Re: Speaker with coil model?

["David Meeker" <dcm3c@xxxxxxxxxxxxx>]

--- In femm@xxxx, "alanbabb" <alan@xxxx> wrote:
> This is an interesting model.
> 
> How do you decide on the area to integrate to get the force? I have 
> always assumed that the force is generated by the resultant field of 
> the ac coil and the dc magnetic structure and this suggests to me 
> that the force is generated over a broader area than that of just the 
> physical space occupied by the coil.

The idea here was to approximate the coil as a region of space with an
evenly distributed current density. This region is basically the a
region that tightly encloses the coil's outer boundary. I just
guesstimated what the coil's cross-section would look like for this
case (I didn't have the actual device at home when I made the model),
so the coil may look bigger than you might have expected.

Unless you are interested in skin or proximity effects, there is
usually no need to model the individual turns in the coil--a "bulk"
coil model is ok.

Dave.