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.

radiated emissions plot

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 […]

crude differential mode surge spice circuit

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 […]

james pawson emc speaking at iot leeds

“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 […]

conducted rf immunity calibration impedance and measurement voltages

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 […]

Q4/17 Updates – A good variety of work!

It feels like it has been a busy couple of months here at Unit 3 Compliance with a wide variety of projects coming through the door. Q1/18 is already shaping up to be busy with some really interesting products booked in for pre-compliance testing and some nice meaty problems to get our teeth into. I’m […]