Transformers: Can we wind them?

[cm961]

I'm working on a new-ish project that I need a nice center (centre, eh?) tapped transformer. I was wondering if the possibility exists to wind our own. Now I know this is common for those of you that have attempted and perhaps succeeded with SMPS projects, but what about when dealing with mains voltages? I would assume that self made transformers might have a lower efficiency and perhaps regulation than manufactured ones like Plitron, but maybe it would be worth it cost wise. For instance, I need two transformers. They're about $70 each at Plitron. I know I can buy cheaper transformers than that, but not as nice. Perhaps I could make one. Does anyone have any info or suggestions on this? (I would buy the core ofcourse)...

Pete

[ashok]

You apparently have a company in the US ( Hand Wound Transformers ?) that has been mentioned earlier on this forum. They supply the core with the primary wound on . You will have to wind the seconday as you desire.
I don't see why they should be poorer in quality than the readymade ones. EI cores are different from Toroid cores. You can't wind a toroid core easily by hand. You need a machine.

The EI is relatively easy to wind by hand but takes some time. Long ago I used to wind transformers manually. I hated it but had to do it . The most difficult part is winding the primary because of the thin wire. The secondary usually is relatively thick wire and is not so tough to wind. Additionally the number of turns is less.

Go ahead and wind your own. It will be just as good as many other commercial transformers provided you wind it evenly and keep the coils reasonably tight. The first one could have problems if you are not sure of what you are doing. I am sure the hand wound transformer company will give you all details required to wind properly.
Have fun.

Edit: Just saw Bob's post. Yes that is one way of winding additional coils on a toroidal transformer. This would however be useful to add some small percentage to an existing secondary on the transformer. Read that as - small number of turns.
Winding the whole secondary might be pretty tough unless the number of turns is also low. Doable I guess, but tougher than an EI core.

Hmm.... Just had a closer look at the URL. They are suggesting that you wind the whole secondary ! I have never wound a toroid .This might be easier that I thought. Check it out.

[BobEllis]

kits http://www.toroid.com/standard_trans...ormer_kits.htm