Variable Transformers

tomy,

Can you restate your question? Steel cores don't actually carry any current, just magnetic flux. Maybe give us some sizes, voltages, currents, etc?

we are manufacturing variable transformers.we adopt the technologies from our experience from another companies where myself worked.For example we are manufacturing 10 amps single phase variable transformer in 18.5 swg copper with the size of lamination(CRGO rounded cores) 100mm inner dia and 75 mm outer dia and height of 60 mm. In this case we are getting 10 amps loading capacity of 240 voltage input and 0 to 240 voltage output, in boosting of 30 volt we are getting 8 amps loading capacity.In this case how we are able to calculate the value of the core what we used in this transformer