Electric power conversion systems inventions 02/08

20080049453 - Resonant switching power source device: A resonant switching power source device is provided which comprises first and second MOS-FETs 1 and 2 connected in series to a DC power source 3, a first transformer 5 which has a first primary winding 6a connected in parallel to first or second MOS-FET 1 or 2 and in... Agent: Bachman & Lapointe, P.C.

20080049454 - Voltage stabilizer circuit of forward converter: A voltage stabilizer circuit of forward converter is disclosed to include a transformer, a first switch, a rectifier, an error amplifier, a control circuit, and a driving circuit. The control circuit outputs a regulation signal that controls turn-on time of the first switch, keeping the output of the load voltage... Agent: John G. Chupa Law Offices Of John Chupa & Associates, P.C.

20080049457 - Switching mode power supply and method of operation: In one embodiment, an SMPS includes a rectifier for generating an input DC voltage from an input AC voltage. A switching transistor is coupled to a primary coil of a transformer for generating power which is transferred to a second side of the transformer according to an operation of the... Agent: Sidley Austin LLP

20080049459 - Programmable feedback voltage pulse sampling for switched power supplies: Disclosed is a method and apparatus that includes a power supply having a primary coil and a secondary coil. The secondary coil generates an output voltage and a feedback voltage related to the output voltage. The feedback voltage is sampled at a time instant that is digitally controllable. The output... Agent: Weinick & Associates, LLC

20080049461 - Power supply having multiple power output: A power supply having multiple power output includes a power source to supply an AC signal to an EMI filter unit and a commutation unit that filter and commutate the AC signal and output a full wave/half wave pulse wave DC signal to an inverter which boosts voltage and outputs... Agent: Birch Stewart Kolasch & Birch

20080049464 - Electronic apparatus, ac/dc conversion device and power factor correction circuit thereof: An electronic apparatus, AC/DC conversion device and power factor correction circuit are provided. The power factor correction circuit includes an inductance, a switch, a power control chip, a first diode and a first capacitor. The inductance has a first end and a second end. The first end receives a first... Agent: Rabin & Berdo, PC

20080049465 - Pre-bias protection circuit for converter: A pre-bias protection circuit for a converter circuit including a switching stage having high-and low-side switches connected in series at a switching node and an output stage connected to the switching node having a capacitor having a pre-existing pre-bias voltage at startup of the converter circuit, the pre-bias protection circuit... Agent: Ostrolenk Faber Gerb & Soffen

20080049467 - Inverter: The present invention provides an inverter with a simple configuration capable of preventing occurrence of excessive rush current. A current detection circuit detects an AC output current flowing out from an output filter circuit. When the absolute value of the AC output current becomes equal to or larger than a... Agent: Oliff & Berridge, PLC

20080049468 - Method and apparatus including multi-drive configurations for medium voltage loads: A method and apparatus for converting X phase intermediate voltages on X intermediate lines to output voltage for driving a single three phase load, the apparatus comprising a positive DC bus, a negative DC bus and first and second three phase drives that each include a rectifier section and an... Agent: Rockwell Automation, Inc./(qb)

20080049471 - Level-shift circuit utilizing a single level-shift switch: A level-shift circuit for use with a half bridge in accordance with an embodiment of the present application includes an oscillator operable to provide a timing signal, a level-shift switch controlled by the timing signal of the oscillator, a high side control circuit operable to provide a high side control... Agent: Ostrolenk Faber Gerb & Soffen

20080049472 - Switching power supply device and electronic apparatus: A switching power supply device includes a primary winding of a transformer that is connected in series to a first switching element, and a secondary winding is provided with a rectifier circuit and an output voltage control circuit arranged to detect an output voltage and feed it back to a... Agent: Murata Manufacturing Company, Ltd. C/o Keating & Bennett, LLP

20080049473 - Control circuit of dc-dc converter and control method thereof: A DC-DC converter of a synchronous rectifier type, a control circuit thereof and control method thereof, facilitates detecting and interrupting negative inductor current IL with low power consumption, high accuracy and a simple configuration and facilitates improving the efficiency under a light load. An ON-period decision circuit determines whether an... Agent: Rabin & Berdo, PC

20080049452 - Ultralow power stan-by supply: A switched mode power supply is equipped with an auxiliary voltage supply (6; 60) supplying electrical energy to a controller (5; 50), which controls the switching of a switching transistor (4; 40). The auxiliary voltage supply (6; 60) receives a feedback signal from a feedback device (7; 70), which is... Agent: Philips Intellectual Property & Standards

