Other news of interest

Announcing EnerHarv 2022
Posted: 2021-11-23
The Second International Energy Harvesting Workshop, EnerHarv 2022 is to be Held In-Person in Raleigh, NC April 5-7, 2022

EnerHarv 2022 will bring together experts from around the world working on all technical areas relevant to energy harvesting, power management and its IoT applications. This non-profit workshop, organized and sponsored by the Power Sources Manufacturers Association (PSMA), will be held on the Centennial Campus of NC State University in the award-winning Hunt Library. The workshop will be hosted by the ASSIST NSF Engineering Research Center.

EnerHarv 2022’s vision is to create a focal point for experts and users of energy harvesting and related technologies to share knowledge, best practices, roadmaps, experiences and provide opportunities for collaboration to increase the uptake of such technologies.  The workshop is targeted at a broad audience from industry and academia working on materials and devices for energy harvesting and storage, low-power sensors and circuits, micro power management, and their applications in powering IoT devices for health and environmental monitoring, assisted living, and monitoring of equipment and buildings.  The workshop program will be divided evenly between lecture sessions, functional demonstrations, and interactive panel discussions with plenty of time reserved for networking and team-building prospects.  More information on the workshop can be found at http://www.EnerHarv.com.

General Chairs

Mehmet C. Ozturk
NC State University,
Electrical Engineering

Brian Zahnstecher
IEEE Senior Member

Technical Chairs

Shad Roundy
Associate Professor
University of Utah,
Mechanical Engineering

Mike Hayes
Head of Group
ICT for Energy Efficiency,
Tyndall National Institute


CDE.com is the New Home for all Illinois Capacitor Products
Posted: 2021-10-27

Cornell Dubilier has brought its Illinois Capacitor brand capacitors to cde.com. Now engineers can view the entire portfolio of CDE and IC capacitors for power electronics applications on one site. This includes such specialized products as IC’s supercapacitors, conduction-cooled (high density resonant) capacitors, rechargeable coin cell batteries, and other new additions. CDE’s updated parametric search tools simplify the capacitor selection process as never before.

As Illinoiscapacitor.com has now been shut down, links to that site will be automatically redirected to cde.com. In addition to combining product data, the site’s Tech Center has been expanded to include additional engineering resources, such as application guides, capacitor formulas, tutorials, and a detailed glossary of terms.

CDE will continue to support all IC branded products, which are available from major distributors and the company’s representative network.

For more information, visit www.cde.com.

TDK Ventures invests in seed round for dry lithium-ion electrode manufacturing startup, AM Batteries
Posted: 2021-10-27

TDK Corporation announced today that subsidiary TDK Ventures Inc. invests in AM Batteries (AMB) to support the commercialization of their dry electrode coating technology that improves the manufacturing of lithium-ion batteries built on a bedrock of unmatched expertise in advanced chemistry, surface science, and precision additive manufacturing. AMB’s electrodes not only have the potential to save cost, but also offer a path toward fast charging, higher-energy density, and adaptability. AMB has early industry attraction to adopt this technology for pilot scale to mass production.

AMB has developed a novel additive Li-ion manufacturing technique by which the active materials (cathode/anode) are charged and sprayed onto metal foil current collectors, which are then processed to its final state to make batteries without the use of toxic solvent. This dry- coating method offers significant cost and energy savings over state-of-the-art “wet coating” procedures, providing a dramatic improvement to the sustainability of the overall cell making process. TDK Ventures' investment in AMB marks its continued focus on core technologies that catalyze broader decarbonization efforts via sustainable and scalable battery technologies.

“Our technology is extremely innovative and outside the box,” stated Yan Wang AMB Co-founder and CEO. “TDK Ventures’ proprietary knowledge and unique insights in the battery-manufacturing space helped validate our own technological progress. They also played a significant role in bringing a broad syndicate of financial, strategic, and OEM partners together by sharing their key techno-economic insights, thereby helping us assemble a world-class set of partners for our company.”

Riding the rising tide of EVs, the demand for lithium-ion batteries has never been higher - with an expected need for more than 2,000 GWh by 2030. With this significant manufacturing capacity demand, environmental and carbon footprint are under increased scrutiny. Current wet-electrode manufacturing techniques consume up to 50% of the total manufacturing energy of the entire battery, require significant factory footprint to dry the solvent, and increase the CAPEX required for manufacturing plants. One of the most fundamental problems for battery manufacturers today is refining manufacturing techniques. Refining manufacturing techniques to remove the solvent is one of the most fundamental problems for all battery manufacturers today in the consumer electronics, large scale energy storage, and EV markets.

During Tesla’s 2020 Battery Day last year, CEO Elon Musk said that dry-electrode technology is one of the most vital components for a step-change in the cost reduction of EV batteries; he also stated significant room for the technology’s maturation and improvement. Tesla acquired Maxwell Technologies in early 2019 with an eye on potentially commercializing their dry-electrode technology.

“AMB has engineered a three-step electro-spraying system that seamlessly aligns with the existing process flow of lithium-battery manufacturing, which is not the case in competitive solutions, putting them at the very forefront of the industry,” said Nicolas Sauvage, President of TDK Ventures. “In the future, we believe that battery manufacturers will not only differentiate on energy density, fast charge ability, or cost/kW, but also on the amount of CO2 emitted per the amount of energy stored, which is a measure of how sustainable one’s electrode manufacturing process is. This positioning is a whole new value proposition for next-generation battery manufacturers and EV OEMs that align with consumer needs.”

Eric Rosenblum, Foothill Ventures' Managing Partner commented: "The battery market for EVs is one of the world's most important markets, and this technology addresses two of the biggest issues: cost and sustainability. Dr. Yan Wang has proven himself to be one of the most successful inventors and serial entrepreneurs in the battery space, and we are also thrilled to partner again with TDK Ventures."

AMB closed its seed round of $3M in funding September 2021 with TDK Ventures and Foothill ventures co-leading the round. SAIC Capital (Tier I manufacturer), VinFast (Vietnamese EV OEM), Doral Energy-Tech Ventures (Israel Renewable Energy Company), Creative Ventures (financial VC firm from Silicon Valley) also participated in the round. In January 2020, AMB’s founders secured a $2.4M three-year research grant by the United States Advanced Battery Consortium (USABC), based on its strong foundational academic progress.

To learn more about TDK Ventures, interested startups or investment partners should visit www.tdk-ventures.com or reach out at contact@tdk-ventures.com.

PSMA White Paper - Energy Harvesting for a Green Internet of Things
Posted: 2021-10-12
This white paper, prepared by an international team of experts from diverse backgrounds, offers a broad range of insights into the world of energy harvesting, especially for IoT applications.

PSMA has announced the availability of a White Paper entitled “Energy Harvesting for a Green Internet of Things.” This seminal work is the result of a multi-month effort by a dedicated team of 28 international experts from a variety of backgrounds in academia and industry, led by Dr. Michalis Kiziroglou from Imperial College London and Dr. Thomas Becker of Thobecore Germany. The PSMA Energy Harvesting Technical Committee supported this work and is responsible for making the White Paper available.

The ubiquitous nature of energy autonomous microsystems, which are easy to install and simple to connect to a network, make them attractive in the rapidly growing Internet of Things (IoT) ecosystem. The growing energy consumption of the IoT infrastructure is becoming more and more visible and impactful. Energy harvesting describes the conversion of ambient energy into electricity, enabling green power supply of IoT key components such as autonomous sensor nodes. Energy harvesting could lead to a lower CO2 footprint of future IoT devices by adapting environmentally-friendly materials and reducing cabling and primary battery usage.

The key findings in the White Paper are as follows:

  • energy harvesting is a key enabling technology for the green Internet of Things;
  • this potential is demonstrated with several use-case studies;
  • industrial adoption is reluctant despite positive costs-benefits and their life-cycle impacts;
  • massive future deployment requires a concerted strategy in research and technology accompanied by disruptive industrial product developments and innovations.

The paper is available at no cost on the PSMA website Energy Harvesting Technical Forum at https://www.psma.com/technical-forums/energy-harvesting/whitepaper.

About PSMA: 

PSMA is a non-profit professional organization with the objective of enhancing the stature and reputation of its members and their products, and improvement of their technological power sources knowledge. Its aim is to educate the entire electronics industry, academia, government, and industry agencies as to the applications and importance of all types of power sources and conversion devices.

The Energy Harvesting Committee is one of 12 committees within PSMA that focuses on particular power electronics technologies (from materials to devices and systems) and/or applications. The committee is planning the 2022 EnerHarv Workshop at NCSU in Raleigh, NC. For more information, visit www.enerharv.com

Green Hydrogen, Myth or Reality?
Posted: 2021-9-27

Extracting clean energy from water has been a dream for more than a century. Many of us remember the book Jules Verne wrote in 1874, 'The Mysterious Island,' and its vision to extract hydrogen from water, an infinite source of energy for future generations. So for 147 years, the use of civil hydrogen has been up for debate and we are unable to hazard a guess at the number of articles, conferences and announcements supporting the inception of hydrogen as an undoubtable source of energy.

For us as power electronics engineers, very much as it was in Jules Verne's vision, hydrogen energy is achieved by electrolyzing hydrogen and oxygen, and then deploying a fuel cell to generate electricity. In reality, production of hydrogen by electrolyzation is currently less than 4% worldwide, with more than 94% of this hydrogen produced from fossil resources, mainly coal and gas, and with production from biomass and other representing just 2%.

70% of the overall hydrogen produced in the world is extracted from the natural gas methane. Its extraction uses a so called 'steam reforming' process in which high-temperature steam (700°C – 1,000°C) is used to produce hydrogen. The steam reforming process, if the carbon dioxide is not captured, is responsible for high levels of greenhouse gas emissions. The amount of CO2 released ino the atmosphere by worldwide hydrogen production is estimated to be around 830 million tons.

Although this is where we are today, with the conundrum 'green hydrogen - myth or a reality' fueling the debate. But things are changing and we are getting closer and closer to Jules Verne's vision!

The shades of hydrogen!

To simplify the understanding of the different production methods and their environmental impact, industry has codified hydrogen by color. In practice, four main categories are commonly used; brown, grey, blue, and green. From time to time sub-categories appear e.g., the hydrogen that is produced by electrolyzers powered by nuclear plants is sometimes referred to as 'pink', but that is more anecdotal than a de facto delineation.

Brown hydrogen:
The color brown has been assigned to hydrogen extracted from coal by gasification. In this process the carbon based material is converted into a mix of carbon monoxide, hydrogen, and carbon dioxide. Gasification is achieved at very high temperatures (>700°C) without combustion with a controlled amount of oxygen and/or steam. The carbon monoxide then reacts with water to form carbon dioxide and more hydrogen via a water-gas shift reaction. The resulting gas from this process is called syngas. The hydrogen produced by this method is known as brown (lignite) or black (bituminous) depending on the type of coal used. However, this process is highly polluting since both the CO2 and carbon monoxide cannot be reused and are released into the atmosphere.

Grey hydrogen:
Nowadays, grey hydrogen represents the highest portion of production. More than 70% of hydrogen currently produced worldwide is classified as grey hydrogen. The most common production process uses steam methane reforming (SMR). In this process high pressure steam reacts with methane resulting in hydrogen and the greenhouse gas CO2. About 9.3kg of CO2 per kg of hydrogen is generated in this process. Although this is lower than brown hydrogen it is still a substantial amount when released into the atmosphere.

Blue hydrogen:
When CO2 produced from the previous methods is captured and stored underground using industrial carbon capture and storage (CSS) the manufacturing process is less harmful for the environment, but this process is more expensive and less efficient than conventional methods. Blue hydrogen is considered an important step in the energy transition towards green hydrogen and the vast majority of new production units are strictly controlled in terms of their environmental impact. However, despite high levels of improvement compared to brown and grey, 10% to 20% of the CO2 cannot be captured and is released.

Green hydrogen
Globally, the amount of hydrogen production from water electrolysis is very small, less than 4%, but it is the most well-known technique, one that some of us will remember from our school chemistry lessons. Using electricity, hydrogen is produced by splitting water molecules into hydrogen and oxygen. In the case of green hydrogen, the electricity is produced by renewable energy sources (less than 1%). In this process the electrolyzers are the 'masterpiece' and have been used for decades with an average efficiency of 73% (compared to 65% for the steam reforming process). As for the power supply, improving its efficiency is obviously vitally important to reduce energy consumption and cost. Intensive research aims to achieve a 95% conversion efficiency, which in fact we are not far away from achieving.

Hydrogen in Europe - state of the business

Many are aware of climate challenges and the Paris agreement adopted by 196 Parties at COP 21 in Paris on December 12, 2015. The ratified agreement was entered into force on 4 November 2016. The Paris Agreement embraces a vision of fully utilizing the development of technology and transfer for both improving resilience to climate change and reducing greenhouse gas emissions.

Illustration 01 – The European Green Deal overview (Source PRBX/ European Commission)

In their response to challenges relating to climate changes, in December 2019 the European Commission communicated the so-called 'European Green Deal', aiming to transform the EU into a fair and prosperous society with a modern, resource-efficient and competitive economy where there are no net emissions of greenhouse gases by 2050 (illustration 01). The European Green Deal is also the lifeline out of the COVID-19 pandemic. One third of the 1.8 trillion euro investments from the 'NextGenerationEU' recovery plan, and the EU's seven-year budget will finance the European Green Deal.


To achieve this goal many activities have been initiated and one of those is to develop and deploy a European strategy for hydrogen. This strategy was published in July 2020, setting out a vision of how the EU can turn clean hydrogen into a viable solution to decarbonize different sectors over time, installing at least 6GW of renewable hydrogen electrolyzers in the EU by 2024 and 40GW of renewable hydrogen electrolyzers by 2030.

To support that strategy, it is important to have global coordination between public authorities, industry, civil society and the research community. A number of alliances have been formed, facilitating synergies and the execution of strategies.

The EU Clean Hydrogen Alliance
As part of the New Industrial Strategy for Europe, in July 2020 the European Clean Hydrogen Alliance (ECH2A) was launched in the context of the hydrogen strategy for a climate-neutral Europe.

The European Clean Hydrogen Alliance is aimed at developing and deploying hydrogen as a viable and competitive energy source in Europe. The Alliance supports the implementation of the hydrogen strategy for a climate neutral Europe, by working towards developing a full and accessible EU wide hydrogen value chain. This will be achieved through, among others things, an investment agenda and a pipeline of projects, as well as by mobilizing resources and actions to install renewable hydrogen electrolyzers to achieve the aforementioned 6GW and 40GW objectives.

In April 2021, the EU Commission sent an invitation to all 1000+ members of the European Clean Hydrogen Alliance inviting them to submit projects for renewable and low-carbon hydrogen technologies and solutions. In June 2021 the second European Hydrogen Forum took place and reported an impressive number of 1,052 submitted projects, from which 997 met the eligibility criteria. This number reflects the very high interest and engagement of European industry to accelerate the development of hydrogen on the continent.

The EU Fuel Cells and Hydrogen Joint Undertaking
Because the importance of developing efficient electrolyzers is a high priority, as long ago as 2003 the European Commission facilitated the creation of the European Hydrogen and Fuel Cell Technology platform with the goal to link public and private research and to create initiatives to accelerate the development of efficient fuel-cell and hydrogen technologies.

From this initiative, in May 2008 the Council of the European Union set up the Fuel Cells and Hydrogen Joint Undertaking (FCH JU) with the objective: To contribute to the implementation of the Seventh Framework Program and in particular the Specific Program 'Cooperation' themes for 'Energy', 'Nanosciences, Nanotechnologies, Materials and New Production Technologies', 'Environment (including Climate Change)', and 'Transport (including Aeronautics)'.

Illustration 02 – AIRBUS Zero emission airplane powered by Hydrogen (Source PRBX/AIRBUS)

Amongst the notable projects and initiatives underway is one very interesting study, commissioned by Clean Sky 2 and Fuel Cells & Hydrogen 2 Joint Undertakings on hydrogen's potential for use in aviation. Using hydrogen in aeronautics will require a huge amount of technical innovation and a new infrastructure, but it is seen as a major step forwards in the reduction of CO2 emissions from the aviation sector. The airplane manufacturer AIRBUS took part in the study and it's worth mentioning the company's ambition to develop the world's first zero-emission commercial aircraft by 2035 (illustration 02).

