and a fuel injection device configured to inject a fuel mixture directly into the pre-combustion chamber. The ignition system may also have a spark plug configured to ignite the fuel mixture within the pre-combustion chamber, and a controller in communication with a primary energy supply and an enhanced energy supply. The controller may be configured to direct a first current from the enhanced energy supply to the spark plug after the fuel mixture is injected into the pre-combustion chamber. The controller may also be configured to direct a second current from the primary energy supply to the spark plug just after the first current is being directed to the spark plug. The second current may have a frequency that is lower than the first current.Type: GrantFiled: July 10, 2015Date of Patent: September 26, 2017Assignee: Caterpillar Inc.Inventors: Arnold Myoungjin Kim, James M. Schultz
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Publication number: 20140360476Abstract: A dual coil ignition system is provided. The dual coil ignition system includes a first inductive ignition coil including a first primary winding and a first secondary winding, and a second inductive ignition coil including a second primary winding and a second secondary winding, the second secondary winding connected in series to the first secondary winding. The dual coil ignition system further includes a diode network including a first diode and a second diode connected between the first secondary winding and the second secondary winding.Type: ApplicationFiled: June 6, 2013Publication date: December 11, 2014Inventors: Garlan J. Huberts, Qiuping Qu, Michael Damian Czekala
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Patent number: 8860317Abstract: There is provided a multi power supply apparatus for driving light emitting diodes that is synchronized with a frequency of one output power of multi output power to control a switching of the multi output power and simplifies power conversion in supplying power for driving light emitting diodes.Type: GrantFiled: January 31, 2011Date of Patent: October 14, 2014Assignee: Samsung Electro-Mechanics Co., Ltd.Inventors: Sang Gab Park, Heung Gyoon Choi, Nam Jin Park, Tae Shik Kim, Tae Hyung Kang
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Patent number: 8829800Abstract: The present disclosure relates to a lighting component with multiple DC-DC converters. Each of the DC-DC converters is used to independently drive a corresponding string of LEDs. In general, rectifier circuitry receives an AC power signal and generates a rectified signal, which is provided to first and second converter circuitries. The first converter circuitry converts the rectified signal into a first drive voltage for a first string of LEDs and provides a first drive current for the first string of LEDs based on a first drive current control signal. Similarly, the second converter circuitry converts the rectified signal into a second drive voltage for a second string of LEDs and provides a second drive current for the second string of LEDs based on a second drive current control signal.Type: GrantFiled: September 7, 2012Date of Patent: September 9, 2014Assignee: Cree, Inc.Inventor: Michael J. Harris
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Patent number: 8754581Abstract: An arrangement wherein a plurality of LED strings are driven with a balanced drive signal, i.e. a drive signal wherein the positive side and negative side are of equal energy over time, is provided. In a preferred embodiment, the drive signal is balanced responsive to a capacitor provided between a switching network and a driving transformer. Balance of current between various LED strings is provided by a balancing transformer.Type: GrantFiled: December 18, 2012Date of Patent: June 17, 2014Assignee: Microsemi CorporationInventors: Xiaoping Jin, Ting-Hui Lin
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Patent number: 8610660Abstract: An LED backlight driving circuit including a boost circuit and a transformer current balance circuit is provided. The boost circuit provides a total current for n LED strings, and the transformer current balance circuit is coupled to the LED strings and includes n?1 transformers. A first LED current-balance-circuit (CBC) includes a switching-transistor connected to a secondary-winding of a first-transformer, and an nth LED CBC includes a switching-transistor connected to a primary-winding of an (n?1)th transformer. An ith (1<i<n, n>2) LED CBC includes a switching-transistor sequentially connected to a primary-winding of an (i?1)th transformer and a secondary-winding of an ith transformer. The passive-transformers are applied in the LED driving circuit to implement current balance/equalization, such that the LED backlight driving circuit is suitable for a system with any odd or even number (greater than 1) of the LED strings connected in parallel, so as to reduce the cost of the system.Type: GrantFiled: July 15, 2011Date of Patent: December 17, 2013Assignees: FSP-Powerland Technology Inc., FSP Technology Inc.Inventors: Ming Xu, Shaobin Zhang
