Where to start with electronics product compliance? - Page 1
Forum section: electronics / general

author: Muffins
author_rank: Regular Contributor
timestamp: February 06, 2025, 10:02:27 am
content: Hi guys.I'm working for a UK company and developing some wifi controlled LED drivers. They are simple boards with external power supplies and drive RGB LED strips.I was wondering if anyone has some advice for electronics product compliance, in terms of what I would need to do to get these ready for sale. There seems to be a lot of information out there and I'm not sure where to start.

author: tom66
author_rank: Super Contributor
timestamp: February 06, 2025, 10:24:04 am
content: So, it depends on your budget, and how many units you intend to make.The question "When do I start designing for EMC?" is best answered with "you haven't started yet??" EMC is not 'bodged' into a product, it is designed in there from the start. EMC consultants love customers who haven't designed products correctly for EMC, because it's lots of extra billable hours for them.Generally you will need to pass at least EMC and LVD for a DC powered product with an external PSU. Using an external PSU will be easy as you can say you use a certified power supply that has already passed LVD and EMC (for the power supply's emissions only!) If you have an internal PSU running from anything more than 50Vdc / 75Vac you will probably need to do tests. EMC can be easy but will usually require tests unless your product is very simple and you can be near-certain that you will pass. All tests are basically a legal backstop: ultimately all that matters is your statement that you believe the product complies with the relevant regulations, and that you are willing to defend your case in court or to the trading standards body, it makes it alot easierif you have documentation to prove that.If you have a radio in the product you will need to pass RED as well. It may be possible to port over some of the existing certifications for your module provided you are using the antenna built into the module (PCB track antenna, SMD antenna etc.) If you are using a different antenna with a different position it is much harder to do so.I can strongly recommend this consultancy having worked with them in the past for some less significant issues, and having attended a training course run by the owner:https://unit3compliance.co.uk/

author: AndyC_772
author_rank: Super Contributor
timestamp: February 06, 2025, 10:55:59 am
content: Just as a quick heads-up:- you mention wi-fi, which means your product intentionally transmits RF. This adds additional compliance requirements that your test lab should be able to describe to you.- you also mention LED strips and external power supplies, which I'm going to assume means you have a power supply delivering significant current along some long, unshielded wires. This has the potential to be very noisy indeed unless the supply and the controller have both been competently designed with this type of application in mind.For these reasons, the "simple boards" you describe could be quite challenging to get through EMC, and I'd be inclined to talk to a good test lab and book a day's pre-compliance testing as soon as you have a working prototype. See what the issues are and where, while you still have the capability to make significant modifications. I think there's a good chance you'll need to.

author: Muffins
author_rank: Regular Contributor
timestamp: February 06, 2025, 02:55:00 pm
content: Seems like I have a lot to learn here.I like the resources available on Unit3 compliance. Do you think it would be worth it to do in house near field testing of the prototypes?

author: tom66
author_rank: Super Contributor
timestamp: February 06, 2025, 04:26:57 pm
content: Near field testing is useful to show up potential sources of emissions, but it is not going to tell you if a product will pass or fail. We've found it useful in the past to debug issues after a test has failed.You can also do precompliance testing. We use a lab near Cambridge for this work (dB technology), they are about £600 per half day. You can usually get most tests for precompliance done in half a day IF the lab you are using is good at that sort of thing... we have found some labs are exceedingly slow and do not have the capability or engineers able to just do a fast sweep and then zoom in on potential issues.

author: Ice-Tea
author_rank: Super Contributor
timestamp: February 06, 2025, 04:39:19 pm
content: Premium source of information: find the DS of a (quality) competing product and find the list which standards they confirm compliancy against.

author: nctnico
author_rank: Super Contributor
timestamp: February 06, 2025, 09:14:24 pm
content: Quote from: Ice-Tea on February 06, 2025, 04:39:19 pmThat is a good one! Also to check if the test lab you are working with knows what they are doing.A good way is to buy some EMC test gear like a spectrum analyser (2GHz is good enough for general purpose EMC testing), near-field probes and a LISN (can be a DIY one as well). Go to a test lab to get some baseline measurements and make sure to get plots which shows the levels and frequencies your device is failing at. With the equipment in your own lab, you can check & modify the circuits at your own pace to make the levels lower. Once convinced everything is OK, go back the test lab for some baseline measurements. Repeat until the baseline measurements show you have chance of passing.However, Wifi gets tricky. For CE (RED) you need to test to 12.-something- GHz, for FCC even to 21GHz to make sure your device doesn't emit too much harmonics. Unless you can get a good deal for a spectrum analyser from Ebay, this can be a difficult measurement to perform cheaply. I'd say that a 13GHz spectrum analyser should be good enough. BTW, Wifi testing is typically done with a wired connection between the device and spectrum analyser. During the actual test, they do a quick check to see if the radiated power corresponds with the direct measurement but everything else is typically tested with a wired connection. Saves time for using the expensive room and the results are the same.

author: Muffins
author_rank: Regular Contributor
timestamp: February 14, 2025, 09:32:24 am
content: Thanks everyone.@tom66, I've got in contact with Unit3 and I'll follow up with the other place for pre-compliance testing.