> 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.
As many have already mentioned, the technical requirements of CFR 47 Part
15 is applicable to almost all digital devices. A digital device is
defined as a device that generates and uses timing signals in excess of
9KHz. If the device is subject to the technical requirements then:
>
> Specifically do I need to:
>
> 1.a) Spend money having someone test emissions.
Yes - the device will have to be tested at a listed FCC site and you will
require a test report. However, if the highest frequency used is below
1.705 MHz and the unit does not plug into the AC power main then no
testing would be required (for devices that generate/use a frequency
below 1.705 MHz the frequency range of the test is limited to 30 MHz).
> 1.b) File some paperwork with the FCC.
Probably not, provided that the device is not an intentional radiator.
If the device is used in a residential environment then it is a Class B
device.
Class B devices that are PC s or PC peripherals require a formal
certification and the choice is to submit an application ($895) to the
FCC or have the device tested at an accredited lab (and self-certify
through a declaration of conformity). If submitting to the FCC, you will
have to obtain a grantee code ($45).
All other Class B devices are subject to verification and you will only
need a test report (results from an FCC-listed lab), the correct labels
on the device and a couple of statements in the user-manual.
> 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.
Yes, you would be in violation in the US - the FCC requires that you have
a valid test report from an FCC-listed site.
> 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).
In Europe you can self-certify without test results, although this is not
recommended unless you are 100% certain that your product meets the
technical standards. In the US there is no such route, test results are
required. I believe the same applies in Canada and also in Australia.
> 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.
Random samplings, complaints etc etc.
Hope this helps,
Mark
Mark Briggs
mbri...@elliottlabs.com
