How are torroidal transformers wound

[malloryn]

Having just read the question on unwinding a toroid, does anyone know how the wind them in manufacture.
You can't just spin a bobbin like a frame transformer. The whole wire would have to be fed trough on each turn.
I'm interested in how it's done in production at low cost.

 

[Centauri]

There was a thread a page or so back http://www.diyaudio.com/forums/showthread.php?s=&threadid=30787 discussing this. There are a few photos of machines, and I had a diagram in an old Elektor mag, but still can't work out how they work.

Interested to find out more myself.

Cheers

 

[Nisbeth]

You use a "former" to hold the wire (imagine a large wheel, similar to the rim of a bicycle wheel which is cut so you can open it) You open the former and close it around the core. You then have what is essentially two rings that are connected like links in a chain so they can move/rotate in each other
The wire is then first wound onto the former and you can then easily unwind the wire from the former to the core of the toroid.

(I hope this helps. Unfortunately I can't find a suitable drawing to illustrate it at the moment)


/U.

 

[Da5id4Vz]

I posted this in the above mentioned thread:

http://www.diyaudio.com/forums/showthread.php?postid=358318#post358318

The first link is a little movie of a machine winding a toroid. If you squint you can see the wire unwinding from the former onto the core.

The second link is for a company selling DIY toroid trasnfromer kits.

I'm not sure anyone looked at the links, as I also had some wise a** coments about winding astin ring transformers.

 

[Centauri]

Thanks - didn't see that link in the other thread.

Video not real clear, but very interesting. Mmmm......must look into this further one day.

Cheers