PSMA website
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Table of contents
  1. APEC The World's Best Power Electronics Event Returns to Anaheim
  2. You are Invited to Attend the PSMA Annual Meeting at APEC 2019
  3. Meet Your Directors
  4. About Our Members
  5. Welcome to PSMA
  6. PSMA Magnetics Committee and IEEE PELS High Frequency Magnetics Workshop
  7. PSMA Capacitor Committee and IEEE PELS Capacitor Workshop:
  8. International Workshop on Integrated Power Packaging (IWIPP) 2019
  9. The 7th Workshop on Wide Bandgap Power Devices and Applications (WiPDA 2019)
  10. INTELEC® 2019 The International Communications Energy Conference
  11. The Silent Power of Supercapacitors
  12. Proper Design of the Power Supply's Input EMI Filter Protects against Power Line Transients
  13. Solar Energy Stock Index: Q4 2018
  14. Solar Energy DealReader: Q4 2018
  15. EMS Quarterly Review: Q4 2018
  16. Events of Interest – Mark Your Calendar
Contents | Next->

If you or anyone in your company is interested in getting on the distribution list for future issues of PSMA UPDATE, please send e-mail to: Be sure to include your name and the name of your company.

Previous issues of update: Q2_2018 | Q3_2018 | Q4_2018

PSMA UPDATE is published and distributed via e-mail quarterly by the Power Sources Manufacturers Association. Send editorial information and comments to:

P.O. Box 418
Mendham, NJ 07945-0418

  (973) 543-9660
(973) 543-6207 (Fax)
Web Site:

Publisher: Stephen Oliver   Managing Editor: Lisa Horzepa

Permission to reprint information and articles as published is granted: a courtesy line is appreciated.

Membership in PSMA is open to any organization or corporation involved in the power sources and supplies industry. For membership information, visit our website or contact us by fax, telephone or email.

If you or anyone in your company is interested in getting on the distribution list for future issues of PSMA UPDATE, please send e-mail to: Be sure to include your name and the name of your company.



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APEC The World's Best Power Electronics Event Returns to Anaheim

B ack in 2004, APEC was held in the Disneyland Hotel and our conference attracted just over 2,000 attendees. Fifteen years later, we're back in Anaheim. But in 2019, we'll be meeting at the Anaheim Convention Center and we expect over 5,000 engineering professionals to participate!  APEC continues to grow, every year, as power electronics continues to drive many product advances across virtually every industry.  

The Conference Committee for APEC 2019 has put together:

  • A Plenary Session on Monday, March 18 that will feature world-class presentations to keynote our week-long conference. And new this year, if you can't make to the Monday plenaries, you can watch them on streaming video, courtesy of
  • Eighteen Professional Development Seminars on Sunday, March 17 and Monday, March 18, presented by world-class experts that are designed to bring you up to speed on critical power electronics design technologies and techniques.
  • A Technical Program from Tuesday, March 19 through Thursday, March 21is made up of an astounding 40 Presentation Sessions plus a Dialog (Poster) event held during the Thursday hosted lunch.  Over 600 high-quality, peer-reviewed papers will be presented.
  • An Industry Session program running concurrently with the Technical Program will once again offer 23 sessions, covering the latest developments from the industry's leading innovators.
  • Three controversial topics will be covered in our annual Rap Sessions on Tuesday, right after the exhibits close at 5:00 p.m. Grab a cool beverage and bring your questions for the panelists.
  • A crowded exhibit hall packed with the latest power electronics products.
  • The annual MicroMouse contest pitting teams from around the world to solve the maze the fastest with their intelligent motorized mice.
  • A terrific social event featuring lineup of 10 acclaimed food trucks, interactive, friendly-competition games, entertainment and music by a live DJ and caricaturists and tons more of fun activities you don't want to miss brings us all together on Wednesday evening.

Speaking for all of us on the APEC Conference Committee, I invite you to come to Anaheim to be part of our annual gathering. You really don't want to miss it.  Check the APEC website for details (

On the Saturday prior to the start of APEC2019, PSMA and PELS will be sponsoring two workshops, the fourth High Frequency Magnetics Workshop "Power Magnetics @ High Frequency" and the second Capacitor Workshop "The Impact of Wideband Technologies on Application of Capacitors - A Deep Dive on Capacitor Technology". For more information see the articles on each workshop in this issue of the UPDATE.

Provided by Greg Evans,
APEC 2019 Publicity Chair


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You are Invited to Attend the PSMA Annual Meeting at APEC 2019

T he 2019 PSMA Annual Meeting will be held in conjunction with APEC 2019 at the Anaheim Marriott in Anaheim, California on Monday March 18. A buffet breakfast at 7:30 a.m. will precede the meeting and individuals from member companies as well non-member guests are invited to attend and participate in a full agenda of topics of interest to the industry. At the meeting, you will have the opportunity to meet and interact with many of the students who received APEC Travel Support to present their papers at the Technical Sessions. Regular member company representatives will participate in the election of four Directors to serve on the PSMA Board for a three-year term beginning immediately and ending at APEC 2022. The detailed agenda for the meeting will be on the PSMA web site and will include reports from each of the technical committees and stimulating discussions on new PSMA initiatives for 2019 and beyond. The APEC 2019 Conference Chair will review the progress on APEC2019 and there will be a report on plans for APEC 2020 in New Orleans. There will also be an invited presentation from European Power Supplies Manufacturers' Association (EPSMA) to review their activities that should be of interest to PSMA members.

Members and guests are also invited to remain for the Board of Directors meeting that will immediately follow the Annual Meeting. Participation in these meetings will provide you with the opportunity to network with colleagues from other companies and to influence the direction of the PSMA and the power sources industry.

Another way to get more out of your company membership in PSMA is to get involved with one of our active technical committees. The Capacitor, Energy Harvesting, Energy Management, Industry-Education, Magnetics, Marketing, Power Electronics Packaging, Power Technology Roadmap, Reliability, Safety & Compliance, Semiconductor and Transportation Power Electronics committees all plan to hold open meetings during the week of APEC 2019. All are invited to participate or to just drop in any of these committee meetings to hear and provide input as the committee activities are being planned for the coming year. Visit the PSMA website to see the schedule of PSMA meetings and events at APEC 2019.

On March 16, 2019, the Saturday prior to the start of APEC 2019, PSMA and PELS will be sponsoring two workshops, the fourth High Frequency Magnetics Workshop - "Power Magnetics @ High Frequency" and the second Capacitor Workshop – "The Impact of Wideband Technologies on Application of Capacitors - A Deep Dive on Capacitor Technology". Information on these workshops are available in separate articles in this issue of the Update.

Be sure to visit us at the PSMA booth, in the APEC hub #539, in the exhibition area during APEC. PSMA is again sponsoring the popular PSMA/ APEC Passport Program in the Exhibit Hall. Visit the booths of participating PSMA members to enter your name into a raffle drawing.

We look forward to a good turnout at the PSMA meetings and a very busy and exciting week.

For the latest information on all of the activities planned during APEC 2019, visit us at


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Meet Your Directors

Four members of the Board of Directors are elected at the PSMA Annual Meeting held every year during the APEC conference. Each Director serves a three year term and is eligible to be reelected for one additional term.

In this issue we would like to introduce you to Brian Zahnstecher who is currently serving his first term.

Brian Zahnstecher
is a Sr. Member of the IEEE and Chair of the IEEE SFBAC Power Electronics Society (PELS) which was awarded 2017 Best Chapter awards at the local/national/worldwide levels concurrently (an unprecedented achievement).  He is the Principal of PowerRox, where he focuses on power design, integration, system applications, OEM market penetration, market research/analysis, and private seminars for power electronics.  .  He has successfully handled assignments in system design/architecting, AC/DC front-end power, EMC/EMI design/debug, embedded solutions, processor power, and digital power solutions for a variety of clients.