20080049455 - Forward converter with synchronous rectification: A commutation switch turning-on control switching element is controlled with a voltage generated at a fourth coil (auxiliary coil) of a main transformer and controls application of a control voltage to a control terminal of a commutation switching element. A commutation switch turning-off control switching element is provided which is... Agent: Ostrolenk Faber Gerb & Soffen

20080049456 - Synchronous rectifying forward converter: A first drive control signal regenerating circuit outputs an ON timing drive signal at turn-ON of a main switch element, and a second drive control signal regenerating circuit generates an OFF timing drive signal at turn-OFF of the main switch element. A rectifying switch controlling switch element connected between the... Agent: Ostrolenk Faber Gerb & Soffen

20080049458 - Environmentally hardened ethernet switch: A circuit for an Intelligent Electrical device (IED) is disclosed. Using this circuit, the IEDs can be used in harsh industrial environments, such as those present in power utility substations. The circuit may comprise a dual stage isolated power supply. The dual stage isolated power supply has a first DC... Agent: Riches, Mckenzie & Herbert, LLP

20080049460 - Open-ended control circuit for electrical apparatus: An AC machine control system for an AC machine (motor, generator, transformer, etc.) having open-ended windings, the control system comprising a drive circuit configured to transfer AC power between a first set of voltages and each end of the open-ended windings without the use of a substantial energy storage device,... Agent: Westman Champlin & Kelly, P.A.

20080049462 - Power level balance of frequency converters connected in parallel: A method and a parallel connection arrangement for equalizing the output powers of power converter units (INU11, INU12), in which power converter units is a semiconductor switch bridge controlled with pulse width modulation, and in which is a control unit arrangement (CU1, CU2) for forming control pulses, with which the... Agent: Birch Stewart Kolasch & Birch

20080049463 - Stabilized power supply: A stabilized power supply for X-ray tubes having a first rectifier circuit, an inverter circuit comprising main switches, a transformer, a second rectifier circuit an oscillation circuit and an inverter circuit. The power supply includes an auxiliary circuit that can be driven and is parallel-connected to the oscillation circuit. The... Agent: Cantor Colburn, LLP

20080049466 - Method for controlling low-voltage using waves ac and system for performing the same: A method of controlling low voltage using a waveform of Alternating Current (AC) power, including; a full wave rectification step of fill-wave-rectifying input AC power; a switching step of performing a switching operation to generate four power outputs, whose voltage level is lower than that of set control voltage, in... Agent: Greer, Burns & Crain

20080049469 - Control method for direct power converter: A power converter directly converting an AC voltage into an AC voltage of any desired magnitude and frequency by turning bidirectional switches ON and OFF without employing any energy buffer, where the peak values of output phase voltage command values are limited, to bring the amplitude of an output line... Agent: Rabin & Berdo, PC

20080049470 - Induction heating apparatus: The present invention provides an induction heating apparatus that can detect that a power factor correction circuit is in operation or in non-operation. The induction heating apparatus includes a power factor correction circuit that corrects a power factor of an inputted direct-current power supply by turning on and off a... Agent: Wenderoth, Lind & Ponack L.L.P.

20080049474 - Power converter and power converting method: A power converter and a power converting method are provided. The power converter for converting an ac input voltage at an input terminal thereof into an ac output voltage at an output terminal thereof includes an energy-storing inductor, a first switching circuit coupled to the energy-storing inductor to selectively switch... Agent: Volpe And Koenig, P.C.

20080049475 - Dc/dc converter: A boost DC/DC includes an inductor connected at one end to the positive-pole terminal of a low-voltage-side port, a transformer of a magnetic-field cancellation type including a primary winding and a secondary winding interconnected in an oppositely-wound configuration, a common terminal of the primary winding and the secondary winding being... Agent: Birch Stewart Kolasch & Birch

20080049476 - Electric power converter: An electric power converter that includes a capacitor module which has a DC terminal, an inverter which coverts a direct current into an alternating current, and heat release fins which cool the inverter, is constructed so that: the inverter has a power module including a plurality of power semiconductor elements;... Agent: Crowell & Moring LLP Intellectual Property Group

20080049477 - Power converter: The power converter comprises a semiconductor device, a driver device, a current sensor, a control device, and a capacitor. The semiconductor device has a plurality of switching elements for converting a direct current to an alternating current, the direct current being supplied from a direct current terminal. The driver device... Agent: Crowell & Moring LLP Intellectual Property Group

20080049478 - Dc-to-dc converter with improved transient response: A DC-to-DC converter with improved transient response, accuracy and stability is disclosed. The DC-to-DC converter includes a comparator, a driver, at least one switch and a stability circuit. The stability circuit receives a voltage signal based upon sensing one of the at least one switch. The configuration with elimination a... Agent: Wang Law Firm, Inc.

