Hi Jon, I'll take the plunge and give you some of my answers below ...
> From: Jon Bertrand <j...@cirris.com> > > Hello Everyone, > > A lot of "budding midnight designers" ask these questions on the > microcontroller newsgroups so I thought I'd ask them here - and learn > something :) > > (If I've missed some FAQ that covers this please let me know.) > > 1) Say I'm building some microcontroller based widget in my home > business that runs model trains (or whatever). It's not an intential > transmitter, its typically used in the home. And I want to sell them. > Do I need some FCC approval. Yes. CFR 47 Part 15 specifies not only minimum frequencies at which your little device operates (I believe anything above 7kHz) but also power (I believe anything above picowatts). I'm positive someone here will list the specifics. I unfortunately do not have the standard in front of me. > Specifically do I need to: > > 1.a) Spend money having someone test emissions. Yes. For reason why see answer to 1.b) below. > 1.b) File some paperwork with the FCC. Yes. Since your device will be used in a residence, you will need Class B which involves registration. Registration will cost you. > 2) If I don't have the money for testing - but I really do know how > to keep my microcontroller quiet (i.e I know loop area, di/dt, and > maybe even have done lots of other 'approved' products) - and a > little in-home testing shows it doesn't bother the rabbit ears or > show-up on the AM or FM radio. Would I be in violation of some law if > I just sold the darn thing. By the book, yes. See CFR 47 Part 15. CFR I'm sure you know stands for Code of Federal Regulations, i.e. Federal Law. You're also assuming that the only reason you'll get in trouble is for interference. Not really true. Take it to a trade show, have it be the quietest thing around, have some representative from the FCC look for a label or proof of testing and there is none, you're in trouble. What's the probability of this happening? Who knows... > 2.a) Would I be in violation if it really was quiet to CISPR (i.e. > would have passed). (i.e. is there now a CE mark like compliance that > lets me self declare and assert who's responsible). Woaw! Wait a minute. CE mark? Thought is was just FCC. You're going to Europe, haven't tested the device, are assuming it's quiet and yet you're marking it? Don't do it. This is not FCC approval. The FCC only validates testing for the US. It really doesn't approve anything (if I remember a previous discussion about this from way back). > 3) How does the FCC verify that I don't pollute the EM band - do they > random sample train widgets or wait for someone to complain. Depending upon some factors - both. Remember, the complaint could be from a competitor... I was at a trade show a long time ago where someone was yanked out of their booth by Federal Marshals. Bottom line for whoever is asking you, get it done, get the thing passed, then don't worry about it. Oh yea, don't forget about UL either. ;) Regards, Doug
