Expert Details

Expert in Power Electronics and Switched Mode Power Supplies

Expert ID: 108497 Arizona, USA

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Expert has spent a large part of his career developing products in technical leadership positions in the general category of power electronics. He is a member of the IEEE Power Electronics Specialists Society and has attended and presented papers and seminars at the IEEE Power Electronics Specialists Conference, the Applied Power Electronics Conference, and High-Frequency Power Conversion Conferences. Expert has developed and published a mathematical model and associated spreadsheet for topology selection and resource allocation for optimal converter design for a given set of operating conditions and is an expert in design tradeoffs. He holds thirty-two patents and has several more patents pending. His inventions include several new converter families with zero voltage switching and universally applicable zero voltage switching cells that can be used to transform hard switching converters into soft switching equivalents. Several power conversion companies are using Expert's inventions on their leading-edge products. He has developed synthesis techniques that transform known circuits with pulsating terminal currents and poor EMC into new circuits with improved terminal ripple current properties and common mode noise cancellation. He has invented other circuit forms that improve efficiency and simplicity. Expert has invented a new planar magnetic structure that improves both efficiency and power density. More recently he has been involved in the design and development of grid-connected inverters for solar cell arrays, circuit design for wide bandgap semiconductor devices, drivers for solid-state lighting applications and drivers for silicon carbide field effect transistors. He has also served as the electronic system architect for the development of a Power Supply In Package (PSIP) product that exceeds the power density and efficiency of prior art products by a wide margin.

Expert has designed single and multi-output AC to DC converters of the forward, boost, and flyback types for various applications. He has designed 115 VAC input types and compliant input types that can operate over both 115 VAC and 230 VAC range for domestic and European mains applications. He has also designed power factor correction systems and holds a patent on a power factor correction system that accomplishes both tightly regulated line current and tightly regulated DC output voltages with significant efficiency, size, weight, and cost improvements over the prior art.

Expert has designed many single and multi-output DC to DC converters including both isolated and non-isolated types for a wide variety of applications. He holds patents and has patents pending on many new DC to DC converter topologies that improve efficiency, packaging density, and EMC over the existing art. One example of a new invention is a buck converter that accomplishes zero current ripples at both input and output terminals. This buck converter requires only two power MOSFETs, one magnetic circuit element (which can be a toroid or an Ecore) a control circuit, and a few capacitors. He has also invented several zero voltage switching techniques that can transform hard switching converters into more efficient soft switching equivalents capable of operating efficiently at the higher switching frequency and higher power density.

Expert has designed both switched-mode and linear power supply circuits as well as special purpose power supply circuits for applications such as forced current sharing parallel redundant systems, inrush current and inrush current slope limiting, multi-output sequencing, hold up circuits, and input and output filters for interface and noise control. Expert has designed low-cost commercial power supplies and high frequency, high density, high-performance circuits for military and space applications.

Expert has performed design, analysis, and modeling of switched-mode power supplies. His work includes a full spectrum of applications, power levels, and topologies. He has been active in all phases of development from conceptualization to manufacturing. Expert is responsible for some of the leading commercial advances in the field of switched-mode power supplies.

Expert has designed, analyzed, and modeled voltage regulator circuits. He has considerable education and experience in control loop stability analysis for amplifiers and voltage regulators. He has contributed an innovative method for improving load regulation under varying load conditions using the concept of negative output impedance about which a paper was published. He has performed trade-off studies, modeling, and analysis comparing line regulation in current mode and voltage feed-forward mode converters.

Expert has designed a wide range of amplifier types including audio power amplifiers, video amplifiers for CRT displays, video deflection amplifiers, audio pre-amplifiers, and control amplifiers for servo systems. He is also highly accomplished at low noise design for sensor interface.

Expert has designed several types of filter circuits including electromagnetic interference (EMI) suppression filters and has performed EMI filter analysis for high-frequency switched-mode power supplies for both differential and common mode noise rejection.

Expert has designed a wide variety of analog circuits for a wide variety of applications including audio, instrumentation, industrial automation control, servo control, communications, and power control.

Expert has designed a variety of switching and timing circuits for security alarm systems, instrument systems, automation systems, and power supply sequencing.

Expert has provided much of the conceptual design and some of the implementation of a 32-bit Windows-based power converter simulation tool which accomplishes precise time and frequency domain simulation of complex power converter systems.

Expert has used electronic modeling extensively as a design and analysis tool for a variety of circuit types. He has used PSPICE extensively to perform both average and real-time modeling of power converter circuits and systems. He has also worked extensively with Analog Workbench and with Excel as a digital signal processing machine. He has written a computer program for the synthesis of active filters. He has developed spreadsheets for magnetic circuit design aids.