Brian leads the Power for the IEEE 5G Roadmap Applications & Services Working Group, authored the Group's position paper, and has lectured on this topic at major industry conferences  He previously held positions in power electronics with industry leaders Emerson Network Power (now Artesyn), Cisco, and Hewlett-Packard, where he advised on best practices, oversaw product development, managed international teams, created/enhanced optimal workflows and test procedures, and designed and optimized voltage regulators.  He has been a regular contributor to the industry as an invited keynote speaker, author, workshop participant, session host, roundtable moderator, and volunteer.  He has over 15 years of industry experience and holds Master of Engineering and Bachelor of Science degrees from Worcester Polytechnic Institute.

Brian is Co-founder and Co-chair of the PSMA Reliability Committee and Co-Chair of the PSMA Energy Harvesting Committee. He has served on the PSMA Board of Directors since 2017.

Provided by Brian Zahnstecher, PowerRox

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  About Our Members 
About Our Members


C oil Winding Specialist or CWS started as a design center for custom inductors, chokes, coils and transformers in the early 1980s in California. Its original objective was to provide custom designs for engineers in need of inductive and transformer products in a hurry. CWS was eventually incorporated in California in 2004 and today it is staffed with professional engineers trained in power electronics and magnetic. All designs are done in our California facility. Manufacturing is done in the U.S. and China with IS0 9001:2008 Certified Quality Management System.

In order to fulfill the original goal of providing a fast delivery of inductive and transformer parts to the engineering community, CWS has developed more than a thousand standard off the shelf inductors, coils and transformers. Also, CWS is the only direct manufacturer in the industry that provides online ordering of magnetic parts, inductors, coils and transformers.

CWS provides full service from design, prototyping, pre-production run to volume production. Our engineers have combined more than 40 years of experience in designing and manufacturing magnetic components from medical to military applications and can assist our clients with all your winding, inductor, coil, coil and transformer design needs. We will fill anything according to our clients needs. We will check your designs, test your ideas and concepts as well as build your magnetic products according to your specifications.

For more information, please visit our website or call 1 (800) 377-3244

Provided by Gennady Nyu, General Manager, Coil Winding Specialist


The ORNL quad and visitor's center.
Oak Ridge National Laboratory (ORNL), which celebrated its 75th anniversary in 2018, provides exceptional researchers with sophisticated equipment and unique facilities to solve some of the nation's most compelling challenges. As the largest US Department of Energy (DOE) open science laboratory, ORNL's mission is to deliver scientific discoveries and technical breakthroughs that will accelerate the development and deployment of solutions in clean energy and global security while creating economic opportunities for the nation.

ORNL's diverse capabilities span a broad range of scientific and engineering disciplines, enabling the Laboratory to explore fundamental science challenges and to carry out the research needed to accelerate the delivery of solutions to the marketplace.

ORNL supports DOE's national missions of:

  • Scientific discovery—We assemble teams of experts from multiple disciplines, equip them with powerful instruments and research facilities, and address compelling national problems;
  • Clean energy—We deliver technology solutions for energy sources such as nuclear fission/fusion, fossil energy, solar photovoltaics, geothermal, hydropower, and biofuels, as well as energy-efficient manufacturing, buildings, and transportation;
  • Security—We develop and deploy "first-of-a-kind" science-based security technologies to make the United States, its critical infrastructure, and the world a safer place.

ORNL supports these missions through leadership in four major areas of science and technology:

  • Computing—We accelerate scientific discovery and the technology development cycle through modeling and simulation on supercomputers, including Summit, the world's most powerful and smartest scientific supercomputer, advance data-intensive science, and sustain U.S. leadership in high-performance computing;
  • Materials—We integrate basic and applied research to develop advanced materials for energy applications. The latest frontier in materials research is at the nanoscale— designing materials atom by atom —and we leverage ORNL assets such as the Center for Nanophase Materials Science for breakthrough materials research;
  • Neutrons—We operate two of the world's leading neutron sources that enable scientists and engineers to gain new insights into materials and biological systems;
  • Nuclear—We advance the scientific basis for 21st century nuclear fission and fusion technologies and systems, and we produce isotopes for research, industry, and medicine.

Partnerships and Collaborations

Partnerships with other research institutions, universities, and industry are a vital resource for maximizing ORNL's impact. ORNL leads two major multi-institutional partnerships for DOE: the Center for Bioenergy Innovation, one of four DOE Bioenergy Research Centers, and the Consortium for Advanced Simulation of Light Water Reactors, a DOE Energy Innovation Hub. ORNL is also the lead institution for two DOE Energy Frontier Research Centers and hosts the project offices of two major DOE initiatives: the Exascale Computing Project and the US contributions to the international ITER fusion project.

Partnerships with academia help to build a robust pipeline of scientific and technical talent for the nation. ORNL and the University of Tennessee employ more than 250 joint faculty, including 14 Governor's Chairs recruited on the basis of their leadership in their fields, and have enrolled 221 students in the Bredesen Center for Interdisciplinary Research and Graduate Education since its founding in 2010. Industry and technology transfer partnerships increase the Lab's economic impact, speed deployment of ORNL-developed technologies, and strengthen innovation ecosystems regionally and nationally.

The laboratory held 746 patents from October 1, 2007 through September 30, 2018. It has some 150 active licenses of its technological developments in place with industry.

ORNL developed new coil designs for fast, wireless charging of electric vehicles.
A new power inverter for solar power installations packs more energy into a smaller package and makes use of 3D printed component.

Recent R&D Highlights:

  • Recent achievements from more than 75 years of scientific and technical contributions at ORNL include the following:
  • Producing actinium-227 to meet the demand for an effective FDA-approved drug to treat prostate cancer.
  • Restoring the nation's ability to produce plutonium-238 for deep space missions.
  • Developing a renewable 3D printing material made with the biorefinery by-product lignin.
  • Discovering an electrochemical process that converts carbon dioxide directly into ethanol.
  • Controlling photons to bring about quantum states and expand the information-processing capabilities of quantum computers.

Demonstrating wireless power transfer in the PEEM Lab.
An EV motor developed at the PEEM lab achieved 75% higher power than a comparably sized commercial motor, using ferrite, iron-based magnets instead of expensive rare earth permanent magnets.

Power Electronics and Electric Machinery Research

The Power Electronics and Electric Machinery (PEEM) Research Group, part of the National Transportation Research Center at ORNL, is a premiere resource for the U.S. Department of Energy's power electronics and electric machinery research.

Recent activities in the grid, automotive, and renewables research have driven advances in wireless and wired power charging, power inverters and converters, efficient motor control technologies, compact electric motors, and packaging. The Group's activities cover all these areas from invention to analysis, modeling, simulation, to in-house evaluation and prototyping of components.

Recent accomplishments include a 120-kW wireless charging system that achieves 97% efficiency, a new toolkit for electromagnetic devices to accelerate motor design, the world's first demonstrations of bi-directional wireless power transfer between a building and a vehicle, and 3D-printed inverters for vehicle and renewable energy applications.

The PEEM Group at ORNL provides science and technology innovations in power electronics and electric machinery from concept to implementation through transformational broad-based research that impacts affordable clean energy solutions for transportation, grid, and renewables.

PEEM provides a broad-based capability and an extensive list of equipment to build and evaluate power conversion circuit prototypes in-house starting from bare die. On the motors side, PEEM does research on electromagnetic characterization of motor materials, modeling and design, in-house prototyping and evaluation.

There are many ways to work with ORNL, including a cooperative research and development agreement, a strategic project partnership agreement, or a user agreement under DOE's User Facility program. Each agreement is developed based on a user's desire to protect research results or inventions.

For more information, visit

Provided by Kim Askey, Communications Coordinator,
Energy and Environmental Sciences Directorate, Oak Ridge National Laboratory


Editors Note: We would like to feature your company in a future issue of the Update. Please contact the Association Office for information about how to submit an article for consideration.

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Welcome to PSMA
   We are pleased to welcome 4 new member companies this quarter. We hope your company is a member. To learn about the benefits of membership, please visit our web site


Robert Roessler
601 Shiloh Rd
Plano, TX 75074
Telephone: 214-326-9537

ABB is a pioneering technology leader in electrification products, robotics and motion, industrial automation and power grids, serving customers in utilities, industry and transport & infrastructure globally. Continuing a history of innovation spanning more than 130 years, ABB today is writing the future of industrial digitalization with two clear value propositions: bringing electricity from any power plant to any plug and automating industries from natural resources to finished products. In 2018, ABB acquired GE Industrial Solutions (GEIS), GE's global electrification solutions business. GEIS will be integrated into ABB's Electrification Products (EP) division. ABB operates in more than 100 countries with about 135,000 employees.


