Re: series of transformers for high voltage?

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Mddeming@xxxxxxx 

In a message dated 11/8/06 3:23:07 P.M. Eastern Standard Time, 
tesla@xxxxxxxxxx writes:
Original poster: "Ryckmans, Thomas" <Thomas.Ryckmans@xxxxxxxxxx>

Hello,

I'm interested in Tesla coils and high voltage... Is it possible to use
a series of transformers to obtain high voltage, as in the sketch below?
>From what I understand of transformers, Vout=Vin * (n2/n1) *
(n4/n3)*(n6/n5) and with this wiring one would save on the TOTAL number
of turns. Something must be wrong - otherwise it would used!

http://hot-streamer.com/temp/serialtransformer.jpg

Thanks for your comments

Thomas

Hi Thomas,

While it is in principle, possible to series transformers built for 
that purpose,  you will destroy most ordinary transformers if you try 
it. Insulation is the main problem. Referring to your diagram, 
primary n3 must be insulated to withstand the voltage on n2, and 
there must be enough insulation between n3 and n4 to standoff n4s new 
output voltage.The insulation on n4 must be able to withstand its new 
output voltage Likewise, n5 must be insulated to withstand the output 
of n4, and the insulation on n6 and between n5 & n6 must be adequate 
to withstand Vout. Most transformers are unhappy at 1.5 times their 
rated input voltage. If your transformers were all 50:1, the stress 
on the n5/n6 insulation would be 2500 times normal!Insulation that 
keeps the sparks from getting out of the wires also keeps heat from 
getting out, so bigger transformers with more cooling area. Remember, 
mass and volume cost money to build and more money to ship. Unless 
you're into burning insulation and melted copper, you'll need custom 
made transformers with special cooling. (That's Tran$$$former$) There 
are other problems with core size and saturation, turns per 
volt,  hysteresis, eddy currents etc. but IMO, the insulation problem 
alone is enough to kill it. Since I don't know the depth of your 
background, I'll leave it to others to tackle those parts.
Hopes this helps explain the problem,

Matt D.