Inductance In The Supply Circuit Patents (Class 315/283)
  • Publication number: 20150115814
    Abstract: In one embodiment, a pulse current light-emitting diode (LED) driving circuit, can include: (i) an AC power supply configured to generate an AC input; (ii) a rectifier circuit that receives the AC input voltage, and generates a DC input voltage; (iii) a sampling circuit that receives the DC input voltage, and generates a DC sense voltage; (iv) a comparison circuit that receives the DC sense voltage, and generates a first comparison signal; (v) a feedback compensating circuit that samples a current that flows through a transistor, and generates a compensation signal; (vi) a signal processing circuit that receives the first comparison signal and the compensation signal, and generates an on signal; and (vii) the transistor having a gate configured to receive the on signal, a drain configured to receive the DC input voltage, and a source coupled to a first terminal of a sampling resistor.
    Type: Application
    Filed: October 29, 2014
    Publication date: April 30, 2015
    Inventors: Xiaodong Huang, Chen Zhao
  • Patent number: 9013112
    Abstract: A system for driving current to the light source may include a first inductor to supply current to the light source, a power source to supply current to the inductor, a first switch SET to supply current to the inductor without supplying the current to the light source and a second switch SET to supply the current from the inductor to the light source. Also a system for driving current to light source may include two inductors or a transformer, to supply current to the light source by connecting the first inductor to the light source by a switch set, while the second inductor may be connected to the voltage source by another switch set. And this role can be exchanged between the two inductor alternately and in sequence, defined by time periods.
    Type: Grant
    Filed: October 28, 2011
    Date of Patent: April 21, 2015
    Inventors: Mahdi Davoodabadi, Nick Nianxiong Tan
  • Patent number: 8917030
    Abstract: An electronic ballast for a lighting unit may include a Power Factor Correction (PFC) circuit, an inverter, and a control circuit for controlling startup of the inverter, wherein the control circuit is coupled between the PFC circuit and the inverter and includes a switching device coupled in a startup loop for the inverter; a unidirectional conductive device coupled between a PFC power supply circuit for providing an operation current to a PFC controller of the PFC circuit and an input of the PFC controller for preventing a startup current flowing through the PFC circuit from triggering the switching device; and a triggering device coupled to the switching device and a connection point between the unidirectional conductive device and the PFC power supply circuit for controlling switch-on and switch-off of the switching device.
    Type: Grant
    Filed: August 25, 2011
    Date of Patent: December 23, 2014
    Assignee: OSRAM GmbH
    Inventors: Hong Dai, Yuancheng Guo, Wei Gao, Changsong Ma
  • Patent number: 8884539
    Abstract: According to one embodiment, a rectifying circuit includes a diode, a switching element, a capacitor and an auxiliary winding. The diode is connected between a first terminal and a second terminal while a direction directed from the second terminal to the first terminal is a forward direction. The switching element includes a first main electrode connected to the first terminal, a second main electrode connected to a cathode of the diode, and a gate electrode connected to an anode of the diode. The auxiliary winding is magnetically coupled to an inductor. The auxiliary winding is connected to the gate electrode through the capacitor, and is connected to the second main electrode of the switching element and the cathode of the diode.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: November 11, 2014
    Assignee: Toshiba Lighting & Technology Corporation
    Inventor: Noriyuki Kitamura
  • Patent number: 8866400
    Abstract: A plasma supply device generates an output power greater than 500 W at an essentially constant basic frequency greater than 3 MHz and powers a plasma process to which is supplied the generated output power, and from which reflected power is returned to the plasma supply device. The plasma supply device includes at least one inverter connected to a DC power supply, which inverter has at least one switching element, and an output network, wherein the at least one output network includes at least one inductance that has at least one magnetic field strengthening element that is a Perminvar ferrite.
    Type: Grant
    Filed: March 21, 2013
    Date of Patent: October 21, 2014
    Assignee: TRUMPF Huettinger GmbH + Co. KG
    Inventors: Thomas Kirchmeier, Michael Glueck
  • Patent number: 8853958
    Abstract: A driving circuit for a solid state lighting apparatus includes a full wave rectifier configured to rectify an alternating current (AC) input voltage signal to generate a rectified input signal, a boost conversion circuit configured to receive the rectified input signal and responsively generate a direct current (DC) output voltage signal and to supply the output voltage signal to a solid state light source, and a boost control circuit coupled to the boost conversion circuit and configured to cause the boost conversion circuit to operate in a constant power mode.
    Type: Grant
    Filed: October 29, 2012
    Date of Patent: October 7, 2014
    Assignee: Cree, Inc.