Shenzhen Honor Electronic

Albert Wang
Gushu 2nd Road, Xinghui Industrial Park
Shenzhen, Guangdong
Telephone: 32937615

Shenzhen Honor Electronic Co.,Ltd is one of the largest suppliers of switching power adapter and IPC, and a service provider of Quick charger, PD charger, type-C charger and intelligent home devices. They have been awarded as "National Hi-tech Enterprise" and "Shenzhen Hi-tech Enterprise" and are members of the California Energy Association and the China Energy Association. All of Honor's products have successfully passed safety certifications all over the world with technology and quality at the international advanced level.

Established in 1996, Honor is headquartered in Shenzhen, with private Industrial Parks in Ganzhou and Vietnam, and branches in USA, Germany, South Korea, Taiwan, HongKong, Beijing and Hangzhou.

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PSMA Magnetics Committee and IEEE PELS High Frequency Magnetics Workshop

Power Magnetics @ High Frequency
 Date: Saturday March 16, 2019
Anaheim, California

The PSMA Magnetics Committee together with IEEE PELS will hold the fourth "Power Magnetics @ High Frequency" workshop on Saturday, March 16, 2019 -  the day before and in the same venue as APEC 2018 at the Anaheim Convention Center, Anaheim, California.

The target audience for this workshop is all who wish to achieve higher power densities, low profile aspect ratio, higher efficiencies, and improved thermal performance.  The workshop content is especially suitable for:

DESIGNERS of power magnetic components
MANUFACTURERS of magnetic materials and magnetic structures
FABRICATORS of magnetic components
PROVIDERS of modelling and simulation software
MANUFACTURERS of test and characterization equipment

Workshop attendees are invited to arrive to the meeting room between 7:00 and 8:00 AM for a buffet breakfast and informal discussions with their colleagues and peers. There will also be an opportunity to preview the technology demonstrations during the breakfast session.

The workshop will consist of morning (ac power losses) and afternoon (thermal considerations for magnetic design) technical sessions and a lunchtime interactive technology demonstration session. The two technical lecture presentation sessions will each be followed by a panel Q&A. The technology demonstrations will also be available during the breakfast prior to the opening session and during the networking session at the end of the day's events.

The morning technical session will feature a keynote presentation and four lecture style presentations concluding with two panel Q&A sessions. There will be a five-minute Q&A after each lecture presentation. The tentative schedule for this session is:

  • Gerald Hurley, National University of Ireland Galway will present a keynote presentation "Factors Influencing AC Power Losses"
  • Marcin Kacki, SMA Magnetics, will present "Magnetic Core Dimensional Effects – Flux Propagation in Ferrites"
  • Gerald Hurley and Marcin Kacki will lead a panel discussion on factors influencing ac power losses. Everyone's participation is encouraged.
  • John Hayes, University College Cork will present "Series-coupling Characterization of High-Leakage Magnetic Components"
  • Charles Sullivan, Dartmouth, will present "Lumped Transmission Line Model for Displacement and Conductive Eddy Currents in Ferrite Cores"
  • Seung Moon, National Energy Technology Laboratory, will discuss "Standardized Testing and Data Sheets"
  • John Hayes, Charles Sullivan, and Seung Moon will lead a panel discussion regarding issues associated with ac power loss issues. Everyone's participation is encouraged.

The second session "Technology Demonstrations" will be coincident with the luncheon period. This will include an interactive session of technology demonstrations and/or presentations each addressing specific technical disciplines and capabilities consistent with the workshop agenda. The individual technology demonstrations will repeat on fifteen-minute intervals with a ten-minute presentation and a five-minute Q&A during each interval. Workshop attendees are encouraged to move between the technology demonstrations on fifteen-minute intervals so they can cover as many of the demonstrations as possible during the session as well as to allow reasonably small groups for each technology demonstration.

The technical capabilities and disciplines that will be demonstrated and displayed during the technology demonstration session are as follows:

  • Seung Moon, NETL: Strain Annealing to Improve Performance of Magnetic Materials
  • Mark Allen, UPENN: Magnetic Materials and fabrication Processes for Micro Inductors
  • Marcin Kacki, SMA Magnetics: Measurements to Demonstrate Dimensional Effects of Ferrites
  • Chris Oliver, Micrometals:  Development of Distributed Gap Powder Core Materials to Address Higher Frequency Applications > 1 MHz at High Operating Temperature Ranges
  • JC Sun, Bs&T:  Pulse Testing of Magnetic Cores and Inductors
  • Jenna Pollock: Fundamentals of L, R, |Z| Measurements
  • Apurva Ingle, Wurth Elektronik: Correlation of Calculated Power Losses with Temperature Rise Measurements
  • Hebberly Ahatlan, Wurth Elektronik: Impact of near Magnetic Fields on Power train Performance
  • Chuck Wild, Dexter Magnetics:  Emerging Magnetic Materials and Magnetic Structures. 
    • TOKIN a KEMET Company: Kenichi Chatani
    • Hitachi: Mark Rine
    • Fair-Rite: John Lynch

The third technical session will feature a keynote presentation and three lecture style presentations concluding with a panel Q&A session. Each presenter will speak for thirty minutes followed by a five-minute Q&A. The tentative schedule for this session is as follows:

  • Peter Wilson, University of Bath will present a keynote overview covering "Recent Trends in Design and Techniques to Influence Thermal Performance of Magnetic Components"
  • Subhashish Bhattacharya, NCSU FRREDM, will present "Thermal Issues Associated with the Design of Solid-State Transformers"
  • George Slama, Wurth Elektronik, will present "Getting the Heat Out"
  • Qichen Yang, Georgia Tech RISE, will present "Design Trade-Offs of Power Losses and Impact on Thermal Performance Of Magnetic Components"
  • Panel Discussion: Peter Wilson, Subhashish Bhattacharya, George Slam and Qichen Yang will address topics of interest relative to thermal performance from the workshop attendees.  Everyone's participation is encouraged.

The workshop will close with remarks by Alexander Gerfer of Wurth Elecktronik addressing the evolution of power magnetics positively contributing to the power electronics industry.

Following the closing remarks will be a networking hour with hors d'oeuvres, soft drinks, wine and beer from 5:00 to 6:00. This will provide an additional opportunity to visit the technology demonstration stations.

After February 1, the registration fee is $425 reduced to $325 for PSMA Members, PELS Members and students. There will be a $25 surcharge for onsite registration, if available. Breakfast, lunch and the reception will be provided as part of the workshop. Electronic copies of all presentations will be made available to the workshop participants via a password protected website.

The latest information on agenda as well as registration information for the workshop will continue to be available on the PSMA website at: .

Organizing Committee

Steve Carlsen, Raytheon Systems Company
Ed Herbert , PSMA
Jenna Pollock, SF Motors
Rodney Rogers, Allstar Magnetics
George Slama, Wurth Elektronik
Fred Weber, Future Technology Worldwide
Chuck Wild, Dexter Magnetic Technologies Inc.
Matt Wilkowski, EnaChip


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PSMA Capacitor Committee and IEEE PELS Capacitor Workshop:

The Impact of Wideband Technologies on Application of Capacitors - A Deep Dive on Capacitor Technology
Date: Saturday March 16. 2019
APEC 2019 Anaheim, California

The Power Sources Manufacturers Association (PSMA) and the IEEE Power Electronics Society (IEEE PELS) are jointly sponsoring an all-day workshop titled, "The Impact of Wideband Technologies on Application of Capacitors–A Deep Dive on Capacitor Technology," on Saturday, March 16, 2019, the day before the start of and in the same venue as APEC 2019 at the Anaheim Convention Center in Anaheim, CA. Less than 5 weeks left to get ready for this workshop. Are you already registered and prepared for a whole day workshop with lots of facts and valuable content about state-of-the-art and future capacitor technologies?