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Patent number: 8598807Abstract: A multi-channel circuit having respective channels powered through transformers having primary windings connected in series allows substantially equal constant currents to be provided through all channels by cross-regulation while only a single channel need be monitored and controlled. The variation in current between channels is generally small and largely insensitive to imbalances between voltages on loads due, for example, to different numbers of LEDs in series connected strings in illumination devices and can be further reduced by inverse coupling between inductors in respective channels. Efficiency is improved through reduction in the number of stages of the constant current source since the respective channels provided both DC-to-DC conversion and constant current regulation.Type: GrantFiled: May 24, 2011Date of Patent: December 3, 2013Assignee: Virginia Tech Intellectual Properties, Inc.Inventors: Shu Ji, Haoran Wu, Fred C. Lee
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Patent number: 8598795Abstract: An arrangement wherein a plurality of LED strings are driven with a balanced drive signal, i.e. a drive signal wherein the positive side and negative side are of equal energy over time, is provided. In a preferred embodiment, the drive signal is balanced responsive to a capacitor provided between a switching network and a driving transformer. Balance of current between various LED strings is provided by a balancing transformer.Type: GrantFiled: May 2, 2012Date of Patent: December 3, 2013Assignee: Microsemi CorporationInventor: Xiaoping Jin
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Patent number: 8541952Abstract: A phase cut angle converter with range detection for a phase cut dimmer constituted of: a phase cut angle detector arranged to detect the phase cut angle presented by the phase cut dimmer blocking a portion of an alternating current mains power sine wave from reaching a power converter, and output a signal whose value is responsive to the detected phase cut angle; a storage functionality constituted of a memory in communication with the phase cut angle detector, the storage functionality arranged to detect each of a minimum value and a maximum value for the detected phase cut angle of the phase cut angle detector and store the minimum value and the maximum value on the memory; and a signal adjustment functionality arranged to convert the detected phase cut angle to a dimming signal responsive to the stored minimum value and the maximum value for the detected phase cut angle.Type: GrantFiled: January 19, 2012Date of Patent: September 24, 2013Assignee: Microsemi Corp.—Analog Mixed Signal Group Ltd.Inventor: Yair Darshan
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Publication number: 20130241429Abstract: A method for actuating a spark plug, in which the spark plug is assigned a first ignition coil and second ignition coil.Type: ApplicationFiled: March 12, 2013Publication date: September 19, 2013Inventors: Ganghua Ruan, Dejan Kienzle
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Patent number: 8436547Abstract: A multi-lamp driving system includes a filter circuit, a switch circuit, a pulse width modulation (PWM) controller, a protection circuit, transformers, and an abnormity detection circuit. Primary windings of the transformers are connected to the switch circuit in parallel, and high voltage terminals of secondary windings of the transformers are connected to lamps respectively. The abnormity detection circuit converts current signals flowing through the lamps into voltage signals, and retrieves highest and lowest voltage signals corresponding to highest and lowest current signal respectively. Then the abnormity detection circuit determines if a difference between the highest voltage signal and the lowest voltage signal exceeds a predetermined value, and generates a trigger signal if the difference between the highest and lowest voltage signals exceeds the predetermined value.Type: GrantFiled: April 29, 2011Date of Patent: May 7, 2013Assignee: Ampower Technology Co., Ltd.Inventors: Chi-Hsien Ho, Chin-Po Cheng
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Patent number: 8373304Abstract: A current-sharing supply circuit includes a current providing circuit, a first output rectifier circuit, a second output rectifier circuit, a first current-sharing transformer, a second current-sharing transformer, a first current-sharing circuit and a second current-sharing circuit. By adjusting the equivalent impedance values of the first current-sharing circuit, the second current-sharing circuit, the primary winding coil of the first current-sharing transformer and the primary winding coil of the second current-sharing transformer, the first output current and the second output current are substantially identical.Type: GrantFiled: July 6, 2010Date of Patent: February 12, 2013Assignee: Delta Electronics, Inc.Inventors: Shih-Hsien Chang, Po-Nien Ko
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Patent number: 8294376Abstract: Embodiments of the present invention provide for the rapid reignition of a high intensity discharge lamp. In one embodiment of the invention, an apparatus for a fast reigntion of a high intensity discharge lamp is disclosed. The apparatus is comprised of a ballast operatively coupled to the lamp that is configured to receive power from a power supply. The apparatus is also comprised of a timer circuit that enters a timing phase and produces a quantum of timing information when the lamp ceases receiving power from the power supply. This timer circuit does not require external power during the timing phase. The apparatus is additionally comprised of a control circuit that receives the timing information and permits the ballast to reignite the lamp based on the information.Type: GrantFiled: May 30, 2010Date of Patent: October 23, 2012Assignee: Lumetric Lighting, Inc.Inventors: Gregory Davis, Moshe Shloush