From small to big, hydrogen is making its way!

Step by step, slowly but surely, green hydrogen is becoming a reality and the number of installed electrolyzers is rapidly increasing. Clearly it would be difficult to list all the projects, but it's interesting to mention a few of them to illustrate the evolving reality.

Illustration 03 – Sweden / Mariestad ElectriVillage solar to hydrogen autonomous station
(Source PRBX / Mariestad Municipality)

Sweden – Mariestad ElectriVillage
Located in the southern part of Sweden on the shore of the lake Vänern, the municipality of Mariestad developed a concept to create a sustainable energy ecosystem based on renewable energy and hydrogen. The original project included a large array of solar panels to power electrolyzers generating hydrogen for an autonomous refuelling station for cars and utility vehicles. Exploring the large range of possibilities offered by this technology, the station could also use the stored hydrogen to supply a fuel cell to generate electricity. The oxygen resulting from the split process in the electrolyzers is captured and stored for medical, industrial or farming applications. This autonomous station is a good example of what could be deployed at a larger scale and even to generate hydrogen for other vehicles such as local trains (illustration 03)

Illustration 04 – Germany / Wesseling EU largest PEM electrolyzers
(Source PRBX / SHELL)

Germany – Wesseling EU Largest PEM electrolyzers
As part of the REFHYNE European consortium and with EU funding through the Fuel Cells and Hydrogen Joint Undertaking (FCH JU), the largest European polymer electrolyte membrane (PEM) water electrolyzers began operating at Shell's Energy and Chemicals Park in Rhineland near Cologne. The Rheinland electrolyzers will use renewable electricity to produce up to 1,300 tons of green hydrogen a year, and plans are underway to expand capacity of the electrolyzers from 10 megawatts to 100 megawatts (illustration 04).


These two examples reflect the scale of hydrogen initiatives in Europe and especially considering the large number of projects, place Europe as a leading player in energy transition and industry decarbonization.

In conclusion
After decades of interest in hydrogen, we have finally entered a new era. Europe began its 'H' engagement more than 20 years ago and the 'Green Deal' boosted research, cooperation and deployment. There is no doubt that Europe has taken major steps to reach the 2050 goal and other countries are also speeding-up their hydrogen strategies. In the US, under President Joe Biden's direction, major activities are taking place. As announced on July 7, 2021 by the U.S. Department of Energy (DOE), an allocation of $52.5 million will fund 31 projects to advance next-generation clean hydrogen technologies and support DOE's recently announced Hydrogen Energy Earthshot initiative to reduce the cost and accelerate breakthroughs in the clean hydrogen sector. These are clear signs that hydrogen is an important part of the US energy transition strategy.

Hydrogen is no longer a myth and Jules Verne's vision: "Water will one day be employed as fuel, that hydrogen and oxygen which constitute it, used singly or together, will furnish an inexhaustible source of heat and light, of an intensity of which coal is not capable" will become a reality.

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




PSMA and IEEE PELS Educational Series for Young Professionals
Posted: 2021-9-20
"Social Networking for Engineers" October 24, 2021

The PSMA  Industry Education Committee and IEEE PELS will be sponsoring a series of seminars for young professionals designed to provide them guidance in their professional careers in the power electronics industry. The series will include in-person, webinar and hybrid events. The seminars will cover a range of non-technical topics that are vital to advancing the careers of engineers starting in the power electronics industry and will be made available at no cost to attendees.

The first of these seminars will be held in-person in conjunction with the 2021 Power Supply on Chip (PwrSoC) Workshop from 5:30 PM to 6:30 PM on Sunday October 24 at the Singh Center for Nanotechnology on the campus of the University of Pennsylvania in Philadelphia PA.

This session is open to all in-person registered attendees of the 2021 Power Supply on Chip workshop and will address the importance of social networking and how to network or connect with people more effectively. Students, young professionals, and even seasoned professionals will gain valuable insights and guidance on making meaningful connections with others.

The presenter and facilitator for this session is Ada Cheng. Ada Cheng was an electrical engineer at Motorola for 11 years before transitioning into a market analyst role at Gartner Dataquest. Consequently, she had to learn how to network quickly. As a result of networking, Ada served over 13 years on the APEC committee in various invited roles. Now as a market consultant with AdaClock and Anagenesis, she shares practical advice and tips for engineers to network effectively as part of their careers.

We look forward to the inaugural seminar of the series and encourage all those who will be attending the seminar on Sunday October 24 to bring their business cards – you will be glad that you did.

For more information and to join the mailing list to receive information on future seminars, visit the PSMA Education Forum. If you have any suggested topics to be included in the series and/or are interested in presenting a seminar, please contact the PSMA Office at power@psma.com.

An article with additional information on the series will be included in the next issue of the PSMA UPDATE.

You Are Invited to the 2021 PSMA Planning Meeting
Posted: 2021-9-20

All members of PSMA companies are invited to attend the 2021 PSMA Planning Meeting and to offer their inputs and suggestions for the projects and activities the Association should focus on in the coming year. Since ongoing concerns with COVID-19 are preventing many from travelling, the meeting will be held virtually on Tuesday October 19, beginning at 10 AM CDT (3 PM GMT). You can view the Agenda for the meeting at www.psma.com/PSMA_2021_Planning_Meeting_Agenda

The Annual Planning Meeting is a key input to the Board of Directors for planning PSMA activities for the upcoming year that will bring benefits to the PSMA membership.  Members are encouraged to share their ideas on how to drive PSMA forward. Many projects have come out of the Annual Planning Meeting including the PwrSoC workshops and 3D-PEIM symposiums, the revitalized Industry-Education Committee and increased collaboration with other industry organizations including iNEMI, IPC, EPSMA, IEEE PELS and others.

This year's meeting will begin with a brief review of the year-to-date accomplishments and a summary of ongoing activities by PSMA Chair Mike Hayes. This will be followed by an update of the six-quarter financial forecast from Treasurer Tim McDonald.

Much of the meeting will feature reports from the active PSMA committees followed by an open forum to introduce and discuss possible special projects, initiatives, and priorities for the coming months. All members of PSMA Companies are encouraged to provide inputs. If you cannot attend the meeting, we invite you to email suggestions to power@psma.com. These will be considered and included in the discussions. In the coming months, the PSMA Executive and Marketing Committees will summarize the results of the meeting and prioritize which projects and initiatives will be included in the focus for the next year.

If you plan to attend the 2021 PSMA Planning Meeting, please email the Association Office at power@psma.com for joining information. We look forward to "seeing" many of you at this important meeting.

Powerbox (PRBX) Sweden Relocates and Expands R&D in Stockholm
Posted: 2021-9-10
Powerbox, one of Europe’s largest power supply companies, and for more than four decades a leading force in optimizing power solutions for demanding applications, announces it has consolidated its Swedish operations to a new facility located at Hägersten, South of Stockholm.
Originally established at Gnesta (Sweden) in 1974, Powerbox (PRBX) has designed and manufactured power solutions for demanding and complex applications requiring a high level of engineering and technology.
From its inception PRBX has grown to become a leading innovator in power solutions for industrial, medical, transportation and defense application.
Embracing new technologies such as Wide Band Gap (WBG) semiconductors and the migration of the power supply switching technology from analog to digital control, PRBX is expanding its R&D department, taking an important step forwards to guarantee its customers the highest level of quality and performance.
To ensure the shortest time to market, PRBX has merged its Swedish operations to one location, optimizing workflow and communications, and offering excellent working conditions to all of its employees.
Located at Västberga Allé 36A – 126 30 Hägersten in a 3,000 sqm building, with a high focus level on R&D and new technologies, PRBX establishes a new home for power designers to develop the most advanced, efficient and robust power solutions that also contribute to reducing customers’ carbon footprint.
In making this move PRBX begins a new page in its history, strengthening its leadership position as the power supply expert for demanding applications.
For more information, visit www.prbx.com.
PSMA and IPC to Collaborate on Software/Firmware Standard
Posted: 2021-9-2

IPC in cooperation with PSMA is developing a new standard on the "Specification for Firmware Design and Test Requirements for Power Subsystem Assemblies".  The proposal for this standard is based on the "PSMA Power Supply Software/Firmware Reliability Improvement Report." This report was written as part of a special project sponsored by the PSMA Reliability Committee.

We are seeking members from PSMA and the greater power electronics community to join this effort.  Topics that are proposed to be a part of this standard include:

  • Firmware design requirements including basic function, error handling, reliability, performance, etc. This will cover basic architecture and design around that architecture as well as upgradeability. A section to be included on understanding intended application environment. 
  • Firmware test/qualification requirements to verify that the design elements are operating at minimum level. Sections would include testing to verify all critical design and application requirements. It will address exerciser code, unit test and integration topics. 
  • Firmware security for protecting against internal threats and external attack. Sections to include library verification, access to source code, physical security, plugging into the IT/OT network, user logging and tracking, virus mitigation, external access security, update/upgrade security, etc.

We are in the process of forming the committee to start drafting this standard and are seeking members interested participating and/or leading the development of various sections to be included in the document.  This is intended to be a requirements standard that can be used to define expectations for firmware design, test, and security in power assemblies and could be considered the start of a family of standards that complement the current IPC-9592B standard.  Please contact any of the following people if interested.

Jerry Strunk (Jerry.strunk@us.abb.com)
Eric Swenson (ebswensn@us.ibm.com)
Brian Zahnstecher (bz@powerrox.com)

Thank you for your consideration. We look forward to hearing from you. 

About Our Members
Posted: 2021-9-2

Solara Technical Sales is a vendor agnostic, Engineering Value-Added Reseller of Power Solutions for Telecom & Datacom applications, as well as an Independent Sales Representative for several leading manufacturers. Our team is made up of degreed engineers, each with decades of experience. We are recognized as the "Industry's Experts" in defining power and battery-backup systems.

Applications Include:

  • Passive Optical Networks
  • Distributed Antenna Systems
  • Microwave Radios (point-2-point, point-2-multi point)
  • Telecom/Datacom Systems

Solara provides Consulting Services in definition and design of power systems, installation program management and site turn-up, technical training, proper site grounding per Motorola R56 and lighting protection to National Fire Protection Association 780.

Staging equipment while properly storing & maintaining batteries is a must. Experienced personnel on site for system review and turn up saves time and money. Our BISCI-accredited 2-hour course on Gigabit Passive Optical Networks is available to you, at your engineering headquarters, from one of Solara's power systems experts.

Science, not magic, governs lightning strikes and protection from them. Correct grounding not only reduces lightning-related failures, but it also reduces nuisance signal quality issues while protecting personnel.

We represent the following companies and their products:

  • ABB Critical Power
  • American Products LLC
  • Benning Power Electronics, Inc.
  • CE+T Power
  • Delta Electronics
  • Eltek (A Delta Group Company)
  • EnerSys
  • Exeltech
  • GNB Industrial Power (A division of Exide Technologies)
  • GS Battery (USA) Inc.
  • La Marche
  • Majorpower
  • MPINarada 
  • NorthStar
  • Packet Power
  • Plug Power
  • Trimm, Inc.
  • VoltServer, Inc.

Solara's deep relationships with the manufacturers allows us to help customers acquire a spectrum of parts and equipment — fast. These Include:

  • Distribution Panels & DC breakers (plug-in, bolt-in, hard to find)
  • Batteries (UPS, Telco, Utility/Industrial)
  • Inverters (modular & monolithic)
  • Complete DC plants

Solara Technical is a member of:

For more information, call us at 214-906-9853, or visit our website www.solaratech.com.

Provided by Jerry Hogan, Director of Engineering & Marketing, Solara Technical Sales

Friends of PSMA
Posted: 2021-9-1

Friends of PSMA introduces readers to organizations that PSMA has cooperative relationship with to better serve our respective memberships and the international power electronics industry. If you have suggestions on other industry organizations to consider or ways that we can improve our current relationship with other industry associations, we would be delighted to hear from you. 

In this article we introduce you to the The European Power Supply Manufacturers' Association (EPSMA).

In the year 2020, the EPSMA celebrated the 25th anniversary of its founding. It was formed from a group of European power supply manufacturers who were participating in a continuous power market survey, organized by IMS, now IHS Markit. The data from the companies was anonymized, but the group made connections with each other and saw an advantage in forming an association for their mutual benefit. IHS agreed to act as the secretariat for the group and it was formally registered as a 'European Economic Interest Group' (EEIG) in 2002. This status allowed companies who were often competitors to meet as a 'trade association' to represent the interests of their members to national bodies and to promote European power supply manufacturers overall. To be able to monitor and influence European standards relating to power supplies, the EPSMA became a CENELEC liaison organization, affiliated with technical committee TC 22X, which is responsible for standards relating to power converters. Some EPSMA members are in fact already members of TC 22X. IHS relinquished the secretariat service in 2015 and the function is now within the EPSMA organization.

Some of the initial work by the EPSMA was related to the protection of the European industry from product and component 'dumping' from the far east which was creating an unfair market with items that were not necessarily meeting acceptable quality standards. The EPSMA identified related products and informed the authorities. Another area of work was an effort to influence and mitigate the effects of the original power factor correction (PFC) requirements, that had been imposed on the industry with little warning.

EPSMA membership originally was limited to power companies headquartered in Europe, but with the globalization of the industry, this was relaxed and any power supply manufacturer or supplier to the industry can join as a full member if they have at least one full-time employee in Europe. There is also an affiliate membership category which typically includes educational establishments such as universities. The EPSMA is controlled by a management committee of around twelve members which meets four times each year, either in person or by teleconference. There is also a technical committee (TC) consisting of experts from member companies, which meets to discuss technical developments in the industry and inform the membership. The TC also generates in-depth technical documents, typically related to standards, for the guidance of members. These documents are available for non-members to purchase. The most popular over time has been the EPSMA's analysis of the PFC or 'harmonic emissions' standard with specific guidance on how to comply. This was updated in 2018 to include the most recent requirements. Other documents published include guidance for compliance with medical, rail, telecomms, DIN rail and hazardous location safety standards.

The TC has also published papers on the implications of the RoHS, WEEE directives and general power supply design guides on 'Accurate Efficiency Measurements', 'Lifetime Prediction', 'Reliability Prediction' and 'Embedded Software verification and Validation'. Some of these documents are free to download for non-members and a full list, including abstracts of 'members only' documents are available at www.epsma.org/technical-publications. The current work by the TC is focused on generating a guidance document about 'Over-voltage Categories' and their implications on power supply design.

As of today, the EPSMA has around 25 members including all of the main European power supply manufacturers. Six universities are affiliate members as is one of the European test houses. Four of the founding members remain active in the association and new members join at a steady rate. The website www.epsma.org is the portal for information on the activities of the EPSMA with member news and product press releases, information about latest publications, member job vacancies and a quarterly newsletter. There are links on the website to industry resources and indeed to the PSMA. For more information about membership or any other aspect of the EPSMA, please contact: secretariat@epsma.org.

Provided by Paul Lee, EPSMA Secretariat

TDK offers a comprehensive calculation and selection tool for film capacitors for PCB mounting
Posted: 2021-7-2

TDK Corporation presents the new, powerful and intuitive CLARA tool (Capacitor Life And Rating Application) for calculating and selecting EPCOS and TDK film capacitors for PCB mounting. The tool offers a versatile parametric search functionality. This includes a search for capacitance, voltage range as well as for rated voltage, RMS and peak current, temperature, maximum dimensions and volume, approvals, reference standards as well as typical applications.

By clicking just once, the performance of up to four capacitors can be simulated under application conditions. This is displayed in a clear table, which may include the following parameters, for example: operating temperature, DC voltage, AC voltage, peak current and expected service life. Furthermore, safety tolerances are specified allowing developers to adjust the configuration in line with their specific requirements. Moreover, a warning is issued if the permitted capacitor parameters are exceeded.

Application conditions, including personal notes, can be stored for future use. STEP files and SPICE simulation data are available for the majority of capacitors. CLARA is linked to the TDK Product Center. The selected capacitors can be easily ordered from there by means of service distributors. The new tool is available for developers at:

White Paper: Energy Harvesting for a Green Internet of Things
Posted: 2021-5-4

The Energy Harvesting White Paper Committee is preparing a White Paper on Energy Harvesting elucidating the enormous opportunities of the technology despite a reluctant adoption in some industries.