This workshop follows the successful inaugural event held in San Antonio, TX, prior to the start of APEC 2018. This day-long workshop will consist of morning and afternoon technical lecture presentation sessions and a lunchtime interactive technology demonstration session. Navitas Semiconductor will open the morning session with a keynote presentation on GaN technologies and its requirements on capacitors. Market-leading capacitor suppliers including KEMET, CDE, Panasonic, Faratronic and Wurth Electronics together with preeminent lecturers from universities around the world including UC Berkeley and the University of Nottingham will discuss technical options and alternatives to meet the challenging requirements.

The "Technology Demonstrations" will be coincident with the luncheon period and will include interactive technology displays and/or presentations each addressing specific technical disciplines and capabilities consistent with the workshop agenda. The technical demonstrations will also be available during breakfast prior to the opening session and during the networking session at the end of the day's events will enhance the areas covered in the lecture presentations and provide an opportunity to interact and provide more detail and insight into the technology discussed during the lecture presentations.

Don't miss the opportunity to meet face to face with professionals who will directly address your questions. Whether you are a young design engineer or technician or already highly experienced with DC-DC converters, frequency drives, inverters and other power conversion applications in the industry, you will get facts, background and latest news on capacitors and emerging technologies to push the performance of your products. The workshop agenda addresses application-based challenges on capacitor technologies rising from the introduction of GaN and SiC topologies, the impact of e-mobility and insights into the latest capacitor developments. The impact of market shortages of specific capacitor products on new developments and possible alternative solutions to overcome actual problems will also be discussed.

After February 1, the registration fee is $425 reduced to $325 for PSMA Members, PELS Members and students. There will be a $25 surcharge for onsite registration, if available. Breakfast, lunch and the reception will be provided as part of the workshop. Electronic copies of all presentations will be made available to the workshop participants via a password protected website.

The latest information on agenda as well as registration information for the workshop will continue to be available on the PSMA website at:

Make your reservation right away to be a part of this exclusive whole day workshop.

Provided by members of the Capacitor Workshop Organizing Team:

    Pierre Lohrber Wurth Electronics
    Fred Weber Future Technology Worldwide

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International Workshop on Integrated Power Packaging (IWIPP) 2019

R egistration is now open for the PSMA sponsored  International Workshop on Integrated Power Packaging (IWIPP) which is a biennial event dedicated to advancing the state-of-the-art in power semiconductor packaging.  Many experts believe that the development of packaging technology has not kept pace with recent advancements in power semiconductor technology, especially with the emergence of fast-switching wide band-gap (WBG) semiconductors.  IWIPP is envisioned to foster and facilitate disruptive change in the development of power packaging technologies in order that the performance entitlement of the latest power semiconductors can be fully realized in practical power electronics applications.

To this end, IWIPP seeks to bring together technical experts in the various engineering disciplines that intersect at the development of high-performance packaging for power semiconductors.  Due to this multi-disciplinary focus and the accelerating industry need, IWIPP is quickly becoming a premier international workshop that attracts leading researchers from around the globe to share ideas on these important topics.

IWIPP 2019 will be held April 24-26, 2019, in Toulouse, a beautiful city on the banks of the River Garonne in southern France and the center of the European aerospace industry. The technical program for IWIPP 2019 has been finalized and is now available at

This year's program includes an exciting set of industry-focused plenary addresses.  The first plenary address will be given by Dr. Ahmed Elasser, Principal Systems Engineer at GE Global Research Center. Dr. Elasser's presentation will provide a historical overview of Silicon Carbide (SiC) power devices from the early days when wafer diameters were small and defects were common, to the current landscape with large wafers and many commercial product offerings.  The second plenary address will be given by Dr. Christophe Lochot, Electrical System R&T Group Leader at Airbus Operations SAS.  Dr. Lochot's presentation will provide a deep dive into some of the challenges associated with the use of power electronics in aircraft applications, including the trend toward development of the more electric aircraft (MEA).

Two focused technical tutorials are also included in the workshop registration fee.  The first tutorial will be given by Dr. Ty McNutt, Director of Business Development at Wolfspeed, Inc. Dr. McNutt's tutorial will provide a detailed technical survey of SiC devices, packaging, and the optimization of power electronic systems through design.  The second tutorial will be provided by Dr. Aaron Brovont, Assistant Professor of Electrical and Computer Engineering at The University of Alabama.  Dr. Brovont's tutorial will provide an introductory- to intermediate-level treatment of techniques for modeling and analysis of conducted electro-magnetic interference (EMI) in power electronic systems.

In addition, the program for IWIPP 2019 includes a set of detailed technical sessions provided by technical experts in both oral and poster presentation format.  These presentations will cover a broad range of related and relevant topics, including magnetic and dielectric materials; power semiconductor devices and modules; integration of sensors; design of gate/base drivers, reliability and manufacturability considerations; electro-magnetic interference mitigation; and many more. 

Please make plans to attend IWIPP 2019 to enhance your understanding of the latest developments in the area of high-performance power packaging and the critical role of packaging in determining the performance and reliability of power electronics applications.  Registration is now open, and early registration discounts are available until March 3, 2019.  Additional information about the workshop is available at  

Sponsored by:
IEEE Power Electronics Society (PELS)
IEEE Components, Packaging, and Manufacturing Technology Society (CPMT)
IEEE Dielectrics and Electrical Insulation Society (DEIS)
Power Sources Manufacturers Association (PSMA)
European Center for Power Electronics (ECPE)

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The 7th Workshop on Wide Bandgap Power Devices and Applications (WiPDA 2019)

T he 7th Annual IEEE / PMSA Workshop on Wide Bandgap Power Devices and Applications (WiPDA) [ ] will be held in Raleigh, North Carolina from October 29 to 31, 2019. This annual event provides engineers and scientists with opportunities to share their expertise in wide bandgap (WBG) semiconductor technology. This year's workshop features tutorials on October 29, 2019.  The following two days will host keynote sessions, panel sessions, technical sessions, and a poster session that covers four technical tracks: silicon carbide (SiC) devices, SiC applications, gallium nitride (GaN) devices, and GaN applications.  Topics in emerging WBG materials will also be solicited. 

There will be many opportunities to network with leading WBG specialists in industry and academia, especially at the Industry and Sponsors Exhibition, which occurs simultaneously with the workshop.  A banquet is planned for October 30, 2019.

The workshop is brought to you by the IEEE Power Electronics Society (PELS), the Power Sources Manufacturer's Association (PSMA), and the IEEE Electron Devices Society (EDS).  The General Chair is Victor Veliadis, Chief Technical Officer and Deputy Executive Director of PowerAmerica and Professor of Electrical and Computer Engineering at North Carolina State University (NCSU).  He is supported by Vice Chair Jin Wang, Co-Director for the Center for High Performance Power Electronics (CHPPE) and Professor of Electrical and Computer Engineering at The Ohio State University (OSU). 

Important Dates (Tentative):

  • June 14, 2019: Abstract submission deadline.
  • July 19, 2019: Notification of the abstract.
  • August 23, 2019: Paper submission deadline for workshop proceedings.

Call for Abstracts and Tutorials:

The abstract submission portal will open mid spring to accept authors' manuscripts.  Researchers are encouraged to submit their latest findings on fabrication of WBG power devices, their insertion in power electronics circuits/systems, and on technology of SiC, GaN, and other emerging, high performance WBG power semiconductors. 

Additionally, tutorial proposals will be solicited from experts that can provide in-depth discussions on WBG power semiconductor materials, devices, and their applications in power electronics, circuits and systems.

Authors and speakers are encouraged to submit their latest research findings in this WiPDA world-renown symposium. For both abstracts and tutorials proposals, the technical topics of interest include:

  • Heteroepitaxial & Bulk Materials Growth
  • Gate Dielectrics & Surface Passivation
  • Device Structures & Fabrication Techniques
  • Device Characterization & Modeling
  • Very-High Efficiency Or Compact Converters
  • Safe Operating Areas Of Wide Bandgap Devices, Including Short Circuit, Spike, &Transient Tolerance
  • Harsh Environment (High Temperature) Operation & Reliability
  • Packaging Power Modules & ICs
  • Hard-Switched & Soft-Switched Application Analysis
  • Gate Drive & Other Auxiliary Circuits
  • High-Performance Passive Components
  • Applications in Renewable Energy & Energy Storage, Transportation, Industrial Drives, & Grid Power Systems

We look forward to seeing you this fall in Raleigh, North Carolina, USA.