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Patent number: 8283871Abstract: A method of driving a light source apparatus includes inverting a direct current voltage to generate a first alternating current voltage, transforming the first alternating current voltage into a second alternating current voltage having a voltage level that is greater than a voltage level of the first alternating current voltage, compensating a driving alternating current voltage based on the second alternating current voltage to generate a compensated driving alternating current voltage such that a substantially equal current flows through each light emitting string of a plurality of light emitting string included in the light source apparatus, and rectifying the compensated driving alternating current voltage to apply a driving voltage to the light emitting strings.Type: GrantFiled: April 21, 2010Date of Patent: October 9, 2012Assignee: Samsung Electronics Co., Ltd.Inventors: Won-SiK Oh, Moon-Shik Kang, Young-Sup Kwon, Hwan-Woong Lee, Min-Soo Choi, Byeong-Hwan Kim
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Publication number: 20120242244Abstract: In an inverter device which includes a plurality of transformers, in which output voltages of the transformers are used as input voltages that are input to a plurality of discharge tube lamps and which is used to drive the discharge tube lamps, at least one of drive frequencies of the transformers is different from the other drive frequencies.Type: ApplicationFiled: October 4, 2010Publication date: September 27, 2012Applicant: SHARP KABUSHIKI KAISHAInventor: Shinji Matsumoto
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Patent number: 8138683Abstract: Disclosed is a method for controlling a series circuit current of a lighting installation at an airfield or the like, in which case the series circuit current which flows through transformers which are arranged on the secondary side of an output transformer and are connected in series, in order to supply lighting appliances is controlled by means of a thyristor module, which is arranged on the primary side of the output transformer and has a variable trigger angle, in which case, when a control unit is in a constant-current mode, the trigger angle is set in such a manner that a series circuit current which corresponds essentially to a rated output current flows. The invention also relates to a constant-current regulator for carrying out the method.Type: GrantFiled: October 9, 2006Date of Patent: March 20, 2012Assignee: ADB BVBAInventors: Pierre Catoul, Daniel Tessens, Jean-Claude Vandevoorde
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Patent number: 8120262Abstract: A circuit is used for driving a plurality of lamps, such as Cold Cathode Fluorescent Lamps (CCFLs). The lamps are paired to form a plurality of pairs of lamps. Each of the plurality of pairs of lamps has two lamps which are coupled to each other in series. The plurality of pairs of lamps are coupled in parallel. The circuit comprises a switch circuit, a transformer, and a plurality of balance chokes. The switch circuit is used for converting a DC electric power into a first AC electric power. The transformer has a primary winding and a secondary winding. The primary winding of the transformer is coupled to the switch circuit for receiving said first AC electric power and energizing the secondary winding to generate a second AC electric power from the secondary winding to energize the plurality of lamps. Each of the balance chokes includes a first winding and a second winding.Type: GrantFiled: November 8, 2007Date of Patent: February 21, 2012Assignee: O2Micro IncInventors: Steve Lee, John Wang, Xuefang Yang
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Patent number: 8120278Abstract: The present invention provides an LED driving circuit including: an inverter unit for switching an input power source; a plurality of transformers including a plurality of primary windings connected to the inverter unit and connected to each other in series and a plurality of secondary windings each of which is coupled with each of the primary windings; a plurality of rectification units each of which is connected to each of the secondary windings; and a plurality of LEDs each of which is connected to each of the rectification units.Type: GrantFiled: May 28, 2009Date of Patent: February 21, 2012Assignee: Samsung Electro-Mechanics Co., Ltd.Inventors: Heung Gyoon Choi, Sung Soo Hong, Sang Kyoo Han, Chung Wook Roh, Sang Ho Cho, Sang Hyun Lee, Sung Ho Kim, Tae Hyung Kang, Jae Sun Won
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Patent number: 8084954Abstract: The present invention relates to a lamp driving circuit capable of achieving miniaturization by using a safe insulation type multi-output transformer.Type: GrantFiled: April 13, 2009Date of Patent: December 27, 2011Assignee: Samsung Electro-Mechanics Co., Ltd.Inventors: Sung Ho Kim, Heung Gyoon Choi
