How about partners, I come to consult the following: I have a fan which uses a two-section reactance to lower its speed (medium speed and low speed), but it burned. Although I can rewind it as it is (the same amount of turns), before doing so I would like to calculate exactly what resistance it will have, since it is not uncommon for it to have little resistance and the speed change is very little, and now I'm going to take the job, I wish it wasn't in vain. Without going any further, I would like to know if there is any kind of calculation to be able to find out the amount of turns that I must do to reach a certain resistance. I have not yet measured the size of the copper wire, but suppose it is 0.20. The coil has a rectangular shape, about 2.5 cm x 6.5 cm. If I unwind a spiral, from the outside, they are approximately 20 cm of wire. On the inside, a spiral has approx. 10 cm The core would become a set of "U" shaped plates, interwoven with each other, to form a kind of square tube through which the coil passes. In total there are two "tubes". More or less these are the data I have, if anyone knows of any formula or similar, I would appreciate it if you let me know. Cheers

Cheers buy a 12v + 12v transformer that is of the same size at 110 / 220v you put it in series and you already have your reactance

Hi francofr13, what German LB Service says is correct, just be careful not to sell you an electronic one because they buzz and it is very annoying.

Thanks for the answers. Yes, I used the impedance of the ceiling fans, my intention was to rewind the burnt ballast. I'm going to rewind it and if I don't get the reduction I need, I'll buy a ceiling fan