Simple RF Current Transformer for EMC / EMI Investigation
This post contains some background info related to the video I posted on YouTube on how to make a simple RF current transformer, a great tool for debugging EMC / EMI issues such as radiated emissions from cables, or tracing conducted RF immunity noise paths. RF current transformers (or probes) are commercially available products from […]
LED Lights, the “Bulb Ban” and EMC / Radio Interference
I’ve just published a new article on LinkedIn titled “LED Lights, the “Bulb Ban” and Resultant EMC / RFI Issues“ where I look at potential EMC effects from increased adoption of LED bulbs following recent EU legislation. If you check it out I’d be interested to hear your thoughts. Please hit comment on the LinkedIn post.
RS-232 to USB Converters – EMC Problems Part Two
A while ago, I wrote about EMC immunity problems with USB to serial converters and how it was easy to fix with a small 100pF capacitor to ground on the TXD and RXD lines for a bit of filtering. Well, now I’ve found the opposite problem of EMC radiated emissions failures caused by these periodically […]
Busy, and a Birthday
It has been a very busy few months at Unit 3 Compliance; it feels like the chamber turntable hasn’t stopped spinning. There has been a wide range of products through the door from prosthetics to video wall controllers, from high spec IoT products to motion sensors, from lighting power supplies to RF amplifiers. I really […]
Surge Testing, MOV Position and Fuse Current
I’ve been working on a power supply product for a customer with a very tight limit on the AC mains fuse rating. One of the problems this causes is during differential mode surge testing. When the metal oxide varistor (MOV) connected line-to-line fired, the resulting current was enough to blow the fuse after a couple […]
“EMC for IoT” Presentation at the IoT Leeds Meetup
I had the pleasure of speaking at the local IoT Leeds meetup, held at the newly (and finally) renovated “Platform” venue just outside of the train station. The views over Leeds city centre from our 10th floor suite where the event was being held were impressive. Paul Wealls of Mokanix had the first slot and gave […]
When is a Test Level Not a Test Level?
Answer: When you don’t read the standard properly! I was verifying my EN 61000-4-6 conducted RF immunity test setup after the construction of some new test adaptors and acquisition of some new equipment when came across something that left me scratching my head. I figured it out eventually and updated my calibration procedure with a note […]
EMC Immunity Issues with RS-232 to USB Converters
These little converters are super handy to interface between your modern PC or laptop and the simpler, lower technology RS-232 serial port used by many pieces of equipment for control or debug purposes. However, like any commodity item there are design compromises, including EMC ones, that you need to be aware of. I was recently […]
IoT EMC Radiated Emissions Investigations
A customer requested some support with one of their products, an IoT bridge device that takes various sensors and provides telemetry back to a central server using a GSM module. Some of the radio pre-compliance spurious emissions testing had suggested there might be some issues at certain frequencies. After a couple of hours of radiated […]
Demystifying EMC 2018 – Silverstone
Rohde & Schwarz held this years’s instance of their excellent Demystifying EMC seminar at the Silverstone race track in the Midlands. The venue was right in the middle of the racecourse with a great view of the start/finish straight. It was good to see so many meaty sounding technical EMC presentations on offer and my […]