20080049479 - Combined modulator and inverter: A combined modulator and inverter for use in transmitting audio files to a receiver. The combined modulator and inverter enables the usage of various devices in a vehicle that utilize different types of power sources. Audio devices may be used with the modulator and inverter to play the devices over... Agent: Wolf, Block, Schorr & Solis-cohen LLP

20080049480 - Semiconductor integrated circuit with voltage generation circuit, liquid crystal display controller and mobile electric equipment: There is to be provided a liquid crystal drive controller with a built-in power supply circuit wherein latch-up is made difficult to arise even if one amplitude level of the segment line drive voltage is set to the ground potential and the levels of other liquid crystal drive voltages are... Agent: Mattingly, Stanger, Malur & Brundidge, P.C.

20080043494 - Resonant converter and burst mode starting method thereof: A resonant converter and burst mode starting method thereof are provided. The resonant converter includes a converting stage, a transformer to induce the output of converting stage from the primary side to the secondary side, a rectifying stage to rectify the output of the transformer, a filtering and load stage... Agent: Volpe And Koenig, P.C.

20080043495 - Clamp diode reset in a power converter: Generally, a DC/DC converter and its associated devices and processes are presented herein. The DC/DC converter may be a switched mode converter that includes a plurality of switching devices that couple between the first and second power supply rails. A transformer is coupled to the switching devices such that the... Agent: Marsh, Fischmann & Breyfogle LLP

20080043496 - Linear-predict sampling for measuring demagnetized voltage of transformer: A linear-predict sampling circuit is developed to generate a feedback signal by detecting a demagnetized voltage of the transformer. A switching signal is generated in response to the feedback signal for regulating the output of the power converter. A signal-generation circuit is used to generate a sample signal in response... Agent: J C Patents, Inc.

20080043497 - Flyback converter with synchronous rectifier: Disclosed is a flyback converter with a synchronous rectifier, in which the synchronous rectifier includes a synchronous switch, a current transformer connected in series between a drain terminal of the synchronous switch and an output terminal, and a secondary synchronous rectification driver connected to the gate terminal of the synchronous... Agent: Madson & Austin

20080043498 - Dc-dc converter recycling leakage inductor losses: A technique performed by a transformer-coupled DC-DC converter is described for recovering energy, due to leakage inductance in the transformer. A main power supply, providing a power supply voltage to a Vin terminal, is intermittently coupled to the primary winding of the transformer by a switching transistor. When the switching... Agent: Patent Law Group LLP

20080043499 - Buck converter fault detection method: A circuit for detecting faults in at least one converter in a converter system, the at least one converter including a switching stage having high- and low-side switches connected at a switching node and fault circuitry for managing a plurality of fault conditions. The circuit including a gate driver circuit... Agent: Ostrolenk Faber Gerb & Soffen

20080043502 - Spread spectrum power converter with duty-cycle error compensation: A spread-spectrum power converter uses an inter-cycle duty-cycle error compensation to achieve a combination of high-precision tracking of a target average duty cycle and a favorable noise signature. The pulse train consists of a series of cycles having cycle durations of a positive integer of clock cycles, pulse durations of... Agent: Clifton L. Anderson Anderson Patents

20080043503 - Method and apparatus for detecting demagnetizing time of magnetic device: A detection circuit for detecting the demagnetizing time of a magnetic device is provided. An input circuit is coupled to the magnetic device for detecting a magnetizing voltage and a demagnetizing voltage of the magnetic device. A control circuit is coupled to the input circuit for generating a demagnetizing-time signal... Agent: J C Patents, Inc.