Although Energy Harvesting methods and devices have reached a credible state-of-art, relatively few devices are currently commercially available and off-the-shelf harvester solutions often require an extensive adaption to the envisaged application. A synopsis of typical energy sources, state-of-the-art materials and transducer technologies for efficient energy conversion, storage and management encompasses a wide range of successful research results. But developing power supplies for actual applications reveals their strong dependence on application-specific installation requirements, power demands and environmental conditions resulting in a less extensive portfolio of successful system integrations.

The industrial challenges for a massive spread of autonomous sensor systems are manifold and diverse. Reliability issues, obsolescence management and supply chains need to be analysed for commercial use in critical applications. On this front, the gap between currently available solutions and use-case scenarios is analysed from the perspective of the user. The white paper then proceeds to identify the key advantages of energy autonomy in environmental, reliability, sustainability and financial terms.

Energy harvesting could lead to a lower CO2 footprint of future IoT devices by adopting environmentally friendly materials and reducing cabling as well as battery replacement. Further research and development is evidently needed to achieve a technology readiness levels acceptable for the industry. From this discussion, this white paper will propose a future research and innovation strategy for industry-ready green microscale IoT devices, as a key and seminal initiative to provide useful information to the different stakeholders involved, encourage more interaction between them and deliver industry ready solutions.

Contact and further information: Thomas Becker, Thobecore (email: thobecore@outlook.de), Michalis Kiziroglou, Imperial College London (email: m.kiziroglou@imperial.ac.uk)

Provided by Thomas Becker (left) and Michalis Kiziroglou (right)
PSMA Energy Harvesting White Paper Committee Co-Chairs


Meet Your Directors
Posted: 2021-5-3


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

At the PSMA Annual Meeting held virtually in March 2021, Tim McDonald was elected for his second terms and three new board members were elected - Ajay Hari, George Slama and Renee Yawger. In this issue we would like to introduce you to Ajay, George and Renee.

Below are the biographies and statements they submitted when running as candidates for the Board of Directors.

Ajay Hari, Applications Director, ON Semiconductor
Ajay Hari
Applications Director, ON Semiconductor

Ajay Hari is an Applications Director at ON Semiconductor, where he leads a team of product definers, systems, and applications engineers working on of Ac-Dc and isolated Dc-Dc applications. Prior to ON Semiconductor, Ajay worked for National Semiconductor/TI, specializing in isolated power conversion. Ajay started his career at General Electric as a design engineer. Ajay has a Master's in electrical and computer engineering from the University of Florida and has authored many technical papers, articles, and holds over 18 patents in power electronics.


I have been actively involved with PSMA since 2015 and co-edited the applications section of the bi-annual PSMA Technology Roadmap for the years 2015, 2017, and 2019. I believe that the PSMA provides an excellent platform for power engineering professionals to give back to the community. The mission of the PSMA to bring together various resources of power sources industry is a worthy mission and would like to support it by bringing in a fresh perspective to the board of directors. With the advent of wide bandgap semiconductors, low cost digital processors, and advances in artificial intelligence, power electronics is at the cusp of another exciting growth phase and if given a chance to serve as a Director I would like to contribute in a meaningful fashion to this new growth phase.

Provided by Ajay Hari, Applications Director, ON Semiconductor

George Slama, Senior Applications and Content Engineer, Wurth Electronics
George Slama
Senior Applications and Content Engineer, Wurth Electronic

George Slama spent nearly two decades working at Electronic Craftsmen, a well-respected custom transformer and power supply manufacturer in Canada serving the industrial market. Being a small business, as many such places are, it was the perfect learning ground allowing the opportunity to move around to many different roles as the company developed, technology evolved and opportunity arose. His move to Midcom in South Dakota in 1997 continued the trend, now at a mid-sized company that had a different emphasis. There he spent many years working on low temperature co-fired ceramic transformers, which eventually became a separate business when Wurth Electronics purchased Midcom. Today George serves as Senior Application and Content Engineer in the Technical Marketing group helping to provide and vet technical literature, presentations and software for customers and internal use worldwide.
George serves as the current chair of the IEEE PELS Electronic Transformer Technical Committee, which writes and maintains standards and recommended practices for the transformer industry. He also serves on the IEC TC51 committee, "Magnetic components, ferrite and magnetic materials", is a co-convener of Working Group 9 – "Inductive Components" and serves as a US technical advisor.


I have been fortunate to spend my entire career in the custom magnetics and power supply industry. At first, it was interesting, then I when through a phase where I was not sure – it just didn't seem high tech. Finally, I embraced it with the realization that no electronic gadget works without power conversion and it was going through a big change. I came to realize that my work was part of many diverse products, both large and small. From telephone systems to elevators to aircraft radar to the United Nations and seemly everything in between... high voltage to low voltage, large to miniature, wide band or narrow, high frequency or low, up to the bleeding edge. Getting involved in custom switching power supplies added more things I contributed too. The entire journey has been one of continuous learning and working with smart and talented people both as colleagues and as customers. The creativity of those designing the final product whether it's a phone or a rocket to the Mars is only possible when matched by the creativity of those who design the components that go into it. Microcontrollers run everything today and they do not work for a microsecond without proper conditioned power, our specialty.

PSMA is about working and cooperating together to advance the industry. The various committees work individually and cooperatively to promote and disseminate new knowledge. We also want to encourage, educate, and raise up the next generation of engineers who will taking the reins. I am currently a co-chair of the Magnetics committee and am part of the Education committee. My goal as a director is to foster good interaction between all members to further our industry and to show young engineers that this is an exciting, challenging and rewarding field.

Provided by George Slama, Senior Applications and Content Engineer, Wurth Electronics

Renee Yawger, Director of Marketing at Efficient Power Conversion (EPC), Director Corporate Marketing at EPC Space
Renee Yawger
Director of Marketing at Efficient Power Conversion (EPC),
Director Corporate Marketing at EPC Space

Renee Yawger has over 25 years of sales and marketing experience within the semiconductor industry.  Prior to joining EPC, she was at Vishay Siliconix for nearly 15 years.  Over her tenure she has held various positions in sales support, customer service, and regional marketing.

In 2010, Renee joined EPC when the company first launched its commercial GaN-based power products.  EPC is the leading provider of gallium nitride (GaN)-based semiconductor power conversion technology, providing greater space, energy savings, and cost efficiency in applications such as DC-DC converters, remote sensing technology (lidar), motor drives, wireless power transfer, envelope tracking, and class-D audio amplifiers. At EPC, she is responsible for product marketing and marketing communication worldwide. She is also responsible for the corporate marketing function at EPC Space, which is a joint venture of EPC and VPT targeting the radiation hardened power electronics market for mission critical applications.  Radiation hardened GaN-based power devices address critical space-borne environments for applications including power supplies, light detection and ranging (lidar), motor drive, and ion thrusters.


It is an honor to be considered for a position on the PSMA Board of Directors. I have enjoyed serving on the semiconductor committee for the past few years and look forward to bringing my experience in marketing and promotion to help grow PSMA membership and contribute to the promotion of the many exciting power technology advances taking place across our industry.

Provided by Renee Yawger, Director of Marketing at Efficient Power Conversion (EPC)



Diving Into Immersed Power Electronics
Posted: 2021-5-2


Figure 01 – Mineral oil cooled PC
(Picture: PRBX / Courtesy of Puget System)

In the quest to increase power utilization efficiency and to achieve the computation of more data in smaller spaces, the computing industry investigated alternative solutions to forced air-cooling. Cold wall and baseplate cooling methods, helped by liquid or gas exchangers have been used for decades and from a laptop, datacenters and on to radio base stations, a well-established technology to extract calories from dissipating components has been achieved. The technology worked well, but to jump from 40kW per rack to 250kW and more, even that technology reached its limits.

How to get more computing power from a datacenter with safety and efficiency has been the concern of many engineers, and the idea to get the full benefit of liquid cooling by immersing heavy computing systems into fluid became an interesting option. After more than 10 years of experimentation, business cases and trials, where does that industry stand in 2021 and how will power supplies adapt and develop to accommodate that technology?

From fish-tank to super high density datacenter

If you are a fan of online gaming requiring huge levels of computing power, you may remember PC conventions where geeks presented oil immersed computers in a fish-tank (Figure 01). Anecdotal as it may seem, beginning in 2005, the idea to benefit from deep liquid cooling technology has been explored by the gaming community but the biggest interest for that technology emerged from Bitcoin mining requiring massive computing power.

Figure 02 – KnC Miner 10 megawatt data center filled with high-powered
computers mining for cryptocurrency in Boden (Sweden)
(Picture: PRBX / KnC Miner-2014) Source: PRBX / Shutterstock / UvGroup

At the origin of Bitcoin mining, many companies took advantage of the cold Nordic environment and the locally produced renewable hydroelectric energy to setup datacenters. Nordic countries began many projects to support those initiatives. One example is the Swedish project, 'The Node Pole' promoting an abundance of stable and competitively priced electricity from renewable energy, inviting datacenter operators to benefit from this specific environment.

Many leading companies launched datacenters in Nordic countries, e.g. in Boden, Sweden. We could mention the Bitcoin company KnC Miner, who in 2014 opened a 10 megawatt data center filled with high-powered computers mining for cryptocurrency, capitalizing on the benefits of hydroelectric power and natural cooling. Although the source of energy powering a Bitcoin farm was renewable, nonetheless the energy dissipated was lost and concern was emerging regarding 'Energy Utilization'. Many Bitcoin mining datacenters all over the world were operating in huge halls, with thousands of computing units cooled by forced air, without any heat recycling (Figure 02).

While Bitcoin mining centers operating in Nordic conditions could 'get by' using forced air cooling, the methodology was definitely not a long term solution, and where massive computing units operating in the rest of the world - and not benefiting from natural cold air - it was not a solution at all. In any case, considering the environmental aspect and impact, wasting energy became a major concern and even in Nordic countries local communities placed high demand levels on datacenters to improve Power Usage Effectiveness (PUE) and to optimize and re-use calories produced during the computing process, for example to heat water for public usage.

Figure 03 – Allied Control 2-phase Immersion Cooling
(Picture: PRBX / Courtesy of LiquidStack)
Source: PRBX / Shutterstock / UvGroup

Besides Bitcoin mining, the growing demand for mass computing architecture for simulations and future networks of autonomous vehicles motivated datacenter operators to consider alternative methods to deliver extremely high computing power in smaller spaces with a PUE close to ONE. The idea to immerse the heavily computing parts of datacenters in fluid grew within the engineering community, with functional systems being tested in 2010.

The road for immersion cooling was opened!

When Bitcoin meets Big Data

We could name many experiments performed all over the world to design immersed, high computing power machines in fluids, but it's worth mentioning the 1.4MW container data center and its 240kW flat racks launched by the Hong-Kong based company Allied Control (now LiquidStack) and rewarded with the 'Best Green ICT Award' in 2014 (Figure 03).

From the first generation launched in 2012 to the third generation launched in 2015, cooperating with 3M under a project named 2PIC (2-phase Immersion Cooling), Allied Control increased the Total Watts Per Square Foot from 0.25kW to 3.23kW while maintaining a Power Usage Effectiveness (PUE) of 1.02. This has been made possible by optimizing the immersion cooling technology with the 3M coolant Novec 7100.

Presented at many conferences, e.g. Open Compute Project Summit (OCP Summit), immersion cooling offers unprecedented benefits in terms of performance. As shown in Figure 04, the power density per rack can increase from 40kW to 250kW (and more), the computing power from 10kW to 100kW per square meter, and the energy used for cooling to reduce from 2.0 pPUE (partial Power Usage Effectiveness) to below 1.02 pPUE.

In addition to improving performance, immersion cooling is also considered by datacenter managers as a possible solution to reduce the risk of fire. We are all able to recall the fire at the French OVH datacenter in Strasbourg and the collateral damage that impacted their customers. Despite all caution and measures in place to prevent a fire, the increased power density of existing datacenters cooled by conventional methods remains a high concern for datacenter managers.

Figure 04 – Comparison of air cooling vs. fluid cooling performances
(Picture: PRBX / Courtesy of 3M)

The dielectric coolants used in immersed datacenters have a dielectric strength that's thousands of times higher than air, so even if there's a short circuit in the coolant, there's no spark or ignition, which clearly greatly reduces the risk of fire. As well, immersed data centers are using a very limited number of fans, mainly used outside the computing environment in the heat exchanger.

All considered, immersed datacenters have lots of benefits and following on from Google, Alibaba and many others, the recent announcement from Microsoft to use two-phase immersion cooling in its Quincy, Washington Azure datacenter confirms the demand for Big Data computation taking over from the original Bitcoin experimentation phase.

Making datacenters more powerful and better in Power Usage Effectiveness is great but is cooling working and what will that mean for power supplies manufacturers?


Two technologies are commonly used for immersion cooling: Single-phase Liquid Immersion Cooling (SLIC) and Two-phase Liquid Immersion Cooling (TLIC). Both technologies make it possible to achieve more than 200kW per rack with impressive PUE. The decision to use one or another technology depends on operational conditions and best practices as applied to specific industries. A lot of literature has been published on both, but in simple terms this is how it works:

Single-phase Liquid Immersion Cooling (SLIC)

Figure 05a – Single-phase Liquid Immersion Cooling (SLIC) basic principle
(Picture: Powerbox (PRBX))

Figure 05b – SLIC DUG immersion-cooled data hall in
Houston hosting more than 40,000 servers
(Picture PRBX/ Courtesy of DUG Technology)


Single-phase immersion cooling (Figure 05a) servers are usually installed vertically in the container and cooled by a hydrocarbon-based dielectric fluid that's similar to mineral oil, as was used by the gaming geek in the early days. The heat is transferred from the dissipating components to the coolant, which is then cooled via a heat exchanger in a cooling distribution unit (CDU). Single phase is very simple to operate and maintain. Beside hyperscale datacenters (Figure 05b), SLIC is the preferred solution for industrial computing systems operating in harsh environments requiring a very high level of safety.


Figure 06b – TLIC servers at Microsoft Quincy, Washington datacenter
(Picture: PRBX / Courtesy of MICROSOFT)

Two-phase Liquid Immersion Cooling (TLIC)

In a two-phase immersion cooled system (Figure 06a), servers are immersed inside a bath of specially engineered fluorocarbon-based liquid. Because the fluid has a low boiling point (often below 50 degrees C vs. 100 degrees C for water), heat from the servers easily boils the surrounding fluid. The boiling of the liquid causes a change of state from liquid to gas, thus giving two-phase immersion cooling its name. The vapor is then condensed back to the liquid form via water-cooled condenser coils that are integrated into the top of the sealed racks. The condensed liquid drips back into the bath of fluid to be recycled through the system (Figure 06b).

Figure 06a – Two-phase Liquid Immersion Cooling (TLIC) basic principle
(Picture: Powerbox (PRBX))

Power to Immersion

The vast majority of datacenter equipments are powered by a front-end rectifier converting the AC voltage to 48V DC. Some are using a High Voltage DC (HVDC) distribution (e.g. 400 VDC). In the case of immersed equipment, the power supplies are often outside the tank and power supplies are off the shelf, however a number of highly integrated, high-density computing units are integrating the complete power solution.

Figure 07 – PRBX AC/DC power supply OFI600A-12
designed for immersion cooling applications
(Picture: Powerbox (PRBX))

Originally used in harsh environments where safety is important and cooling is complicated, immersed electronics has been in practice for many years. With the high demand for small networks with high computing capacity, the development of a new generation of highly integrated, immersed servers began, including the AC/DC power supply (Figure 07).


Although most of the power supply components are compatible with the different coolants used in SLIC and TLIC, power designers must carefully select electrolytic capacitors. Electrolytic capacitors are designed to sustain humidity, however their sealing capsule properties can be affected when permanently immersed. Because operating such a capacitor in an immersed conditions may be outside its normal specifications, it is important to simulate, test and verify capacitors' life time when immersed for deployment as such.

