Re: Dr R's 16KV 300ma transformer

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

Original poster: "Hydrogen18" <hydrogen18-at-bellsouth-dot-net> 

The 1600 watts isnt going to heat, it is magnetizing the core.

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

---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
 >
 >
 >