    Inventors: Praneet Athalye, Qingcong Hu, Michael Walters, Eric Menzel, Michael James Harris
  • Patent number: 8749152
    Abstract: A switching power supply includes a first switching element, a rectifying element, a first inductor and a second inductor. The first switching element supplies a power supply voltage to the first inductor and al lows a current to flow when the first switching element is on. The rectifying element is connected in series to the first switching element, and allows a current of the first inductor to flow when the first switching element is turned off. The second inductor is electromagnetically coupled to the first inductor, a potential to turn on the first switching element is induced when the current of the first inductor increases, and a potential to turn off the first switching element is induced when the current of the first inductor decreases. The induced potential is supplied to a control terminal of the first switching element. The rectifying element includes a diode and a second switching element.
    Type: Grant
    Filed: March 20, 2012
    Date of Patent: June 10, 2014
    Assignee: Toshiba Lighting & Technology Corporation
    Inventors: Yuji Takahashi, Noriyuki Kitamura
  • Publication number: 20140152183
    Abstract: The present invention discloses an LED lighting apparatus. The LED lighting apparatus includes a converter for transforming rectified voltage in accordance with a switching operation according to a driving pulse and outputting the transformed voltage, a current regulator for generating the driving pulse having a pulse width varied in response to a control signal and the amount of current of the converter and switching the operation of the converter using the generated driving pulse, and a peripheral circuit module for providing the control signal for controlling the dimming of an LED lighting.
    Type: Application
    Filed: December 2, 2013
    Publication date: June 5, 2014
    Applicant: SILICON WORKS CO., LTD.
    Inventors: Yong Guen KIM, Sang Young Lee, Gyeong Sik Mun, Ki Chul An
  • Publication number: 20140152192
    Abstract: Disclosed are a power supply apparatus for an LED lighting and an LED lighting apparatus using the power supply apparatus. The LED lighting apparatus includes a power source unit configured to supply a rectified voltage, a voltage converter configured to include at least one first inductor and to convert the rectified voltage, an auxiliary coil configured to include a second inductor and to supply a detection voltage corresponding to the current of the first inductor of the voltage converter, a controller configured to control the current of the voltage converter using a driving pulse generated in response to a control signal and a sensing voltage, and a voltage regulation circuit configured to regulate the detection voltage and to supply the regulated voltage as an operating voltage for the controller.
    Type: Application
    Filed: December 2, 2013
    Publication date: June 5, 2014
    Applicant: SILICON WORKS CO., LTD.
    Inventor: Yong Guen KIM
  • Publication number: 20140111111
    Abstract: An amount of filament voltage supplied by a reconfigurable ballast may be adjusted based on a lamp type with which the ballast is operating. The filament voltage may be reconfigured dynamically and/or may be reconfigured via a user-provided value. An electronic dimming ballast may include a control circuit configured to control generation of the AC filament voltage in accordance with a reconfigurable AC filament voltage value. Reconfiguring an electronic dimming ballast may include reconfiguring an AC filament voltage applied by the electronic dimming ballast to a filament of a lamp installed in the electronic dimming ballast. Reconfiguring the AC filament voltage may include computing a hot-to-cold cathode resistance ratio associated with the filament. Reconfiguring the AC filament voltage may include determining whether the computed hot-to-cold cathode resistance ratio is within a range specified for the electronic dimming ballast.
    Type: Application
    Filed: March 1, 2013
    Publication date: April 24, 2014
    Inventors: Venkatesh Chitta, Jonathan Robert Quayle, Brent M. Gawyrs
  • Publication number: 20140084807
    Abstract: A representative apparatus controls current supplied to solid state lighting, such as light emitting diodes. The apparatus includes an inductor, a memory adapted to store a plurality of current parameters and a controller. The controller is configured to control a power source to supply current to the inductor to start an energizing cycle, monitor an inductor current level, reduce the inductor current level in response to the inductor current level reaching a predetermined peak inductor current, and increase the inductor current level in response to the inductor current reaching a predetermined minimum current is reached. In at least one embodiment, the controller modulates a current provided to the solid state lighting such that a DC average current level is substantially proportional to one-half of a sum of the predetermined peak current level and the predetermined minimum current level.
    Type: Application
    Filed: December 3, 2013
    Publication date: March 27, 2014
    Applicant: Point Somee Limited Liability Company
    Inventors: Anatoly Shteynberg, Harry Rodriguez
  • Patent number: 8593072
    Abstract: A circuit arrangement for operating a high-pressure discharge lamp with an operating circuit for the high-pressure discharge lamp with an input for receiving a switch-on/switch-off signal for the high-pressure discharge lamp and at least one output for providing an operating signal to the high-pressure discharge lamp, wherein the operating circuit is designed to reduce the power of the operating signal provided at the at least one output once a switch-off signal has been received at its input, wherein the operating circuit furthermore designed to provide the operating signal as an AC signal above a predeterminable power threshold value and as a quasi DC signal below the predeterminable power threshold value.
