Re: Saturation/the real meaning?

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

Original poster: "BunnyKiller by way of Terry Fritz <twftesla-at-uswest-dot-net>" <bigfoo39-at-telocity-dot-com>

Tesla list wrote:

> Original poster: "Malcolm Watts by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <m.j.watts-at-massey.ac.nz>
>
> snipperz...
>
> Windings (copper size) are rated for current carrying capacity aren't
> they? The core rating has more to do with applied MMF peak flux
> density. Consider the case of a rather puny (by pig standards) core
> in a welder SMPS carrying 100A+.
>
> Malcolm

Hi Malcom....

you have a point there...  but when you start using the welder at that
range the duty cycle time is
drastically increased towards time off. Also, the amperage rating we see on
most welders is the secondary
side amp rating, so in effect, the primary sees about 1/3 - 1/2 of the
secondary rating ( most welders
have a secondary voltage of 30 -55V ).

Even my cheap Sears welder has a core area of 11.5" square ( 3 and 3/8"
square leg) with about 120 winds
on the primary. If I were to rewind this core as an inductor and use 200 or
so turns, the MMF would be
nearly doubled from the actual design of the welding machine, and if I were
to pump 40+ amps thru it
while trying to limit a pig, it would be close to or at saturation.


Scot D