I have small single phase AC induction motor. It runs on mains voltage (230 V) and I'd like to modify it to run from 12 V transformer. Motor has two stator coils.
How to calculate new number of turns for the coils?
My guess is that stator must give same magnetic flux before and after rewinding. Therefore number of ampturns must stay constant.
Current with no load is 0.09 A and with blocked shaft it is 0.1 A. Apparent power is about 230 * 0.1 = 23 VA. To get the same power but with 12 V current must be about 23 / 12 = 1.9 A. Solving for new number of turns I get: old number of turns * 0.1 / 1.9. Does it sound reasonable?
As for wire thickness I guess that I have to keep DC resistance constant and scale up the wire size.