    Type: Grant
    Filed: November 13, 2007
    Date of Patent: November 26, 2013
    Assignee: OSRAM Gesellschaft mit beschraenkter Haftung
    Inventors: Christian Breuer, Andreas Huber, Bernhard Reiter
  • Patent number: 8525430
    Abstract: A plasma lamp apparatus includes a post structure with a material overlying a surface region of the post structure, which has a first end and a second end. The apparatus also has a helical coil structure configured along the post structure. The apparatus includes a bulb with a fill material capable of emitting electromagnetic radiation. A resonator coupling element configured to feed radio frequency energy to at least the helical coil causes the bulb device to emit electromagnetic radiation.
    Type: Grant
    Filed: June 4, 2010
    Date of Patent: September 3, 2013
    Assignee: Topanga Technologies, Inc.
    Inventors: Timothy J. Brockett, David P. Schmelzer, Mehran Matloubian, Frederick M. Espiau
  • Publication number: 20130127367
    Abstract: A lighting device includes: a DC converter including at least an inductor, a switching unit and a diode and being configured to output an energy accumulated in the inductor to a load via the diode by using an input from a DC power source when the switching unit is turned off; a load voltage detection unit connected to the load to detect a load voltage of the load; and an abnormality determining unit configured to determine an abnormality when the load voltage is equal to or less than a preset threshold voltage. The device further includes an output control unit configured to drive the switching unit so that oscillation of the switching unit is stopped or the output of the DC converter is decreased when the abnormality is determined.
    Type: Application
    Filed: November 15, 2012
    Publication date: May 23, 2013
    Applicant: PANASONIC CORPORATION
    Inventor: PANASONIC CORPORATION
  • Patent number: 8441200
    Abstract: An electronic ballast for operating at least two discharge lamps is provided, which may include a starting detection apparatus for detecting whether one of the discharge lamps has been started; wherein a drive circuit includes an input, which is coupled to a starting detection apparatus, wherein a threshold value entry apparatus is designed to enter a second threshold value for a setpoint value of a total current through at least two inductances, wherein the second threshold value has a smaller magnitude than a first threshold value; and wherein the drive circuit is designed to drive a first electronic switch and a second electronic switch taking into consideration the first threshold value as setpoint value prior to detection of the starting of a discharge lamp by the starting detection apparatus, and taking into consideration the second threshold value as setpoint value.
    Type: Grant
    Filed: November 9, 2007
    Date of Patent: May 14, 2013
    Assignee: OSRAM Gesellschaft mit beschraenkter Haftung
    Inventors: Olaf Busse, Siegfried Mayer, Arwed Storm
  • Patent number: 8436543
    Abstract: A plasma supply device generates an output power greater than 500 W at an essentially constant basic frequency greater than 3 MHz and powers a plasma process to which is supplied the generated output power, and from which reflected power is returned to the plasma supply device. The plasma supply device includes at least one inverter connected to a DC power supply, which inverter has at least one switching element, and an output network, wherein the at least one output network includes at least one inductance that has at least one magnetic field strengthening element that is a Perminvar ferrite.
    Type: Grant
    Filed: January 11, 2010
    Date of Patent: May 7, 2013
    Assignee: Huettinger Elektronik GmbH + Co. KG
    Inventors: Thomas Kirchmeier, Michael Glueck
  • Publication number: 20130057171
    Abstract: A switch circuit utilizes an LED for illumination. A diode is connected in parallel with the LED but in opposite orientation, with the LED anode connected to the diode cathode, and the LED cathode connected to the diode anode, to permit discharging of a power supply capacitor of a ballast of a lamp such as a compact fluorescent light (CFL) bulb. Undesirable flickering of the CFL are then avoided.
    Type: Application
    Filed: August 30, 2012
    Publication date: March 7, 2013
    Applicant: HUBBELL INCORPORATED
    Inventors: Stephen M. Liscinsky, Gregg R. Schelmetic
  • Publication number: 20120326621
    Abstract: A system for driving current to the light source may include a first inductor to supply current to the light source, a power source to supply current to the inductor, a first switch SET to supply current to the inductor without supplying the current to the light source and a second switch SET to supply the current from the inductor to the light source. Also a system for driving current to light source may include two inductors or a transformer, to supply current to the light source by connecting the first inductor to the light source by a switch set, while the second inductor may be connected to the voltage source by another switch set. And this role can be exchanged between the two inductor alternately and in sequence, defined by time periods.
    Type: Application
    Filed: October 28, 2011
    Publication date: December 27, 2012
    Inventors: Mahdi Davoodabadi, Nick Nianxiong Tan
  • Patent number: 8339063
    Abstract: A driving circuit includes a first inductor coupled in series with a light source for providing power to the light source. A controller coupled to the first inductor can control a switch coupled to the first inductor, thereby controlling a current flowing through the first inductor. A current sensor coupled to the first inductor can provide a first signal indicative of the current flowing through the first inductor, regardless of whether the switch is on or off. The switch is controlled according to the first signal. A second inductor magnetically coupled to the first inductor is also electrically coupled to the first inductor via a common node between the switch and the first inductor for providing a reference ground for the controller. The reference ground is different from the ground of the driving circuit.
