EMC design and testing - Page 1
Forum section: electronics / general

author: John Coloccia
author_rank: Super Contributor
timestamp: February 26, 2015, 10:53:39 pm
content: Looking for some guidance. I have some upcoming products may have to go through EMC verification. Honestly, I haven't a clue what I'm doing. Can someone point me to some resources that will get me started in terms of designing and testing for EMC? I appreciate the help!

author: Wilksey
author_rank: Super Contributor
timestamp: February 26, 2015, 11:17:36 pm
content: Don't know if these resources will help:Free EBook:http://www.emcfastpass.com/Some guidelines:http://www.learnemc.com/tutorials/guidelines.html

author: KJDS
author_rank: Super Contributor
timestamp: February 26, 2015, 11:20:55 pm
content: It will work out cheaper in the long run to hire a contractor to help with the design and testing.

author: Christe4nM
author_rank: Unknown
timestamp: February 26, 2015, 11:52:17 pm
content: I've been through this (starting at almost 0 to getting a bit of feeling for EMC design) the past year. Among all the application notes, books, webinars etc, this is what helped me the most.First of all, do you know against which standards your products are tested? If not, that's your first goal to find out. They will provide the requirements for your product to comply to. Also talk with your intented test house, they should be able to help you understand what those standards mean in practice.Next, find user "interference technologies" on YouTube and watch the webinars with Keith Armstrong. He does a great job explaining what is involved in EMC and design.If you want just one book, I'd recommend Henry Ott's Electromagnetic Compatibility Engineering.The first part explains the concepts, the second part is on applying it to your design. The third part is on testing. His book is very complete, and to my experience you can read a chapter quite separately from the others. So skip the sections that go over your head the first time.Finally, understanding EMC and engineering for it takes a while as it is a broad subject that isn't the most intuitive imho.

author: Christe4nM
author_rank: Unknown
timestamp: February 26, 2015, 11:56:59 pm
content: Quote from: KJDS on February 26, 2015, 11:20:55 pmThat might very well be the case. So if you do, make sure he teaches you along the way. He will never go out of business as he is still the expert, and they'll be needed more and more in this field as I see it.

author: John Coloccia
author_rank: Super Contributor
timestamp: February 27, 2015, 12:55:51 am
content: Quote from: Christe4nM on February 26, 2015, 11:52:17 pmThat's very helpful, thanks!

author: CatalinaWOW
author_rank: Super Contributor
timestamp: February 27, 2015, 01:04:12 am
content: Hiring a contractor is often the right answer. A good one will have all the appropriate test standards at his/her fingertips, and either have, or have good connections with the necessary test labs. The contractor will also know quite a few tricks of the trade to aid in suppressing the inevitable leaks and popups. Getting them involved early will minimize your pain.You will still need to learn quite a bit about this to aid in selection of the contractor, and to understand what they are telling you.Depending on who you are testing for the US Mil Standards and Handbooks provide guidance from some of the first people to worry about this topic. Readily available on the internet.Try MIL-HDBK-235. MIL-STD-461, and MIL-STD-464They can be turgid and dated, but do have some good information

author: John Coloccia
author_rank: Super Contributor
timestamp: February 27, 2015, 02:21:22 am
content: Quote from: CatalinaWOW on February 27, 2015, 01:04:12 amPretty much my thoughts too. Whether or not I hire someone to help, no one's getting hired to do anything until I have a solid working knowledge of exactly what's going on.Maybe some specifics would be helpful as well. Part of what I do is design and manufacture guitar effects pedals. Guitar signal goes in, processed signal comes out. I have a couple of projects in mind that would be based on a DSP, most likely a SHARC. It would only ever be powered by battery or wall wart. Input and output will be bandwidth limited to the audio range. Maybe that will help someone visualize the scope of what I'm doing. It's about as basic as it gets, while still managing to tickle the EMC rules.

author: John Coloccia
author_rank: Super Contributor
timestamp: February 27, 2015, 10:06:21 am
content: You know, it occurs to me that EMC testing and design would make a great EEVBLOG episode. Maybe have a couple of test setups to demonstrate some concepts, and maybe even tour a test facility.

author: Neilm
author_rank: Super Contributor
timestamp: February 27, 2015, 04:55:26 pm
content: Go towww.compliance-club.comand look for the articles by Keith Armstrong. I found them incredibly useful when trying to learn about EMC

author: Galenbo
author_rank: Super Contributor
timestamp: February 27, 2015, 06:47:46 pm
content: Quote from: John Coloccia on February 27, 2015, 10:06:21 am+1

author: John Coloccia
author_rank: Super Contributor
timestamp: March 01, 2015, 06:19:31 pm
content: So I've been going through the resources, and the videos by Keith Armstrong are particularly useful. Thanks! I still hope Dave does something on this. It's one of those things where the equipment to play around with it is just prohibitively expensive right now, but I'm sure he has a way to scrounge some up.

author: AndyC_772
author_rank: Super Contributor
timestamp: March 01, 2015, 07:17:15 pm
content: Most places I've worked haven't had any EMC equipment as such. You might be able to see what frequencies your equipment is producing, but won't have any idea whether or not they're being emitted at levels which are likely to be over the limit.Do by all means learn what you can, but there's a lot to be said for hiring someone experienced to help you out the first time you design something that'll have to pass EMC. It's an area in which there's really no substitute for experience.