Electromagnetic Interference (EMI) is always a potential problem with switched-mode power supplies, both AC-DC and DC-DC converters. Modern designs can perform well for emissions and immunity but external connections must still be correct for the best performance. Sometimes, extra filtering is necessary to meet specific application requirements. However, incorrect filter … [Read more...]
Risk of ESD-Sensitive Devices in Proximity to ANSI/ESD STM2.1-Compliant Garments by Field-Induced Model Discharge
Bob Vermillion CPP/Felow Certified, ESD Engineer-INARTE RMV Technology Group, LLC A NASA Industry Partner During ESD assessments, it is not uncommon to see personnel wearing wool, silk, cotton, polyester blends and static control overalls (ESD Garments). Some ESD garment types consist of an embedded conductive grid network (Figure 1) in combination with cotton or polyester … [Read more...]
A National Plan for EMP Protection (Part 2) – Protection of Buildings
Don White Consultant, Don White Consultants Jerry Emanuelson Consultant Part 1 of this article addressed a proposed national plan for U.S. EMP protection. Part 2 of the article presents methods and techniques for EMP protection of buildings, solar rooftops and other structures. As such, Part 2 covers details of shielding, bonding, grounding, and cable or device surge … [Read more...]
Mitigating Excessive Emissions, 2nd Edition
Donald L. Sweeney and Marilyn Sweeney D.L.S. Electronic Systems, Inc. Mitigating Excessive Emissions was originally written in 1988 and presented at the IEEE EMC Symposium in Atlanta Georgia. The concept and paper have been used by the author hundreds, if not thousands, of times to illustrate what he calls “The Barbell Model.” This illustrates, in very simple terms, how … [Read more...]
EMC War Stories: Letters from Home
Candace Suriano Suriano Solutions John Suriano Nidec Automotive Motors Americas PART 1: MY CELL PHONE CAN TALK TO ME IN STEREO Dear John, I am snowed in here at home with the kids. You may be in an EMC lab solving some tough issues, but I’ve been very busy here at home with some interesting problems of my own. We’ve been bothered by the behavior of our computer … [Read more...]
A Design Review of the Automotive Radiated Emissions Test Fixture
Tom Mullineaux RF Engineer From a cold, dispassionate RF engineering perspective, the automotive radiated test set-up is a strange looking transmit/receive arrangement, with the cable harness of the equipment under test (EUT) suspended above a large copper sheet acting as the transmitter, and a huge antenna close to the chamber floor, and partly in the shadow of the copper … [Read more...]
2014 EMC Directory & Design Guide
Every year, Interference Technology publishes the EMC Buyers’ Guide — our most up-to-date look at the providers of hundreds of EMC-related products and services. In this issue is articles on testing and design, listings of products and services, company directories, calendar events and more! To read this issue, click here. … [Read more...]
EMC Practice – Measurement Under Interference
Clean transmission of signals from the EUT. Jorg Hacker Langer EMV-Technik GmbH It is uncommon to use an oscilloscope to monitor signals from the EUT when testing immunity to interference. The complicated environmental conditions in the anechoic chamber during RF irradiation or burst and ESD tests lead to measuring errors and unwanted interference in the EUT. Modifications to … [Read more...]
Inexpensive Radiated Immunity Pre-Compliance Testing
As an EMC consultant, it seems that lately I’ve run into many client projects where radiated immunity has cropped up as the major issue. One reason for this may be the trend in using digital and analog circuits that are powered by 3.3 volts, and lower, which decreases noise margins significantly. Sensitive analog circuitry is also greatly affected. The compliance testing for … [Read more...]
Potential Impacts of Electromagnetic Weapons on the Critical Infrastructures (View from 2012)
William A. Radasky IEEE Life Fellow WHAT IS IEMI? In recent years, Hollywood has indicated that criminals and terrorists could use electromagnetic (EM) weapons to black out a portion of Las Vegas (Ocean’s 11) or take down a counter-terrorism computer center (24). Is this fact or fiction? It turns out that Hollywood in this case is leading the public and police agencies in … [Read more...]
