Re: [CAD_CAM_EDM_DRO] Re: FCC Approval

George Potter wrote:

> > I think internal cards are supposed to be UL
> > or FCC approved or something. But external boards run from wall
> xfmr
> > has no regulation.
>
> If the "external board" has a clock frequency higher than 9 Khz, it
> will have
> to go through FCC Part 15 testing (assuming that this is a commercial
> product for sale ..... not home built one off's). I suspect that if
> the data rate
> through this card is greater than 9 Khz (when in use) it could be
> argued
> that part 15 testing is also required.

This gets into a very murky area. In the FCC part 15 rules, there are
exceptions for test instruments, industrial plant equipment, and other
devices which would not be expected to be used in a residential area.
Test instruments like logic analyzers may be impossible to properly
shield and still have them function. Machine tool servo drives and
such may be noisy enouh that heavy shielding will only knock the
radiation down to 'tolerable' levels in the vicinity.

Of course, some people are putting machine tool controls in the
basements of their homes (like me). Well, nobody has complained
yet, and I can run a radio right on top of my CNC control, but it
is a problem to be concerned with.

Jon