>
> The last diagram. It explains:
> Fresp = 1/(2*pi * ((L*C)^1/2));
>
> There is no capacitor within the circuit. The
> capacitance comes from the inductor itself.



the mechanical resonance is probably much more significant than the
electrical.

Also, you really need to not drive an inductor directly from a PIC pin.
Relative to the other thread on pin protection, you CANNOT stop the current
in an inductor instantly.
The field WILL collapse, and that energy WILL go somewhere.  You have the
option of choosing where it goes :)
-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist