Re: Inductor question . . . permeability vs. AC flux

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br> 

Tesla list wrote:
 >
 > Original poster: dhmccauley-at-spacecatlighting-dot-com

 > Now, the second interesting phenomenon is that if you have a core with some
 > DC bias on it, and now you have some AC ripple on that bias, it turns out
 > the more
 > AC ripple (or AC flux) there is on the core at that point, the permeability
 > starts increasing dramatically again.
 > So my particular core is almost saturated with 20A of DC current and
 > permeability is about 20% of nominal at this point on the B-H curve.
 > However, if there happens to
 > be 10A ripple current (which there is) riding on this 20A of DC current, the
 > permeability increases by over 250%.
 >
 > Can anyone explain this phenomenon and what is causing it?

First, how are you measuring this? How is the core made?

Antonio Carlos M. de Queiroz