Re: chokes

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

Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-qwest-dot-net>" <evp-at-pacbell-dot-net>

> I don't know how to do it either...  The high voltage on the outer windings
> "thing" is an unproven theory.  Failed NSTs do seem to blow on the outside
> winding.  That is also a high voltage gradient area without any doubt as
> well.  The inductance of that outside layer combined with the say 300kHz
> can drop a lot of voltage on the winding but there also needs to be a place
> for the current to flow which would have to be from inter layer capacitance
> I would think.  Judging from how complex the secondary has been shown to be
> from Paul's work, I bet this is far worse to model.
> 
> However, if one had a secondary winding exposed, a signal generator, and a
> high impedance scope probe...,  one could inject a say 300kHz signal into
> the winding and measure the voltage drop.  That would give a very good idea
> as to what proportion of an incoming signal gets dropped into the outer
> winding.  A good thing for that half blown depotted NST sitting on the shelf.
> 
> I have the generator and the scope stuff but since I use protection filters
> I don't have any blown NSTs :o)))
> If anyone has a spare old NST winding they could send me, I could give it a
> test (terellf-at-qwest-dot-net ;-)).  I could figure out a temporary core to stick
> in it so only the single NST winding itself would be needed.  I would have
> to scratch into the wire to make contact so it may ruin the winding.
> 
> There is also a nasty high voltage spike at the beginning of gap condution
> that is rich in up to GHz harmonics, but will will just try crawling
first ;-))
> 
> Cheers,
> 
>         Terry

	I suspect that there are guys designing high power pulse and power
transformers who could handle that sort of thing.  Certainly they must
be interested in the voltage distribution resulting from a lightning
strike, for example.  Guess we don't have any power engineers and
transformer designers in the group (they're getting pretty scarce
anywhere these days) or someone would have spoken up.  As for the CS
measurements, I think a lot could be learned if you could somehow dig
into the transformer and measure voltage distribution without wrecking
it.  Impossible, of course.  Hope there'll be other information on this
subject.

Ed