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Re: Pri-Sec Phasing
---------- Forwarded message ----------
Date: Mon, 06 Oct 1997 22:09:31 -0700
From: Bert Hickman <bert.hickman-at-aquila-dot-com>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Pri-Sec Phasing
Tesla List wrote:
>
> ---------- Forwarded message ----------
> Date: Sun, 05 Oct 1997 23:17:32 +0000
> From: Greg Leyh <lod-at-pacbell-dot-net>
> To: Tesla List <tesla-at-pupman-dot-com>
> Subject: Re: Pri-Sec Phasing
>
<SNIP>
> > Anyway, "same winding sense, same polarity", is at least easy to
> > remember!
> >
> > O
> > O<----------------------
> > O + + |
> > O Vx ------> |
> > O - Iout |
> > -------------* |
> > + -----> O |
> > Iin O Vout LOAD
> > O |
> > Vin O |
> > O |
> > O |
> > - O - |
> > --------------*-----------------------
>
> I agree that your variac should work as advertised, but, but...
> what about the 'Right Hand Rule'? Can't it be applied here???
>
> My confusion is further compounded by my copy of the "Practical
> Transformer Design Handbook", by E. Lowdon. On p.366 it says that
> in a xfmr where the windings are wound in the same direction,
> (and most are so that the bobbin doesn't have to be removed)
> the start of the primary winding has the same polarity as the
> end of the secondary winding. This confirms the Right Hand Rule.
>
> Perhaps their definitions of start and end are different.
>
> -GL
Greg and all,
Well, if the windings have the same "sense", the induced current flow in
the secondary, per Lenz's Law, must be in a direction opposing the
primary's magnetic field, and thus the secondary current flow must be in
a direction opposite to that of the primary. Sounds like Lowdon is wrong
(?)...
-- Bert --