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Patent number: 8058809Abstract: A circuit comprises a power tank, a pair of transformers and multiple loads. The power tank converts a DC input voltage to an AC voltage. The pair of transformers comprise a pair of primary windings and a pair of secondary windings and transform the intermediate AC voltage to an output AC voltage. The pair of primary windings are coupled to the power tank for receiving the intermediate AC voltage, and the pair of secondary windings provide the output AC voltage. The loads are coupled to the pair of secondary windings for receiving the output AC voltage. The pair of secondary windings are serially coupled to each other through the series-coupled loads to achieve current balance among the loads.Type: GrantFiled: July 1, 2008Date of Patent: November 15, 2011Assignee: O2Micro, Inc.Inventors: Youling Li, Sheng Tai Lee, Yingpeng Hu
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Patent number: 7902765Abstract: The invention provides a circuit system for driving a high-intensity discharging lamp, comprising a boosting circuit, an ignition coil circuit and a clamp circuit. The boosting circuit includes a first transformer and a first switch, in which the primary of the first transformer receives an input power, the secondary of the first transformer produces a boosting DC voltage, and the first switch is connected to the first transformer to control turning-on and turning-off of the first transformer. The ignition coil circuit is connected to the boosting circuit for converting the boosting DC voltage into a switching AC voltage to drive a load. The clamp circuit is connected to the boosting circuit and the ignition coil circuit for directing energy, reflected from the secondary of the first transformer to the primary of the first transformer, to the secondary of the first transformer as the first switch is turned off.Type: GrantFiled: May 9, 2008Date of Patent: March 8, 2011Assignees: Tatung University, Tatung CompanyInventors: Hung-Ching Lu, Te-Lung Shih
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Patent number: 7891820Abstract: The invention discloses a method for igniting a lamp of a projector. The method includes steps of: (a) sensing a first temperature difference in response to power-off of the projector; (b) in response to power-on of the projector, detecting an aftercooling time and judging whether it is smaller than a predetermined cooling time, if YES, perform step (c); otherwise, perform step (g); (c) sensing a second temperature difference; (d) judging whether a ratio of the second temperature difference to the first temperature difference is larger than a threshold, if YES, perform step (e); otherwise, perform step (g); (e) calculating a re-cooling time; (f) controlling a fan to operate for the re-cooling time to cool the lamp down; and (g) igniting the lamp.Type: GrantFiled: October 19, 2007Date of Patent: February 22, 2011Assignee: BenQ CorporationInventors: Chi-Hung Hsiao, Chun-Ming Shen, Ke-Chun Chuang
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Patent number: 7872425Abstract: A light source driving device includes a power stage circuit, a first transformer circuit, a second transformer circuit, and a feedback control circuit. The power stage circuit converts a received signal to an alternating current (AC) signal, which includes a synchronizing switching bridge arm, a first bridge arm, and a second bridge arm. The synchronizing switching bridge arm has a Soft-Switching function, and forms a first full-bridge circuit with the first bridge arm and forms a second full-bridge circuit with the second bridge arm. The first transformer circuit is connected to the first full-bridge circuit, for converting the AC signal. The second transformer circuit is connected to the second full-bridge circuit, for converting the AC signal. The feedback control circuit is connected between the light source module and the power stage circuit, for controlling output of the power stage circuit.Type: GrantFiled: December 21, 2007Date of Patent: January 18, 2011Assignee: Hon Hai Precision Industry Co., Ltd.Inventors: Chih-Chan Ger, Wen-Lin Chen
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Patent number: 7859195Abstract: Provided are an apparatus for controlling a lamp driving, and a light unit. The apparatus comprises a trans-portion, a plurality of lamps, a first cable, and a current attenuator. The trans-portion outputs a first AC power and a second AC power. The plurality of lamps are lighted-on by the first and second AC powers. The first cable and a second cable transfer an output power from the transformer to both ends of the lamps. The current attenuator removes a deviation in currents input to both ends of the lamps.Type: GrantFiled: July 23, 2008Date of Patent: December 28, 2010Assignee: LG Innotek Co., Ltd.Inventor: Chang Sun Yun
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Patent number: 7852018Abstract: A method of driving a lamp of a liquid crystal display device includes generating a control signal; generating a first drive signal using the control signal; generating a second drive signal by shifting a voltage level of the first drive signal; selectively outputting one of a high potential supply voltage and a low potential supply voltage in response to the second drive signal; transforming the selectively outputted voltage; and supplying the transformed voltage to a lamp.Type: GrantFiled: August 25, 2008Date of Patent: December 14, 2010Assignee: LG Display Co., Ltd.Inventors: In Ho Ahn, Pu Jin Kim, Jae Hun Song, Chang Ho Lee
