Path: ...!news.mixmin.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: john larkin Newsgroups: sci.electronics.design Subject: Re: EMC compliance question Date: Sat, 12 Oct 2024 16:30:26 -0700 Organization: A noiseless patient Spider Lines: 61 Message-ID: References: <67070ba9$1$1783$882e4bbb@reader.netnews.com> <0k4lgjl2vb6jd1f2ssguddcfaa2buq9coi@4ax.com> <670aa2f7$1$2385536$882e4bbb@reader.netnews.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Injection-Date: Sun, 13 Oct 2024 01:29:11 +0200 (CEST) Injection-Info: dont-email.me; posting-host="6278ed7f9bdf2133d1829bd56ee7b738"; logging-data="388486"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX190+yV/YlBA7vm+zeHOBfxw" User-Agent: ForteAgent/8.00.32.1272 Cancel-Lock: sha1:U4f3SmTBAF6PT7iMBAH/HQs3sj4= Bytes: 3846 On Sat, 12 Oct 2024 23:30:46 +0100, John R Walliker wrote: >On 12/10/2024 18:07, john larkin wrote: >> On Sat, 12 Oct 2024 12:25:27 -0400, bitrex wrote: >> >>> On 10/12/2024 11:22 AM, john larkin wrote: >>> >>>> 48 is super common now. All our phones are PoE powered, which is >>>> typically about 54 volts. Digikey sells warts up to 65. >>>> >>>> The phones are cool. I can take one to Hawaii and plug it in and it >>>> works just like it does here. >>>> >>>> I imagine that europe has tens, maybe hundreds of millions of PoE >>>> devices with the chinese version of the CE mark molded into the case. >>>> >>>> So if european manufacturers realy have to do all the CE certs and >>>> testing, they have one more reason that they can't compete with >>>> imports. >>>> >>> >>> So as of 2019 it looks like the US rules are similar to the European >>> "can't enforce" rules in that the manufacturer takes responsibility for >>> everything and it's up to the mfgr how and what tests they perform to >>> determine compliance: >>> >>> >>> >>> This makes it sound like it's not too expensive to do some basic >>> compliance tests on a small-volume product in house: >>> >>> >>> >>> Need a 1 GHz-ish spectrum analyzer at least as the main tool which >>> aren't exorbitantly expensive nowadays. >> >> I can buy a spectrum analyzer and a surfboard antenna for under $1000, >> and can take a product out in the country and do an open-field test >> and crudely ballpark its EMI signature. >> >> CE requires screen room testing and more quantitative measurement. >> >> The reality today is that few products are honestly certified for EMI >> or safety, and life goes on pretty well. If a product causes massive >> EMI problems or hurts people, civil and criminal liabilities apply. > >My experience differs. Every product that I have been involved >with has been independently tested by Intertek or a test lab of >similar status. > > It's impressive how few EMI problems there are in real life. >> >Maybe that is because many products are actually tested and compliant. >I can remember when audio equipment was very susceptible to >interference from many sources. Those days are mostly gone. >I have come across exceptions of course. > >John Most audio equipment is digital now.