20080043504 - System and method for providing control for switch-mode power supply: System and method for providing control for switch-mode power supply. According to an embodiment, the present invention provides a system for regulating a power converter. The system comprises a signal processing component that is configured to receive a first voltage and a second voltage, to process information associated with the... Agent: Townsend And Townsend And Crew, LLP

20080043500 - Snubber circuit and power semiconductor device having snubber circuit: A snubber circuit as a conventional protection circuit for inverters, which is composed of an anode reactor, a Si diode and a resistance, needs to keep junction temperature of the Si diode at 125° C. or lower during operation and therefore requires mounting of a large-size heat sink, which causes... Agent: Nixon & Vanderhye, PC

20080043501 - Parallel inverters and controlling method thereof: Parallel inverters without any communication buses and the controlling method thereof are provided. The parallel inverters are controlled by an instant voltage. Each inverter includes an output voltage waveform controller and a load-sharing controller. The output voltage waveform controller is connected to an output terminal of the inverter to control... Agent: Volpe And Koenig, P.C.

20080043505 - Half bridge inverter with dual n-mos: A half bridge inverter with dual N-MOS includes a push/pull control chip outputting a first control signal with a duty cycle greater than 50% and a second control signal with a duty cycle greater than 50%. Moreover, both a first buffer circuit and a second buffer circuit are coupled to... Agent: Rosenberg, Klein & Lee

20080043506 - Dc-ac converter: A DC-AC converter directly converts DC voltage to AC voltage. A voltage conversion circuit receives DC voltage at a pair of first input terminals, converts the DC voltage to voltage having a polarity corresponding to the AC voltage, and outputs the converted voltage from a pair of first output terminals... Agent: Woodcock Washburn LLP

20080037289 - Multi-channels power converter with switching frequency modulation circuit for power saving: The present invention provides a control circuit for multi-channels power converter to save power at light load. The control circuit comprises a modulation circuit and an oscillation circuit to modulate the switching frequency of switching signals for power saving. The modulation circuit generates a modulation signal in response to a... Agent: Jianq Chyun Intellectual Property Office

20080037292 - High-voltage generator: A high-voltage generator includes a high-voltage transformer having a primary coil, a secondary coil, and an auxiliary coil, and a PNP bipolar junction transistor. Based on the self-oscillation theory of a LC oscillator, an oscillating voltage is generated across the primary coil. The oscillating voltage is amplified to a high-level... Agent: Madson & Austin

20080037293 - Forward power converter controllers: This invention relates to control techniques and controllers for resonant discontinuous forward power converters (RDFCs). We describe a controller for a resonant discontinuous forward converter (RDFC), said forward converter including a transformer with first and second matched polarity windings and a switch to switch dc power to said first winding... Agent: Tarolli, Sundheim, Covell & Tummino L.L.P.

20080037294 - Switch mode power supply controllers: This invention generally relates to discontinuous conduction mode switch mode power supply (SMPS) controllers employing primary side sensing. We describe an SMPS controller which integrates a feedback signal from a point determined by a target operating voltage to a peak or trough of an oscillatory or resonant portion of the... Agent: Schwegman, Lundberg & Woessner, P.A.

20080037297 - Digitally controlled current-mode switched power supply: Disclosed is a current mode switched power supply. The current mode switched power supply includes a switching element and a power stage coupled to the switching element and configured to provide, in response to the switching of the switching element, an output voltage and a feedback voltage related to the... Agent: Law Office Of Jeffrey M. Weinick, LLC

20080037296 - Green-mode flyback pulse width modulation apparatus: A green-mode flyback pulse width modulation apparatus adopting a bipolar transistor structure IC process is used in a power supply. An oscillator circuit outputs a periodic clock signal to a control terminal of a power switch through an amplifier circuit for periodically turning on the power switch. A latch circuit... Agent: Rosenberg, Klein & Lee

20080037300 - Control apparatus for semiconductor power converter: The three-phase semiconductor power converter 1 provides an AC output. The voltage of the AC output is changed by the transformer 12. The control apparatus 14 for controlling the power converter 1 includes an asymmetrical magnetization suppressive controller 15 to generate a correction value for each of basic fixed-pulse switching... Agent: Oblon, Spivak, Mcclelland Maier & Neustadt, P.C.

