Re: [femm] (unknown)

[David Meeker <dcm3c@xxxxxxxxxxxxx>]

marco valcavi wrote:

> Hi all,
> I read a question (992) and his answer(994) about the
> meaning of the term "2x frequency" in the Lorentz
> force for frequency problems.
> Now, I understand that if B and J have a fixed
> frequency the force has two component: the steady
> state and the 2*frequency.
> But
> if I make a electro-mechanical transducer, I apply an
> electric current with frequency x and the mechanical
> parts move with double frequency?
>

Depending on your actuator design, you really can get a 2x frequency
component of force. With an actuator that works in this way, you'd
design the drive frequency to be high enough so that the amplitude of
motion resulting from the force ripple is "small enough," doesn't excite
structural resonances, and so on.

Dave.
--
David Meeker
http://femm.berlios.de/dmeeker