(Correct me if I'm wrong, I'm quoting the 93 CFR edition, the newer one should only differ in the new DoC schemeage.)
There are two fundamental concepts in the FCC rules: technical requirements (testing/marking/certification....), general requirements (non-interference). All digital devices are always subject to the general requirements (non-interference to communications, accepting interference that may make your product croak). You have to dig for the exemptions to the technical requirements, while they do exist I think you're out of luck, IMO. 1. By the definition of a digital device, if it clocks at 9 kHz or higher it is subject to the rules, see 15.3(k). (A train controller might be clockable at maybe 8.8 kHz with a stable RC timing circuit and therefore escape this definition, some microcontrollers are designed for RC timing, check your databook.) 2. Although your product is "home built", you are selling the "darn" product and therefore the exemption offered by 15.23 does not apply. Even if you didn't sell it, it is limited to the "five or less for personal use" restriction, and you are expected to make an effort, by design, to be compliant to the technical requirements anway. 3. If (per 15.103h) the product was strictly battery operated, and (if rechargable) can not operate when connected for recharging, then you can clock at any rate less than 1.705 MHz without being subject to the technical requirements. 4. If by some remarkable feat your power requirements did not exceed 6 nanoWatts, you're exempt. Reference/quotes, edited: 15.23 Home-built devices. (a) Equipment authorization is not required for devices that are not marketed, are not constructed from a kit, and are built in quantities of five or less for personal use. (b) [...] the builder is expected to employ good engineering practices to meet the specified technical standards to the greatest extent practicable [...]. 15.15 General technical requirments. (a) An intentional or unintentional radiator shall [...] in no case shall the emanations exceed the levels specified in these rules. [...] 15.103 Excempted devices. The following devices are subject to the general conditions of operation in Sections 15.5 and 15.29 and are exempt from the specific technical standards and other requirements contained in this Part. [...] strongly recommended [...] endeavor to [...] meet the specific technical standards in this Part. (a) A digital devices utilized exclusively in any transportation vehicle including motor vehicles and aircraft. (b) A digital device used exclusively as an electronic control or power system utilized by a public utility or in an industrial plant. [...] (c) A digital device used exclusively as industrial, commericial, or medical test equipment. (d) A digital device utilized exclusively in an appliance, e.g., microwave oven, dishwasher, clothes dryer [...]. (f) Digital devices that have a power consumption not exceeding 6 nW. (g) Joystick controllers or similar devices [...] only non-digital circuitry [...] simple circuit to convert the signal [...] (e.g., an integrated circuit for analog to digital conversion) [...]. (h) Digital devices in which both the highest frequency generated and the highest frequency used are less than 1.705 MHz and which do not operate from the AC power lines [...]. [...] The likelyhood of being caught? It would take a formal complaint of harmful interference to trigger FCC interest, rare, but they do happen. If it happened, then the severity of the fines would likely depend on whether the FCC engineer was a train enthusiast and had room in his/her basement for a train set. :) This is a curious problem, if you are selling a limited number of a product (say, to friends in your local model train club) with an intentionally low profit, you could end up spending it all or more on compliance testing. Since you are good with your hands you might consider building the FCC's dipoles yourself and renting an old spectrum analyzer for a day or two for some down-home testing, at least you'd find out just how bad off you are. Regards, Eric Lifsey National Instruments "Jon Bertrand" <[email protected]> on 02/20/98 10:13:27 AM Please respond to "Jon Bertrand" <[email protected]> To: [email protected] cc: (bcc: Eric Lifsey/AUS/NIC) Subject: FCC Questions. 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. Specifically do I need to: 1.a) Spend money having someone test emissions. 1.b) File some paperwork with the FCC. 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. 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). 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. Thanks, Jon Bertrand [email protected]