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Publication number: 20100283400Abstract: Disclosed is a method for controlling a series circuit current of a lighting installation at an airfield or the like, in which case the series circuit current which flows through transformers which are arranged on the secondary side of an output transformer and are connected in series, in order to supply lighting appliances is controlled by means of a thyristor module, which is arranged on the primary side of the output transformer and has a variable trigger angle, in which case, when a control unit is in a constant-current mode, the trigger angle is set in such a manner that a series circuit current which corresponds essentially to a rated output current flows. The invention also relates to a constant-current regulator for carrying out the method.Type: ApplicationFiled: October 9, 2006Publication date: November 11, 2010Inventors: Pierre Catoul, Daniel Tessens, Jean-Claude Vandervoorde
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Publication number: 20090224682Abstract: A discharge lamp lighting circuit for supplying an AC power to a discharge lamp includes first and second converters for receiving a DC voltage and stepping up the voltage. A controlling circuit drives the first and second converters CON1, CON2 alternately at a first frequency and stops an operation of a side that is not driven such that the AC power is supplied to the discharge lamp to execute a lighting operation.Type: ApplicationFiled: March 5, 2009Publication date: September 10, 2009Applicant: Koito Manufacturing Co., Ltd.Inventors: Takao Muramatsu, Tomoyuki Ichikawa, Shinji Ohta
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Publication number: 20090184651Abstract: The invention provides a circuit system for driving a high-intensity discharging lamp, comprising a boosting circuit, an ignition coil circuit and a clamp circuit. The boosting circuit includes a first transformer and a first switch, in which the primary of the first transformer receives an input power, the secondary of the first transformer produces a boosting DC voltage, and the first switch is connected to the first transformer to control turning-on and turning-off of the first transformer. The ignition coil circuit is connected to the boosting circuit for converting the boosting DC voltage into a switching AC voltage to drive a load. The clamp circuit is connected to the boosting circuit and the ignition coil circuit for directing energy, reflected from the secondary of the first transformer to the primary of the first transformer, to the secondary of the first transformer as the first switch is turned off.Type: ApplicationFiled: May 9, 2008Publication date: July 23, 2009Applicants: Tatung University, Tatung CompanyInventors: Hung-Ching Lu, Te-Lung Shih
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Patent number: 7560872Abstract: A phase-modulated, double-ended, half-bridge topology-based DC-AC converter supplies AC power to a load, such as a cold cathode fluorescent lamp used to back-light a liquid crystal display. First and second converter stages generate respective first and second sinusoidal voltages having the same frequency and amplitude, but having a controlled phase difference therebetween. By employing a voltage controlled delay circuit to control the phase difference between the first and second sinusoidal voltages, the converter is able to vary the amplitude of the composite voltage differential produced across the opposite ends of the load.Type: GrantFiled: July 6, 2005Date of Patent: July 14, 2009Assignee: Intersil Americas Inc.Inventors: Robert L. Lyle, Jr., Steven P. Laur, Zaki Moussaoui
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Patent number: 7439686Abstract: A discharge-lamp lighting apparatus includes first and second cold cathode fluorescent lamps (CCFLs) and first and second transformers. The first transformer has a primary winding and a secondary winding. The primary winding receives an AC voltage generated by turning on/off a first switching element pair that is connected to a first DC power source. The second transformer has a primary winding, a first secondary winding, and a second secondary winding. The primary winding of the second transformer receives an AC voltage generated by turning on/off a second switching element pair that is connected to a second DC power source. Polarities of the first and second secondary windings of the second transformer are set so that a voltages of each of the first and second secondary windings becomes additive to a voltage of the secondary winding of the first transformer.Type: GrantFiled: May 15, 2007Date of Patent: October 21, 2008Assignee: Sanken Electric Co., Ltd.Inventor: Hiroshi Usui
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Publication number: 20080252226Abstract: A light source driving device includes a power stage circuit, a first transformer circuit, a second transformer circuit, and a feedback control circuit. The power stage circuit converts a received signal to an alternating current (AC) signal, which includes a synchronizing switching bridge arm, a first bridge arm, and a second bridge arm. The synchronizing switching bridge arm has a Soft-Switching function, and forms a first full-bridge circuit with the first bridge arm and forms a second full-bridge circuit with the second bridge arm. The first transformer circuit is connected to the first full-bridge circuit, for converting the AC signal. The second transformer circuit is connected to the second full-bridge circuit, for converting the AC signal. The feedback control circuit is connected between the light source module and the power stage circuit, for controlling output of the power stage circuit.Type: ApplicationFiled: December 21, 2007Publication date: October 16, 2008Applicant: HON HAI PRECISION INDUSTRY CO., LTD.Inventors: CHIH-CHAN GER, WEN-LIN CHEN
