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Re: Self-built power transformer

Hi Doug,
          Some important things about your proposal:

> Original Poster: Doug Brunner <dabrunner-at-earthlink-dot-net> 
> 
> What I meant is, it's wound on a solid iron core and placed in a pipe to
> contain
> the oil and provide magnetic coupling.

First off, eddy current losses will be high as the core is one big 
shorted turn. So is the pipe you are going to surround it with. It 
should be laminated. It's also a rather lossy shorted turn as iron is 
not a good conductor so expect some heating. Next, plain old iron 
will exhibit rather high hysteresis losses as it is easily magnetized 
and tends to stay that way. Thirdly, coupling will be very poor as 
there are huge end-end airgaps. Expect a low induction factor (= lots 
of turns required for primary and secondary windings to avoid 
saturation). It will also exhibit a lot of leakage inductance. I 
agree with Erik. I don't think this is a good proposition.

Malcolm

  > Tesla 
List wrote: > 
> > Original Poster: ESchulz531-at-aol-dot-com
> >
> > Hi,
> >         Your not using a pipe are you?  The flux would be way to high on
> > the little amount of iron you have and would probably saturate below
> > 30 volts unless you added a lot more turns in series.  Since the flux
> > wouldn't have a closed path your mutual inductance will be really low.
> > This means that you will have an efficiency less than 25%.  If you
> > want to make a good/decent HV transformer get a real transformer
> > core.
> >
> >         I am not trying to bite your head off I am just trying to stop
> you from
> > making that pretty smoke and wondering why it didn't work.
> >
> > Erik Schulz
> >
> > > Original Poster: Doug Brunner <dabrunner-at-earthlink-dot-net>
> > >
> > >  It's currently not a closed core. However, I can probably put
> something in.
> > >  One
> > >  idea I want to check: it'll already be in a iron pipe (to contain the
> oil).
> > > If
> > >  it's got good magnetic coupling with the end caps, will it work OK?
> > >
> > >  Tesla List wrote:
> > >
> > >  > Original Poster: "D.C. Cox" <DR.RESONANCE-at-next-wave-dot-net>
> > >  >
> > >  > to: Doug
> > >  >
> > >  > I assume your core is a closed core -- if you try this with a
straight
> > > core
> > >  > and no closed magnetic path your losses will be horrible.
> > >  >
> > >  > DR.RESONANCE-at-next-wave-dot-net
> > >  >
> 
> 
> 
> --
>            --Mr. Postman (Doug Brunner)
>                 <dabrunner-at-earthlink-dot-net>
> 
> 
> 
>