Provided by Mark Scott
WiPDA 2019 Publicity Chair


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INTELEC® 2019 The International Communications Energy Conference

F or 40 years, IEEE's INTELEC® (International Communications Energy Conference) has been the premier international technical forum where the science and engineering of energy systems for communications networks is canvassed amongst academia, industry and infrastructure operators.

The 41st annual edition of INTELEC® takes place 13-17 Oct, 2019 at the Resorts World Sentosa in iconic Singapore. This is the first time INTELEC® will be in the South-east Asia region. The theme for INTELEC® 2019 is Tackling the challenges of powering ICT infrastructure.

INTELEC® in contemporary times…

There is an artisan component in the discipline of providing highly-available energy to power information and communications technologies (ICT) systems. Telecommunications requires electricity. Back-up power schemes involving redundant power conversion, energy storage, and distribution schemes have traditionally been used to prevent communications service loss in the event of failure of the primary source of electricity. The reporting of research and development in power conversion electronics, energy storage, such as batteries, and power system architectures are core to INTELEC®.  But digital convergence has greatly changed the traditional landscape and ICT networks have evolved into highly distributed systems in which there is no direct electrical connection between the edge network elements and the central facilities.

Digital communications are now ubiquitous, and digital communications networks and information hubs continue to expand and grow throughout the world. The growth is energy hungry and the demand for new energy to support information and communication technologies has continuously been increasing.

This growth has been, in a great part, motivated by society's increased dependence on ICT networks. Hence, society expects that quality of service remains unchanged even during abnormal operating conditions caused by a disruptive event. But as the value of the content of digital transmissions increase, so too does the dependency on the availability of the energy systems supplying the network. The electrons must be there when they are needed. For instance, 5G is seen as a catalyst for enabling a bold new future of an Internet-of-Things (IoT). However, 5G will be more highly distributed than previous cellular networks, and due to expected human-machine and machine-machine interactions enabled by 5G, there is an implicit need for power supply availability and resilience higher than with current networks. Legacy architectures and networks will exist for many years throughout the world and operators must find ways to ensure practical interoperability. Emerging concepts with local (low power) generation forming DC nanogrids and wider-area microgrids creating district energy systems, integrated with the distribution networks of the traditional AC electricity grid are areas of current research.  At the same time, developments in power conversion electronics and batteries provide new opportunities to better manage and extend legacy powering infrastructure. INTELEC® is the place to report, share and discuss such ideas and developments.

Call For Papers

INTELEC® 2019 Technical Program Co-chairs, Prof. PS Lee, (University of Singapore), and Prof. Alexis Kwasinski, (University of Pittsburgh), invite technical contributions from the following multi-discipline matrix:

If you are working in any of these areas, please submit a paper or poster. Digests for peer-review selection closes on 8 April 2019. Notification of acceptance by 31 May 2019, and accepted full papers are required by 15 August 2019. Technical papers and posters presented at INTELEC® 2019 will be up-loaded to IEEE Xplore (subject to IEEE rules). 

If you have not already received the call for papers, go to for full details, and ensure you register on the mailing list.


INTELEC® 2019 is a full technical conference with an associated Industry Exhibition to showcase the latest in power conversion equipment, energy storage options, and system integration designs for ICT energy systems. INTELEC® is where you will meet colleagues in the same field, exchange ideas and hear from academic and industry leaders about important emerging trends and developments.

The preliminary program overview for INTELEC® 2019 are: -

  • A pre-conference day of educational tutorials
  • 150+ (expected) peer-review selected papers & posters
  • approximately 35 oral and 2 poster presentation sessions
  • Special Interest Seminars.
  • Daily Plenary or Keynote talks
  • Plenary-Forum (workshop) theme streams
  • A Commercial Product Exposure stream
  • Social events
  • Technical tours.
  • 4-day Industry Exhibition

INTELEC®'s long success is linked to the structure of the Industry Exhibition where academia & researchers, industry product developers and vendors, end-users and infrastructure operators mix and network throughout the conference.
If none of the above is enough, the lure to go to INTELEC® 2019 then must surely rest with the location - iconic Singapore. If you have not been to Singapore, maybe use INTELEC®2019 as your excuse to get there. It is truly a magnificent modern city, with impressive architecture, and full of very friendly and welcoming Singaporeans.

For more information on the INTELEC 2019 conference please visit the conference website

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The Silent Power of Supercapacitors (Part 2*)

F rom harvesting energy to power plants, the use of power electronics is everywhere and there isn't an application that doesn't require power. The power electronics industry is very dynamic and many new technologies have made the impossible, now possible. In the unceasing quest to increase performance levels, reliability and sustainability, new components and technologies such as Wide Bandgap Semiconductors and Digital power management are getting a lot of attention and coverage. However, hiding in the shadows there is a component that is very important and intrinsically involved in many vital applications; The Supercapacitor.

In the part 1 of this article we reviewed the origins of the supercapacitors, how they work and the amazing potential, someday, to supersede batteries, but will that happen?

Will supercapacitors supersede batteries?

Figure 1.

Following Elon Musk's speech at Cleantech Forum 2011, there has been a lot of interest in supercapacitors. The potential offered by nanotechnologies is keeping hopes high that at some point in the future supercapacitors might reach a point where they equal the performance of batteries. As can be seen in Figure 01, energy vs power density for different types of energy-storage devices, at the present time the performance levels of fuel-cells, batteries, ultracapacitors and conventional capacitors do not overlap. However, they are complimentary, and recent technological advancements are reducing the gap between batteries and supercapacitors.

Each of those technologies has their advantages and disadvantages  that power designers take into consideration when developing power systems. In Figure 02 we compare the key parameters of Li-ion batteries and supercapacitors, and it is obvious that one of the key benefits of the supercapacitor is its extremely high cyclability. It can be charged and discharged virtually an unlimited number of times, which is unlikely ever to be the case for the electrochemical battery which has a defined, much shorter life cycle.

Ageing is also in favor of supercapacitors. Under normal conditions, from an original 100% capacity they only lose 20% in 10 years, which far exceeds the levels achieved by any battery. For systems designers working to power systems in harsh environments, supercapacitors will operate in very low to high temperatures without degradation, which we know is not the case for batteries. On the downside supercapacitors discharge from 100 to 50 percent in 30 to 40 days, whereas lead and lithium-based batteries self-discharge about 5 percent during the same period; but technology is improving daily and supercapacitors are becoming better and better.

Figure 2.

With the growing demand for renewable energy and issues relating to energy storage, there is a rising question about the reasoning behind building huge banks of Lithium Ion batteries. We all know that these batteries have a limited lifetime, and there's the associated environmental risks since as well as consuming precious raw materials they're not easy to recycle. This is where research is very interesting and the disclosure presented by the Universities of Surrey and Bristol in February 2018 on the development of polymer materials is appealing. They achieved practical capacitance values of up to 4F/cm2 when the industry standard is 0.3F/cm2, and they are expecting to reach 11-20F/cm2 in the near future. When such levels of capacity are achieved we will be able to talk about 180Wh/kg, which is similar to lithium ion batteries.

The level of research in supercapacitors is really impressive and the gap is closing. How fast that will happen remains unknown, but considering the number of patents filed, papers presented and levels industry interest, it shouldn't take too long.

In silence they do the job

Supercapacitors are almost everywhere, from the Shanghai bus experiment to run a fleet of buses powered only by supercapacitors to smart meters and harvesting energy, it is almost impossible to draw up an exhaustive list of applications. For sure it is their ability to sustain high charge and discharge cycles that makes them ideal for private and public electrical vehicles and machinery such as port-cranes to accumulate and re-use energy. But in many applications, when designers need peak power, they are there.

If you are an audiophile, your audio amplifier might contain a supercapacitor bank able to deliver kilowatts of peak power to your bass loudspeaker when Ferruccio Furlanetto bellows out the deep notes in Don Quichotte. If you have a smart meter at home, it most probably contains a supercapacitor able to deliver peak power when transmitting stored data via the GPRS module. And again, if you are a technology geek following the Lamborghini 'Terzo Millennio' project, you will have noticed how important a role supercapacitors play in the motorization of this very special, electric powered sport car.

