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Re: MOT core
Original poster: "Richard W." <potluckutk-at-comcast-dot-net>
I've been using that for so long I've forgotten where I got it from. The
factor 0.16 is for the more common material used in laminations and includes
the frequencies 50 to 60Hz. In the years I've been building transformers
that formula has always done right by me. Besides, all I've ever built were
transformers for 50 to 60Hz using the E and I configuration.
The other one that goes hand-in-hand with that formula to calculate voltage
per turn, E = (.16 x CS), has also proven it's worth in practice.
VA = (CS/0.16)^2
E = (.16 x CS)
E = voltage per turn
CS = Cross-Section of the center leg for E and I transformers.
Rick W.
Salt Lake City
----- Original Message -----
From: Tesla list <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, February 02, 2004 5:43 PM
Subject: Re: MOT core
> Original poster: "Hydrogen18" <hydrogen18-at-hydrogen18-dot-com>
>
> Where did you get that formula? How does it include frequenct into the
> equation? I'd like to use in my transformer calculator I'm developing but
it
> needs to change with frequency.
>
> ----- Original Message -----
> From: "Tesla list" <tesla-at-pupman-dot-com>
> To: <tesla-at-pupman-dot-com>
> Sent: Monday, February 02, 2004 8:58 AM
> Subject: Re: MOT core
>
>
> > Original poster: "Richard W." <potluckutk-at-comcast-dot-net>
> >
> > Actually decreasing the core cross-section by half will drop the power
> > capability almost by a factor of 4.
> >
> > Let's say we have a core who's center leg measures 1" x 2" for 2 square
> > inches.
> >
> > CS = 2 sq.in. (Cross Section)
> >
> > VA = (CS/0.16)^2
> > VA = (2/0.16)^2
> > VA = 12.5^2
> > VA = 156
> >
> > Cutting the core in half = 1 sq.in.
> >
> > VA = (CS/0.16)^2
> > VA = (1/0.16)^2
> > VA = 6.25^2
> > VA = 39
> >
> > Rick W
> > Salt Lake City
> >
> > ----- Original Message -----
> > From: Tesla list <tesla-at-pupman-dot-com>
> > To: <tesla-at-pupman-dot-com>
> > Sent: Sunday, February 01, 2004 7:34 PM
> > Subject: Re: MOT core
> >
> >
> > > Original poster: "Hydrogen18" <hydrogen18-at-hydrogen18-dot-com>
> > >
> > > The only thing I know to say here is stack the cores. Alternatively
you
> > > could use very small wire for the secondary to achieve the HV
output.
> > > Stacking the cores(inserting 1 E into each end of the "bobbins")
will
> > halve
> > > your power output but double your winding window.
> > > ----- Original Message -----
> > > From: "Tesla list" <tesla-at-pupman-dot-com>
> > > To: <tesla-at-pupman-dot-com>
> > > Sent: Sunday, February 01, 2004 6:49 PM
> > > Subject: MOT core
> > >
> > >
> > > > Original poster: "Dan" <pbursa-at-cfl.rr-dot-com>
> > > >
> > > > Hello !
> > > > I am curious if someone here has experience with rewinding
microwave
> > > > transformer.
> > > > I cut of the I part of the core, removed old windings and split
the
> E
> > core
> > > > in half so now I have two identical E cores .
> > > > Together they make 5.5 inches long, 4.15 wide and 1.35 thick core
> with
> > > > about 1.72 square inches area...
> > > > This looks like I'll need over 400 turns on primary... this would
> > require
> > > > 40000 turns for 12KV secondary and there is not enough space for
> this,
> > I'm
> > > > afraid.
> > > > My question is - if I use less primary windings (say 150 - 200),
how
> it
> > > > affect performance, core saturation, ...
> > > > I noticed that original MOTs primary was also less than proper
> amount
> > of
> > > turns.
> > > > Also, since MOT core is welded together, how the weld affect the
> core
> > > > losses and eddy currents? isn't the very purpose of using
laminated
> > core
> > > to
> > > > minimize these loses ?
> > > > How about potting finished transformer in oil ?
> > > > Thank you in advance
> > > > Vladan
> > > >
> > > >
> > > >
> > >
> > >
> >
>
>