Another important parameter to take into consideration is thermal conditions, which in the case of a liquid coolant is very much different to that when operating in air conditions. In both cases, by circulation in the case of SLIC, and evaporation in the case of TLIC, the calories are evacuated from dissipating components much faster than in air. In some components such positive temperature coefficients (PTC) are temperature-dependent and in the case of immersed applications the gradient between low and high temperatures is much lower. Power designers must take this into consideration.

Coolants have high dielectric properties and there is no problem in operating high voltage switching topologies in immersed power supplies, although it is important to maintain a high physical isolation e.g. the use of a conformal coating to prevent corrosion from electrolyte effect that might happen when immersed in fluid.

Most of the layout principles used in air-cooling apply in immersed applications but it is important to make sure the fluid circulation is optimized within the power supply.

Last but not least, when operated in immersed conditions temperature measurement can be a challenge. Although conventional temperature sensors are often used with specific coupling to the dissipating components, other types of monitoring by digital measurement are often used instead. Also, techniques such as ripple and noise envelope analysis help to monitor the overall performance and to apply preventative maintenance when parameters are outside critical limits.

What's the next step?

What was started by gaming geeks immersing their computers in fish-tanks, and now to hyperscale massive computing datacenters, the immersed computing world is aimed to grow fast. The outbreak of COVID-19 is boosting Datacenter service demand and also new technologies such as autonomous vehicles, and 5G in its early stages. SLIC and TLIC will continue to improve performance levels, as will power supplies manufacturers working on highly efficient topologies using Wide Band Gap semiconductors (SiC and GaN). After 10 years of experimentation and local initiatives, the world of immersed computing is opening up nicely.

Power designers love a challenge and developing multi kilowatts immersed power supplies is a challenge they cannot resist.

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





PSMA Signs MOU with iNEMI
Posted: 2021-5-2

The International Electronics Manufacturing Initiative (iNEMI) and the Power Sources Manufacturers Association (PSMA) have signed a memorandum of understanding (MOU) to collaborate and share information. The two organizations will continue to partner in key areas such as roadmap development and anticipate co-hosting technical webinars for benefit of the members of each organization and  industry at large.

"iNEMI has had a long working relationship with PSMA, particularly in the area of roadmapping, and we hope to further expand our interaction to the mutual benefit of our respective memberships," said Shekhar Chandrashekhar, iNEMI CEO.

"All electronic assemblies need a power source, all power sources require expertise in interconnect, packaging, assembly, manufacturability and testability," said Mike Hayes, PSMA Chair. "The synergies between our organizations are obvious, and we look forward to building further our collaboration with iNEMI especially in educating, guiding and cross connecting our respective


When Efficient Power Solutions Meet Light in Medical Lasers
Posted: 2021-3-23

When in 1900 Max Planck deduced the relationship between energy and the frequency of radiation, his theory marked a turning point in physics and inspired up-and-coming physicists such as Albert Einstein. Few could have seen the implications of that discovery to the medical world.

From Max Planck to Tattoos

From Planck's discovery it was another 60 years of publications, inventions and innovations up to March 22, 1960 when two researchers at Bell Labs, Charles Townes and Arthur Schawlow, were granted US patent number 2,929,922 for the optical maser, now called a LASER (Light Amplification by Stimulated Emission of Radiation) (Figure 01).

Figure 01: Charles Townes and Arthur Schawlow, researchers at Bell Labs, granted a US patent for the optical maser, now called a LASER

2020 marks the 60th anniversary of the birth of LASER technology, it is also the anniversary of the first application in the medical field.

Figure 02: Close-up of laser tattoo removal from a woman’s hand.
Source: PRBX / Shutterstock / UvGroup

May 16, 1960: Theodore H. Maiman constructed the first laser using a cylinder of synthetic ruby measuring 1cm in diameter and 2cm long, with the ends silver-coated to make them reflective and able to serve as a Fabry-Perot resonator, using photographic flash-lamps as the laser's pump source. In 1962 a dermatologist named Leon Goldman experimented with a version of the Maiman ruby-laser to remove unwanted tattoos. In fact it is fair to say that Maiman's and Goldman's inventions and discoveries have contributed to one of the most popular uses of the medical-laser in the year 2020 - to remove unwanted tattoos (Figure 02).

If removing tattoos seems anecdotal, from that early application medical lasers have found their way into a wide variety of medical applications and without naming all, there are many examples of laser treatments in ophthalmology, oncology and other forms of surgery that we have all either benefited from or heard about.

When a power supply makes light emission possible

If the nature of the laser source is specific to the targeted treatment, i.e. generating light emission in the range of 193 nanometers (Excimer ArF) to 10.600 nanometers (CO2) (Figure 03) and pulses from 5 nanoseconds to 1 millisecond, they all have something in common - a power supply.
Besides powering the embedded computing and other electronic equipment, medical lasers require very specific power systems able to deliver repetitive high peak energy (voltage or current), with safety and reliability.

Figure 03: Wavelengths and examples of laser applications in the medical field.

A function of the final application, each type of laser requires a different type of power supply which can vary from a current generator for continuous-wave diode laser, to complex power solutions in the case of gas-lasers or lamp-pumps using flash-lamps as a light generator.

We could probably identify as many power supplies as there are types of laser used in the medical space, although as a power supply manufacturer we simplify it to two:

  • Constant current types to power Light-Emitting Diode (LED) laser type
  • High voltage types to power flash-lamps and discharge tubes

Powering LED lasers

Originally limited in their power, diode lasers were not very common in medical applications, however with the development of a wide range of diodes generating wavelengths from 405 nanometers to 2200 nanometers, they become popular in the field of photodynamic therapy where the wavelength is more crucial.

As it is for other applications using LEDs (e.g. lighting) the power supply is often defined as an LED Driver. Used both in the new generation of solid-state lasers or as a generator as such, laser LED drivers require particular attention to the stability of the current and compensation of the energy delivered in terms of the temperature of the LED element. Modern current generators for LED lasers are based on digital technology with an input/output (I/O) interface making it possible to monitor and control the power supply to meet application requirements. Using predictive algorithms the power-stage can be programmed to operate safely and to deliver the specific energy required by a single pulse.

An LED laser could operate in the range of few milliwatts to more than 100 watts when using an LED matrix such as the ones used in LED solid-state pump-lights. With the development of supercapacitors, LED drivers for lasers often use them as energy storage. In such cases the power supply includes special circuitry that controls the energy stored in the supercapacitor to optimize, cycle-by-cycle, the level of energy delivered to the load.

Seen from a power supply designer's viewpoint, powering and LED laser applications are very similar to conventional current generators, which is not the case when designing power solutions for gas lasers or lamp-pumps using a discharge tube.

Powering gas and high energy solid-state lasers

Gas and high-energy solid state lasers use flash-lights or discharge tubes that require high voltages to generate the necessary energy levels needed to initiate the 'pumping process'. In this type of application the design of the power supply requires specific knowledge in high voltage switching and energy storage.

Lamp-pumped solid-state lasers and gas-laser power supplies have complex specifications, requiring two elements: a power supply converting the AC line voltage to the high voltage required by the emitting element, and a high-voltage capacitor energy bank for energy storage. Voltage will depend of the level of energy required to activate the pumping, but in conventional medical applications it is often between 600VDC and 3,000VDC.

Similar to your flash camera, the power supply charges a capacitor, which then delivers the energy to the flash lamp. However, while we can accept a small delay in charging the capacitor of our personal camera, in the case of a medical laser the energy needs to be available without delay, requiring a capacitor-bank to store high amounts of energy.

For power designers not used to dealing with high energy transfer topologies, it can be difficult to estimate the size of the energy envelope and preferred control method to optimize the power stage.

The required output power needed for lamp-pumped solid-state or high-powered pulsed-excimer lasers is usually given in terms of joules per second, which is a function of charge time, repetition rate, output voltage, and component characteristics. During a charge-discharge cycle, the rate of change in voltage is not constant, which differs very much from conventional applications where usually the peak-current and charge rate are pretty well defined. Designing such types of power supplies requires very close cooperation with the equipment manufacturer to test the power solution in real conditions.

Figure 04: PRBX High peak load power supply for medical laser use
Source: PRBX / Shutterstock / UvGroup

It is very common for medical laser manufacturers to split the power solution into two parts. These are the power supply itself (Figure 04) and the high-voltage capacitor bank, which for safety reasons could be in a sealed tank.

In terms of technology, modern power supplies use digital control techniques, not only improving efficiency but in the case of medical lasers, also improving the reliability of the equipment due to its operating principle being based on pulsed energy which is known to be stressful for electronic components. As presented previously in the LED laser power solution part of this article, using digital control offers huge benefits in terms of energy management. It is possible to control the power unit to a single bit and to adjust all parameters cycle by cycle. For example during surgery the surgeon could request more power or longer pulses for tumor ablation. Controlled by the embedded computer, the power supply can be programmed in between two pulses to change the charging voltage and/or the amount of energy required by the emitting element.

What else should power designers consider?

Safety - There is no doubt that dealing with high voltages and significant amount of energy requires close attention to safety. Usually built into a final equipment, obviously the power supply must comply with overall safety and environmental regulations, but during the design process power designers must pay special attention to all risks related to hazards inherent to high voltages.

Risk - Regarding power supplies included in final equipments and not medical equipment as such, certain customers are requiring a full risk assessment analysis e.g. ISO 14971, which must be considered from day one.

EMI - High-peak energy switching generates electromagnetic emissions and line disturbances which may interfere with other medical equipment. Filtering and power factor correction requires special attention during the design phase to not only comply with standards and regulations at the time of certification, but to take cognizance of the aging of filtering components e.g. electrolytic capacitors during the all life time of the equipment.

Noise & thermal – In addition to local regulations, hospital, medical and para-medical institutions are requiring electronic equipments to operate without audible noise. Considering that laser equipment includes a number of dissipating elements, forced cooling is often required. To achieve good cooling with the lowest audible noise, manufacturers are using large fans rotating at low speeds to cool down their systems. For safety, capacitor-banks and power supplies are housed in sealed boxes, limiting cooling to conduction through the chassis. This is an important point to consider during the design of power supplies for medical lasers.

How can new power technologies benefit medical lasers?

For many years the size of a power supply for medical laser use hasn't been a real concern - but things are changing. Medical laser manufacturers are considering a new generation of 'portable' lasers for homecare and to increase the mobility of medical services. Research to develop more powerful, and with combined wavelengths LED lasers are showing good progress. Operational control is easily performed on a tablet (no more built-in displays) but of course parts of the equipment will require a serious diet to achieve portability.

In the case of LED lasers, supercapacitors based on nanotechnologies are offering impressive capacity levels to store high energy and together with the use of  Wide Band Gap semiconductors e.g. Gallium Nitride, Silicon Carbide, the size of the power supply could be shrunk by a factor of x3. This is very promising and I have no doubt that LED medical lasers will benefit from the latest technologies and innovations happening in the power supply industry.

Last word:

In 1917, Einstein proposed the process that makes lasers possible, called stimulated emission. He theorized that besides absorbing and emitting light spontaneously, electrons could be stimulated to emit light of a particular wavelength. It took nearly 40 years before scientists transformed Einstein's proposition to fact, putting lasers on the path to becoming the powerful and ubiquitous tools that they are today, but he also said: "I have no special talent. I am only passionately curious", and that is the motto of many power designers developing power solutions for the next generation of medical lasers.

The future of power supplies for medical lasers is bright!

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




International Future Energy Challenge (IFEC 2020) Winners Announced
Posted: 2021-3-23

Organized by Aalborg University, Denmark, the 13th International Future Energy Challenge (IFEC) 2020 announced awards for the student project competition on power supplies for nanosatellites, a fast-growing satellite industry segment.  In 2020, the student teams were challenged to design and build a power supply for nanosatellites with specific requirements for efficiency, power density, weight, and dynamic performance. The competition included a preliminary proposal submitted in November 2019, two virtual technical workshops (April and August 2020), and a final competition with prototypes sent to and tested at Aalborg University in November 2020.  A total of 26 project proposals were received from 13 countries and regions. Initially, 17 teams were shortlisted for the first workshop, and 10 teams were later invited for the second workshop. The final competition involved prototype testing of the four finalist teams. These tests were conducted locally at Aalborg University, where Chroma ATE Inc. sponsored the testing system. The winners are as follows:

  • The Grand Prize ($10,000) - Zhejiang University
  • The Outstanding Performance Award ($5,000) - National Ilan University
  • The Outstanding Performance Award ($5,000) - University of Belgrade
  • The Ingenuity Award ($1,000) - India Institute of Technology Kanpur

The following teams received the Certificate of Excellence:

• Leibniz University Hannover
• Technische Hochschule Köln
• University of Alberta

• Virginia Polytechnic Institute and State University

Examples of the developed prototypes by the IFEC 2020 student teams.

Initiated in 2001, the IFEC is sponsored by Power Sources Manufacturers Association (PSMA)IEEE Power Electronics Society (PELS)IEEE Power & Energy Society (PES), and IEEE Industry Application Society (IAS). In all, the IFEC 2020 was a big success, despite the challenges associated with COVID-19 and the contingency plans for the technical workshops and final competition. All participating teams and, in particular, the finalists showed excellent skills in teamwork and solving technical problems. Congratulations to all the teams on their remarkable work and innovation. We look forward to future IFECs, more importantly, to see more brilliant students disseminate and share knowledge across continents and institutions.

More information can be found on IFEC 2020 website: http://energychallenge.weebly.com/ifec-2020.html.

Provided by IFEC 2020
General Chair Huai Wang

  IFEC 2020 General Chair Huai Wang



1991-2000: Reminiscences from an early PSMA Board Member and APEC Publicity Chair
Posted: 2021-3-23


The PSMA Strategic Agenda for the 90s included:

  • Fostering communications and cooperation between the various segments of the power sources industry. 
  • Educating manufacturers on improving quality and reliability of their products.
  • Encouraging and promoting industrywide ethical practices, policies and procedures.
  • Continuing to identify and communicate the needs of the user community to the manufacturing community.

APEC 1991
( Click to enlarge )


As mentioned in my article in the last issue of the Update "In the Beginning", in 1990 PSMA joined IEEE IAS and PELS as a co-sponsor of APEC. I would opine that "1991 was a turning point for PSMA and APEC." 

APEC 91, the first conference sponsored by the 3 organizations, was led, as continues today, by a team of volunteers representing the 3 sponsors, including General Chair Chuck Harm, PELS; Program chair Dr. Tom Jahns, IAS; and Exhibits Chair Dave Kemp, PSMA. The conference was a huge success, though not without its challenges. The Gulf War had an impact with a reduction in our projected international attendance. Our initial concerns were confirmed when David Fields of TDK-Lambda U.K. a Plenary Session speaker, cancelled. His presentation was to address the world market for power supplies. I was asked to take his slot and presented "Global Power Supply Implication...the squeeze is on." I also led an evening rap session titled "Are Power Supply Manufacturers a Band of Liars and Thieves?" During his Keynote Speech, W. J. Warwick, President of AT&T Microelectronics, mentioned the topic of my rap session, saying "he will need to know if it's safe to go back to the office."

Some notable moments from APEC social events in the 1990s:

  • APEC '93 was held in the Town and Country resort in San Diego. The social event was a harbor dinner excursion on the San Diego Bay. They had to add a second ship!
  • APEC '98 was held at the Disneyland hotel where we negotiated for the Adventureland Area to be re-opened for our exclusive use for the Wednesday social event. Yes, Indiana Jones was working that night!
  • APEC '99 was held in Dallas. We tried something new for the social event - a bull was brought up to the Adam's Mark hotel ballroom in a freight elevator. Each of the attendees had a chance to ride him. Note: He was surely drugged, I survived.

Dilip Amin riding the bull, APEC 1999
Bob White, General Chair APEC 2000

APEC 1998 Marketing Session Speakers Marshall Miles, Connie Heath, Laurence Bloom,
Larry Gilbert, Mohan Mankikar, John Bowers, Chris Stratus, Linnea Brush

Governor Bush APEC 1999
Governor Bush APEC 1999
Welcome Letter

( Click to enlarge )

President Carter Letter
APEC 1996

( Click to enlarge )


One challenge I undertook as APEC Publicity Chair, that did not have much success, was to invite a local VIP to greet us. While most declined due to restrictions and other obligations, many did send nice letters welcoming APEC. Some of these VIPs include Presidents George H. W. Bush and Jimmy Carter; and Governors Mike Foster, Louisiana; George W., Texas; and Arnold Schwarzenegger, California.

