Letter From the Editor

Celebrating 15 Years of Innovation and Empowerment

Dear Readers,

Fifteen years ago, when we launched In Compliance Magazine, we could never have imagined the incredible journey awaiting us. Born out of a dream shared by three determined women, In Compliance has grown from a fledgling publication to a respected and influential voice in the world of electronics compliance engineering.

As we celebrate this milestone anniversary and the publication of our 16th August issue, I reflect on the challenges we’ve faced and the triumphs we’ve achieved along the way. When Conformity closed its doors in March 2009, it felt like a tragic loss. But that setback turned out to be the fertile ground in which we sowed the seeds of our dream.

Columns

Departments

FCC Plans Reporting Requirements for Router Security

The U.S. Federal Communications Commission (FCC) has proposed new rules intended to improve internet router security against cyberattacks.

In a Notice of Proposed Rulemaking (NPRM), the FCC mapped out plans to require broadband providers to submit confidential filings with the Commission, detailing their plans to mitigate potential vulnerabilities in their use of the border gateway protocol (BGP), the technical protocol critical to the routing of information across the internet…

Thank you to our Premium Digital Partners

It’s All About the People:
The Pioneers of Today’s EMC Society

The Contributions and the Legacy of the Society’s Founding Members

By Daniel D. Hoolihan

n the mid-1950s, a group of professionals in the electrical engineering specialty of radio frequency interference (RFI) began to formulate the idea of creating an organization devoted to their specific technical area of expertise. These informal discussions reached a new level at a luncheon on February 27, 1957, during the Third Conference on Radio Interference Reduction, sponsored by the United States Army Signal Engineering Laboratories and conducted by the Armour Research Foundation of the Illinois Institute of Technology in Chicago.

In his luncheon speech, Fred Nichols, Vice-Chairman of the Radio Interference Technical Committee of the Los Angeles area, proposed starting a National Professional Group on RFI. Six other individuals at the luncheon, including Anthony Zimbalatti, Milton Kant, Harold Schwenk, John Lucyk, Albert Ruzgis, and S. Nellis, enthusiastically endorsed the idea and volunteered to make it happen.

Hardening the Power System from HEMP and IEMI

A Cost-Effective Plan to Harden Existing Facilities

Dr. William A. Radasky, Ph.D, P.E.

his article provides an extension of my article in the June 2021 issue of In Compliance Magazine, describing the different ways to protect power system electronics in high-voltage power control houses found in HV substations [1]. The intention here is to provide a specific plan to start to harden power grids against the fields produced by high-altitude electromagnetic pulse (HEMP) and intentional electromagnetic interference (IEMI). In addition, we will discuss the differences in protecting power company substation control houses and control centers and even power generation stations against these threats. Finally, there will be a discussion of the approach to protect the high voltage transformers (V ≥ 100 kV) against the late-time portion (E3) of the HEMP, which also will provide protection against an extreme geomagnetic storm if it were to occur.

While the worst-case levels of the early-time (E1) HEMP environment have not changed, this is not the case for the late-time (E3) HEMP environment, due to the work of the U.S. EMP Commission [2]. The worst-case level of E3 HEMP has doubled, and the IEC is in the process of increasing the worst-case level in IEC 61000-2-9 Ed.2 draft [3]. While this increase is significant, the same new draft version of IEC 61000-2-9 also discusses the fact that the worst-case E1 HEMP field occupies a very limited portion of the ground exposure. And, when considering that there are over 9000 high voltage substations in the U.S., they all cannot be illuminated at the worst-case E1 peak HEMP level with a single high-altitude burst. Also given the costs of hardening a large number of buildings, there have been discussions in the IEC and in other standards organizations considering resilience aspects to reduce the cost burden of protection [4].

3-D Modeling and Characterization of Ferrite and Nanocrystalline Magnetic Cores for EMI Applications

IEEE EMC+SIPI 2023 Best Symposium Paper

By Rafael Suárez, Maria Tijero, Roberto Moreno, Aitor Arriola, and Jose Manuel González

I. Introduction

Ferrite and nanocrystalline magnetic toroids are commonly utilized in interference suppression part of electromagnetic compatibility (EMC), but their implementation is often based on a trial-and-error approach under the guidance of experienced senior engineers. Several studies have been conducted for modeling the behavior of magnetic toroids using equivalent circuits [1]–[3]. However, these studies do not account for certain surrounding environmental effects, and they are limited to tens of MHz. Consequently, 3-D electromagnetic simulation is currently being investigated to consider these effects [4]–[6]. 3-D electromagnetic simulations have gained widespread use in high-frequency design, such as for RF antennas or filters [7], [8]. Nevertheless, research in the field of magnetic toroids is more recent, and new difficulties related to accurately modeling magnetic materials appear.

PRODUCT Showcase

Common-Impedance Coupling

Impact of the Return Path Impedance and the Return Current Levels

By Bogdan Adamczyk and Nick Koeller

his month we explore the impact of the return path impedance and the return current level on common-impedance coupling between circuits. The measurements presented here were performed on a custom PCB containing audio, video, and high-current circuitry, where the return paths for each circuit were selectively shared with other circuits. This topic had been previously discussed in [1], where the measurements were taken with a first-generation PCB. The PCB has since been redesigned to lend itself to future modifications and to contain off-the-shelf, readily available components.

1. Common-Impedance Circuit Model

Consider the situation shown in Figure 1, where two circuits share the return path with a non-zero impedance.

Does an ESD control program require humidity controls?

By Matt Jane and Andy Nold, on behalf of EOS/ESD Association, Inc.

ANSI/ESD S20.20 Humidity Requirements

Humidity control in relation to an ESD control program continues to be misunderstood across the industry. Humidity does help in the reduction of charge accumulation, but it does not control charge accumulation to reduce the risk to sensitive items. The differences in electrostatic charge accumulation on insulators from 20% to 30% RH at room temperature are minor. As a result, the EOS/ESD Association, Inc. does not rely on humidity as part of a control program in ANSI/ESD S20.20.

If a company meets the requirements of ANSI/ESD S20.20 or IEC 61340-5-1, the ESD control items used to mitigate risks of ESD shall be qualified prior to their initial use within the ESD control program. Most of the ESD control items require environmental conditioning during the product qualification testing process. This is typically conducted at 12% ± 3% RH and 23°C ± 3°C. If the ESD control item being qualified meets the requirements of ANSI/ESD S20.20 or IEC 61340-5-1, then humidity controls are not required as the item has been shown to function in a worst-case environment.

Using Reciprocity Theorem to Troubleshoot Immunity Issues

By Dr. Min Zhang

hen I first started working as an independent EMC consultant, I didn’t have nearly half of the equipment I do now. The first piece of equipment I owned was a Siglent swept-type spectrum analyzer, and I made my own near-field probes and RF current probes following Ken Wyatt’s book [1].

I remember a case in which I needed to troubleshoot an immunity issue, but I didn’t have any equipment to inject noise into the system. At the time, I called my mentor, Keith Armstrong, and asked him if there was any way to solve the problem, given the limited kit I had. He said to me, “Have you heard about the reciprocity theorem?”

Here, I quote Henry Ott’s explanation in his book [2]:

Advertiser Index