    Type: Grant
    Filed: April 16, 2010
    Date of Patent: December 25, 2012
    Assignee: O2Micro Inc
    Inventors: Tiesheng Yan, Youling Li, Feng Lin, Xinhe Su, Ching-Chuan Kuo
  • Patent number: 8319451
    Abstract: A ballast to power a lamp includes two switches, each to selectively connect the ballast to respective high voltage terminals, each having two states (ON and OFF). The ballast also includes a converter circuit that provides a voltage to energize the lamp, and a detector circuit. The detector circuit includes two inputs, each coupled to a respective switch; two resistors, each coupled to a respective input; two outputs, each connected to the converter circuit; a transistor network; and a capacitor. One output provides the converter circuit with power, and is connected to the input via the resistors. The other provides the converter circuit with a control signal, indicating a voltage level so as to power the lamp to a particular light level, depending on the switches' states. The transistor network detects a differential voltage between the inputs, generating the control signal as a result. The capacitor smoothes the control signal.
    Type: Grant
    Filed: February 10, 2011
    Date of Patent: November 27, 2012
    Assignee: OSRAM SYLVANIA Inc.
    Inventor: Viatcheslav Anissimov
  • Publication number: 20120286693
    Abstract: A circuit assembly for operating a discharge lamp (5) comprising a full-bridge assembly (1), which supplies the discharge lamp (5), wherein the circuit assembly can operate the discharge lamp (5) at a low-frequency and at a high-frequency voltage, and the circuit assembly is configured: to operate the discharge lamp (5) directly after starting the lamp at a high-frequency voltage, and to operate the discharge lamp (5) above a predetermined lamp voltage (UT) at a low-frequency voltage, wherein the full-bridge assembly (1) always operates in discontinuous conduction mode.
    Type: Application
    Filed: November 15, 2010
    Publication date: November 15, 2012
    Inventors: Alois Braun, Walter Limmer, Maximilian Schmidl
  • Publication number: 20120274213
    Abstract: A driving apparatus for fluorescent tubes and a method thereof are provided. The provided driving apparatus changes a sinusoidal driving signal used for driving a fluorescent tube by detecting a current flowing through the fluorescent tube. Accordingly, the current flowing through the fluorescent tube can be conformed to specifications/regulations. Under the condition of being capable of detecting current(s) flowing through fluorescent tube(s), the provided driving apparatus can be suitable for driving fluorescent tubes with different specifications, categories and brands, and would not affect the lifetime of the fluorescent tubes and would not cause the problem of insufficient luminance.
    Type: Application
    Filed: January 18, 2012
    Publication date: November 1, 2012
    Applicant: BEYOND INNOVATION TECHNOLOGY CO., LTD.
    Inventors: Chiu-Yuan Lin, Chien-Pang Hung, Chen-Lung Kao
  • Patent number: 8278843
    Abstract: A method for operating a switching power supply is provided. A switching element is switched on and off by a switching signal with a variable switching frequency. A frequency bandwidth is predefined for determining average levels of a frequency spectrum of the switching signal. The switching frequency is modulated by a modulation frequency greater than a frequency bandwidth.
    Type: Grant
    Filed: October 6, 2008
    Date of Patent: October 2, 2012
    Assignee: Siemens Aktiengesellschaft
    Inventors: Harald Demoulin, Ewald Lohninger
  • Publication number: 20120242246
    Abstract: A lighting device includes: a series circuit of an inductor and a switching element; a diode which regenerates and supplies an energy of the inductor; and a control circuit which controls on/off of the switching element. The control circuit includes a drive signal generator which outputs a high frequency pulse drive signal; and a drive control section which turns on and off the switching element based on the high frequency drive signal and a PWM signal. The drive signal generator changes an ON time of the high frequency drive signal such that, after the PWM signal is changed from OFF to ON, a peak value of the load current gradually drops along an envelope of a specific slope, and the specific slope of the envelope is changed based on a duty ratio of the PWM signal.
    Type: Application
    Filed: March 9, 2012
    Publication date: September 27, 2012
    Applicant: Panasonic Corporation
    Inventor: Masahiro NARUO
  • Patent number: 8232734
    Abstract: An electronic ballast for driving a gas discharge lamp comprises an inverter circuit that operates in a partially self-oscillating manner. The inverter circuit comprises a push-pull converter having a main transformer having a primary winding for producing a high-frequency AC voltage, semiconductor switches electrically coupled to the primary winding of the main transformer for conducting current through the primary winding on an alternate basis, and gate drive circuits for controlling the semiconductor switches on a cycle-by-cycle basis. The drive circuits control (e.g., turn on) the semiconductor switches in response to first control signals derived from the main transformer, and control (e.g., turn off) the semiconductor switches in response to second control signals received from a control circuit. The control circuit controls the semiconductor switches in response to a peak value of an integral of an inverter current flowing through the inverter circuit.
