Re: AC->HV Transformer

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Mddeming-at-aol-dot-com 

In a message dated 7/13/04 8:46:44 AM Eastern Daylight Time, 
tesla-at-pupman-dot-com writes:
Original poster: "Uldis" <cobalt-at-pit.lv>

Where to get ac to high voltage transformer, i live in Europe, Latvia(220v
50hz), what replacemets you could suggest(MOT's NST's and Pole pigs isnt
easy to get in here).
Maybe there is some devices which has 220 to lower voltage transformer which
can work (does not damages, and can give enough current) if i use it in
opposite direction.
Yesterday i made a little coil with tv flyback and secondary on small
candle, as I see for larger coil flyback would be too weak.

So just write your suggestions where i could get HV transformer, maybe where
did you got yours, I hope it will help me get mine. My goal is to get 10-15
kv 15-30ma transformer :)

Hi Uldis,

     Using a low-voltage step-down transformer in reverse is usually a bad 
idea for several reasons. First, the ratio is too small. Assume you had a 
220V to 22 V step-down transformer. The ratio is only 10:1 running it 
backwards you would only get 2200 V output. Second, the insulation in these 
transformers is not designed for ten times the rated voltage. The 
interwinding insulation would break down rather quickly leaving you with a 
bad smell, a molten mess of copper and possibly a fire.
     If you are in a metropolitan area such as Riga, Daugavpils, Liepaja, 
or Jelgava, getting either NSTs or MOTs should be easier than getting a 
pole pig. A source of an NST might be either a sign shop, or if you find a 
closed business that used a neon sign, you might be able to get it for 
free, especially if the building is being torn down.  I don't know the 
situation where you are, but here in the US, many people will throw away 
non-working microwave ovens because repair charges here often exceed the 
cost of a new one. The list archives have information on building a 4-pack 
or 6-pack MOT-based power supply. Another possible source of coil power is 
the OBIT (Oil-burner-ignition-transformer) These are usually 10-13 ma -at- 
10KV. and might be more readily available, especially if you are in a rural 
area. A pair of them in parallel would get you into the range you are 
looking for: 20+mA-at- 10KV.
   If you buy transformers on the Internet, you may find that the shipping 
charges can exceed the purchase price. Scrap yards and abandoned industrial 
sites are often good sources of TC parts, Some coal-burning power plants 
used oil burners to ignite the coal and an industrial-size OBIT might be 
findable. Hope this helps,
Labe,
Matt D.