Voice Coil Motor with Aluminum bobbin

["tano1938" <rgarritano@xxxxxxxxxxx>]

I'm trying to model a voice coil motor such that I can check the 
performance at different frequencies. The voice coil is wound on a 
thin aluminum bobbin for support which I suspect will effect the 
performance at high frequency due to eddy currents in the aluminum. 
The coil is modeled as a current sheet with zero conductivity. This 
is the first time I've used a frequency other than zero with this 
design and I'm not too sure how femm operates in this mode. The 
only "field" in this model is the current in the coil, so I'm 
assuming that this current is oscillating when I set a frequency 
other than zero. The results I get even when running very low 
frequencies are not possible. 

The file in the files section is "Eddy_VC.FEM"

Thanks for your help