Other news of interest

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

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.

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 ( Click to enlarge )

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 ( Click to enlarge )

PEC 1990 ( Click to enlarge )

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 ( Click to enlarge )

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

ver 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.

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

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.

he 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:

• EEDB www.psma.com/technical-forums/energy-management/database
• SCDB www.psma.com/technical-forums/safety/database

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.