Question about apparent power of transformer

[namster]

an example of a 250 Watt Isolation Transformer Design was given in the transformer and inductor design handbook ,i don't understand why the apparent power was calculated by summing the Primary Power and charge Power ?

[IanB]

They are basically saying that the primary winding has to handle the total power and so does the secondary winding. So the total apparent power "seen" by both windings inside the transformer is the sum of the input power and the output power.

I don't quite understand this, but that is what they are saying.

[Benta]

What they're saying is, that secondary power is 250 W to the load. This is a design specification.
Primary power is 263 W.
You're supposed to allocate the winding cross-section areas accordingly to ensure equal power sharing. As the core material is also mentioned, you should probably add in magnetizing current for the primary calculation.

[namster]

@Benta that's it
after some research it appeared that the apparent Power is calculated in a way that we chose the right Core geometry Kg which allows the equal power sharing