    Type: Grant
    Filed: September 19, 2011
    Date of Patent: July 31, 2012
    Assignee: Lutron Electronics Co., Inc.
    Inventors: Robert C. Newman, Jr., Mark S. Taipale
  • Patent number: 8164271
    Abstract: The present invention uses series connected capacitive impedance and inductive impedance, whereof the inherent series resonance and the frequency of the bi-directional power can produce series resonance, thereby the bi-directional divided power being generated at the two ends of the capacitive impedance and inductive impedance is rectified to output DC power to drive the uni-directional light emitting diode.
    Type: Grant
    Filed: January 12, 2009
    Date of Patent: April 24, 2012
    Inventor: Tai-Her Yang
  • Patent number: 8159142
    Abstract: A ballast comprising a first input terminal, a second input terminal, a switch circuit, and a plurality of lamp sets is provided. The switch circuit comprises a first switch and a second switch connected with the first one. The switches are connected with the first and second input terminals respectively. The lamp sets are connected in parallel with each other and have an arrangement sequence. Each of the lamp sets is coupled to the first and second switches and comprises a first lamp having a first filament. The filaments are connected in series according to the arrangement order so that at least one junction is formed in the at least one connection point. The first one of the first filaments is coupled to the first switch. The last one of the first filaments is coupled to the second switch. Thereby, the ballast can be implemented by less internal connection terminals and leads.
    Type: Grant
    Filed: September 18, 2008
    Date of Patent: April 17, 2012
    Assignee: Delta Electronics, Inc.
    Inventors: Ching-Ho Chou, Yuan-Yuan Zhong, Wei-Qiang Zhang, Jian-Ping Ying
  • Publication number: 20120074861
    Abstract: An exemplary power regulator apparatus provides power for illumination of a display object, such as a merchandise package or container, which has a light emitting apparatus comprising a secondary inductor and an illumination source. A support structure, such as a point of purchase display, typically contains or supports one or more power regulators and display objects. The power regulator comprises a controller and a primary inductor, and the controller is adapted to provide a voltage or current to the primary inductor to generate a primary inductor voltage. The controller may also comprise a plurality of switches and a memory adapted to store values for switching frequency or switch on-time durations or pulse widths. The illumination source emits visible light when the power regulator is in an on state and when the secondary inductor is within a predetermined distance of the primary inductor.
    Type: Application
    Filed: June 13, 2011
    Publication date: March 29, 2012
    Applicant: NTHDEGREE TECHNOLOGIES WORLDWIDE INC.
    Inventors: Mark D. Lowenthal, William Johnstone Ray, David R. Bowden, Peter Michael Bray
  • Publication number: 20120062139
    Abstract: An illumination assembly, comprising: at least one luminous means having at least one luminescence diode chip as light source, and at least one energizing means, which is connected to the at least one luminous means via a connecting line, wherein the energizing means is designed to energize the at least one luminous means.
    Type: Application
    Filed: February 2, 2010
    Publication date: March 15, 2012
    Applicant: Traxon Technologies Europe Gmbh
    Inventors: Holger Ruether, Dirk Beiner
  • Patent number: 8115409
    Abstract: A driving circuit includes a signal generator, a resonant circuit, a control circuit and an adjusting circuit. The signal generator is utilized for generating an alternating current (AC) signal having a fixed frequency. The resonant circuit is coupled to the signal generator, and is utilized for generating an oscillation signal to drive a backlight source according to the alternating current signal. The control circuit is utilized for providing a control signal. The adjusting circuit is coupled to the control circuit, the resonant circuit and the backlight source, and is utilized for providing an impedance according to the control signal to thereby adjust a current value of the backlight source.
    Type: Grant
    Filed: April 15, 2009
    Date of Patent: February 14, 2012
    Assignee: Chunghwa Picture Tubes, Ltd.
    Inventors: Chi-Hsiu Lin, Shin-Chang Lin, Chien-Yang Chen
  • Publication number: 20120001565
    Abstract: The present invention is generally related to an electronic ballast, an ignition control apparatus used therein and associated method of operation. In one embodiment, an electronic ballast comprising an inverter and an ignition control apparatus which comprises a stability monitoring circuit and a controlled ignition circuit. The inverter converts a DC input voltage into an AC voltage to drive a gas discharge lamp. The stability monitoring circuit monitors whether the DC input voltage is stable. The controlled ignition circuit is electrically coupled to the stability monitoring circuit and the lamp, ignites the lamp based on the monitoring result. The controlled ignition circuit does not ignite the gas discharge lamp until the DC input voltage becomes stable.