20080037301 - High voltage generator of the dac-controlled type: A high voltage generator of the DAC-controlled type, has an input terminal connected to a first voltage reference and an output terminal providing an output voltage and comprises at least a voltage control circuit and a charge pump circuit inserted, in series to each other, between the input and output... Agent: Seed Intellectual Property Law Group PLLC

20080037290 - Ac-dc converter and method for driving for ac-dc converter: A device for converting AC voltage to DC voltage. The device includes an AC input circuit, a rectifier circuit, a first switch, and a second switch. The AC input circuit includes a pair of first input terminals to which AC current is input, a pair of first output terminals, and... Agent: Woodcock Washburn LLP

20080037291 - Dc-ac converter and method of supplying ac power: A dc-ac converter capable of supplying a finely regulated ac drive voltage to a load is provided. For this purpose, the converter includes, in a primary winding of a transformer, a full-bridge or half-bridge type semiconductor switch circuit whose switches can be controlled, by pulse-width modulation. Transformer has a secondary... Agent: Hogan & Hartson L.L.P.

20080037295 - Dc-ac converter and method for protecting dc-ac converter from overcurrent: A DC-AC converter for converting DC voltage to AC voltage. The converter includes a conversion circuit for converting DC voltage to voltage having a polarity corresponding to AC voltage. A filter circuit receives the converted voltage, smoothes the converted voltage, and outputs the smoothed voltage as AC voltage. A first... Agent: Woodcock Washburn LLP

20080037298 - Common-mode filtering device and speed variator comprising such a device: The invention relates to a filtering device which includes a common-mode inductor (LF) comprising a winding (L1, L2) on each line of an AC power supply and a magnetic core made up of a first torus (T1) and a second torus (T2). The first torus (T1) has a first magnetic... Agent: Oblon, Spivak, Mcclelland Maier & Neustadt, P.C.

20080037299 - Method for driving dc-ac converter: A method for driving a converter that converts DC voltage to AC voltage. A voltage conversion circuit has first input terminals and first output terminals insulated from the first input terminals. A filter circuit has second input terminals and second output terminals. A first switch circuit connects the first output... Agent: Woodcock Washburn LLP

20080037302 - Synchronous rectification circuit for power converters: A synchronous rectification circuit for power converters operable under fixed and/or variable frequencies where no current sense circuit or phase-lock circuit are needed is provided. It has a power switch coupled to a transformer for the rectification. A signal-generation circuit is used for generating a control signal in response to... Agent: J C Patents, Inc.

20080037304 - Inverter device and method for designing duty cycle setting section of inverter device: An inverter device has a DC/AC inverter section that converts input DC voltage into AC voltage with a rectangular wave and outputs the AC voltage. A duty cycle setting section sets a duty cycle for controlling turning on and off of a switching element of the DC-AC inverter section by... Agent: Woodcock Washburn LLP

20080037303 - Light emitting device: An object of the invention is to suppress the amount of heat generated by a light emitting diode and prevent the light emitting diode from being overheated without reducing the amount of emitted light even when the light emitting diode is a high-power light emitting diode. A light emitting device... Agent: Reed Smith, LLP Attn: Patent Records Department

20080037305 - Monopolar dc to bipolar dc to ac converter: An electrical DC-to-AC power conversion apparatus is disclosed that is primarily intended for use with solar photovoltaic sources in electric utility grid-interactive applications. The invention improves the conversion efficiency and lowers the cost of DC-to-AC inverters. The enabling technology is a novel inverter circuit topology, where throughput power, from DC... Agent: Thelen Reid Brown Raysman & Steiner LLP

20080037306 - Power management method and device for low-power displays: A device and method for supplying a display, such as a liquid crystal display, for example a bistable ChLCD, with drive voltages for extremely low power operation. The method and the device implementing the method provides an energy storage device and a voltage converter being utilized to store energy in... Agent: Pearne & Gordon LLP

20080031015 - Switching mode power supply (smps) device, image forming apparatus including the smps device, and method of driving the smps device: A switching mode power supply (SMPS) device includes a power converting part that converts an input voltage into an output voltage according to a switching signal, and outputs a primitive switching signal for use in varying a frequency of the switching signal based on power drawn by a load receiving... Agent: Stein, Mcewen & Bui, LLP

20080031016 - Simple zero current switch circuit: A simple zero current switch circuit includes a first coil set and a second coil set that are wound at a selected coil ratio and bridge electrically an energy storing inductor, an output diode and a conduction switch of a power-factor corrector. The leaking inductance of the first coil set... Agent: Birch Stewart Kolasch & Birch

