Re: Dr R's 16KV 300ma transformer

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

Original poster: "Malcolm Watts" <m.j.watts-at-massey.ac.nz> 

On 2 Aug 2004, at 18:11, Tesla list wrote:

 > Original poster: "Hydrogen18" <hydrogen18-at-bellsouth-dot-net>
 >
 > The 1600 watts isnt going to heat, it is magnetizing the core.

I never said it was going to heat, somebody else did. I assumed (!)
that you were actually meaning VA.

 > I thought the voltage drop relative to current draw was intrinsic to a
 > transformer. My mains voltage drops when current draw increases.

By how much? (rhetorical question). Mind you, if it drops
significantly (Like more than a couple of volts or so) it might be an
indication of underrated wiring or the hint of some fault being
present. No transformer is lossless but unless they are specifically
designed to have poor regulation, they are usually pretty good.

Malcolm



 > ---Eric
 > ----- Original Message -----
 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > To: <tesla-at-pupman-dot-com>
 > Sent: Monday, August 02, 2004 8:07 AM
 > Subject: Re: Dr R's 16KV 300ma transformer
 >
 >
 >  > Original poster: "Malcolm Watts" <m.j.watts-at-massey.ac.nz>
 >  >
 >  > On 1 Aug 2004, at 19:15, Tesla list wrote:
 >  >
 >  >  > Original poster: "Hydrogen18" <hydrogen18-at-bellsouth-dot-net>
 >  >  >
 >  >  > I guess shunted transformers can be done right(although the only
 >  other >  > kind I can think of are welders, which dont really matter
 >  much as long >  > as they burn well). But with my 4 pack I have a
 >  HUGE magnetizing >  > current(1600 watts!). I guess part can
 >  attributed to bad power factor >  > and the fact that the cores are
 >  running at 70000+ lines of flux per sq >  > inch. But why dont all
 >  transformers have shunts? I know the winding >  > over winding method
 >  prevents the use of them, but I'm sure shunts >  > could save more
 >  than one small transformer which was accidentally >  > shorted/wired
 >  wrong/etc. > > Time for a bit of basic transformer theory perhaps.
 >  The reason most > transformers don't have shunts is because it would
 >  degrade their > regulation. NSTs and other current limited
 >  transformers are designed > to have poor regulation so that they
 >  don't deliver an unlimited load > current with a short circuit parked
 >  across the output. You can > imagine the mayhem that would be caused
 >  by shunted distribution > transformers - as soon as someone turned on
 >  a heater, the lights > would dim. The winding-over-winding method
 >  ensures that the coupling > between the primary and secondary is as
 >  high as possible given > insulation requirements. > >       Shunts
 >  *do not* prevent core saturation. Using enough pole area > so that
 >  the flux density is kept within the ratings of the core > material
 >  does. Any transformer which has an excessively high > magnetizing
 >  current flowing in its primary either doesn't have enough > pole area
 >  for the core material used or has too high a voltage > applied to it.
 >  > > Malcolm > > >
 >
 >
 >