Expert has designed both linear and switched-mode audio power amplifiers for a number of different applications. He recently designed a zero voltage switching amplifier with 1 megahertz ripple frequency for an audio noise cancellation application.

Expert designed a high power 60-hertz input, 3 phase 400 hertz output uninterruptible power supply combining a power factor corrected AC to DC converter and battery charger and three DC to AC converters.

Expert has been involved in the development of a very high-efficiency grid-connected inverter for a solar cell array application. He has designed a high power DC to AC converter as part of an uninterruptible power supply system.

Expert has designed high power UPS with AC output. He has also designed DC output supplies with substantial hold up capability and charging systems.

Expert has designed control systems for factory automation, instrumentation, engine control, and quality control. He has used board-level computers with microprocessor development systems, embedded microcontrollers, desktop computers, and programmable controllers. He has worked with a wide variety of motors and actuators, sensors, switches, and display devices, and has developed circuits for interfacing, multiplexing, decoding, and driving these devices under computer control.

Expert has done control loop dynamic stability analysis for many types of closed loop systems including engines, power converters, motor systems, valve systems, electro-surgical generators, and high and low-frequency amplifiers. He has also been active in modeling new types of control systems with performance improvements over the conventional PID-type controllers. He has experience using network analyzers for generating Bode plots for control loop stability analysis.

Expert has authored several papers which describe converters with resonant transition designs. He developed and holds a patent on a low parts count converter topology which accomplishes zero voltage resonant transition switching and low-recirculating energy. He has also developed high-power resonant transition phase shift modulated converters and resonant transition switching audio power amplifiers.

Expert has been involved in the development of power factor correction schemes for a variety of applications. As part of an uninterruptible power system, Expert designed a boost pre-regulator power converter that achieved near unity power factor. He holds patents and has others pending on power factor correction schemes.

Expert has taken a special interest in electromagnetic interference for power converters. He has designed power converters with exceptional performance in regards to electromagnetic interference for noise sensitive space applications. He holds four patents on circuits and techniques for improving electromagnetic compatibility of power conversion circuits. He has also taught a professional advancement course on EMC enhanced power supply design and will be teaching expanded courses on EMC for power supplies in the future.

Expert has designed very successfully electromagnetic interference filters for power supplies and has taken a special interest in this subject area. He has taught electromagnetic interference filter design as a part of a professional advancement course on EMC enhanced power supply design.

Expert has designed many electronic circuits for power conversion. He has invented many new circuits and new circuit synthesis techniques for power conversion circuits. Most of his 15 granted patents and three patents pending reveal new electronic circuit designs for power conversion.

Provided Galil Medical with an approach for improving power factor correction and increasing deliverable power to a motor for the compressor for a cryogenic cooler. Provided Microsemi with a system circuit design for the first commercially available driver IC for Silicon Carbide vertical JFETs and bipolar transistors and helped with the debugging process that leads to its successful release. Provided ASIC Advantage/Microsemi with a working model and an electronic system design for high efficiency, high-density Power Supply In Package product. Provided system and circuit design and debugging help for several isolated and non-isolated high efficiency and high-density product designs to Elektra. Provided a power conversion design review for Belmont Industries that pointed out design flaws that would have resulted in greater cost, size, and weight.

Expert may consult nationally and internationally, and is also local to the following cities: Phoenix, Arizona - Glendale, Arizona - Scottsdale, Arizona - Peoria, Arizona - Flagstaff, Arizona

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Education

Year Degree Subject Institution
Year: 1986 Degree: M.S.E.E. Subject: Electrical Engineering Institution: Johns Hopkins
Year: 1972 Degree: M.S. Subject: Physics Institution: Lehigh University
Year: 1970 Degree: A.B. Subject: Mathematics and Physics (two majors) Institution: Franklin and Marshall College

Work History

Years Employer Title Department Responsibilities
Years: 1990 to Present Employer: Undisclosed Title: Consultant Department: Responsibilities: Designs high-frequency, high-efficiency, high-density power converters and power supply simulation software. Expert gives professional advancement courses on EMC enhanced power supply design, high efficiency power supply design, numerical topology selection, gate drive design, and soft switching circuits and techniques. He invented some of the most compelling power converter circuits in existence.
Years: 1999 to 2000 Employer: Agincourt Power Title: Technical Consultant Department: Responsibilities: He designed high-density, high-frequency power supplies and invented new power converter circuits.

