Re: [femm] current density

[Dave Squires <djsquires@xxxxxxxx>]

Dave,
Hmmmm. Never thought of that. Didn't know you could do it
that way. I guess there is quite a bit still to learn about FEMM.
That is one advantage you have being the author of the program.
It is hard for me to know all the little tricks that can be used.

Thanks for the tip.

Dave Squires

David Meeker wrote:

> Well, you could always apply a "circuit property" to each coil region.
> This is just a constraint on the total current carried by a coil. For
> magnetostatic problems, it effectively chooses the current density to be
> whatever it has to be to get the right total current.
>
> Dave Meeker
>
> Dave Squires wrote:
>
> > Dave,
> > You are right of course.
> >
> > But, the problem I have run into is where you have odd shapes
> > that perhaps are not symmetrical and the areas don't match.
> >
> > In particular with a toroid type winding, it is nearly impossible
> > to get the inner winding area to match the outer winding area.
> > If you try to use area current densities it is a nightmare and
> > you can't get the two to sum to zero without a lot of pain
> > and frustration.
> >
> > So it is much easier to just use point properties and the
> > same number of points to represent real coil winding turns.
> > Then the sum is always zero with no headaches.
> > At least this is what I have found from experience.
> >
> > Regards,
> > Dave Squires
> >
>
>
>
>
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