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Protective Earth in EMC: Why the Safety Ground Wire Often Increases Conducted Emissions
Protective earth is mandatory for safety, but in many power electronic systems it forms the dominant return path for common-mode current, which can increase conducted emissions if not carefully managed.


EMI Filter Insertion Loss Explained: Why Off-the-Shelf Filters Fail in Variable Speed Drives
Insertion loss is often treated as a simple datasheet value, but in real systems it strongly depends on source and load impedance. This article explains why off-the-shelf EMI filters can underperform—or even worsen EMC issues—when applied to variable speed drives and power converters.


Upcoming training event: 2-Day EMC Troubleshooting Course in March 2026
Update (February 2026): This course is now fully booked. We would like to thank everyone for their interest and support. We also sincerely thank Telonic Instruments for kindly providing the training venue and equipment. If you would like to attend a future session, please keep an eye on our website for upcoming course announcements. Our highly popular and well-received EMC Troubleshooting Course is now confirmed for its next public session. See the details below. Dates Tuesd


From Concept to Compliance: Understanding EMC Risk in Future Propulsion Systems
Min Zhang, PhD As future propulsion systems continue to push towards higher power, higher power density, higher efficiency, and reduced size, the industry has good reason to be excited about what lies ahead. The adoption of high-speed switching devices such as GaN and SiC is enabling products with significantly improved performance, efficiency, and functionality. However, beyond the PowerPoint pitches and technology roadmaps, engineers and engineering managers alike under


PCB Layout and Failure Considerations for TVS Diodes
Rod Macpherson When using transient voltage suppressor (TVS) diodes for surge protection, particular care must be taken with PCB layout—especially the tracking between supply rails and the TVS device. For example, in systems with a 12 V rail and a separate 0 V reference (not chassis ground), a TVS diode may be placed between 12 V and 0 V to clamp surge events. In such cases, the routing to the TVS must not be implemented as a spur branching off the main power tracks. Spur con


Bench-Top Conducted Emissions Testing: How to Set Up In-House EMC Pre-Compliance
In-house bench-top conducted emissions testing is a highly effective pre-compliance method for design engineers developing electronic products. Before sending a product to an accredited EMC lab, a proper conducted emissions test setup enables early detection of noise problems that can lead to test failures and design iterations. This article explains how to establish a bench-top conducted emissions test setup for mains-powered products, following CISPR 32 / CISPR 25-aligned p


Using a Comb Generator to Test the Quality of Coaxial Cables
When you buy coaxial cables from a trusted distributor, you typically review the datasheet, ensure the specifications meet your requirements, and place your order. But as a seasoned engineer, do you fully trust the cables without testing them first? Most engineers take a “trust but verify” approach, so in this blog, we’ll present a method for testing coaxial cables. The equipment you’ll need: A spectrum analyser; in this case, we used a Siglent SSA 3032X-R model. An RF cu


Effective Ways of Measuring “Noisy Ground” Currents
Introduction If your job involves electronics design, system development, electromagnetic interference (EMI) testing and troubleshooting, you might encounter the terms "noisy ground" and "clean ground." Technically, there is no such thing as "noisy or clean ground." However, these terms are commonly used in the engineering world despite their inaccuracies. They often give engineers the impression that the earth/ground is an infinite sink of electrical noise, disregarding the


How to Write an Effective Bench-Top EMC Pre-Compliance Test and Troubleshooting Report
A step-by-step guide to excellent engineering practice Bench-top EMC pre-compliance testing is often carried out under time pressure, yet the quality of the test report directly determines how effective troubleshooting will be Before committing to writing this article, I had two main thoughts: First, I’ve seen far too many subpar test reports from engineers. They often do excellent work but aren’t given enough time to document it properly. As a result, when teams sit down to


Bench-Top Conducted Emissions Testing for Automotive and Vehicle Components
Conducted emissions testing on a bench-top setup is a valuable pre-compliance method that helps engineers assess and debug EMC performance before formal lab submissions. In automotive applications, this test setup follows the CISPR 25 standard, where the ground plane represents the vehicle chassis and requires direct LISN bonding to the test plane to achieve accurate results. Previously, we discussed how to set up a conducted emissions test for a consumer product. This requir


EMC SIPI Technical Discussion Group Meeting
On December 11th, we successfully organized our first EMC+SIPI Technical Discussion Group session. This is an exclusive, small community where members share hands-on experience and lessons learned in a trusted environment. The purpose of the group is to exchange ideas, enhance practical design expertise, and foster meaningful professional connections within a social and collaborative setting. Meeting notes from the session are shared below. If you are a Senior or Principal En
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