I am in the process of building a switching transformer. The transformer requires Grain Oriented Electrical Steel and a high permeability.

The transformer is meant to operate below 300kHz, most likely between 100-300kHz.

How do I go about picking what type of core material, and the thickness of the core material needed?

 

You'll probably need ferrite or powdered iron core material at those frequencies.

 

It should have low electrical conductivity at such operating frequencies as to reduce eddy currents and thus losses. Make an air core transformer.

 

Hello,

Perhaps this page will give some information:
http://users.catchnet.com.au/~rjandusimports/tut_2a.html
There are some links to pictures and tables.
The page comes from this page:
http://users.catchnet.com.au/~rjandusimports/index.html

And this link was found on this page:
http://www.educypedia.be/electronics/transformertypesrf.htm

Greetings,
Bertus