Figure 3.
Safety is another benefit of supercapacitors and that is the reason why they are the first choice when backup or peak power is required in a restricted environment. Critical applications operating in hostile or confined environments are strictly regulated in terms of chemical and other hazardous risks, reducing or forbidding certain type of batteries such as Lithium Ion. For safety reasons, those applications must have a power backup long enough to run alarms and safety shutdown processes. In such arduous conditions, conventional batteries are replaced by supercapacitor banks whose values could be from a few Farads to 200 Farads for general applications (Figure 03).

What's coming next?

As we have seen, supercapacitor technology is moving extremely fast. The challenges posed by the energy storage issue is the most likely area where we will see the more immediate benefits of nanotechnologies being implemented in supercapacitors.

One example to close this article is the very interesting research conducted by the University of Central Florida on combining distribution cable with the capacity of supercapacitors. Assistant professor Jayan Thomas of the NanoScience Technology Center has found a way to improve a regular copper wire to transform it into a supercapacitor cable. Based on nanowhisker technology it could transform the standard copper wire into a supercapacitor capable of storing and delivering large amounts of power.

So in some degree of silence supercapacitors are becoming the most promising component for the future. Many power designers are already implementing power solutions based on supercapacitors but considering how fast research takes place and the huge challenges that humanity faces due to climate change, one day in the not too distant future, supercapacitors will be the heart of modern power solutions.


  1. Powerbox (PRBX)
  2. Howard I. Becker "Low voltage electrolytic capacitor" US Patent US2800616A
  3. Robert A. Rightmire "Electrical energy storage apparatus" US Patent US3288641A
  4. University of Bristol
  5. University of Central Florida
  6. Elon Musk speech at Cleantech 2011 in San Francisco

Provided by Patrick Le Févre
Chief Marketing and Communications Officer, Powerbox


*Editor's note: This is the second in a 2-part series, read Part 1 in the Fourth Quarter 2018 Issue of the PSMA Update.

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Proper Design of the Power Supply's Input EMI Filter Protects against Power Line Transients

A s part of my design activities at Spangler Prototype Inc., and as a member of the Safety and Compliance Committee of the Power Sources Manufacturers Association (PSMA), I [James Spangler] was gathering the needed information for future products. These are power supplies that have an EMI filter between the ac line and the switcher. Initially, I had not considered ac power line or lightning transients, so I looked at the PSMA Safety and Compliance website for transients.

I reviewed two IEEE standards: IEEE Std C62.41.2-2002[1] and IEEE Std C62.45-2002.[2] These IEEE standards talk about the voltage spikes, waveforms and surge voltage values that are part of the lightning surges. There are three different types of transient voltages: 100-kHz ring wave, combination wave open circuit (front time=1.2 µs and duration=50 µs), and combination wave short circuit (front time = 8 µs and duration = 20 µs). 

Besides the transients produced by lightning, there are other ac line transients to consider. For example, there are transients generated when the utility switches from other feed lines to supply power during electrical power outages. There are also transients generated when high-voltage ac power lines are grounded from falling trees caused by high winds that cause the lines to touch the earth ground.
It is believed that the above IEEE standards consider these events with the various transient waveforms. But there are other standards as well. So, I did a literature search to understand what standards including the IEEE and IEC affect how power supplies protect against such ac line transients. In the process, I gained some perspective on how these requirements were developed. The results of that search are shared in this article.

With that information as background, I then look at the protection elements that are typically in place in ac- dc power supplies. Most of these elements are implemented within the front end section of the power supply that contains the EMI filter. The EMI filter prevents noise generated by the switching action of the power supply from radiating back into the ac mains. But the EMI filter is a passive element and it works in both directions. So, in addition to suppressing noise coming out of the power supply, the EMI filter also protects the power supply from ac line transients.
It's important for power supply designers and users to understand first, how the EMI filter provides this transient protection, and second, whether any changes or additions to this protection are required to meet the regulatory requirements. After dissecting the various protection elements found in the EMI filter, I'll discuss some test circuits that can be used to gauge transient protection performance of a power supply's EMI filter.

Before beginning the discussion about standards, it's necessary to clarify differences in the roles of certain organizations and distinctions between standards, regulations, and the actual product requirements. First of all, governmental bodies like Federal Communication Commission (FCC), United States Department of Energy (DoE), and California Energy Commission (CEC) are the ones that have mandatory regulations. Other bodies like Underwriters' Laboratories (UL), American National Standards Institute (ANSI), National Electrical Manufactures Association (NEMA), International Electrotechnical Commission (IEC), etc. produce standards that are guidelines, unless stated by the governmental regulating bodies like the DoE as required in their regulation. However, it is often the end customer (the purchasing customer) that specifies which standards (IEC, UL, or other) the power supply must meet.

Tracing the Origins of Transient Protection Requirements

The earliest literature I found on ac line transients was from Bell Labs,[3] this was listed in the application note TND335/D[4] reference from ON Semiconductor. The Bell Labs paper was published in March 1961 as it was related to telephone lines.

My best source of ac line voltage transient information is from the GE "transient voltage suppression manual, second edition".[5] When a product is able to survive ac line transients, the product is more reliable; the consumers and owners of the products are satisfied. The information in the GE manual was used to help understand how to protect capacitive drop power supplies for ac-powered smoke detectors and electronic fluorescent lamp ballasts so that they survive ac line transients.

UL 217 Standard for Smoke Detectors[6] has many editions. The first edition was published in 1976, and it had a transient voltage generator circuit. This circuit was built up by Larry Ratzlaff[7] at Fyrnetics of Elgin, IL and used to test smoke detectors and electronic fluorescent lamp ballasts for the ability to withstand input transients from the ac line. (The UL 935 Fluorescent Lamp Ballast Standard[8] did not have any voltage surge test in 1976.)

The generator can produce 6000-V peaks and was used up to 10,000 Vdc for some worst-case test, which was the limit of the tester. This testing occurred during the 1978 to 1980 timeframe. Note that at 10,000 V, any structural wiring that falls within installation categories I through IV, starts to break down, so it's not of much value to design above 10 kV.
But returning to GE's transient voltage suppression manual,[5] (see Fig. 1), we see that it not only provided data on transient lightning strikes; it also provided guidance on what level of circuit protection was needed in the targeted appliances. On page 5 of the manual, it states that "devices (products) that have a 2-kV withstand capability will have a poor service life in an unprotected residential environment. Prudent design will aim for a 3-kV capability. Where safety is of the utmost concern, design for 6 kV that can cope with these rare possible occurrences. The flashover for typical wiring spacing is between 6 kV and 8 kV." (I assume this to be the wall socket).
Looking closer at the graph in Fig. 1, there is a probability that a U.S. household can expect to experience a single 5-kV transient once a year. The first curve points to rural areas with overhead power lines, which could possibly experience a single 18-kV pulse due to lightning. The second curve is the U.S. 120-Vac composite curve. The graph also shows other curves that could be used to gauge the vulnerability of other types of installations to lightning transients.

Fig. 1. Frequency of ac voltage transients per year with peak value of transients shown. (Source GE manual, reference [5], page 5, Figure 1.7.)

The data in the graph was collected in the 1970s, and at that time many products did not experience failures because the power supply consisted of an isolation transformer and linear regulator, which are believed to reduce and absorb much of the transient energy. The transformer construction used silicon steel laminations with copper wire that could limit the secondary current.  In addition, the aluminum electrolytic capacitor could absorb energy. The linear pass regulator kept the transient voltage sufficiently low, so the control electronics did not see high voltages that could cause failure. 

The GE manual not only provided data on transient strikes, it also provided guidance on what level of circuit protection was needed in the targeted power supplies. On page 5 of the manual,[5] it states: "that experiences with devices (products) that have a 2-kV withstand capability will have a poor service life in an unprotected residential environment. Prudent design will aim for a 3-kV capability. Where safety is of the utmost concern, design for 6 kV that can cope with these rare possible occurrences. The flashover for typical wiring spacing is between 6 kV and 8 kV." (I assume this to be the wall socket.) 

