EEVblog #548 - EMC Pre-Compliance Conducted Emissions Testing

Dave demonstrates how to do some basic in-house EMC Pre-Compliance conducted emissions testing on a DC powered product using an open source hardware Line Impedance Stabilisation Network (LISN) box, and a low cost Rigol DSA815 spectrum analyser
NOTE: As stated on the product page, this product and technique is for DC powered products only, it is not to be used for the mains supply.

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[GeorgeTsiros]

Every time he starts with "Hi!". Every single time, his enthusiastic intonation makes me smile! :D

[twomorestars]

Awesome video. I do EMC testing for a living, was surprised to see this in my subscription box. We divide our EMC tests into 2 main groups: "Ground Plane" and "RF" testing. The RF stuff I do includes this, Conducted Emissions, as well as Radiated Emissions, Conducted & Radiated Immunity, Click (which is a form of conducted emissions testing using a specialized click tester), Harmonics, and Flicker. We use an anechoic chamber for most of this testing with filtered power feeding the chamber.
The "ground plane" side performs tests like: PQF, EFT, ESD, and Surge. All of which are meant to test the electronics robustness to undesirable voltages and currents entering the product through various paths.
There's never a shortage or things to learn or standards to read with EMC testing. Fun stuff.

[rovfitta]

This is not taught in school and therefor EMC is considered black vodo magic for many people. Excelent video! 

[AndyMarsh]

Rigol have a reasonable piece of EMC test software which is worth using.... Incidentally I tested the Rigol DSA815 against a PMM9010/30, a Keysight N9038A and a Rohde & Schwarz ESIB26 on Conducted emissions from LED Lighting in a fully screened room and found the results were functionally identical. just a DB/uV here or there different. The real difference is the time it takes to make the QP sweep!

[gavincurtis]

#555 will have to be dedicated to the humble yet trusty 555 timer!

Excellent tutorial with detailed explanation! Thankyou very much .

[MattClimbs]

Thanks Dave!  A Pre-Compliance Radiated Emissions Testing video would be cool to see some time.  I wonder if others would be interested in this too...  

The EMC legislation in Australia is so vague..

[moons]

This is very informative. Although sometimes Ferrite cores dont work. Sometimes an inline filter has to be added. I like your reaction when it does bring it under the limit though. "Beauty" :)

[peshozmiata]

"This will be just a relatively quick followup video" - nearly half an hour :D

[ronaldlijs]

Excellent tutorial Dave, keep them coming. I am at that stage now I need to get my product EMC compliant and this helps to get some perspective, will have to get myself a Spectrum Analyzer for sure!
Now, if my product has got for example audio line input and output, would I still be using the same kind of test box in series to measure conductive EMC? I think it would be MUCH appreciated if you did some more videos on compliance, KEEP THEM UP!

[martinrickes]

Hi Dave, I'm wondering why you set the internal Attenuator to 0dB Manually?! The risk of killing the Input of your Analyzer is rather high by doing that. The dynamic of the Rigol is not that great, but it should be enough for this. Normally I'd use at least 10dB internal and a dedicated external 10-dB Attenuator as a protection for the receivers.

[fergaletto]

You´re the best Dave! I really enjoy your videos! thanks...

[assadij]

*** WARNING ***
This LISN and the setup is totally incorrect for mains powered devices (CISPR 22).
This LISN designed for testing in accordance to CISPR 25 (Vehicles, boats, internal combustion engines). Probably only DC supplies.

[andrewferg]

Any suggestions for eliminating noise from a BLDC cooling fan in an RF circuit?

[theonlyari]

Switched power supplies are a real bitch. Especially when you are doing RE, CE, CS, and RS for FAA DO-160... because they dont allow you to put ferrites on your power lines to make noise disappear. Great tutorial, more EMC stuff!

[assadij]

LOL!
I have never seen anyone use a common-mode clamps like that (differentially)  :D

[DanielErba]

Excellent tutorial Dave, I was wondering why there are some rigol equipment with a blue logo. I'm about to buy a Rigol DSA815TG spectrum analyzer and it has the blue logo, why?

[BrackenDawson]

When did you get that DSA and why haven't you taken it apart?

[dwalden]

Is it possible to use an oscilloscope with the LISN device, instead of buying a spectrum analyzer?

[funlw]

"...but I would love to see a mini-series on designing and etching boards at home if you are into that sort of stuff."

Unfortunately, he is a pro :(