Why dont people use Minimum Cross sect area for B(sat) calculation in ferrite core

[treez]

Most ferrite cores have a minimum and maximum area. Do you agree, the B(sat) calculation should always be done using the minimum area?
Eg, i(sat) = B(sat).A.N/L

where A = Minimum core area

 

[Easy peasy]

The min area does not apply to the CP ( centre pole ) but rather other parts of the structure - typically the fan out from the CP - this is why it is often ignored in flux calcs - it is a small part of the core and the extra heat that may be generated there is simply ignored by most ...

 

[FvM]

If you'd use magnetic material with sharp B/H characteristic near saturation, the answer would be different. But ferrite isn't of this kind.

 

[Easy peasy]

I think what FvM is trying to say is that square loop B-H loop material is shaped so that there is no squeezing of the area , e.g. toroid ...

 

[mtwieg]

I'm having a hard time thinking of a realistic core shape where using Amin instead of Aeff would make sense. You'd just be handicapping yourself.

 

[treez]

Thanks, why do they bother giving the Amin value in the datasheet eg of the PQ32/20 core?....why not just give Aeff?

https://ferroxcube.home.pl/prod/assets/pq3220.pdf

 

[Easy peasy]

some people just want to to know it ...