Fast forward to the present day and we can look to the IEC 60664-1[9] standard. According to Mark Cantrell[10] of Analog Devices  this standard indicates that the IEC transients stop at 12 kV for the low voltage mains. In a recent edition of this Spotlight on Safety and Compliance[12] the following Fig. 2 and Table 1 was published, which defined how the IEC views transients. Another version of this data is shown in Table 2 which is presented slightly differently than the data presented by Vishay's Application Note 43.[12] Scott Aldous[13] presented the data shown in Table 2. (Permission was received from the IEC to use this table).     

It can be argued that the old GE Manual and the newer IEC 60664-1[9] are in agreement. Francois Martzloff [14], of GE published "A Guideline on Surge Voltages in AC Power Circuits Rated up to 600V" in 1979 which agreed with the figures cited above along with other information for an 1978 IEEE PES meeting. F. Martzloff gave the same data used Fig. 1 in his presentation along with other information not presented here.

Fig. 2. Installation categories. (Courtesy of Vishay)

Table 1. IEC 664 table of impulse withstand voltages as presented in Vishay Application Note 43.[12]

Most appliances and computer equipment fall within Category II while some appliances like cooking ranges are in Category III. A smart meter for utility reading applications belongs in Category IV due to its direct connection to the utility mains. In some applications both an IEC-664, and IEC 60664 insulation category along with a UL 1577[15] rating is needed. This all depends on the safety agency defining the test and the end application.

Table 2. Another presentation of what is essentially the same data from IEC-60664-1, Ed.1.2.[9] (Permission was received from the IEC to use this table.)

Today the linear regulator power supply system has been replaced with an electronic switch mode power supply. The lightning transients are still present as shown in Fig. 1. The devices that limit the transients are discussed below. 

Transient Protection In AC-DC Power Supplies

Today most of the power supplies are of the switch-mode type with an ac-dc section as shown in Fig. 3. This figure will be used to discuss the elements that suppress transient voltages and limit the surge current that can destroy the control electronics in a piece of equipment and cause a product failure. The earth ground is not shown in the example since most of the lightning and transient voltage and current flow on the ac hot and ac neutral. 

It is true, however, that if there is a lightning strike near a building, there can be a rise in ground voltage. But in many cases, the ground rise voltage will also be on the neutral since both the neutral and earth ground (safety) are tied together at the service panel.

Fig. 3. The front end of a power supply.

Input Protection C1, MOV, And Gas Discharge Tube

When there is a voltage transient on the ac supply lines, in most cases, the first device providing protection is the metal oxide varistor[5,16,17] (MOV). An exception to this would be if the control electronics are part of a medical device. In that case, the first item might be a gas discharge tube or spark gap (not shown). 

In Fig. 3, we see that there are three devices in parallel that can limit the lightning or voltage transient—the MOV, an X rated class capacitor, and a common-mode choke. The breakdown or clamping voltage of the MOV is normally 1.5 times the peak of the ac line voltage. The breakdown voltage for an MOV is specified when a 1-mAdc current flows through the device. Both Littelfuse and Vishay have application notes on the selection of the voltage for varistors. C1 is an X class capacitor specified for ac line operation. Both MOVs and gas discharge tubes[18] take time to operate, so downstream elements like the common-mode choke, C2 and C3 need to be able to absorb energy.

Included is the resistance of the power leads from the service panel or fuse box to the product and the hot resistance of the NTC surge limiting thermistor[19] for limiting surge currents during transients and turn-on power. The resistance and capacitance of the building electrical supply distribution system is built-in and assumed in the IEC-specified Installation Classes for the equipment. This reduces the peak energy of the power line disturbance.

For example, a utility watt-hour meter (Smart-Meter) that is connected upstream of the panel would need a reinforced transient rating for a 120- to 240-Vrms single-phase line of 6000 Vpeak. This is Installation Class IV. But a device plugged into an outlet within the building, which is Installation Class II, would need to be rated for 2500 V. The evaluation of the EMI input filter and protection should be near 2500 Vpeak and not reduced further by line impedance, per Tables 1 and 2 above.

The supply wiring resistance can be considered small but this resistance limits the current if there is a 6-kV to 8-kV power type transient. The longer the line and the smaller the wire diameter the greater the limiting effect.  In many Smart-Meter applications, there is a gas discharge tube which can be used to limit the voltage.  A Smart-Meter (utility watt-hour meter) is installed prior to the service panel and is considered an Installation Category IV. Gas discharge tubes (GDTs) have a follow-on current until the next ac zero crossing of a transient. This may cause a nuisance blowing of the fuse. If a GDT is used, the fuse should be a user-replaceable type.

Common-Mode Choke

The common-mode choke is the next device that helps limit the lightning transients. Besides the mutual inductance, there are leakage inductances on each leg. The leakage inductance (shown as a dashed line in Figs. 3 and 4) can be a single device or split into two devices. The leakage inductance is a differential-mode inductance. Some designs have separate inductors. 
The coil resistance of the common-mode filter is very important and serves two purposes: first is to help limit some of the transient surge current, and second is to limit the inrush current when the ac power is first applied. The full bridge diodes have a peak surge current rating and the coil resistance helps limit the inrush current seen by the diodes. In cost-sensitive designs, the common-mode choke resistance can eliminate a special negative temperature coefficient NTC resistor to protect the diodes in the full-wave bridge from inrush surge current.

C2 and C3

The capacitors C2 and C3 absorb voltages that are not stopped by the other elements. C2 is an X rated class capacitor placed across the ac line. The rise time of the voltage is reduced by the combination of inductance of the common-mode filter, C1, C2, and C3. The slower surge rise time, which is lower in frequency, and is rectified by the bridge rectifier, causes the voltage on C3 to rise. The rise above the normal depends on the capacitance value of C3. A power factor correction (PFC) circuit can be inserted between the bridge rectifier and the power supply box shown in Fig 3. 

Lightning Surge Testing

In 1978 during the development of the electronic fluorescent lamp ballast, lightning surge testing was performed on a number of designs using the voltage transient test circuit described in UL 217. All of the designs tested had an EMI filter and a PFC circuit. The EMI filter was required in order to pass the FCC Part 15 and Part 18 specifications. All of the systems survived the testing without any apparent damage to the power switches. 

Two additional pieces of information might be of interest; both of these are shown in Fig. 4. The first item is a pc board slot to prevent arching over the board surface. In compact, small power supplies like those used in USB cell phone chargers, slots are being used to add spacing between components to meet isolation voltage requirements. In electronic ballast designs, the board had a conformal coating, which allowed closer spacing of input components and no slots were used. 

If the capacitance values of C1 and C2 are large, they may hold a charge and be a source of a shock hazard.  These parts need to be discharged so the consumer does not receive an electrical shock if they happened to touch the power cord plug blades. One solution is to add a newer component from Power Integrations called a CAPZero[20] as shown in Fig. 4.

Fig. 4. PC board slot and discharge of C1 and C2.

Application Circuits

In writing this article a quick search was made for application circuits that test for transients. Power Integrations[21] has published a number of circuits with construction techniques, line conducted EMI test results, and line surge testing. Please review the Power Integrations information given on page 49 of DER-535[22], which shows a lighting surge test for a 65-W power supply design. An EMI line conducted test is also in the document. The test results are repeated here in Table 3.

Table 3. Lightning Surge Test for DER-535 application board.

In addition, look at DER-613[23] on page 87 for details on line surge testing of a 27-W USB charger design. Test results are repeated here in Table 4. This document also shows EMI line conducted test results.


All switching power supplies have some sort of EMI filter. This filter is a passive filter and is bidirectional. The EMI filter prevents noise from escaping from the power supply and prevents various power line surges from entering the power supply.

Table 4. Line Surge test results for the DER 613 applications board.

There are two IEEE standards that should be reviewed: IEEE Std C62.41.2-2002[1] and IEEE Std C62.45-2002[2]. These IEEE standards talk about the waveforms and transient voltage surge values. There is another document: IEC 61000-4-5[25], that describes similar ac power line transient tests.