20080031017 - Light load regulator for isolated flyback converter: A regulator may include a load voltage sensing circuit configured to generate a feedback signal representative of output voltage from an isolated flyback converter. The regulator may include a pulse generator configured to controllably generate the pulses and to increase at least one off time and at least one period... Agent: Mcdermott Will & Emery LLP

20080031018 - Regulator for isolated flyback power supply using primary side sensing: A regulator for an isolated flyback power supply using primary side sensing. The regulator may include an error circuit configured to generate an error signal representative of the difference between a target value and a measured value, a sample and hold circuit, and a controller circuit. The controller circuit may... Agent: Mcdermott Will & Emery LLP

20080031020 - Circuit and method for detecting electric current: Provided are a circuit and method for detecting an electric current which are capable of controlling the amount of electric current by detecting a load current of a current source using a switching type converter when controlling the load current of the current source which requires a high current, and... Agent: Sughrue Mion, PLLC

20080031022 - Dc power conversion circuit having self-auxiliary power and self-protection: A DC power conversion circuit having self-auxiliary power and self-protection against a short or open load circuit includes a DC voltage source, a driving circuit, and an auxiliary circuit. The DC voltage source is used for providing a DC power. The driving circuit includes a switch, a first resistor, a... Agent: North America Intellectual Property Corporation

20080031023 - Semiconductor integrated circuit including charge pump and electronic device including the semiconductor integrated circuit: A semiconductor integrated circuit is electrically connected to first to fourth capacitors and includes first to eleventh switches. A tenth switch has a first terminal electrically connected to a second terminal of the second capacitor, and a second terminal electrically connected to a first terminal of the third capacitor. An... Agent: Fish & Richardson P.C.

20080031024 - Method in connection with network converter, and network converter: A method in connection with a network converter, and a network converter, the network converter comprising two or more network converter modules coupled in parallel, and first control means for controlling the network converter modules. The method comprises the steps of controlling the network converter modules by the first control... Agent: Dykema Gossett PLLC

20080031025 - Dc power conversion circuit with constant current output: A DC power conversion circuit with constant current output includes a DC voltage source, a driving circuit and a control signal generator. The DC voltage source is used for providing DC power. The driving circuit includes a switch, a resistor, a diode, and an inductor. The switch has three ends,... Agent: North America Intellectual Property Corporation

20080031014 - Ac/dc converter comprising plural converters in cascade: The present invention relates to an AC/DC converter (1) of the type having an AC/DC conversion stage (2) and a DC/DC conversion stage (3), the AC/DC conversion stage (2) comprising an input filter stage (4), an input rectifier stage (5) and a tracking boost converter stage. The boost converter stage... Agent: Birch Stewart Kolasch & Birch

20080031019 - Universal power conversion methods: Methods and systems for transforming electric power between two or more portals. Any or all portals can be DC, single phase AC, or multi-phase AC. Conversion is accomplished by a plurality of bi-directional conducting and blocking semiconductor switches which alternately connect an inductor and parallel capacitor between said portals, such... Agent: Groover & Associates

20080031021 - Ac/dc converter with low anharmonic currents: This AC/DC converter is an isolated converter with switch-mode current regulation by means of a controlled switch (5). The controlled switch (5) is protected by a current limiting device (9, 7) obeying a peak current setpoint proportional to the instantaneous voltage from the power supply source (Vin). This allows the... Agent: Lowe Hauptman & Berner, LLP

20080031026 - Automatic sensing power systems and methods: An automatic sensing power system automatically determines a power requirement for an electrical device, converts power to the required level, and outputs the power to the electrical device when the electrical device is connected to the automatic sensing power system... Agent: Polsinelli Shalton Flanigan Suelthaus PC

20080031027 - Method and apparatus for reducing body diode conduction of synchronous rectifiers: A circuit for controlling the operation of synchronous rectifiers. The circuit delays the turn-off of the synchronous rectifiers in accordance with the load current. The magnitude of the load current is examined to determine which of a plurality of delay elements is selected to delay turn-off of the synchronous rectifiers.... Agent: Harness, Dickey & Pierce, P.L.C

20080031028 - Dc-ac converter and controller ic thereof: A semiconductor switch circuit is connected to a primary winding of a transformer having a secondary winding connected to a load. The semiconductor switch circuit has switches controlled by PWM to provide a controlled constant current. In the inventive inverter, constant current control is performed by PWM operation of the... Agent: Hogan & Hartson L.L.P.