Re: Saturation/the real meaning?

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

Original poster: "Malcolm Watts by way of Terry Fritz <twftesla-at-uswest-dot-net>" <m.j.watts-at-massey.ac.nz>

On 5 Apr 01, at 18:04, Tesla list wrote:

> Original poster: "BunnyKiller by way of Terry Fritz
> <twftesla-at-uswest-dot-net>" <bigfoo39-at-telocity-dot-com>
> 
> Tesla list wrote:
> 
> > Original poster: "harvey norris by way of Terry Fritz
> <twftesla-at-uswest-dot-net>" <harvich-at-yahoo-dot-com>
> >
> > I see numerous posts where it is mandated that when a
> > ballast method is being used to control the amperage
> > input to a tesla coil, that if the inductor is
> > saturated this will cause its amperage consumption to
> > go way up. I can accept that fact. But I cannot accept
> > the numerous quotes I have seen where it is
> > additionally stated that at saturation the inductance
> > or impedance goes to zero, which is the cause for the
> > large amperages. Perhaps I have misread the context or
> > meaning of that statement.
> 
> BIG snipperz....
> 
> Hi Harvey....
> 
> like you, I am still fighting that horrendious learning curve of
> inductance ;)
> 
> what you have mentioned is correct.
> 
> I need to see things in a more simple way ....  ( i hate math) the way
> i see it is that as the flux increases, the amount of lines increase,
> which "saturates" the core with the lines of flux. As this saturation
> increases, the ability of the steel core to resist the magnetic fields
> change decreases, thus becoming more like an air core inductor (
> becoming more apt to allow current flow up to a point, because an air
> core inductor cant saturate but considering its physical makeup it
> will have alot less inductance compared to the same coil with a core).
> Thus the increased amp flow thru the inductor eventually fries the
> insulation of the coils and WALA smoke.
> 
> sooo.. what I have come to conclude ...
> 
> is that the core of an inductor to be rated for 60A + should be at
> least a minimum of 12" square ( center leg) and the wire should be a #
> 6 or # 8 with about 200 turns.
> 
> since # 6 wire is not easy to find, consider using 3 # 10 wires for
> about 90A worth of current capacity.
> 
> 
> 
> Scot D

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