It is important to test your power supply with the EMI filter in place. Test the power supply system for transients and surges to see what level the unit passes before making changes to your circuit. You may be surprised that the EMI filter did all the work and no additional components were needed to pass the voltages of 4 kV peak. 

I wish to thank Dave Pacholok[24] for his assistance, providing several references, and a review of this article. 


  1. IEEE C62.41.2-2002 - IEEE Recommended Practice on Characterization of Surges in Low-Voltage (1000 V and less) AC Power Circuits.
  2. IEEE C62.45-2002 - IEEE Recommended Practice on Surge Testing for Equipment Connected to Low-Voltage (1000 V and less) AC Power Circuits
  3. "Lightning Surges in Paired Telephone Cable Facilities" by D.W. Bodle and P.A. Gresh, The Bell System Technical Journal, Vol. 4, March 1961, pp. 547-576 (available from IEEE on request).
  4. "Transient Overvoltage Protection", TND335/D, On Semiconductor, April 2008.
  5. Transient Voltage Suppression Manual. 2ed, copyright 1978, GE Technical Information Exchange, Schenectady, NY  12301.
  6. UL 217 Standard.
  7. Larry Ratzlaff
  8. UL 935, Fluorescent Lamp Ballast Standard,
  9. IEC-60664-1.
  10. Mark Cantrell, phone conversations Aug, Sept, and Dec. of 2018.
  11. "Isolation Standards Say Little About Isolator Performance" by James Spangler and Kevin Parmenter, How2Power Today, September 2018.
  12. "Design Guidelines for Optocoupler Safety Agency Compliance," Vishay Application Note 43
  13. "Product Safety Considerations for Insulation Coordination of Low-Voltage Equipment" by Scott Aldous, Advance Energy.
  14. "A Guideline on Surge Voltages in AC Power Circuits Rated up to 600 V" by Francois Martloff, General Electric Company, Schenectady NY, Proceedings, 3rd International Symposium on Electromagnetic Compatibility, Rotterdam 1979.
  15. UL 1577 Standard for Optical Isolators.
  16. "Selecting a Littelfuse Varistor," Application Note AN9771.1, July 1999.
  17. "The ABCs of MOVs-Littelfuse," Application Note 9311.
  18. Gas Discharge Tube, Littelfuse,
  19. Thermistor.
  20. CAPZero.
  21. Power Integrations design examples.
  22. DER-535 Power Integrations
  23. DER-613, 27 Watt USB.
  24. David Pacholok.
  25. IEC-61000-4-5 › Electromagnetic compatibility (EMC) - Part 4-5: Testing and measurement techniques - Surge immunity test.
Kevin Parmenter
Director of Applications Engineering
Taiwan Semiconductor America

  Jim Spangler
Spangler Prototype Inc. (SPI)

Editor's Note: This article was first published in the December 2018 issue of How2PowerToday (

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Solar Energy Stock Index: Q4 2018

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EMS Quarterly Review: Q4 2018

L incoln International is pleased to present the latest issue of its EMS Quarterly Report: Q4 2018

In 2018, there was an increase in transaction activity due to the favorable M&A market conditions. In addition, M&A opportunities were stronger as companies are performing well due to the electronics "supercycle". This issue of the EMS Quarterly Report provides perspectives on:

  • Review of 2018
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  • EMS stock performance
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This data is included with the permission of Lincoln International. For more information, you may contact John McManus ( or the Association Office.


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Events of Interest - Mark Your Calendar
Feb 26, 2019 - Feb 28, 2019
Feb 26, 2019 - Mar 1, 2019
Kalinga Institute of Industrial Technology,
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Feb 27, 2019 - Mar 1, 2019
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Apr 15, 2019 - Apr 16, 2019
Apr 22, 2019 - Apr 23, 2019
Apr 24, 2019 - Apr 26, 2019
Apr 26, 2019 - Apr 29, 2019
Apr 28, 2019 - May 1, 2019
Bloomington, MN
Apr 29, 2019 - Apr 30, 2019
May 5, 2019 - May 8, 2019
Calgary, AB
May 6, 2019 - May 9, 2019
Shenzhen Convention and Exhibition Center
May 7, 2019 - May 9, 2019
May 8, 2019 - May 9, 2019
Milwaukee Convention Center
Milwaukee, WI
May 11, 2019 - May 15, 2019
San Diego, CA
May 19, 2019 - May 22, 2019
May 19, 2019 - May 23, 2019
May 20, 2019 - May 23, 2019
Matsue, Shimane
May 22, 2019 - May 24, 2019
San Jose
Costa Rica
May 23, 2019 - May 25, 2019
May 26, 2019 - May 28, 2019
May 27, 2019 - May 31, 2019
Korea (South)
May 30, 2019 - May 31, 2019
May 31, 2019 - Jun 2, 2019
Jun 3, 2019 - Jun 6, 2019
Jun 4, 2019 - Jun 7, 2019
Hotel Del Coronado
San Diego, CA
Jun 12, 2019 - Jun 15, 2019
Urgup Nevsehir
Jun 12, 2019 - Jun 13, 2019
Le Bourget Du Lac
Jun 16, 2019 - Jun 19, 2019
Toronto, ON
Jun 17, 2019 - Jun 18, 2019
Le Bourget Du Lac
Jun 18, 2019 - Jun 21, 2019
United Kingdom
Jun 18, 2019 - Jun 21, 2019
United Kingdom
Jun 19, 2019 - Jun 21, 2019
Metro Detroit, Michigan
Jun 20, 2019 - Jun 21, 2019
Rochester, NY
Jun 25, 2019 - Jun 29, 2019
Jun 27, 2019 - Jun 29, 2019
Jul 1, 2019 - Jul 3, 2019
Jul 6, 2019 - Jul 7, 2019
Jul 9, 2019 - Jul 12, 2019
Jul 10, 2019 - Jul 11, 2019
Jul 28, 2019 - Jul 31, 2019
Madison, WI
Aug 6, 2019 - Aug 9, 2019
Westin Crystal City Hotel
Arlington, VA
Aug 14, 2019 - Aug 16, 2019
Westin Crystal City Hotel
Arlington, VA
Aug 20, 2019 - Aug 23, 2019
Aug 26, 2019 - Aug 27, 2019
Aug 27, 2019 - Aug 30, 2019
Aug 27, 2019 - Aug 29, 2019
Sep 2, 2019 - Sep 5, 2019
Sep 2, 2019 - Sep 4, 2019
Sep 6, 2019 - Sep 9, 2019
Yi-chang, Hubei
Sep 9, 2019 - Sep 10, 2019
Sep 10, 2019 - Sep 12, 2019
Novi, MI
Sep 24, 2019 - Sep 27, 2019
Sep 27, 2019 - Sep 28, 2019
NCR New Delhi
Sep 29, 2019 - Oct 3, 2019
Baltimore, MD
Oct 13, 2019 - Oct 17, 2019
Oct 15, 2019 - Oct 17, 2019
Oct 21, 2019 - Oct 24, 2019
Oct 22, 2019 - Oct 24, 2019
Oct 22, 2019 - Oct 23, 2019
Arlington, VA
Oct 23, 2019 - Oct 25, 2019
Aswan City
Nov 19, 2019 - Nov 21, 2019
Dec 1, 2019 - Dec 4, 2019
Jan 2, 2020 - Jan 4, 2020
Hotel Le Meridian Cochin
Jan 12, 2020 - Jan 16, 2020
Mar 2, 2020 - Mar 6, 2020
Reno, NV
Mar 15, 2020 - Mar 19, 2020
New Orleans, LA
Mar 16, 2020 - Mar 18, 2020
Calgary, Alberta
Apr 25, 2020 - Apr 30, 2020
San Antonia, Texas
Sep 7, 2020 - Sep 10, 2020
Oct 11, 2020 - Oct 15, 2020
Detroit, MI
Mar 7, 2021 - Mar 12, 2021
Tucson, AZ
Mar 21, 2021 - Mar 25, 2021
Phoenix, AZ
Oct 9, 2021 - Oct 14, 2021
Vancouver, BC

If you know of any upcoming conferences or events of interest to
PSMA members please notify the Association office.

Fax: 973-543-6207

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