Toroidal Transformer Construction

I bought a kit that had pre-wound primaries. I wound the secondary. This document describes this process:

http://quadesl.com/pdf/trans_inst.pdf

I did mine by hand but I understand there are winding machines.

A piccy here shows how I re-wound one. I took off the original secondary and wound on to suit.

Cheers

http://www.diyaudio.com/forums/showthread.php?s=&threadid=43331&perpage=10&pagenumber=8

Winding machines for toroid transformers and inductor are pretty amazing and complex (expensive). Look at the picture and you will know what I am talking about

Essentially a toroid winding machine works like this:

A split bobbin is passed through the toroid and closed.
The right amount of wire is then wound onto the bobbin, by spinning the bobbin through the toroid.
The wire is attached to the toroid.
The bobbin is spun again, winding wire onto the toroid, while unwinding from the bobbin.
The empty bobbin is opened and removed.

The whole process is pretty cunning.

A pic of the bobbin/toroid arrangement (thanks to POVRAY!)->

Thanks for the picture.

Now for wrapping my own toroids, I need to find/make a bobbin.

A DIY'er doesn't need an expensive machine, all it matters is that he wraps a good transformer.

I use to always wonder how in the world those 100+ turn toroids were wrapped by machine.

For a hand wound toroid a wire shuttle might be easier than the bobbin. A shuttle is a flat piece of stock that you wind the wire onto. Kite string is sometimes wound onto something like a shuttle. The idea is that it will easily pass through the toroid center hole allowing you to wind easily. Just make sure the shuttle can't damage the enamel on the wire.