T&L Publications

I've been carefully studying the DC to DC converter article in March 2009 N&V. I am confused on one point. On page 48, u (mu) for the toroid made of 3C90 material is given, "From the 3C90 specification sheet," as 4 x 10 to the minus 3. Yet as far as I can see on the spec sheet from the manufacturer, Ferroxcube, the value of u is listed as being between 2300 and 5500.

http://www.ferroxcube.com/prod/assets/3c90.pdf

Can anyone clarify this difference for me? The difference is obviously critical and I don't know how to proceed with any calculations. Many thanks!

Gary

On the spec sheet the units box is empty.

Perhaps coincidence BUT,
4000 micro somethings equals 4 x 10^-3 somethings.

A unit micro Mu abreviated would be "uu", confusing! I think magazine and spec sheet are giving the same number in different formats, plus the spec sheet is giving the range instead of typical.

How's that for double talk meaning "I don't see a value conflict."

Cheers,