How much wire do i need for this transformer?

Question

I want to make a 12V/120V step up transformer the main power source is 12v 800A im want to run a 120v 3.8A motor

how thick should the wire be not to overload. wat awg size 18 ?19?

Answer 1

looking at your other question:

transformers do NOT work on DC.

Answer 2

Secondary: 3.8 Amps -- double that for safety margin to about 8 amps.  19 gauge is more than sufficient for the secondary.  Even 20 gauge would be OK.

Primary: 38 amps nominal; add some for safety margin to say 45 Amps and you need a minimum of 10 gauge.

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