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Patent number: 7394213Abstract: A multi-lamp driver t disclosed, comprising a power driver coupled to a plurality of lamps to supply power thereto, a feedback circuit coupled to at least one of the lamps to generate a feedback signal, a control circuit coupled between the feedback circuit and the power driver to control the power driver according to an illumination control signal and the feedback signal for total illumination adjustment of the lamps, and at least one switch controlled by the control circuit to turn at least one of the lamps on or off. In a total illumination adjustment of the lamps, the switch turns on or off timely. The difference between the maximum and minimum value of the total illumination of the lamps is thus increased.Type: GrantFiled: July 26, 2006Date of Patent: July 1, 2008Assignee: QISDA CorporationInventors: Chung-Jung Huang, Yung-Yi Hsu
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Patent number: 7388334Abstract: A high frequency sinusoidal wave is generated and applied directly to a gas discharge lamp in multiple phases in a power efficient electronic ballast. Uniting a high frequency current fed oscillator with a transformer, where direct current may be applied to the center tap of the transformer primary winding through an appropriately sized inductor to enable the impression of a sinusoidal alternating current at the secondary winding. This sinusoidal alternating current is applied directly to a gas discharge lamp. Feedback from the transformer controls the switching of the oscillator at resonant frequency.Type: GrantFiled: April 2, 2004Date of Patent: June 17, 2008Assignee: PureSpectrum, Inc.Inventors: Earl F. Crandall, Robert C. Smallwood, Sr., Robert G. Crandall
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Patent number: 7372211Abstract: A cold cathode tube lighting device is provided which is capable of obtaining stable luminance when a cold cathode tube is driven by applying voltages to input terminals on both ends of the cold cathode tube. A first current flowing through each of transformer secondary sides of transformers is detected by a tube current detecting circuit from a low-voltage side of each of the transformer secondary sides and a second current flowing through each of resonance capacitors is detected by the tube current detecting circuit and a difference between the first current and the second current is calculated for every separately-excited inverter and, based on the difference, a tube current of the cold cathode tube is obtained and frequencies of driving pulse voltages are changed by a voltage controlling oscillator for setting so that the tube current maintains a predetermined value.Type: GrantFiled: February 28, 2006Date of Patent: May 13, 2008Assignee: NEC LCD Technologies, Ltd.Inventor: Nobuaki Honbo
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Patent number: 7294972Abstract: A feedback circuit for push-pull inverters aims to improve the existing push-pull inverters that provide input electricity to a discharge lamp at a phase difference of 180 degrees without feedback electricity to regulate frequency signals and cannot effectively control uniform luminance of the discharge lamp. The invention includes a feedback device to get a detection electricity of the driving electricity of the discharge lamp through non-contact coupling induction. The detection electricity is transformed by the feedback device and output to a frequency control unit. The control unit can regulate and output the frequency signal in response to the luminance of the discharge lamp to timely adjust input electricity of a push-pull inverter.Type: GrantFiled: July 15, 2005Date of Patent: November 13, 2007Assignee: Zippy Technology Corp.Inventors: Chin-Wen Chou, Ying-Nan Cheng, Chin-Biau Chung
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Patent number: 7279851Abstract: An apparatus and methods for balancing current in multiple negative impedance gas discharge lamp loads. Embodiments advantageously include balancing transformer configurations that are relatively cost-effective, reliable, efficient, and good performing. Embodiments include configurations that are applicable to any number of gas discharge tubes, such as cold cathode fluorescent lamps. The balancing transformer configuration techniques permit a relatively small number of power inverters, such as one power inverter, to power multiple lamps in parallel. One embodiment of a balancing transformer includes a safety winding which can be used to protect the balancing transformer in the event of a lamp failure and can be used to provide an indication of a failed lamp.Type: GrantFiled: October 20, 2004Date of Patent: October 9, 2007Assignee: Microsemi CorporationInventor: Newton E. Ball