    Type: Application
    Filed: April 15, 2011
    Publication date: January 5, 2012
    Inventors: Jin Hu, Qing Xu, Quansong Wu
  • Patent number: 8084952
    Abstract: The invention discloses a method and system to detect zero current conditions in a buck inductor by monitoring the voltage across the buck inductor. Once zero current and voltage conditions are present, an inverter circuit changes the operational state, i.e. conducting or non-conducting, of the switching transistors driving the lamps to reduce power loss associated with changing the operational state of switching transistors when under a load.
    Type: Grant
    Filed: September 22, 2008
    Date of Patent: December 27, 2011
    Assignee: Universal Lighting Technologies, Inc
    Inventors: Yu Shiwei, Gao Qin, Guo Sui
  • Patent number: 8049432
    Abstract: An electronic ballast for driving a gas discharge lamp comprises a measurement circuit for measuring a lamp current flowing through the lamp and a lamp voltage produced across the lamp. The ballast comprises a first winding magnetically coupled to a main transformer of an inverter circuit, and a second winding magnetically coupled to a resonant inductor of a resonant tank circuit. The first and second windings are coupled in series electrical connection to generate a voltage representative of the magnitude of the lamp voltage. The ballast further comprises a current transformer having primary windings coupled in series with the electrodes of the lamp. The measurement circuit integrates the current conducted through secondary windings of the current transformer only during every other half-cycle of the lamp voltage to generate a control signal representative of the magnitude of the lamp current that is in-phase with the lamp voltage.
    Type: Grant
    Filed: September 5, 2008
    Date of Patent: November 1, 2011
    Assignee: Lutron Electronics Co., Inc.
    Inventors: Mark S. Taipale, Robert C. Newman, Jr., Scott E. Rhodes
  • Patent number: 8049430
    Abstract: An electronic ballast for driving a gas discharge lamp comprises an inverter circuit that operates in a partially self-oscillating manner. The inverter circuit comprises a push-pull converter having a main transformer having a primary winding for producing a high-frequency AC voltage, semiconductor switches electrically coupled to the primary winding of the main transformer for conducting current through the primary winding on an alternate basis, and gate drive circuits for controlling the semiconductor switches on a cycle-by-cycle basis. The drive circuits control (e.g., turn on) the semiconductor switches in response to first control signals derived from the main transformer, and control (e.g., turn off) the semiconductor switches in response to second control signals received from a control circuit. The control circuit controls the semiconductor switches in response to a peak value of an integral of an inverter current flowing through the inverter circuit.
    Type: Grant
    Filed: September 5, 2008
    Date of Patent: November 1, 2011
    Assignee: Lutron Electronics Co., Inc.
    Inventors: Robert C. Newman, Jr., Mark S. Taipale
  • Publication number: 20110148313
    Abstract: The invention relates to a method for controlling an LED load. First an input voltage is supplied to an inductive element. Subsequently, a current is drawn through the inductive element for a first predetermined time period. Finally, a current is supplied from the inductive element to a first terminal of the LED load during a second time period. The first predetermined time is controlled to maintain a predetermined average current through the LED load.
    Type: Application
    Filed: August 28, 2009
    Publication date: June 23, 2011
    Applicant: LEMNIS LIGHTING PATENT HOLDING B.V.
    Inventor: Antonius Everardus Theodorus Ramaker
  • Publication number: 20110133664
    Abstract: A driver circuit includes a plurality of switches, forming two switching legs, each of at least two switches and connected between two DC voltage buses. The switches are matched to form diagonal pairs. The driver circuit also includes a load circuit connecting the legs, with a first inductor connected between one leg's switches, and a second inductor connected between the other leg's switches, and lamp terminals between the inductors and in series with the second inductor. The driver circuit also includes a capacitor in parallel with the series-connected lamp terminals and the second inductor, and a control circuit connected to the plurality of switches. During a commutation period, a diagonal pair operates in a non-conductive state and the other in a conductive state, until a current through the first inductor reaches a predefined value. Then the other operates in a non-conductive state until the current through the first inductor reaches zero.
    Type: Application
    Filed: December 8, 2010
    Publication date: June 9, 2011
    Applicant: OSRAM SYLVANIA INC.
    Inventors: Afroz M. Imam, Sivakumar Thangavelu
  • Patent number: 7938548
    Abstract: A projection device includes: a projector unit that has at least a light source and a projection optical system housed in a chassis; a control unit that is assembled with a chassis separate from the chassis of the projector unit; and a rotation support member that rotatably supports the projector unit and the control unit around a rotation axis that extends perpendicular to a surface of the chassis of the projector unit and a surface of the chassis of the control unit, with these surfaces facing to one another.
