Re-winding tranformers

[rybitski]

I read in alot of projects and articles about the need to re-wind old transformers to fix them or modify their output.

I've searched the internetand there is nothing (that I could find anyway) about how to do this. How would you do it???

From what I can tell the case is welded together...

curious,

[ante]

Hi Chris,

It depends on what kind of transformer you have to begin with and what you like to do (what you want to change). There are different ways to go about it, some harder then others.

[rybitski]

Well I don't have any reason to re-wind a transformer right now, but I am curious as to how you would go about it.

[ante]

Not all are welded and not all are E I core, some are toroide transformers. Usually the secondary winding is the outer layer (on top) and can be removed and replaced with some effort. When removing a secondary its always a good idea to count the turns, this gives an idea of how many turns you have to put on to get a desired voltage (knowing the original voltage). If the core is welded you can still do this, it’s just like stitching only backwards! Some transformers just isn’t suitable for this kind of surgery like when they are molded in epoxy or some resin. Even these can be dismantled if left for some time submerged in paint stripper but it’s too much trouble unless the transformer is a very special specimen!