San Jose Mercury News
March 6, 1996

( Click to enlarge )

On the other hand, I was successful in getting APEC print and broadcast media attention with a few (Micro-) mice running around a maze. The APEC '93 Micro Mouse contest was broadcast on ABC in San Diego.  The San Jose Mercury News had a full color photo of the contest in their Mar 6,1996 edition. And both the Orange County Register and FOX local channel 11 covered our 2004 event in the Disneyland Hotel ballroom. 

APEC 2016 in Long Beach was the last APEC I attended. It was overwhelming to see how much APEC has grown - the program committee had to sort thru 1212 Technical Session Abstracts submitted from 45 different nations. There were an amazing 370 booths in the exhibit hall! I learned a new topic called "Internet of Things." And I can reflect back to 1995 in Dallas where we offered 140 technical papers in 21 sessions with four parallel tracts.

Wishing PSMA much success as you move forward into the future.

Larry Gilbert, Mohan Mankikar, and Pat Patel at APEC 2016 in Long Beach, CA

Provided by Larry Gilbert,
former PSMA Board Member
and APEC Publicity Chair




TDK offers a comprehensive calculation tool for aluminum electrolytic capacitors
Posted: 2021-3-11

TDK Corporation (TSE:6762) presents the fully revised version 4.0 of the tried and tested Online AlCap Useful Life Calculation Tool for EPCOS aluminum electrolytic capacitors. The tool covers all new high-voltage capacitors (>150 V DC) with screw, snap-in and solder pin connections. These DC link capacitors are particularly suitable for new designs of converters for industrial applications, such as photovoltaics and wind power generation, as well as uninterruptible power supplies.

The AlCap tool enables up to 15 load profiles to be simultaneously entered, calculated and, if so desired, stored for later use. This powerful function allows applications to be developed both with single capacitors and capacitor banks. Furthermore, the tool can perform on a customer-specific basis calculation. This merely requires the CSC code specified in the respective data sheet to be entered.

Once all relevant values have been entered, in addition to the useful life of the capacitors under defined load conditions, the user also obtains data regarding the hot-spot temperature, power dissipation and much more. Coupled with its useful lifecycle under defined load conditions, the AlCap tool provides industrial designers a solution that meets the needs of their demanding applications.

For more information visit http://www.tdk-electronics.tdk.com/en/alcap_tool

WBG Semiconductors Pose Safety and EMI Challenges in Motor Drive Applications
Posted: 2021-3-10

For years we've been told that silicon (Si) power MOSFETs and IGBTs have largely reached their performance limits and that wide-bandgap (WBG) power semiconductors such as SiC and GaN MOSFETs will soon take over. One area where this is supposed to happen is in variable-speed motor drives, where SiC MOSFETs are competing with silicon IGBTs to be the power switch of choice for driving permanent magnet synchronous motors (PMSMs). GaN FETs are also being positioned for use in these applications. Despite the hype, there are serious obstacles to overcome in making the WBG power switches viable in large motor-drive applications.

With their fast rise and fall times, WBG power switches generate serious EMI that not only threatens a product's electromagnetic compliance (EMC) but could also lead to power switch failures. While those types of problems might be somewhat expected, you may not be aware that the fast edge speeds of WBG devices also threaten the integrity of insulation materials. It turns out that the varnish used on transformer and motor windings becomes lossy at the fast edge rates produced by SiC and GaN devices, which can lead to heating that compromises winding insulation. Product failures due to partial discharge (PD), corona, inception and burning are possible.

There is a path to overcoming these problems and we can turn to the industry's experience with class D audio amplifiers for an enlightening history lesson. We'll review that experience before diving into the problems faced when designing WBG power switches into motor drives. This discussion is about the real problems and real solutions that are encountered in designing and building products—not the ideal world of simulations. But first, a few words about disparity between WBG marketing and reality.

The Gartner Hype Cycle chronicles the stages of product marketing experienced by many new technologies. Currently, WBG semiconductors such as SiC and GaN seem to fall somewhere on the curve between the trough of disillusionment and the plateau of productivity. (Source: Gartner).[1]

WBG Marketing Hype Meets Design Reality

The untiring marketing campaigns told us "wide bandgap semiconductors will replace all silicon in all things by 2010…." Then it was 2012…2015… 2020, etc. While that's a fine strategy to pump and dump shares of semiconductor company stock and sell companies, the WBG replacement of silicon didn't actually happen. As it would turn out, the variable frequency drive (VFD) that hangs on the wall in the pumphouse really doesn't need to have a 15-ns commutation time. Nor is there a budget in that standard catalog product for the premium "WBG parts" that we are told have taken over the world.

And then the "experts" came along, having never really touched hardware, designed anything, debugged, taken the waveforms, done the work, built a system, or pushed a product through the safety agency and EMC directives. The experts of course took out the silly silicon and put in their WBG devices, perhaps wearing a cape to the meetings like batman or superman. "Go statements" included things like "it works great in simulation, thereby it works great" at power levels that senior folks knew wouldn't fly.

Learning from Class D Audio

But what went wrong? It's a secret, don't tell anyone, but WBG devices in motor drives, particularly SiC MOSFETs, are in the same place class D audio was 25 years ago. The supported switching frequencies aren't high enough yet to build in the integrator economically or within a reasonable space, so the motor, the insulation system applied therein, the line set, the gate driver, the dc-dc converter and the inverter output have to see the fast rise and fall times associated with the higher frequency switching.

Some, of course, have sidestepped this by slowing down the WBG devices to perform like the old Si devices. At that point, the price premium for the WBG devices is absolutely fruitless. One could get the same performance with a Si IGBT for much less cost.
What then happened with class D audio? You may recall, the early amplifiers relied on the voice coil inductance to integrate the current waveform. The same voice coil was wound with wire that had significant skin effect losses at the switching frequencies in play. Then the wire was often wound in layers, which took us into the Dowell curves where Rac/Rdc became exponentially worse. So, by having the voice coil integrate the current waveform, the ripple current simply caused heating.

Now if you are running perhaps classic audiophile stock, like a tangerine phase plug Altec Lansing transducer, with only one or two replacement diaphragms left on earth, the notion of having your voice coils "cook" was disheartening, expensive and ultimately full of distortion as the wire/varnish/glue loosened up from the heat and started to rub in the gap.

After a little suffering, the class D audio designers discovered that it was smart to add the integrator to the output. They upped the switching frequency a bit to make the L and C small while also minimizing phase distortion and added lag. The LC then integrated the high-frequency ripple and delivered fundamental program material to the voice coils (with careful consideration of Q). Problem solved. On behalf of the audiophiles: WHEW!

Why then would this matter to the WBG inverter? The secret is one the experts never knew. The high frequency energy in that WBG device's fast switching excites problems that the slower Si speeds did not. Let's consider a system: motor, drive, line set, control, gate driver and dc-dc converter.

At the inverter output, the switching frequency may have gone up a bit. Perhaps the Si IGBT-based drive switched at 5 to 10 kHz. The WBG inverter may switch at 20 to 40 kHz in a practical design. The rise and fall times of the midpoint of the inverter in a Si IGBT design may have been in the 200-ns to 600-ns range while the rise and fall times of WBG power switches are in the 10- to 20-ns range. In terms of bandwidth, the best means I've found to quantify the spectral envelope of a given waveform is to have dominant poles at 1/π*tr and then at 1/π*ton. This method is as antiquated as Ohm's law and it still works just as well.

Why is Edge Speed Important?

If we consider the line set connecting the drive to the motor, the line set has a characteristic impedance. Most line sets will be a twisted-pair type of cable, perhaps with a shield and an earthing conductor as well as U, V and W conductors of appropriate ampacity. The impedance of most any reasonable conductor insulation, from THHN to SOO cable, is usually on the order of 100 Ω. It's easy enough to measure this with lumped parameters (inductance per unit length, capacitance per unit length) and then calculate Z0 = √(L/C).

But why would power electronics care about the characteristic impedance of this line set? What if the line set were relatively long? Relatively needs to be carefully considered.

Let's say that 1/π*tr of the output commutation was in the 30-MHz range. A quarter-wave stub of transmission line at this frequency range will be on the order of 2.5 meters in length. If the line set is 2.5 meters in length or longer, there may then be a quarter wave effect or a standing wave. The fast pulse causes a standing wave in the line set such that the whole line set radiates common-mode noise at this wavelength.

The second problem is that of reflections. Neither end of this transmission line is terminated with the characteristic impedance. The impedances in play are much lower (this is why power electronics people often can't "speak RF language").

These impedance mismatches will then cause reflections at both the motor (read as voltage spikes on the edges) and then reflected back to the drive output (and possibly avalanche on those delicate WBG power switches!!). A proper design will have terminations at both the machine and the inverter output to offer a reasonable match and damping to the high-frequency reflections.

The Threat to Insulation

Then what happens at the motor? Old salts may remember that the large "inverter-grade motors" were actually larger and heavier than the older line-locked beasties. I always found that perplexing. I understood the added losses, the frame current, bearing race galling from circulating currents… but high tech is supposed to be smaller and better, no?

WBG inverters are heading down the same path as silicon-based motor drives, only it will be tougher this time around. One may note that the permittivity tensor of common motor-winding insulators like varnish goes lossy well within the bandwidth of the WBG rise and fall times. Loss is heat. Heat makes varnish fail. Failure comes in the form of partial discharge (PD), corona, inception and burning. The insulation will fatigue around the points of maximum E-field, such as the sharp bends where the conductor channel loops from one slot to the next.

There's More! Transformer and Driver IC Stressors

With those considerations for the power path, most stop there. It's a big bite, and it's a lot to deal with at design. The motor, the line set, and the drive didn't get cheaper by going to WBG. But that's not all.

The high-side driver connects to the high-side gate-source terminals. This means that the high-side driver's galvanic isolation boundaries have to deal with the very same fast dv/dt and the very same insulation stress seen by the motor windings. One might note that the dc-dc transformer is often comprised of similar insulation systems and allowable temp ranges as the motor. Varnish, tape, etc. are present in the transformer too.

So, this transformer will see the same stressors in common mode from primary to secondary. The silicon on insulator (SOI) substrate in the isolated gate driver IC will see these stressors as well. For a practical consideration, if we consider perhaps an "older" IGBT type isolated dc-dc converter transformer, having perhaps 35 pF from primary to secondary, with an inverter commutating 700 V in 15 ns, we then have I =35 pF * 700 V/15 ns or 1.63 A of peak common-mode current flowing to ground on each and every switching edge. This will be an EMI problem.

Back to the Lab for Hi-Pot

If we take these concepts back into the lab and block out the insipid experts spouting the right answers without ever asking the right questions, we will discover some things quickly. A hi-pot test is most always performed with a sinusoid at 50 or 60 Hz. That dv/dt can never approach that of the WBG edge speeds. A 60-second hi-pot test that yielded transformers that never had PD, corona or arcing problems may fall on its face with WBG edge speeds and the aforementioned old school insulation systems.

Further, the partial discharge test does not capture the fast edge speeds. It does look for the RF signature of corona. (This was often detected on the production line with an AM radio receiver. If the receiver was tuned to a strong station and went into desense during a hi-pot or PD test, the next step was to turn off the lights and look for the purple glow, which meant that corona was happening!) But at these fast edge speeds, corona signatures are in band! How does one test for that? That dramatically changes the block diagram of the PD tester!

Field Solvers are Our Friend!

While most austerity metrics and enforcing accountants will balk at the purchase, installation and use of a field solver, this software will become paramount in understanding the insulation system interactions and stackups with faster edge speeds and in predicting the EMI signatures of near-field magnetic loops and electrostatic surfaces.[2]

WBG takes power electronics into the RF domain, plain and simple. We have to adopt the RF tools if we are to build successful designs with WBG. While the old hyper-abrupt junction Si FREDS would ring at 6 MHz or so, the WBG parts are ringing up into VHF and UHF ranges in some cases.

Back to the Integrator

Shhhh! It's a deep secret, but the WBG inverters don't have much choice but to take the class D audio direction of yesteryear. If the motor is to stay cost effective, with a reasonable insulation system, then the high-frequency ripple must be integrated so that only the fundamental is presented to the motor. This will also mitigate standing waves, reflections, and high-frequency radiation from the line set. However, the integrator needs a little more consideration than the 4-Ω or 8-Ω transducers.

A strong PMSM may have a stall current of 500 A and a run current of a few amperes. If the machine was designed for a stall current that high, we wouldn't want the impedance of the series inductor in the integrator to restrict that stall torque. Present switching frequencies won't allow for this as the integrator components are too large, too heavy and too costly. But if the switching frequency of a WBG inverter were to approach the switching frequencies in class D audio amplifiers, that would be the essential win/win.

Perhaps then the integrator could become a stripline to deliver fundamental waveforms to the machine while not detracting from stall torque performance. Further work may compensate out the added impedance of the LC integrator in the Park transform, like adding peak current mode control, only in glorious software. The benefit of this would be very useful in high-torque applications that do work into and out of stall conditions (like a wheel loader moving gravel).


  1. "Understanding Gartner's Hype Cycles"
  2. "Field Solvers: A Different Perspective On EMI In Power Electronics," How2Power Today, October 2019.
Author: Kevin Parmenter
Director of Applications Engineering
Taiwan Semiconductor America


Editor's Note: This article was first published in the January 2021 issue of
How2Power Today (http://www.how2power.com/newsletters/index.php).

TDK Selection Tool for PTC Inrush Current Limiters
Posted: 2021-2-24

TDK Corporation presents a new, user-friendly tool to help users select the right PTC inrush current limiters (ICL) for a range of different power supply and converter topologies. The intuitive tool is available online and does not need to be downloaded. The selection process is divided into four stages: After specifying the circuit structure and the capacitor bank's total capacitance, the developer must then enter the charging voltage and the maximum ambient temperature of the PTC inrush current limiter. After this has been done, the tool displays a list of suitable components for the user, and if a parallel connection is required, the number of components required is also shown. The most important key figures are also shown, as well as links to service distributors that sell the PTC ICLs.

One significant advantage of PTC inrush current limiters is the fact that they are intrinsically safe. In the event of an internal short circuit in the device when it is switched on, this component quickly limits the current to non-critical levels. Furthermore, this component ensures gentle charging of the DC link capacitors.
In addition to their use in converters and power supplies for industrial and household electronics, PTC inrush current limiters are also used in the field of e-mobility – such as in on-board charging circuits and for the charging and discharging of DC link capacitors in hybrid and electric drives.
You can find further information at www.tdk-electronics.tdk.com/en/ptc_icl_tool
Positronic Becomes Part of Amphenol Corporation
Posted: 2021-2-2
Positronic, a global manufacturer of high reliability electronic connector products based in Springfield, Missouri, USA, announced that the company has been acquired by Amphenol Corporation. This acquisition brings together industry-leading knowledge and experience in the market and provides customers with a broad range of products and technical design support for their interconnect solutions.
“Positronic is a strong fit with Amphenol, aligning well with its technological expertise, manufacturing versatility, and customer support,” states David Kean, recently named General Manager for Positronic. “As part of Amphenol, Positronic will continue to provide the connector products and services our customers demand.”
Positronic products complement the Amphenol offering, and the acquisition will allow customers to take advantage of a broad D-sub military / aerospace connector portfolio and have access to new, innovative technologies in the future.
Prior to the acquisition, Positronic was a privately held company, founded in 1966. Over its 50 plus year history, Positronic has expanded globally with a broad range of power, D-sub, rectangular and circular connector products. The company has locations in the United States, France, Singapore, Indonesia, India, and China. Additional information can be found at www.connectpositronic.com.
About Amphenol Corporation:
Amphenol Corporation is one of the world’s largest designers, manufacturers and marketers of electrical, electronic and fiber optic connectors and interconnect systems, antennas, sensors and sensor-based products and coaxial and high-speed specialty cable. Amphenol designs, manufactures and assembles its products at facilities in the Americas, Europe, Asia, Australia and Africa and sells its products through its own global sales force, independent representatives and a global network of electronics distributors. Amphenol has a diversified presence as a leader in high-growth areas of the interconnect market including: Automotive, Broadband Communications, Commercial Aerospace, Industrial, Information Technology and Data Communications, Military, Mobile Devices and Mobile Networks. Visit www.amphenol.com for more details.


