My experience with other magnetic devices has been that frequency is
mostly a function of how much noise is tolerable.  24kHz and above
is generally not audible.

On Sun, 23 May 1999, Bob Russo wrote:

>    Is there any rule of thumb for the frequency one uses
> to run a (small in my case) DC motor at various speeds?
> It seems obvious that the duty cycle determines the
> speed.  What's not so obvious is what range of frequency
> & why.
>
>   Thanks
>
> _________________
>
> Bob Russo
> Guilford, CT
> brusso@iconn.net
> _________________
>