Vice President and Co-Founder This company was not able to find funding. I helped develop marketing materials for funding and began the development of a first product which was to be a high efficiency, high density isolated PFC converter for high power external adapter application. The PFC external adapter includes a mechanism which reduces the amount of power processed compared to all other isolated PFC external adapters. A patent application has been filed for the invention.
Years: 1988 to 1990 Employer: Power Trends Title: Staff Engineer Department: Responsibilities: Designed power supplies, deflection circuits, and video circuits for CRT displays.

Principal Staff Engineer, Highest position on the technical ladder, parallel to VP Engineering, designed a 30 watt dual output high efficiency, high density power supply under budget for datacom/telecom and DSP applications. Contributed 8 invention disclosures and contributed new innovations and know how to all the designs of the other design engineers.
Years: 1987 to 1988 Employer: Honeywell BCASD Title: Engineer Department: Responsibilities: Staff Engineer ( Staff Engineer is the Honeywell technical track equivalent to Engineering Section Head.)
Principal Engineer Solved technical problems in production designs for avionics CRT display systems including video and deflection amplifiers, analog signal processor, high and low voltage power supplies, and sensor interface circuits. For a new product designed a video amplifier, ambient light detection system, phosphor protection circuit, and a multi-output multi-feature low voltage switching power supply.
Years: 1979 to 1987 Employer: United Silicon Carbide Title: Consultant Department: Responsibilities: Designed automated test and sorting systems.
Years: 1972 to 1978 Employer: Anne Arundel Community College Title: Assistant Professor of Physics Department: Responsibilities: Instructor Performed instruction of college physics, student advising, division, and college administrative committee work. Served as faculty adviser to the outing club and student-operated FM broadcast station.

Assistant Professor
Instructor Performed instruction of college physics, student advising, division and college administrative committee work. Served as faculty advisor to the outing club and student-operated FM broadcast station.

Government Experience

Years Agency Role Description
Years: 1990 to 1992 Agency: U.S. Navy Role: Consultant to Quadri Electronics Corp. Description: Developed space power supplies for the MSX Satellite, a "star wars" experimantal satellite to assess mid-course correction detection.
Years: 1994 to 1995 Agency: U.S. Air Force Role: Consultant to AEL Defense Industries Description: He developed a high power high density high efficiency power cnverter for electronic warfare application.
Years: 1992 to 1993 Agency: U.S. Navy Role: Consultant to Tiernay Turbines Description: Developed power supplies, power drivers, and electronic engine control circuits for the Universal Jet Engine Starter Unit for carrier-based aircraft.
Years: 1987 to 1988 Agency: NSA Role: Engineer for EVI, Inc. Description: He developed a compact power supply for an intelligence application.

International Experience

Years Country / Region Summary
Years: 1996 to 1998 Country / Region: China, Hong Kong Summary: Worked with a Chinese assembler operation correcting design flaws in existing designs and implementing a new power supply design that is currently in high volume production with very high yields.
Years: 1996 to 1996 Country / Region: Canada, Britsh Columbia Summary: He provided a working breadboard of a servo amplifier for a robotics welding application.
Years: 1986 to 1987 Country / Region: France, Paris Summary: Served as a technical liaison to the French chemical/biological defense establishment for the U.S. Army.
Years: 1985 to Present Country / Region: France Summary: He served as technical liaison to a French government organization for over a year. He visited Paris and received French counterparts during that period.

Career Accomplishments

Associations / Societies
Expert is a member of IEEE, the Audio Engineering Society, Pi Mu Epsilon, and Sigma Pi Sigma.

Member-at-large APEC 2006 Program Committee and Topic Chairperson
PSMA 2003 through 2005, Energy Efficiency Committee
IEEE Life Member
Sigma Pi Sigma (Physics Honor Society)
Pi Mu Epsilon (Mathematics Honor Society)
Awards / Recognition
He received the U.S. Army CRDEC Most Outstanding In-house Laboratory Independent Research Project Award.
Publications and Patents Summary
Expert has 32 patents issued and many others pending. He has authored ten conference publications and has authored several articles for trade publications. He has also authored one of the leading power conversion simulation/analysis commercial software packages.

Additional Experience

Expert Witness Experience
Expert has conducted prior art searches for several clients involved in patent infringement litigation. He has been a plaintiff in a patent infringement lawsuit and has prepared, with the help of attorneys, briefs, expert witness reports, compliance matrices, interrogatories, document production requests, requests for admission, illustrative presentation materials for hearings, and strategy and questions for opposition witnesses. Expert provided almost all of the technical input for this litigation. Ex[ert has been deposed for approximately 24 hours and has prepared and performed a technical presentation at a Markman Hearing. As a litigation consultant Expert has advised about patent validity, reviewed products offerings to determine potential infringement and provided technical input to complaints to ensure technical correctness. He has provided advice and education to patent attorneys regarding technical issues related to infringement.
Training / Seminars
Expert taught a professional advancement course on EMC enhanced power supply design. Power Electronics Conference (APEC), and Power Systems World (PSW). He has taught seminars in High Efficiency Design and PSW. He taught a seminar in Soft Switching Circuits and Techniques at APEC. He taught a seminar on Gate Driver Design, Component Parasitics and Non-idealities. Most of the seminars he presented at the APEC conference were the highest attended seminars of the conferences and 3 of his seminars were standing room only. He also prepared a circuit board layout guidelines document for Quadri Electronics as an aid to less-experienced engineers in laying out power supply printed circuit boards for low EMI.
Vendor Selection
As an engineer designing power conversion circuits, Expert has much experience locating and selecting vendors for power conversion applications.
Marketing Experience
Expert has spent a great deal of time and effort studying the issues of optimal topology selection, design trade offs and optimal resource allocation. As a result of his efforts he was able to develop a mathematical model for numerical topology selection. He has published a series of articles in Power Electronics Magazine on this model. He has taught this model as part of his seminars on High Efficiency Power Supply Design. He is clearly a leading industry expert in the area of design trade offs and optimal design for a given set of operating conditions. Many,if not most, power supply designs either do not use the best available topology or do not allocate resources optimally.

Expert has also studied issues related to EMC in detail and has a deeper understanding of how to go about designing electromagneitically compatible products as part of an original design.
Other Relevant Experience
Expert invented the commercially viable forms of the ZVS active clamp flyback converter and ZVS coupled inductor buck converter and improved versions of these converters with zero ripple terminal currents. These inventions are in high volume commercial production. He invented an enabling technology in the form of a new isolated topology that offers the highest available power density of any known isolated topology for most isolated applications. He invented universally applicable zero voltage switching cells. He invented hundreds of new converter topologies for high-density applications and new versions of old converters with non-pulsating, zero ripple terminal currents, and other EMC enhancing properties. He also invented a new planar magnetic structure with improved efficiency and power density.

More recently Expert has developed new circuits that achieve both lower conduction losses and elimination of switching losses applicable to many isolated products. He has also developed some new simple ZVS bridgeless PFC circuits and a converter topology that is more efficient than a buck converter for high step down ratios.

Language Skills

Language Proficiency
German Has had some formal education (five years) in German, but this education is pretty well dated.

Fields of Expertise

power electronics, high-frequency electric power converter, resonant transition power converter, alternating-current to direct-current conversion, alternating-current to direct-current converter, DC to DC conversion, DC-to-DC converter, power-supply circuit, linear power-supply circuit, switched-mode power supply circuit, voltage regulator, regulating electric circuit, amplifier, electric filter, analog circuit, analog multiplier, switching power converter design, timing device, electronic circuit modeling, electronics modeling, audio power amplifier, alternating-current to alternating-current conversion, direct-current to alternating-current conversion, uninterruptible power system, control electronics science, control loop dynamic analysis, resonant transition power conversion, power factor controller, electromagnetic interference, electromagnetic interference filter, electronic circuit design, sensor noise, Bessel filter, doubler, direct-current inductor, electronic filter, automation control, three-phase power, military standard-461, voltage-controlled amplifier, voltage-regulator circuit, Analog Workbench, video amplifier, compressor (compander system), logarithmic amplifier, PSPICE software, analog circuit application, Microsoft Excel, linear amplification, voltage-controlled oscillator, deflection yoke, electronic display instrument design, primary winding, converter, analog signal processor, analog design application, alternating-current to alternating-current converter, direct-current to alternating-current converter, constant-current source, electric-power converter, electric-power conversion, energy conversion, analog-signal processing, analog circuit design, alternating-current transformer, digital circuit design, circuit design, wave-generating circuit, electronic circuit, magnetic amplifier, cathode-ray tube, analog signal, power transformer, current transformer, magnetic field, audio-frequency amplifier, power amplifier, voltage regulator diode, power inductor, microcontroller, low-pass filter, high-power amplifier, half-wave rectifier, full-wave rectifier, frequency filter, expander (compander system), electric circuit, digital signal processing, digital circuit, control loop, battery charger, all-pass filter

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