In this practical tip from InCompliance magazine, instructor Arturo Mediano discusses the importance of using the actual load of your device rather than substituting and equivalent resistor when testing for EMI.
Successfully troubleshooting EMI/EMC problems isn't easy. You need time, you need a strategy, and you need to remain calm. Sometimes, you need a special "sixth sense" that only comes from experience because in some cases, your problems aren't even related with the EUT (equipment under test).
Article by instructor Arturo Mediano about near-field scanners.
I love near field probes because they let me "see" magnetic and electric fields with an oscilloscope or with a spectrum analyzer. They let locate sources of emissions in board, cables, and systems. Near-field scanners also let you see emissions, particularly all over a board. That's hard to do with a single probe.
Established in 1970, Interference Technology helps EMI/EMC engineers find solutions to their various testing, design, application and regulatory issues by publishing articles, news and other practical content. We help suppliers in these areas to find the right customers for their components, materials, test equipment and services through a wide range of marketing services, including lead generation, branding, market research and events.
This blog post is a few years old, but remains very interesting to see the difference in performance among USB wall chargers. Ever wonder about the difference between the expensive name-brand charger and the cheap imitation? This article gives in depth examination of the noise emanating from these devices. An interesting side effect of unwanted electrical noise from the chargers is that the touch-screen on your device can become unresponsive or erratic in some cases.
Arturo Mediano teaches courses on EMC/EMI and Signal Integrity for Besser Associates. He is a frequent contributor to industry magazines and journals on these topics. This article appears in the "Practical Tips" section of InCompliance magazine.
Ferrites for EMI suppression are usually chosen looking for high (resistive) impedance at the frequency of interest; but, sometimes, that ferrite is not working as expected. Perhaps you have saturation effects?