the transformer changes high voltage,so isolation between primary and secondary is very importance, I guess current of primary and secondary are not big, so you can use copper wire which can bear high voltage(e.g. QPN wire), it ensures wire and wire in a winding will not short,you can estimate coil dimension according to diameter of wire and turns and insulation tape, and estimate if coil can be combined the core, the coil is too fat to be assembly into core, when we design the transformer, we ofter calculate these dimensions and estimate if the coil is available.
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the transformer changes high voltage,so isolation between primary and secondary is very importance, I guess current of primary and secondary are not big, so you can use copper wire which can bear high voltage(e.g. QPN wire), it ensures wire and wire in a winding will not short,you can estimate coil dimension according to diameter of wire and turns and insulation tape, and estimate if coil can be combined the core, the coil is too fat to be assembly into core, when we design the transformer, we ofter calculate these dimensions and estimate if the coil is available.