Re: REVISED Need NST

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

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi Jim,

Some of the "pro" coilers do have custom transformers made and the prices
are not bad at all ~$1000 for that perfect high-pot guaranteed, well over
designed, just the right size..., HV transformer.  Of course, the average
fella buying in quantities of "one" and not knowing the fancy technical
details they ask, does not have a chance...  Far easier and cheaper just to
adapt one's coil plans to common transformers.  As you say, potential
transformers are very attractive.  Finn is on of the gifted few who
actually has made his beautiful transformer from scratch.  But most of us
are not that good ;-))

The custom made trannies typically use external inductive reactors for
current limiting since that is much easier and cheaper than making a true
shunted core transformer in small numbers.  The details are easy for a
transformer house and your price tends to depend only on quantities and
weight since the house engineer can probably "design" it in minutes...

If one already has a big core, then rewinding it is not a great technical
challenge but the problems is just in getting and winding all that wire and
perhaps making an oil bath enclosure.  With nice rebuilt pigs running
around $300 bucks, such effort are usually not worth it.

Cheers,

	Terry


At 05:53 PM 9/26/2001 -0700, you wrote:
>Actually, much as for capacitors, nobody is interested in selling to the 
>Tesla Coiler market, per se.  We tend to be pretty hard on the equipment, 
>with overvoltages, transients, etc., not to mention that your basic TC 
>design isn't what you would call well controlled and well defined in terms 
>of requirements.
>
>Interestingly, when I was buying some big HV transformers from Peter Dahl (a 
>small/medium builder of custom HV transformers, mostly for the radio 
>transmitter market in the 2-10 kVA range), they mentioned that they hated 
>dealing with Tesla Coilers... They wanted cheap transformers, had no idea of 
>the real requirements, and tended to send back the transformer for warranty 
>after having destroyed it either by overloading or overvoltage. 
>
>
>There ARE multi-million dollar companies making transformers for the TC 
>market: Actown, France, Allanson, etc. for high leakage inductance current 
>limited units; and GE, Magnetek, ABB, Siemens, etc., for the higher power, 
>non current limited unit.
>
>And, their products are quite reasonably priced for NEW units built to some 
>consistent catalog specifications (which may or may not align with what a TC 
>builder might want).
>
>A few years back, I actually put some thought into what the "ideal" 
>transformer specs for a TC might be.  Say, 110V in, 10-15 kV out, around 1-2 
>kVA. As it happens, standard commercial potential transformers happen to fit 
>the bill quite well, and are reasonably priced on both the new and used
market.
>
>Granted "reasonable" from a manufacturing cost and retail markup standpoint 
>(i.e. several hundred dollars) might not be "reasonable" for a hobby 
>scrounger, but, just the cost of the iron and copper in a decent transformer 
>is a pretty sizable chunk of cash, and adding the R&D cost, assembly, 
>testing, quality control, shipping, etc. and it adds up.  For these sorts of 
>things, if you figure that the raw parts cost is roughly 1/10th of the 
>retail price, you won't be far off.  If you've bought enameled copper wire 
>new, you realize that $30 for the parts cost on a 5 kVA pole pig probably 
>isn't unrealistic
>
>Tesla list wrote:
>> 
>> Original poster: "mbarbani by way of Terry Fritz <twftesla-at-qwest-dot-net>" 
><mbarbani-at-yahoo-dot-com>
>> 
>> Welcome to the world of Tesla coil building..where very little is cheap or 
>easy
>> to come by! The Neon Sign Transformer--manufactured exclusively for, you
>> guessed it, neon signs..not Tesla coils! That's the pickle we're all in, 
>and if
>> some company were to make transformers especially for our coils it would no
>> doubt be a multi-million dollar outfit by now. I got my NST from a sign shop
>> for $25..not free like some say. Only thing I can say is don't give up! 
>You are
>> destined to find one. Good luck and Godspeed in your quest! Marc B.
>> 
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>