    Type: Grant
    Filed: June 29, 2006
    Date of Patent: May 10, 2011
    Assignee: Nikon Corporation
    Inventors: Hirotake Nozaki, Nobuhiro Fujinawa, Akira Ohmura
  • Patent number: 7919926
    Abstract: A high frequency ballast for a metal halide lamp comprises a controller, a switch, and an oscillator. The controller selectively enables and disables the oscillator via the switch to ignite the lamp. The ignition method includes enabling the oscillator such that the oscillator provides the lamp with a pulse train comprising a rapid series of short ignition pulses, cools for a period of time, and provides an addition pulse train to the lamp if necessary to ignite the lamp. When the lamp ignites, the ballast maintains enablement of the oscillator.
    Type: Grant
    Filed: July 2, 2008
    Date of Patent: April 5, 2011
    Assignee: OSRAM SYLVANIA Inc.
    Inventors: Andrew Johnsen, Phillip Whitt, Harold Rothwell
  • Publication number: 20110006700
    Abstract: A charge pump electronic ballast for use with low input voltage is described. The charge pump electronic ballast includes a DC/AC inverter circuit having two switching transistors, a resonant circuit having an inductor and a capacitor. The charge pump electronic ballast further includes a voltage multiplying rectifying circuit for transforming low input AC voltage into high output DC voltage, and a charge pump circuit having an inductor and a first pump capacitor.
    Type: Application
    Filed: January 28, 2008
    Publication date: January 13, 2011
    Applicant: OSRAM GESELLSCHAFT MIT BESCHRAENKTER HAFTUNG
    Inventors: Wei Chen, Shu Dong Li
  • Publication number: 20100277088
    Abstract: A system for supplying current to a load is disclosed. One embodiment provides a switching converter for providing a load current to the load. The switching regulator includes a switching circuit. A current control unit generates a modulated current control signal representing a desired load current. The switching circuit is driven dependent on the modulated current control signal. A logic circuit receives a pulse-width-modulated control signal representing a desired dimming ratio and is configured to generate a gate signal for driving the switching circuit dependent on the current control signal during a duty cycle of the pulse-width-modulated control signal. The logic circuit is configured to activate the switching converter, independent on the state of the current control signal, at the beginning of the duty cycle of the pulse-width-modulated control signal.
    Type: Application
    Filed: April 30, 2009
    Publication date: November 4, 2010
    Applicant: Infineon Technologies Austria AG
    Inventor: Emanuele Bodano
  • Publication number: 20100253235
    Abstract: A non-flashing brightness adjusting device for a non-resistive light-emitting load has a brightness adjuster and a conductive current sustainer. The brightness adjuster has an AC silicon-controlled rectifier (SCR) and an adjustable trigger unit. By adjusting the adjustable trigger unit and setting a trigger angle of the TRIAC, a total output current of the brightness adjuster is adjusted. The conductive current sustainer is connected to the output terminal of the brightness adjuster for a non-resistive light-emitting load to connect. When the trigger angle of the TRIAC is greater than 90 degrees, the conductive current sustainer keeps the current flowing through the anode and cathode of the TRIAC not lower than its threshold current to maintain the conduction of the TRIAC. Therefore, the non-resistive light-emitting load keeps receiving the required working power and does not flash.
    Type: Application
    Filed: May 12, 2009
    Publication date: October 7, 2010
    Inventor: Tsung-Ein Tsai
  • Publication number: 20100194305
    Abstract: An electronic ballast for a discharge lamp includes a predictive circuit and a correction circuit in addition to a power conversion circuit including an inverter circuit and a resonant circuit, a drive circuit and a frequency control circuit. The inverter circuit applies load voltage across a load circuit including the lamp via the resonant circuit. The predictive circuit predicts a resonance frequency of the combination of the resonant circuit and the load circuit after ignition of the lamp. The resonance frequency is predicted based on an input signal representing the load voltage in the period of time from the start of sweep of the inverter circuit's operating frequency through a time point immediately after ignition of the lamp. The correction circuit changes the end frequency of the sweep to the resonance frequency.
    Type: Application
    Filed: July 25, 2008
    Publication date: August 5, 2010
    Inventors: Shinji Makimura, Hiroshi Kido
  • Patent number: 7755299
    Abstract: The invention relates to a transformer (10) for balancing the current in an AC circuit, comprising a primary winding (12), a secondary winding (14) and a main inductance (16). The transformer is characterized in that a capacitive component is connected in parallel to the primary winding (12) or to the secondary winding (14), whose capacitance value is determined such that the reactive current IL brought about by the main inductance (16) is substantially compensated. A transformer of this kind can preferably be employed in current balancing circuits as used, for example, in systems for backlighting LCD displays.
    Type: Grant
    Filed: August 15, 2007
    Date of Patent: July 13, 2010
    Assignee: Minebea Co., Ltd.