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Patent number: 7279849Abstract: This invention relates to a backlight driving apparatus of a liquid crystal display device, and more particularly to a backlight driving apparatus of a liquid crystal display device that includes: first and second transformers that boost an AC voltage to a boosted AC voltage that is supplied to a U-shaped lamp; and a virtual ground fixing device that causes a virtual ground of the U-shaped lamp to be fixed at the center of a bent part of the U-shaped lamp by causing the boosted AC voltage that is output from the first and second transformers to be identical in size.Type: GrantFiled: June 19, 2006Date of Patent: October 9, 2007Assignee: L.G.Philips LCD Co., Ltd.Inventor: Jeong Geun Lee
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Patent number: 7250726Abstract: An apparatus and methods for balancing current in multiple negative impedance gas discharge lamp loads. Embodiments advantageously include balancing transformer configurations that are relatively cost-effective, reliable, efficient, and good performing. Embodiments include configurations that are applicable to any number of gas discharge tubes, such as cold cathode fluorescent lamps. The balancing transformer configuration techniques permit a relatively small number of power inverters, such as one power inverter, to power multiple lamps in parallel. One embodiment of a balancing transformer includes a safety winding which can be used to protect the balancing transformer in the event of a lamp failure and can be used to provide an indication of a failed lamp.Type: GrantFiled: October 20, 2004Date of Patent: July 31, 2007Assignee: Microsemi CorporationInventor: Newton E. Ball
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Patent number: 7230390Abstract: A cold cathode fluorescent lamp (CCFL) assembly includes a pair of CCFLs, and an inverter-type drive circuit. The drive circuit includes a first transformer having a primary winding adapted to be coupled to a power supply module, and a secondary winding with a pair of terminals. The CCFLs are coupled respectively to the terminals of the secondary winding. The drive circuit further includes a push-pull drive circuit coupled to the primary winding of the first transformer, and adapted to be coupled to the power supply module. The push-pull drive circuit excites the primary winding of the first transformer upon receiving power from the power supply module such that power is transferred from the primary winding to the secondary winding, thus activating the CCFLs coupled thereto.Type: GrantFiled: August 5, 2005Date of Patent: June 12, 2007Assignee: Top Victory Electronics (Taiwan) Co., Ltd.Inventor: Chao-Hua Wu
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Patent number: 7173379Abstract: An incremental distributed driver divides power delivered to multiple lamps into two power delivery stages. The first power delivery stage operates in voltage-mode to provide a partial operating voltage to the lamps. The second power delivery stage operates in current-mode to regulate current levels for each of the lamps and to provide additional operating voltages for the respective lamps. Each of the power delivery stages includes a polarity-switching network and a common set of driving signals from a controller can be used to drive the polarity-switching networks of both power delivery stages. The first power delivery stage delivers a majority of the power to the lamps and the second power delivery stage facilitates control of individual lamps while providing the remaining power to the lamps.Type: GrantFiled: July 14, 2005Date of Patent: February 6, 2007Assignee: Microsemi CorporationInventor: Newton E. Ball
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Patent number: 7166969Abstract: In case of driving a plurality of lamps with the use of a plurality of output transformers, a difference in the bright-ness of each lamp occurs by a dispersion of characteristics of the output transformers, and an object is to prevent such troubles. For this purpose, a primary side of a plurality of output transformers of a one input-plural output type are respectively connected, and illumination units are connected to the secondary side of each output transformer. All of the secondary output terminals of each output transformer are connected to the secondary output terminals of counter phase and are connected by forming a loop circuit with the connection of the output terminals in series in closed loom form. The illumination units are connected between the secondary output terminals of the output transformer and the output terminal of the other output transformer of counter phase with the output terminal.Type: GrantFiled: October 20, 2004Date of Patent: January 23, 2007Inventor: Kazuo Kohno
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Patent number: 7126289Abstract: The present invention provides a driving circuit with protection function for driving a set of external electrode fluorescent lamps (EEFL). The drive circuit includes a transformer connected to the set of EEFLs, a switching network connected to the transformer which delivers power to the transformer, a sensing circuit connected to the set of EEFLs which detects disconnection if one light source is disconnected, and a controller connected to the switching network which controls the switching network to reduce the total current supplied to the EEFLs which remain connected, if the sensing circuit detects that one EEFL is disconnected. Appropriate protection can therefore be implemented when the EEFL is disconnected on one end or both ends.Type: GrantFiled: August 20, 2004Date of Patent: October 24, 2006Assignee: O2 Micro IncInventors: Yung-Lin Lin, Da Liu
