design of transformer for switching mode power supply

[amirtaha2541]

hi
how the Kfe(core loss coefficient) and B(core loss exponent) are calculated.
(Pfe=Kfe*(Bmax^B)*Ac*lm)

 

[FvM]

The said expression is an empirical formula, that is fitted to measurements rather than calculated. There are various similar
formulas in use. As ferrite manufacturer application notes clarify, the parameters depend both on material and core shape.

I would generally suggest to use the manufacturer provided design tools for transformer calculation, e.g. the
Epcos Ferrite software.

 

[karesz]

Hallo,
Some good calculation SW/sides too, especially for transformers in detail = PI`s Expert Suite:
SwCADIII _ Linear Technology
PI Expert Suite 7.0 _ Power Integration
WEBENCH® Power Designer _ National
K.

 

[amirtaha2541]

hi
how the Kfe(core loss coefficient) and B(core loss exponent) are calculated.
(Pfe=Kfe*(Bmax^B)*Ac*lm)

 

[FvM]

Can you hear (respectively read)?
These parameters are not calculated.

 

[amirtaha2541]

how to measurement the Kfe(core loss coefficient) and B(core loss exponent) in equation fe=Kfe*(Bmax^B)*Ac*lm?