Re: Homemade Transformers
Alex M, Sun Feb 26 2012, 09:15AM

That looks very neat ( :

Here are mine,



Messy looking things but they work well for what I made them for as you can see.

Skip to 3:34 and 7:15

Re: Homemade Transformers
ZakWolf, Sun Feb 26 2012, 09:27AM

Nice, thats a lot of current. What gauge wire did you use?

Re: Homemade Transformers
Alex M, Sun Feb 26 2012, 09:39AM


Thanks, the higher voltage one is about an estimated 1kV @ 300mA and the smaller one can do about 600v max using the taps with the highest resistance between them.

Not 100% sure on the gauge as the wire came out of an old CRT's degaussing coil, but I guess its around 26SWG judging by the thickness.

Re: Homemade Transformers
ZakWolf, Sun Feb 26 2012, 10:06AM

I wound my first coil (1250 turn) one with the wire from a microwave fan. I think its 28 gauge.

I want to wind more but i need a bigger flyback core x)

I have know idea what the voltage is of the second one(3000 turns) its starts at 2.5 " or 6cm at 35 volts.

Re: Homemade Transformers
TwirlyWhirly555, Sun Feb 26 2012, 10:59AM

Hey , this is my transformer , on have a picture of it under oil , its 9 layers of so many turns of 0.2 mm wire , insulation material is 3 layers of A4 paper between each layer ,

here is a video of it on 40 volts

Re: Homemade Transformers
ZakWolf, Sun Feb 26 2012, 11:12AM


Very nice

what driver where you using?

The transformer with 3000 turns is by far the best i have made, i plan on making more turns as soon as a get a bigger core.

Re: Homemade Transformers
TwirlyWhirly555, Sun Feb 26 2012, 11:36AM

Thanks , im using the ZVS driver with IRF150 Mosfets , No zener diodes as there is a 12 volt supply for the gate side of it .

Yeah , i was going to make a larger one , im not sure how many turns i used in the end , just i ended up with 9 layers worth , i may try for alot more , but use something othere than papaer as the insulation material .

Re: Homemade Transformers
ZakWolf, Sun Feb 26 2012, 11:56AM



Im looking into pulling a vacuum on one of them because i have some corona forming between the wingdings under oil.

I used two layers of over head projection sheets

Re: Homemade Transformers
Adam Munich, Sun Feb 26 2012, 02:50PM

If I had a bigger core I'd outdo it, but unfortunately I don't :-/

Re: Homemade Transformers
dude_500, Sun Feb 26 2012, 04:58PM

Here are a few of mine:










A variable power inductor by adjusting core gap

Re: Homemade Transformers
ZakWolf, Sun Feb 26 2012, 10:44PM


Those cores are huge!

Finish any of them ?

Gren, those are some long arcs(~12inches?) and hi current

Mine dont have that much current but it starts and arc at 2,5 inches

Re: Homemade Transformers
Newton Brawn, Wed Feb 29 2012, 01:49AM

Hi ZakHolf !

Umbelieve the banana baking process!
I have baking bananas im microwave oven, very tasty too.

Re: Homemade Transformers
dude_500, Fri Mar 02 2012, 07:11PM


Yes, I finished all of them. The giant x-ray transformer was about 40 hours of winding and was a total waste of time, it didn't perform well at all. I think it may have arced over internally. The ferrite ones all did quite well and can process significant power. The one with 8 U-halves could probably sustain 5-10kW and can surge higher, although insulating it is a nightmare and it really needs to be in an oil tank to do well at jacob's ladder duty etc. since it makes immense voltage when there is no load on it (enough to have the corona literally catch the bobbin on fire within seconds).