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Patent number: 7081717Abstract: A discharge lamp lighting apparatus for lighting a plurality of discharge lamps comprises: a control circuit adapted to output driving signals; a plurality of step-up transformers; and a plurality of bridge circuits, each of which is connected to a DC power supply, and drives the primary side of each of the step-up transformers according to the driving signals from the control circuit so as to light each of the discharge lamps connected respectively to the secondary sides of the step-up transformers. In the discharge lamp lighting apparatus, each of the bridge circuits is connected to the control circuit via synchronous switching elements, and the synchronous switching elements, according to each of synchronizing signals applied thereto, switch on and off the driving signals from the control circuit so as to controllably cause each of the bridge circuits to start and stop its operation.Type: GrantFiled: June 14, 2005Date of Patent: July 25, 2006Assignee: Minebea Co., Ltd.Inventor: Shinichi Suzuki
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Patent number: 6870326Abstract: A ballasting circuit is configured with a circuit having a capability of providing an isolated power supply to various external ballast accessories that interface with a circuit or device for determining the amount of illumination. The ballasting circuit also has a capability of providing isolated power for circuitry within itself such that they can be connected to communication wires external to a lighting fixture without the need of an additional power supply. The ballasting circuit includes one or more gas discharge lighting devices, a source of input power, an electronic ballasting circuit having a regulated direct current requirement and coupled between the one or more gas discharge lighting devices and the source of input power, a heater transformer, a low voltage direct current power supply, a switching device, a regulator circuit, a full wave rectifier, and windings.Type: GrantFiled: August 18, 2003Date of Patent: March 22, 2005Inventor: Carlile R. Stevens
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Publication number: 20040100207Abstract: The invention relates to a device (101) for switching on and powering discharge lamps comprising at least a current limiting device, at least a square wave generator, at least an igniter, at least two high tension connection cables (107, 107′), at least a lamp holder (103) with at least a discharge lamp (104) coupled, said at least one igniter comprising at least a high tension transformer and at least an overlapping transformer, said device being characterised in that said at least an igniter is divided into a first stage of the igniter, or pulse generator transformer (102), and a high tension transformer (108), and in that said first igniter stage, or pulse generator transformer (102), and the relevant high tension transformer (108) are assembled along with the above mentioned components.Type: ApplicationFiled: November 13, 2003Publication date: May 27, 2004Inventors: Fabio DeSisti, Mario DeSisti
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Patent number: 6661181Abstract: A connection of electrode lines of lamps for supplying a light source for a backlight assembly of a liquid crystal display (LCD) device is improved to minimize the size of the LCD device while reducing the manufacturing cost. The LCD device includes the backlight assembly having a light emitting unit formed by plural lamps for generating light and a light controlling unit for guiding the light from the light emitting unit, and a display unit placed to the upper plane of the light controlling unit for receiving the light from the light emitting unit via the light controlling unit to display an image. A driving unit is further provided for converting an external power source of a DC component into an AC component to supply first and second driving signals having phases respectively different from each other to the light emitting unit.Type: GrantFiled: January 16, 2002Date of Patent: December 9, 2003Assignee: Samsung Electronics Co., Ltd.Inventor: Chung-Hyuk Shin
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Patent number: 6617807Abstract: In a discharge-lamp lighting circuit for turning on a plurality of discharge lamps, starting circuits 8 for supplying starting pulses to the respective discharge lamps are provided. Each starting circuit 8 has transformers T1 and T2 equal in number to the discharge lamps and each of the transformers has a primary and a secondary winding. The discharge lamps 6—1 and 6—2 are connected to the respective secondary windings T1s and T2s. Capacitors C1 and C2 are connected to the respective primary windings T1p and T2p of the transformers and one switch element SW is provided in a circuit including the primary windings and the capacitors. When the accumulated charge in each capacitor is discharged via the primary winding of the transformer as the switch element SW conducts, the starting pulse is generated and supplied to each discharge lamp via the secondary winding of each transformer.Type: GrantFiled: February 13, 2002Date of Patent: September 9, 2003Assignee: Koito Manufacturing Co., Ltd.Inventors: Masayasu Ito, Hitoshi Takeda