1980 - A Pivotal Point in the Power Industry!
Posted: 2020-12-19


October 29, 2020, after seven months of silence due to a major upgrade of the 70 meter wide radio antenna located in Camberra, NASA sent a set of commands to the 43 year-old spacecraft, Voyager 2 that has travelled billions of miles from earth since its launch in 1977. Voyager 2 acknowledged it had received the call and executed the commands without any issue. Interesting for sure - but what is the significance of this to power engineers?

Although often considered as the last cog in the wheel by system designers, in truth the power supply is probably one of the most important parts of their equipment. From the thyratron tubes used in the type REC-30 power rectifier to supply HV power to teletype teleprinters in 1930 [1], through to the latest Wide Band Gap semiconductors, without their curiosity and passion, power designers would not have made a lot of things possible. Voyager 2 is a good example of that, but who remembers what happened in the late seventies and early eighties within the power industry and how leading power engineers changed the face of our industry?

Back in time to the battlefield!

Voyager 2 (NASA)

Launched on August 20, 1977, Voyager 2 was powered by a Radioisotope Thermoelectric Generator (RTG) that turns heat from the decay of a radioactive material into electricity. The generated voltage is regulated and distributed to the 14 scientific instruments and to the master control board. The overall power system has been designed to accommodate the RTG and despite the schematic being kept secret, a brand new technology was mentioned, the 'switching power supply'!


Known since 1930, switching power supply principles have been explored by power designers for decades with the aerospace industry with NASA being the driving force in research and development. Considering the astronomical cost of a launch, and also the lifetime of space probes and satellites, space power designers sought for lower weight, higher energy efficiency and compactness. In the sixties NASA had already used switching power systems in a number of satellites e.g. Telstar in 1962.

In parallel with secret research conducted by aerospace and military organizations to miniaturize embedded power systems, power designers in the civil industry also considered alternative solutions to the old, heavy, bulky conventional architecture of transformer, rectifier, and linear regulation. Who launched the first commercial switching power supply is up for debate, but we can mention RO Associates who in 1967 introduced a 20Khz power solution, followed by a wave of products e.g. 1970 NEMIC Japan, 1973 HP 500W.

Figure 01

For leading power designers it was obvious that switching power technology was the future. But at that time linear power supplies were the standard and 'switching' was considered to be a suspicious technology. Some were predicting that the interference field generated by switching could cause major damage to the final application.

We should remember that in the seventies linear power supplies were the norm, and despite Lambda introducing a line of 'standardized' linear power supplies, the launch of Power-One's 'H' series is considered by many as the first 'off the shelf' power solution, first in USA and then in Europe. Based on a genius level concept of a folded aluminum plate used as case and power dissipater, Power-One launched an amazing number of variants offering systems designers a ready to use power supply (Figure 01).

Figure 02

Simultaneously in Japan - with very little information coming out from that country – power supplies manufacturers not only launched a complete range of linear power supplies but only few years after, a range of switching power solution. One example is the company ELCO/COSEL, which launched the linear "G" series in 1975, followed in 1977 by a complete range of switching power supplies, the "H" series (Figure 02)! In truth, Japan was really ahead of the curve. Another example being SONY who in 1960 at the time when the TV industry used electronics tubes (valves), were the first to use transistors in their TVs and were probably the first to implement a switching power supply in TV equipment in the early seventies.

We should also remember that in the late seventies and early eighties, the vast majority of companies developing electronics equipment had their own in-house power departments designing dedicated power solutions for their applications. Not surprisingly, for many in-house power designers the launch of the Power-One 'H' series was perceived as a threat. Many equipment manufacturers adopted standardized 'off the shelf' power supplies, refocusing their internal power department's R&D to the emerging switching power technology in order to stay ahead of their competitors.

With passion, talent and curiosity!

The seventies was full of talented engineers researching enhanced switching power solutions and it would require a dedicated article to name them all. Among all of them, I will mention here two 'power gurus', Robert J. Boschert (Boschert Associates) and Frederick Rod Holt (Apple), both working at the same time on more efficient power solutions. In both cases, as it was in the aerospace industry, they aimed to make the power supplies smaller, lighter and more efficient.

Figure 03

According to legend, in his kitchen in 1970, Robert Boschert started to develop a more cost effective, competitive and lighter power supply as an alternative to the bulky transformer and linear regulation model. He focused on developing a switching power supply for wheel and band printers that he produced in volume in 1974. In 1976 he launched one of the first 'off the shelf' switching power supplies and applied for patents 4,037,271 and 4,061,931 to protect its IPR (Figure 03). The two patents were granted in less than a year, followed by the commercial success of the OL25 switcher that received high profile coverage in the press and media e.g. "Flyback converters: solid-state solution to low-cost switching power supplies" published 21 December, 1978 in Electronics. Robert Boschert was also a pioneer in selling licenses of its IPR and in 1977 Boschert Inc. had more than 600 employees and was certified to design switching power solutions for space and military aircrafts.

At the same time Steve Jobs, known for his curiosity in new technology, considered switching power technology as being of interest, but due to lack of time the Apple I, launched in April 1976, featured a conventional linear power supply. But then, working on the Apple II Rob Holt designed a 38W multi-output off-line flyback switching power supply (Figure 04) for which he filled a patent in February 1978 and got it granted in December (4,130,862). Apple II was a success and with volume levels increasing, Apple outsourced the manufacturing of the power supply to ASTEC, beginning the long history of OEM power supplies for computers.

Figure 04

Perhaps anecdotal but nonetheless illustrating the competitive landscape within the power industry which suffered a number of IPR disputes, in Walter Isaacson's Steve Jobs biography it is written that Jobs said: "Instead of a conventional linear power supply, Holt built one like those used in oscilloscopes. It switched the power on and off not sixty times per second, but thousands of times; this allowed it to store the power for far less time, and thus throw off less heat. That switching power supply was as revolutionary as the Apple II logic board was." Jobs later added: "Rod doesn't get a lot of credit for this in the history books, but he should. Every computer now uses switching power supplies, and they all rip off Rod Holt's design."

For sure, as a good marketer Steve Jobs would like APPLE to enjoy the accolade of implementing switching power supplies in PCs, though many others e.g. IBM and HP followed the same path at the same time, all aiming for higher performance and reduced costs. However, despite the huge benefits of that technology, its implementation and market adoption has been relatively slow and market analysts have estimated that only 8% of the power supplies manufactured in 1978 were based on switching topology.

Make my Teletype smaller, lighter and faster!

In the introduction, I mentioned the thyratron power rectifier type REC-30 powering a 1930 Teletype teleprinter [1]. Few know that, in those days, Teletypes used to be state of the art telecommunication machines, motivating power designers to invent and innovate long before the introduction of 1, 2, 3, 4 and 5G.

Besides topologies, one major evolution in the switching power supply industry occurred in 1976 when Robert Mammano, cofounder of Silicon General Semiconductors introduced the first control IC dedicated to switching power supply. The launch of the SG1524 was a major step forward within the power supply community, and its first application was a new generation of Teletype machines marketed as being 'smaller, lighter and faster'.

Originally developed to solve a Teletype manufacturing problem, the introduction of the SG1524 became the kick-off of modern switching power supplies, opening the way to inventions and innovations that we all benefit from today.

The race for switching power is open!

With the development of the personal computer and IT equipment, the demand for high efficiency and low weight increased the demand on power designers to improve performance further. Despite Steve Jobs' perception, computer leaders such as IBM had impressive power departments and the launch of the IBM 5150 Personal Computer set the tempo for the design of a dedicated power supply using the NE5560 and later the SG3524 chip. Unique to the PC industry, switching power supplies are specific to a motherboard and are not as such 'off the shelf' for common applications use, although the snowball effect on contracted manufacturers contributed to boost their own products' development, launching complete ranges of commercial products.

On the industrial side it is impossible to name all the products and innovations but since we mentioned the Power-One 'H' series, it is fitting to mention a young engineer who joined Power-One in the early eighties, Steve Goldman, who led the team that designed the new generation of switching power supplies, the MAP series. Anecdotally, MAP stands for the name of Power-One's Chief Engineer/Designer at that time, Michael Archer (Michael Archer Product).

Simultaneously the computing and industrial industries moved towards switching power architectures and although it took years before that technology prevailed over the well-established linear solution, a number of power electronics conventions started all around the world, providing a forum for power engineers to learn and share knowledge about new technologies.

1980, the pivotal point in the power industry!

At the end of the seventies and the beginning of the eighties the power industry forged the foundations of where we are today. While the IEEE Power Electronics Specialist Conference (PESC) started in 1970, power designers and industry leaders sought a different type of forum to share technology knowledge, new ideas and best practices. POWERCON took place in Beverly Hills, CA, March 20 to 22, 1975, followed in 1978 by a conference primarily focused on telecommunications called INTELEC. Unfortunately, after nine years POWERCON ceased in 1984 leaving the power community as an orphan.

Back in days when the grandfather of the internet, ARPANET had just adopted the TCP/IP protocol (January 1983), power engineers were still miles away from chatting and blogging, and with the growing demand for tighter cooperation within the power industry the need for a 'one place to share' became obvious. In 1983 the China Power Supply Society (CPSS) was founded, and in 1985 the Power Sources Manufacturers Association (PSMA) was incorporated. Both organizations aimed to share knowledge and to facilitate communication within their respective power communities, and 35 years later both are still supporting power engineers.

At the same time that PSMA was formed, a group of eight passionate engineers, Bill Hazen (Prime Computer) ; Don Drinkwater (DEC) ; Phil Hower (Unitrode) ; Jonathan Wood (Data General) ; Marty Schlecht (MIT) ; Jack Wright (GE) ; Trey Burns (Data General) and John Kassakian (MIT) had an idea to create a power conference which would embrace research, applied electronics, and serve to connect electronics engineers to a larger community including industry, and the provision of an exhibition. It was to be called the Applied Power Electronics Conference and Exposition (APEC), and the first edition took place on 28 April to 1 May, 1986 in New Orleans.

And the story continues…

The power electronics industry has been through many periods of evolution, disruption and revolution. If the introduction of the Bipolar Junction Transistor was arguably the 'first' technological revolution, there is no doubt that the migration from linear power conversion to switching technology was the second, and the beginning of a long evolutionary path.

Forty-three years after it was the launched, Voyager 2 has travelled 14 billion miles into deep space and the power supplies that pioneers designed in the early seventies are still doing their jobs. This is what makes all of us excited by what we do in the power industry and thanks go to all the genius power designers that I have been unable to name in this article that have contributed to make the transition from linear to switching technology possible.


  1. Teletype Model 19 Thyratron Power Supply - https://youtu.be/WX74GoHuwHk

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




In the Beginning
Posted: 2020-12-19
Reminiscences from an early PSMA Board Member

WOW!. Happy 35th Anniversary PSMA.

In the 1970s and early 80s the power electronics industry encountered a huge leap in power supply design technology driven in part by the introduction by Apple and IBM of personal computers. Up until that time, the technology primarily used was large and heavy linear technology power conversion, "boat anchors" manufactured in two car garages as the expression went. During that time, the industry also began to face the challenge of transitioning to bi-polar and high frequency MOSFET designs that would create more efficient, smaller, and lighter products. This encouraged a group of design engineers and marketing leaders to explore creating a new industry group to focus on educating themselves and their customers as the industry began to implement and accept these evolving power technologies. At that time Electro, PowerCon and Westcon were the trade shows and conventions focusing on power electronics. 

On Nov 15, 1985, the Power Sources Manufacturers Association, PSMA, was founded as a 501 C (6) nonprofit industry association. Three months later, in Feb of 1986, the first Board of Directors were elected at a meeting held in Dallas, TX. Tim Parrott served as President and Ron Koslow was PSMA's first Chairman. The Bylaws identified three levels of membership – Regular (Manufacturers of power sources and conversion equipment), Associate (Users of power sources and conversion equipment, or manufacturers of components designed for incorporation into power sources and conversion equipment) and Affiliate (Organizations involved in the power industry, including Manufacturer's Representatives, Distributors, Advertising, Marketing, Consulting, Publications).

PSMA launches third year

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To establish early credibility, the Board decided to create a "Handbook of Standardized Terminology for the Power Sources Industry". Michael Foldes led the Technical Committee that also included Dan Ketchum, Earl Crandall, Emilie Creagar, Chris DuBiel, Gene Goldberg, Sydele Petch and myself. This was before email and online collaboration tools; Michael sent us each an 8" disc for making our corrections suggestions and additions

PEC 1989

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PEC 1990

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To provide industry exposure PSMA co-sponsored the Power Electronics Conference, PEC, in San Jose in Feb of 1989. PSMA Chairman Art Hamill said, "we believe there is a need for an industry-wide forum which brings together the component suppliers, manufacturers and users of power sources and suppliers. That conference and exposition offered six half day Professional Education Seminars and nine Technical Sessions. One year later, in February 1990, PEC was held at the Long Beach California Convention Center and featured three tracks of "Issue Forums" to discuss industry trends.

To create "deliverables" a Research and Development Committee was formed, led by Donald Staffiere of Digital Equipment and John Woodard of ITT Power Systems, with members representing suppliers, users and university members. In 1990, the committee completed its first report to the Association on the status of R&D in the world and presented the results at the PSMA Annual Convention held in Long Beach, CA in conjunction with PEC. This report evolved over time into the current PSMA Power Technology Roadmap.

In March of 1990, John Steel represented PSMA at an IEEE PELS Power Electronics Retreat with leaders from industry and academia. Interestingly, the meeting minutes contained a sidebar that read, "This was the high energy point of the day. Even though we didn't quite know what that meant, we liked the words 'GREEN ENERGY".

Larry Gilbert, John Rowbottom and Dave Kemp at the PSMA booth at the 1990 Canadian High Technology Show

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Expanding PSMA's exposure, later that year we participated at the Canadian High Technology Show in Toronto. We conducted a Customer-Supplier partnership forum, Norm Berkowitz of Computer Products and myself representing the US, and Glen Belland (Electronic Craftsman) and John Rowbottom (NCR) representing Canada.

After the 1990 PEC and APEC conferences, a group representing PSMA negotiated with representatives of PELS and IAS to become the third financial and technical sponsor of APEC (Applied Power Electronics Conference). The Sponsor Agreement on the Continuing Operation of APEC was written by Bob White and the signers were John M. Steel, PSMA Chairman, Ronald M. Jackson, President IEEE Industrial Applications Society (IAS), and Thomas G. Wilson, President IEEE Power Electronics Society (PELS). In Jan of 1991, Dave Kemp and I were appointed Co-chairs of the APEC Technical Program Committee.

There are so many more names that deserve a shout out in the first five years of PSMA. A partial list of the PSMA family at that time includes: Norm Berkowitz, Mike Brown, Lee Campbell, Frank Cathell, Earl Crandall, Emilie Creagar, Chris DuBiel, Mike Foldes, Paul Fulton, Gene Goldberg, Art Hamill, Albert Himy, Dave Kemp, Dan Ketchum, Jim Kimball, Ron Koslow, John Lombardi, Sr., Doug McIlvoy, Mohan Mankikar, Chuck Mullett, Tim Parrott, Sydele Petch, Stu Roberts, Jeff Shepard, Don Staffiere, John Steel, David Thompson, Dean Venable, Ole Vigerstol, Bob White and John Woodard.

We hope to include another article on the early history of PSMA in a future issue of the UPDATE

Provided by Larry Gilbert,
former PSMA Board Member
and APEC Publicity Chair




Message from the PSMA Executive Committee
Posted: 2020-12-17


Without a doubt we are approaching the end of a quite different and challenging year not only for our organization but also for all our member-companies and individuals who support, participate and volunteer for PSMA.  As the world and businesses continue adjusting to a new pandemic-imposed reality, PSMA not only confronted the challenges, but with creative and agile support of its numerous volunteers, the dedicated people who run the office, the board and the executive committee,  co-sponsors and partners responded with agility and creativity to minimize financial loss and risk, while maintaining the valuable services to its members and the community.

