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ME?!? Winding my own transformer???



> Hi Sam,
>
>I know how you feel about your transformer problems. I have the same in
>germany. Read up on the latest posts (from me and other crazy guys) 
about=
> home
>brew transfomers. Tell your electric companies to go to hell AND go and 
w=
>ind
>your own. This will save you bucks, let you make a custom xformer 
exactly=
> for
>your needs. And you can brag to everyone about having built your coil
>completely from ground up.
>
>Forget about using MOT=B4s. I =B4ve done some extensive testing (some 
of =
>the info
>is available on back issues) and found only one type (2.3kv-at-700mA from 
Ga=
>rdner
>in the U.K.) will hold up to TC use. And (of course what did you 
expect) =
>this
>type is almost non exsistant. You would need to have all MOTS coming 
from=
> the
>same manufacturer. You can=B4t (at least from my experience) mix 
differen=
>t MOT
>types, even if the voltage/current rating are the same. You can string 
2 =
>sets
>of three of the Gardner type in series, with a grounded center tap 
betwee=
>n MOT
>3 and MOT 4. This will give you a nice 13.8 kV-at-700mA psu. The 
insualtion =
>will
>take this. But (yeah there is always a but) you will have to:
>
>a.) use a safety gap across each single MOT (not just across all MOTS)
>b.) run them under oil to prevent arc overs.
>
>I learned the hard way by killing two of mine. I only had a safety gap 
ac=
>ross
>the whole setup, but not across each MOT. The sparks from the TC where
>great....until... well you guessed it........ it went pop and two MOTS 
ar=
>ced
>from somewhere in the secondary to the core, leaving a nice carbon 
trail.
>***###*-at--at-*!!. As you have to run them under oil and have a safety gap 
acr=
>oss
>each MOT it makes your setup pretty complicated. In other words not 
worth=
>while
>because you would have to feed thru each MOT connection for the safety 
ga=
>ps
>(as you can=B4t fire them under oil). At the prices you mentioned for a 
n=
>ew MOT
>I wouldn=B4t even dream of trying this. For $150 you will be able to 
find=
> an old
>welding xformer and rewind it for HV. You could even get a defective 
one =
>(read
>even cheaper). If the secondary is burned out, it wouldn=B4t make a 
diffe=
>rence,
>but even if your primary is toast you still have the core. So get to 
read=
>ing
>and winding. It=B4s your (and mine, too) best bet.
>
>Forget about using PVC as a cap material. It=B4s pretty lossy compared 
to=
> PE at
>TC frequency. Plexiglass gets brittle when exposed to oils, so expect 
you=
>r cap
>to crack after a while.
>
>Have you tried looking for PE at your local building/hardware store ? 
Ove=
>r
>here in germany thick PE (6.7 mils) is used as a seperator when pouring 
i=
>n
>concrete walls, etc. It comes in 2 meters wide and 25 m long and the 
pric=
>e of
>about $25 per roll is still reasonable. This type of PE does have some 
di=
>rt
>enclosed, but as you will be using more than one sheet it doesn=B4t 
matte=
>r much.

>Hope I could help,
>Coiler greets from germany,
>Reinhard


  Thanks a lot for the help, Reinhard.

 I guess maybe winding my own transformer would be the best (well, 
actually the only) option. It's just that winding some 20000turns of 
wire by hand and than watching it smoke (yes, I know I am very 
pessimistic) is not my idea of fun...
 Well, I could give it a try... It'll probably cost me some 300 dollars 
in materials alone (knowing the price of things in Holland) but it would 
be OK...
 What kind of core would I need for, say, a 5KW unit? Where could I get 
the materials from?


 Sam Barros.

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