old welder questions

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Original poster: "Metlicka Marc by way of Terry Fritz <twftesla-at-qwest-dot-net>" <mystuffs-at-orwell-dot-net>

hello all,
I am hoping some coilers may be able help me with an old welder? I have
a lincoln model (sae 200-1) 3 phase motor driven dc welder that uses a
massive continuous tap resistor that looks like a crane resistor unit?
It also has a "BIG" diamond shaped split core inductor that looks like
it may be a saturable reactor????
The one side of the reactor uses a flat inductor wrapped edgewise around
the core, the other side has 12g windings. The problem is that the
reactor side is fed from the generator through a 50 watt rheostat and is
labeled "voltage" , the "continuos current" side runs through the
massive resistor unit.
So, What the heck have i got here? At first glance i thought "now here
is a dandy ballasting setup" resistive and saturable reactor current
control all in one unit that just MAY be built into the ultimate 0-200
amp power control rack, But now i'm confused.
How is the saturable reactor used for voltage, or is this a funky auto
transformer?
Any help from those that have seen or understand this setup will be a
blessing.
Thanks,
Marc M.