We at the executive committee are excited to implement and work in alignment with the newly adapted four pillars of our organization: (i) build on strengths, (ii) become more applications oriented, (iii) integrate performance metrics to assure value add to our community, and (iv) engage with the stakeholders.  Using these guidelines, we hope to drive success and growth of a more vibrant, more active, and more relevant PSMA.

As the member of the executive team who champions the third pillar, the implementation of key performance indicators throughout the operations and activities undertaken by PSMA, I hope to establish a measurable understanding of the "value-add" to "asset allocation" ratio in order to prioritize and improve the effectiveness of our efforts and resources.  Ahead of us is another financially challenging year and this task is critical for sustaining short- and long-term financial viability.

Some of the areas that we plan to implement performance metrics so that we can better understand impact on growth and revenue include:  membership movement comparable to the number of professionals in the industry, web activity tracking, differentiation and consumption of PSMA exclusive offerings such as special projects, reports, databases and other contributions as well as feedback received on our activities. 

We also plan to apply these metrics to activities related to popular workshops and webinars to maximize the value to our members and the wider power electronics industry, return on investment and exposure for PSMA. Remember, as a not for profit organization of volunteers, we need to spend our income from memberships, studies, and events prudently and maximize the use of in-kind human capital from our volunteers. We hope to expand the key performance indicators across the whole organization for example to support and help optimize the numerous committee efforts so as to attract more participation and increase activity.

The Executive Committee will not be able to establish, build and strengthen the performance metric pillar to become an impactful potency without the support and the collective effort of all the members and the volunteers of our organization.  We are encouraging all of you on an ongoing basis to provide feedback, thoughts, and new ideas as we continue to grow a successful PSMA.

Please feel free to contact me or any of the executive team members or the PSMA office anytime. We would love to hear from you and need your inputs!

Trifon Liakopoulos
PSMA Vice President
Enachip, Inc.





Keeping Up with IEC 62368
Posted: 2020-12-15

The UL/EN/IEC 62368 standard is a merger of two standards—UL/EN/IEC 60065 Audio and Video Equipment and UL/EN/IEC 60950 Information and Communication Equipment. As with other standards, there are different versions or editions of the standard such as IEC 62368-1 2014. As this standard applies to a broad range of popular applications, many designers are affected by its requirements.

Most designers probably have some familiarity with 62368 because the industry has been transitioning to this standard for several years, and, within the U.S., this standard replaced the legacy standards in June 2019 for any new products seeking certification. However, there's another regulatory milestone looming as the legacy standards in the European Union are about to be withdrawn on December 20, 2020, making this essentially the adoption date for 62368 in the EU. (1)

As this deadline approaches, many designers may still need to come up to speed on what the standard requires, and understand what variations of the standard are being applied as well as aspects of the standard that are still in flux. With that in mind, we present a brief overview and update on UL/EN/IEC 62368, noting the status of various versions of the standard in different countries and sources for further information. We also highlight a few elements of IEC 62368 such as standards-related terminology, touch temperature limits and two application areas that will be impacted by anticipated changes in IEC 62368, namely indoor and outdoor equipment and products with USB and PoE interfaces.

Label Reform

Under the emerging regulatory changes, the label on each of the appliance products changes and there are new requirements for each product. For example, the labeling required in the old (EC) no 642/2009 and (EU) 1062/2010, which apply to TVs and monitors, changes in the new regulation. While the existing product ratings assign A, A+, A++, and A+++, the new rating system goes from A through G (more on this in the section on Displays).

Safety and Hazard Based

IEC 62368 is not a rule-based standard but rather a safety and hazard-based standard. Audio and video equipment and information communications equipment have many ports such as USB and the newer USB Type C ports. The computer monitor has ports that the consumer or user can touch. The manufacturers are now requested to present hazards to the safety agencies including voltage, and temperatures of the various surfaces. 

Table 1. IEC 62368 implementation by country or region. [2]

It has taken time for the various agencies to create a harmonized standard. Each region of the world has its own version and implementation date as seen in Table 1.

UL has given a number of presentations and overviews concerning the standard. One of the earlier presentations was an IEC 62368-1 overview given by Thomas Burke a principal product safety engineer, Consumer and Enterprise Tech Equipment at UL, on June 7, 2017 to PSMA. A recording of the presentation along with the slides is available on the Safety and Compliance Forum on the PSMA website.

More recently Dennis Butcher, senior project engineer, Ctech EULA, gave a webinar presentation on July 28, 2020 "The Adoption of IEC 62368-1 3rd Edition and IEC 62368-3."[3] This presentation is available from UL's Toolkit page. This web page offers resources to help engineers and compliance engineers navigate the IEC 62368-1 3rd Edition from UL 60065 and the UL 60950 standards. 
There are a number of editions to IEC 62368-1 including 62368-1 2nd Edition 2014, which is often cited in the literature. There's also UL/CSA 62368-1 3rd Edition. which was published Oct. 4, 2018. This paper cannot address many of the differences found in the variations because these variations apply to different products and each product is different and has different uses. 

Testing and Design Assistance

Many companies have a compliance engineering department. This department gathers the standards for the products for safety and regulations for various parts of the world where the company's products are sold. The compliance department needs to have a good understanding of the language used in the standards because in many cases, this language may not be understood by design engineers. The following was taken from the Thomas Burke presentation defining some differences. 

Table 2. Definitions used by IEC 60950-1 verse IEC 62368-1. [2]


In products where consumers can touch various parts of the product, there are issues with both temperature and electric shock. Table 3 lists temperature limits under the standard for accessible (touchable) parts.

Table 3. Touch temperature limits imposed by IEC 62368-1. [2]

Indoor Outdoor Equipment

Because the 62368 standard did not address all industry concerns, there are cases where it has not supplanted the old standard. This is true for outdoor applications. As the following excerpt [3] explains, the second edition of 62368 still references IEC 60950-22 with regard to outdoor equipment. However, the third edition of the standard will include the 60950-22 requirements in an Annex Y as noted. Some of these requirements are still not fully defined. So, some unsettled issues remain and other agencies will need to help address what is to be applied.  


Another case where the legacy 60950 requirements have remained in effect are the interfaces that transmit both data and power. For example, many pieces of equipment use USB for both data and power. This is true for the newer USB Type C cables that can eliminate product power supplies and the associated ac power cords.

Similarly, many security cameras and monitors use CAT 5 and CAT 6 cables for both power and data information following the power over Ethernet (PoE) standards. Both of these interfaces will be covered in the third edition of IEC 62368-1 as shown in the following excerpt. [2]
There are newer lighting products that are using CAT 5 and CAT 6 cable systems for both hallway lighting in hotels and security cameras. Some of these systems have backup dc power in case of a power outage. These systems use the new LED lights, allowing lower power consumption and long periods of operation such as two or three hours, which was unheard of with emergency exit lighting and security cameras in the past.
These lighting products came onto the market after the 62368 was initially published so they weren't covered. And there are others such as video doorbells, which can use the existing power and can even have a battery backup using Li-ion batteries. But it's expected that these products will be covered in the third or fourth editions.


  1. "Getting to Know IEC 62368-1—How Does A TV/Stereo Standard Affect My Industrial Power Electronics Design?" by Kevin Parmenter and James Spangler, How2Power Today, November 2017
  2. "IEC 62368-1 Overview" by Tom Burke, UL Presentation to PSMA Safety & Compliance Committee, 6/7/2017.
  3. "The Adoption of IEC 62368-1 3rd Edition and IEC 62368-3"webinar by Dennis Butcher, July 2020, available at "UL's ToolKit for Your 62368-1 Transition".


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 September 2020 issue of How2Power Today (http://www.how2power.com/newsletters/index.php).

PSMA Core Loss Studies
Posted: 2020-9-29

Over the past five years, the PSMA Magnetics Committee has sponsored five Special Projects to better understand the flux propagation in ferrites and the reasons why the performance of large inductor cores performed so poorly compared to the expectations based on published specifications from the suppliers.

The first three projects - PSMA -Dartmouth Core Loss studies- were undertaken by Dartmouth under the leadership of Professor Charles Sullivan and the results are available on the Magnetics Forum on the PSMA web site. Based on some of the insights from these projects formed the basis for the 2 most recent projects – PSMA- SMA Core Loss Studies Phase 1 and Phase 2.

The last two Core Loss Studies are now complete, and this article highlights some of the most interesting findings.  This article is not as comprehensive as the reports, and the reader is encouraged to read the full reports on the PSMA web site for more information.

PSMA–SMA Core Loss Study Collaboration

SMA Magnetics was interested in why large inductor cores performed so poorly compared to expectations based upon published specifications. At the the same time, PSMA was interested in flux propagation in ferrites and why the performance factor B*f was lower and peaked at a lower frequency for larger cores.

Charlie Sullivan (Dartmouth) recognized that there was significant overlap in these interests and arranged an introduction which resulted in the Phase I PSMA-SMA core Loss study. The findings of the Phase I study were so intriguing that a Phase II study followed, which built upon the data from Phase I.

The Phase I and Phase II test reports can be found on the PSMA website Core Loss Studies tab of the Magnetics Forum. The Phase I report is publicly available; Phase II is currently only available to PSMA members, and will be publicly available in late 2021.

PSMA - SMA special project – Phase I

The purpose of the Phase I PSMA-SMA Core Loss projects was to study the flux distribution within ferrite cores while operating.  The concept is that a small area internal to the core can be enclosed by a test winding inserted into drilled holes.  The voltage on the test windings shows the dφ/dt of the flux.

Initially, eight specially machined cores, two each of four materials, were made by Fair-Rite.  Three holes were drilled into each core so that flux in the innermost 1/9th of the core area could be compared to the excitation.  These cores were shipped to SMA for study.


Although the original scope was to test these eight cores, SMA drilled seven more 50 mm cores of various materials to provide a larger sample.

A surprising result for some of the cores was that the flux density in the center of the core was much higher than the average flux density, peaking at just over 2.5 times.  Further, it had a large leading phase.


PSMA - SMA special project – Phase II
Phase II was a larger study comprising five parts:

1. Large core testing–flux propagation in ferrites

Several large cores were drilled with nine holes so that three sets of wires enclosed progressively smaller internal areas.  In this way, the flux and flux density can be measured in three shells and the center for comparison with the excitation voltage.



Two other large cores were drilled so that the voltage can be measured around any of 49 segments.  Each segment is the same size, 1/49 of the total, so one-to-one comparisons could be made.

2. Core power loss comparison with different sized cores of the same material.



Large cores of the same material were found to have significantly higher losses when compared on the basis of mw/cm3.  This suggests that core loss for different core sizes cannot be calculated based on material specifications, which are usually taken using a "standard" core of about 2.5 cm outside diameter.

3. Core shape effect on power loss


Core losses were significantly lower for a core that was laminated.  The second core above has the same area, volume and weight as the first core, but it comprises 5 thinner laminations.


Core losses were significantly lower for a core that was hollowed out.  The second core has the same ID, OD and height as the first core.  Its area, volume and weight are lower, so higher losses may be expected at very low frequencies.


The four cores above all are the same weight and volume.  Cores 1, 2 and 3 have the same ID but cores 2 and 3 are stacked and have the same area, volume and weight as core 1. Core 4 has five times the area because it is wound with only one turn, but it has the same volume and weight as the others. 

The inductances of the four cores are very close to the same value, as are their other electrical properties except the core loss.  The multi-core stacks have significantly lower core loss.

4. Ferrites electrical properties

The electrical parameters (permittivity, permeability, and conductivity) of various ferrites were measured.  These must be known accurately to model the core performance successfully.

As an example, Finite Element Analysis (FAE) did not model the observed flux distribution very well using traditional parameters from data sheets.  Once the analysis was modified to use accurate parameters, the analysis was greatly improved.

5. Rectangular wave core loss tester

Part of the Phase II core loss program was developing an improved full-bridge rectangular wave driver for core loss testing.  The wave shape is determined by an arbitrary waveform generator under software control.  The voltage is controlled by a programmable power supply.  The time, voltage and current are measured using a high accuracy digital sampling oscilloscope and the parameters are exported to a spreadsheet for post processing and storage.  All of the software operations are written in Python.

PSMA Magnetics Committee

In addition to sponsoring these five core loss studies, the PSMA Magnetics Committee continues to be very active. They have organized 5 "Power Magnetics @ High Frequency" workshops in addition to conducting very successful APEC Industry Sessions each year.  They also presented two educational webinars as part of the "PSMA Basics of Magnetics for Switching Power Webinar Series" in early 2020. The committee meets about once a month by webconference and anyone interested is invited to participate. Contact the PSMA office at power@psma.com for more information.

Provided by Ed Herbert, PSMA Magnetics Committee Co-Chair

iNEMI Publishes Best Practices for Protecting the Reliability and Integrity of Electronic Equipment when Disinfecting for COVID-19
Posted: 2020-8-20

The International Electronics Manufacturing Initiative (iNEMI) today announced publication of “Recommended Best Practices for Protecting the Reliability and Integrity of Electronic Products and Assemblies when Disinfecting for SARSCoV- 2 (COVID-19).”

Developed by a team of experts from across the member organizations of the International Electronics Manufacturing Initiative (iNEMI), this document provides guidance on how to mitigate the possible detrimental impact of disinfecting procedures on electronic equipment and assemblies. Groups such as the U.S. EPA, CDC and the World Health Organization (WHO) have published general guidelines regarding cleaning and disinfecting for COVID-19, but none of these specifically address the impact of disinfectants and their application methods on electronic equipment and assemblies. Many commonly recommended disinfection substances and/or application methods could potentially cause failures in electronic equipment.

To develop these best practices, the iNEMI team reviewed key industry, government and technical sources. They also assessed the chemicals included in the U.S. EPA List N: Disinfectants for Use Against SARS-CoV-2 (COVID-19) and common application methods, identifying those substances that minimize the risk of negative impact on electronic equipment when applied in an appropriate manner. 

“With the COVID-19 crisis, several of our members have contacted iNEMI for guidance on how to mitigate the possible detrimental impact of disinfecting procedures on electronic equipment and assemblies,” said Marc Benowitz, iNEMI CEO. “There are guidelines from groups such as the U.S. EPA, CDC and the World Health Organization (WHO) regarding cleaning and disinfecting for COVID-19, but none of these address the impact of disinfectants and their application methods on electronic equipment and assemblies.” 

“Many commonly recommended disinfection substances and/or application methods could potentially cause failures in electronic equipment if the internal electronics were inadvertently exposed to them,” continued Benowitz. “This is an obvious concern for electronics manufacturers who are wanting to ensure the safety of their employees, supply chain partners and customers, while protecting the reliability and integrity of their products.”

Benowitz explains that, in response to this industry need, a team of experts from across iNEMI member organizations reviewed key industry, government and technical sources and assembled a best practices document. The team assessed the chemicals included in the U.S. EPA List N: Disinfectants for Use Against SARS-CoV-2 (COVID-19) and common application methods, identifying those substances that minimize the risk of negative impact on electronic equipment when applied in an appropriate manner. 

iNEMI’s best practices are now available to download here.

PSMA Energy Efficiency and Safety & Compliance Databases Access Now Open
Posted: 2020-6-30
No Registration Required

The Power Sources Manufacturers Association (PSMA) announced the opening of the popular Safety & Compliance Standards Database (SCDB) and Energy Efficiency Regulations Database (EEDB) to the industry with no registration required. You can find information about a Regulation or Standard, its most recent version, revision history, or the latest agency updating work. PSMA has successfully offered the EEDB and SCDB databases to the industry at no charge to the user for several years. Now access is even easier with neither a registration nor log-in required to access all of this industry regulations and standards information.

Every product sold today must meet the requirements of agency regulations, and ultimately standards. Each country or group of countries may have different requirements. It is critical to know the specific ones which your product must comply and the ones requiring compliance within the next two to four years, products you are probably just commencing to design. Since there are numerous regulations and standards, the SCDB and EEDB databases simplify access to the one you need to find. The specifics for each of these databases and how you can easily find them is as follows.