    Inventor: Robert Weger
  • Publication number: 20100066259
    Abstract: A circuit arrangement for starting a high-pressure discharge lamp (LA), having a main combustion chamber (HaBk) with a first and a second main electrode (HaE1, HaE2) and an auxiliary combustion chamber (HiBk), comprising: an inverter (10), which has at least one first and one second electronic switch (S1, S2, S3, S4) and one first and one second output terminal (WA1, WA2); a drive circuit (12) for driving the electronic switches (S1, S2, S3, S4) of the inverter (10); and an auxiliary starting circuit (14).
    Type: Application
    Filed: November 28, 2006
    Publication date: March 18, 2010
    Inventor: Friedrich Witzani
  • Publication number: 20090267531
    Abstract: A driving arrangement for feeding a current generated by a high frequency generator (10) coupled with a magnetic element (11) to a plurality of LED cells (33) each including at least one LED. The arrangement includes a respective plurality of LED channels (1, 2, 3, 4; 1?, 2?, 3?, 4?) arranged in a parallel configuration and one or more coupled inductors (L12, L23, L34) the couple in pairs the channels of the plurality of LED channels (1, 2, 3, 4; 1?, 2?, 3?, 4?).
    Type: Application
    Filed: November 16, 2006
    Publication date: October 29, 2009
    Applicant: OSRAM GESELLSCHAFT MIT BESCHRANKTER HAFTUNG
    Inventor: Nicola Zanforlin
  • Patent number: 7598685
    Abstract: The present invention creates an LED driver in which all feedback signals are derived from a power stage media, and presents an isolated off-line LED driver with an accurate primary side controller only to power one or more LEDs. The present invention further provides an effective off-line LED driver comprising AC current shape controller with a minimum number of components. The present invention further provides a high quality luminous system based on LED drivers with the integrated synthesized optical feedback to compensate for imperfections of the LEDs as sources of light.
    Type: Grant
    Filed: September 19, 2005
    Date of Patent: October 6, 2009
    Assignee: Exclara, Inc.
    Inventors: Anatoly Shteynberg, Harry Rodriguez
  • Publication number: 20090218953
    Abstract: In an instant start ballast, dimming control is provided over a range of operation in which lamps driven by the ballast do not require external cathode heating. An interface circuit (92) includes a winding (90) that is inductively coupled to windings (68, 70) of an inverter circuit (12). The interface circuit (92) also includes a variable impedance in parallel with the winding (90) where the variable impedance includes a transistor (96) and a Zener diode (98). By varying an input voltage across control leads (94), the apparent inductance of the winding (90) is varied. This variance affects the switching frequency of the inverter circuit (12) affecting the frequency of a drive signal provided to the lamps. Thus the instant start ballast can be dimmed without use of multiple ballasts and/or external cathode heating.
    Type: Application
    Filed: February 29, 2008
    Publication date: September 3, 2009
    Inventors: Louis R. Nerone, Melvin C. Cosby, JR.
  • Publication number: 20090179582
    Abstract: The present invention uses series connected capacitive impedance and inductive impedance, whereof the inherent series resonance and the frequency of the bi-directional power can produce series resonance, thereby the bi-directional divided power being generated at the two ends of the capacitive impedance and inductive impedance is rectified to output DC power to drive the uni-directional light emitting diode.
    Type: Application
    Filed: January 12, 2009
    Publication date: July 16, 2009
    Inventor: Tai-Her YANG
  • Patent number: 7443109
    Abstract: An arrangement for supplying a constant current to at least one LED includes a current source (2; 2a, 2b) with an output capacitor (3) connected across the terminals of the current source. An output inductor (4) is associated with the output capacitor (3) whereby the current supplied flows through the inductor (4). A smoothing resistor (5) is preferably connected in parallel to the output inductor (4).
    Type: Grant
    Filed: August 16, 2005
    Date of Patent: October 28, 2008
    Assignee: Patent-Treuhand-Gesellschaft für Elektrische Glühlampen mbH
    Inventors: Paolo De Anna, Ugo Francescutti
  • Publication number: 20080143271
    Abstract: The present invention aims to provide an inrush current limiting resistor for suppressing inrush current, and to avoid an excessive current flowing through the inrush current limiting resistor even if the lamp is operated at a dimmed level by mistake. A compact self-ballasted fluorescent lamp 1 is composed of a holder 20 and a case 30 attached to each other. The case 30 houses therein a lighting unit 50 for operating an arc tube 10. The lighting unit 50 is composed of a rectifier/smoothing circuit module having an electrolytic capacitor 53, an inverter circuit module, and a resonant circuit module having a resonance capacitor 54. The circuit modules are mounted on a printed wiring board 51. An inrush current limiting resistor 62 is connected to the input end of the rectifier/smoothing circuit module and in contact with the electrolytic capacitor 53 and the resonance capacitor 54 at their outer circumferential surfaces.
    Type: Application
    Filed: February 4, 2005
    Publication date: June 19, 2008
    Inventors: Akira Takahashi, Masayoshi Gyoten