To find the databases, go the PSMA Home Page www.psma.com and follow the links to the database or use the direct links:

The Energy Efficiency Database (EEDB)

PSMA Energy Management Committee sponsors the Energy Efficiency Database, which covers energy efficiency regulations globally for power supplies and motor drives. This database presently tracks on a daily basis 56 agencies and 521 regulations. A significant number of regulations are presently under revision, or revision is complete to become active in 2021/2022.

Figure 1 shows the regulation selection page. You can select a specific agency by application, country or state, or global region. You can also select a regulation by the application. The "Recent or Upcoming Events" section lists all the latest work on all regulations tracked by the database with the most recent date first.

Figure 1 – Energy Efficiency Database Regulations Page

The Safety & Compliance Database (SCDB)

The PSMA Safety & Compliance Committee sponsors the SCDB, which monitors the Power Electronics Standards globally. Presently, this database tracks 778 standards from 50 agencies. The Standards categories include: Product Safety, EMC, Material Toxicity, Environmental, Quality Standard, Performance, Energy Efficiency, and Fundamental Standard.

Figure 2 shows the standard selection page. As with EEDB, you may select a specific agency by application, country or state, or global region. If you have the standard number, you can find it quickly in the bottom selection menu box. The "Recent or Upcoming Events" section lists all the latest work on all standards tracked by the database by the latest date first.

Figure 2 - Safety & Compliance Database Standards Selection Page with Agency Drop List Shown Expanded

And… PSMA Helps You to Stay Up-to-Date Weekly

PSMA further simplifies your access to Regulation updates and Standard updates by offering weekly email announcements containing the latest "Recent or Upcoming Events". This permits you to stay current automatically with present change considerations and work in process on standards and regulations upgrades. There are an average of 30 updates each month from agencies around the globe which the PSMA database team gathers and includes in the weekly email updates. To receive this service, which is provided at no cost to the recipient, you just need to sign up, provide your email address and select the update announcements you want to receive -  SCDB,  EEDB or both.

The direct links to sign up for email updates to the EEDB data base  is https://www.psma.com/webforms/psma-energy-efficiency-database-email-sign.

The direct link to sign up for email updates to the SCDB is https://www.psma.com/webforms/psma-safety-compliance-database-email-sign.

35th Anniversary of PSMA & APEC
Posted: 2020-6-30


Can you believe that the PSMA & APEC are both 35 years young this year? We can look back on our accomplishments and look forward to what we will achieve in the next decade. That means that there is still time to add to the list of accomplishments. For inspiration, here are some PSMA accomplishments over the years:

  • Sponsored APEC (Applied Power Electronics Conference)
    • Created and organized various APEC Industry Sessions
    • Pioneered APEC Presentation Awards
    • Pioneered APEC Student Travel Support
    • Pioneered pre- APEC Magnetics & Capacitor Workshops
  • Supported and contributed to the International Future Energy Challenge (IFEC)
  • Supported Industry input on proposed regulations and standards
  • Created the Energy Efficiency and Safety & Compliance Databases, a collection of international standards and regulations.
  • Pioneered the Power Technology Roadmaps.
  • Pioneered the PwrSoC Workshop, 3D-PEIM Symposium and EnerHarv Workshop
  • Published series of reports on trends and advances in power packaging and 3D Power Packaging working with leading universities and technical organizations.
  • Republished and made available several out of print industry reference books on magnetics

If your company is not yet a member of PSMA, visit www.psma.com/membership/benefits to learn more about joining PSMA and adding your voice to the almost 200 companies, organizations and educators who for 35 years have worked together to support the mission and initiatives of PSMA and to influence the directions of the Power Sources Industry.

Consider how you can contribute to the many opportunities this year, here are few to get started:

  • Contact the Power Technology Roadmap Committee on how you can help the upcoming Power Technology Roadmap 2021.
  • Attend an Energy Management Committee meeting to learn how you can stay informed and help shape upcoming regulations from the US Department of Energy in external power supplies.
  • Attend a Semiconductor Committee meeting to contribute to the adoption of wide bandgap semiconductors.
  • Attend a Transportation Power Electronics Committee meeting to understand the electrification of automobiles and other vehicles.
  • Attend a Reliability Committee meeting to address power supply communication bus issues.
  • Help lead the Safety and Compliance Committee to discuss emerging electromagnetic compliance and certification testing issues facing designers and meeting customer demands.

If you are interested in any of these opportunities, email power@psma.com.

In addition, all of the PSMA Technical Committees welcome your participation in planning and organizing industry sessions for APEC 2021. Help to raise the bar for APEC 2021 Industry Sessions with new presenters with different views discussing their perspectives. Regardless of whether APEC 2021 is the traditional in person conference or virtual event, people still need to hear new points of view and interact with others to discuss the emerging opportunities in the power electronics industry.

APEC has grown and evolved from the first conference in 1986 with 250 Attendees and 20 Exhibitors while staying true to the original ideals, solidifying its status as the leading conference for practicing power electronics professionals. View the APEC 35th Anniversary presentation to see the conference roots and learn more about the volunteers starting with the original "Gang of 8" who have made APEC so successful!

First APEC Social (All 250 Attendees)

Provided by Ada Cheng and Frank Cirolia
PSMA Marketing Committee members


PSMA Launches Webinar Series to Prepare for the Next Power Technology Roadmap (PTR)
Posted: 2020-6-30
This Online webinar series will feature industry experts who will discuss ongoing trends in power technology. The biweekly seminars will be held throughout 2020 and extend into 2021 and will set the stage for the next PSMA Power Technology Roadmap

The Power Sources Manufacturers Association announces a series of webinars as a lead-up to the next edition of the PSMA Power Technology Roadmap (PTR). The webinar series, organized by the PSMA Power Technology Roadmap Committee, will feature invited experts from different fields to offer a range of technological perspectives. In addition to setting the groundwork and providing input for the next PTR, the webinars will give participants access to expert opinions on technology trends and include a question and answer session at the end of each session.

The webinar series will include a number of highly regarded industry and academic experts covering a variety of topics covering components, systems, packaging and applications. The series began on February 20 with a presentation by Ajay Hari of ON Semiconductor "Utilizing WBG Devices in Next Generation Power Converters." Two webinars were held in May, "JEDEC JC-70 Issues Industry First Guidelines for Testing and Evaluating Wide Bandgap Power Devices" presented by Stephanie Watts Butler, Texas Instruments and Peter Friedrichs, Infineon; and "Powering & Retrofitting IoT Devices for Industry 4.0" by Mike Hayes and Peter Haigh, Tyndall National Institute. Future topics include "Ultra-High Density Double-Sided Half-Bridge Packaging with Organic Laminates", "Advanced Packaging Concepts for Wide Band Gap Power Electronics", "Switching Performance of Wide Band Gap Devices", and many others.

Webinars are tentatively scheduled to be held every other Thursday from 10:00-11:00 a.m. Central Time. For updates to the schedule and news of webinars that will be added, please visit: www.psma.com/technical-forums/roadmap/news-events and follow us on LinkedIn and Twitter. To join the PSMA mailing list to receive invitations to all upcoming webinars, sign up at  www.psma.com/webforms/psma-email

The Power Technology Roadmap provides a consolidated outlook of trends in power conversion technology for the next two to five years. The trends provided in the report are intended to give a broad outlook of the power conversion technologies, components and applications. The complete Roadmap document has been published every two or three years, incorporating the content of the Roadmap Webinars Series conducted over the months prior to publication. The other content for the PTR is sourced from recognized industry experts and comprises write-ups about trends in components, applications, emerging technologies and university research. It also includes a comprehensive projection of key metrics evolution in four selected power conversion technologies (ac-dc front-end power supplies, ac-dc external power supplies, isolated dc-dc converters and non-isolated dc-dc converters).

Conor Quinn of Artesyn Embedded Technologies and Dhaval Dalal of ACP Technologies, Power Technology Roadmap Committee Co-chairs, stated; "The PTR webinars provide a window into technology trends and the presentations are unique in terms of their diversity of perspectives, commercial-free tone and the opportunity they offer for the audience to interact with industry experts. We are always looking to enrich and expand our panel of webinar presenters and we welcome suggestions and proposals from prospective speakers." Joe Horzepa, PSMA Executive Director, added that the Committee "welcomes and invites subject matter experts who are willing to actively participate and contribute to the development of the next PSMA Power Technology Roadmap to contact the PSMA Association Office at power@psma.com."

PSMA Safety & Compliance Technical Committee Leadership Opportunity
Posted: 2019-6-2

The PSMA Board of Directors is seeking one or more volunteers interested in providing leadership for the Safety & Compliance Technical Committee. The membership in all the PSMA Technical Committees is comprised of individual volunteers from both Member and non-Member Companies who have a technical, business or personal interest and are involved in the focus of the specific Technical Committee.

An important role of the Technical Committee leadership is to coordinate the mission and focus of the committee to address the current issues and changing trends in the technologies. Each of the Technical Committees normally meet monthly via teleconference for one hour to discuss special Projects that PSMA might fund that would benefit the membership and industry, to consider and plan Industry Sessions for upcoming APEC meetings, and to support the PSMA Power Technology Roadmap with relevant Webinars and technical content. The leadership position is the chair (or co-chair) for each meeting and is responsible for generating the monthly meeting agenda and to facilitate the meeting to meet the interests of the participants.

The benefits of Technical Committee leadership are many, including:

  • Being acknowledged as an important participant and factor in the technical community
  • Opportunity to interact with National, State and Independent Agencies involved with the specific technologies
  • Anticipate and influence changes especially in regulations and technologies
  • Identify your company as an important participant and contributor in the industry segment
  • An expanded ability to network with others in the industry

Additional information on this opportunity is available here.

Please contact the Association Office (power@psma.com, 973-543-9660) for more information on the specific responsibilities for the Chair and/or Co-chair of the Safety and Compliance Technical Committee.

Why Should Your Company Be A Member Of PSMA?
Posted: 2014-12-21

The PSMA is a not-for-profit organization incorporated in the state of California whose purpose is to enhance the stature and reputation of its members and their products, to improve their knowledge of technological and other developments related to power sources, and to educate the entire electronics industry, plus academia, as well as government and industry agencies as to the importance of, and relevant applications for, all types of power sources and conversion devices.

By joining with other leaders in the Industry, you and your company will have a greater voice and influence on the directions of the Power Sources Industry. Some specific benefits of membership include:

Networking: The opportunity to meet and interact with counterparts in other companies on an ongoing basis.

  • Involvement: The opportunity to contribute to the planning of APEC Industry sessions that focus on the specific interest of members.
  • Participation: The opportunity to work experts in committees, workgroups and special studies resulting in a better understanding of market trends, industry trends and better operational procedures to improve performance.
  • Discounts: Individuals from PSMA member companies receive discounts on registration fees for attending APEC and other PSMA sponsored workshops and events.
  • Industry Trends: Increase your awareness and knowledge of trends and factors that can impact your career and provide valuable inputs for your company's product planning.
  • Company Profile: All member company profiles are listed on the PSMA Web Site together with a hyperlink directly to the company website.
  • PSMA Publications: Regular member companies receive a free copy of all new PSMA publications and reports with discounts for additional copies. Affiliate member companies can purchase PSMA publications at a discount.
  • Benchmarking: The opportunity to participate in benchmarking studies with other companies in your industry.
  • PSMA Newsletter: Receive "Update" the quarterly newsletter of the PSMA, with informative articles on activities in the industry and a calendar of upcoming industry events.
  • Spotlight Banner: Your company's products can be featured as a banner on the PSMA Home Page with a link to your website.

PSMA membership dues are modest in comparison to the benefits offered. Is your company a member of PSMA? If not, why not? You can find the membership application on the PSMA web site at http://www.psma.com/webforms/psma-membership-application.

We look forward to receiving your application in the near future so you can take advantage of the registration discount at APEC. The 2015 Power Technology Roadmap will be available in mid March and all Regular and Associate members of PSMA will receive a free copy of the report as a benefit of membership. Affiliate members will receive a discount on the Roadmap and other PSMA reports.


Power Electronics Timeline DRAFT
Posted: 2011-6-29

The Power Sources Manufacturers Association has drafted a power electronics timeline and a "corporate" genealogy chart for the industry to review. As we get inputs, we will be updating these files on a periodic basis. Consequently these files are subject to change until we hear from all affected parties or until enough time has transpired at which time the files will be finalized.

If you have any inputs to share, please contact ada@adaclock.com or the PSMA office.

Handbook of Standardized Terminology now available on "Members Only"
Posted: 2008-1-4

The Handbook of Standardized Terminology For The Power Sources Industry-Third Edition - has been made available as a download on the Members Only area of the PSMA website. Revised and expanded, this unique publication includes definitions for more than 1200 terms related to power electronics which were especially selected for the power electronics professional. The Third Edition also contains illustrations and four new appendices, including a listing of EMI specifications, excerpts from international standards of units and symbols, along with guides for authors of technical papers. Many new magnetic terms are described in this new 126-page third edition that are of particular interest to the practicing designer and marketer of power supplies and related products. Valuable information regarding worldwide power sources, standards agencies, and military specifications has been retained, updated and expanded from the previous edition. Titles of the appendices are: Testing and Standards Agencies; Designer's Reference; World Voltages and Frequencies; Military Specifications; EMI Specifications; Writing Technical Papers for Archival Publications; Units, Symbols and Style Guide; A Brief Writing Guide. These added resources provide concise, easy-to-use references for engineeers involved in technical writing and presentations. If your company is a member of PSMA, you may register for the "Members Only" area using your email address. The registration form requires you to enter your company PSMA member number. You may contact the Association Office if you do not know the member number.

An Engineer's Guide to using Google by Chuck Mullett
Posted: 2005-8-23

Years ago we had to surround ourselves with printed reference material to provide the data on components used in our designs and applications papers to help in their use. Many of these were free, but some others cost over $100 each and became obsolete almost as fast as we obtained them. Today, the picture has changed dramatically. Most of this information is available at no cost through the Internet; the amount of information is so huge that the new challenge is sorting it out. When the semiconductor committee of PSMA began to study the problem of helping engineers find the information needed, the change in the way we do our jobs became blatantly obvious. Even this task has been made easier, because of help from the Internet.

Here is our conclusion: Google is perhaps the most advanced search engine in the world at this time. Surprisingly, it’s not just for lay people who are looking for new recipes or ways to remodel their bedrooms. Its capability to provide us with the sophisticated technical help we need is astounding. It has the capacity to improve its performance, on its own, as it is used. Our job in helping our members and others in the industry has been reduced from one of searching, rating and cataloging materials to one of simply providing a few hints about using Google. We suggest you try it for yourself, get familiar with its capability, and use it the next time you need information. Here are some examples for you to try:

1. Go to Google.com and type in power factor correction. Our result was that 2,190,000 references were retrieved in 0.23 seconds. Now, type in “power factor correction” and see the difference. We got 155,000 references in about the same amount of time. What is even more amazing is that the references were valid! Even in the first case---we looked through the first 120 on the list, and didn’t find even one irrelevant citing.

2. Try “mag amp” and retrieve 8,870 references. All were valid until we got down to the 29th one on the list, which referred to a slow-release garden fertilizer. 28 out of 29 is a validity score of 96.6%---not bad for software!!!

In Example 1 we saw the difference of enclosing the phrase in quotation marks. Doing so causes the search engine to look for precisely that phrase. Without this, the search engine will find hits on each of the words individually, inviting irrelevant references.

To the right of the search window on the home page you will find “Advanced Search.” Clicking on it will produce a page full of easy-to-use tricks to improve the search, including “Advanced Search Tips” on the top line of the page. This gives even more useful information to produce more effective results. Google is so easy that if you’ll spend only 5 minutes with it, you’ll be producing better results than you can find in a world-class library, without leaving your desk. Try it first, then try other search engines. We did this, and found a plethora of irrelevant “hits.” We invite your comments.

Power Supplies - Make vs Buy
Posted: 2003-1-24

A discussion of criteria to consider when deciding whether you should make or buy power supplies when creating equipment.

Power Supplies - Make vs Buy



Technical Writing Guides
Posted: 2003-1-24

The following documents are provided to assist you in your technical writing. Please note that if you would like a hard copy of the Units, Symbols & Styles Guide in a handy one-page format, you may purchase copies in the Publications Section.

Units, Symbols and Style Guide

A Brief Writing Guide


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