> I'm looking for: info, ideas, pointers, etc.
>
> I need to pass 40-60A thru a wire to insure the capacity, but where do I get
> this much current without having to use a humungous load to drop the voltage
> and control the current.
>
> I thought on using a relatively large power transformer, replacing the
> secondary winding with a few turns of really heavy gauge to get a low
> voltage (0.5-1V maybe) at a high current.
>
> What do you suggest?
>
> TIA
>
> Gabriel
>
I did someting like this many years ago when we were testing the ground
voltage rise on some hospital equipment when we put a large current
between the equipment chassis and the earth ground.  We got a pair of
2.5VAC high current output filament transformer (rated for 20 amps
continuous output) and wired them in parallel (make sure the phasing
is correct so that the current outputs add to each other), and we
wired the primary in parallel to an variable transformer.  Using a
100-amp-to-50-millivolt shunt resistor (resistors made for measuring
currents) in series with the secondary and a meter across the shunt,
we would turn the variable transformer up until we got the desired
current.  These measurements were very accurate.

If you want to cheap, crude way to do it, get an old-fashion soldering
gun -- I found a 150 watt unit a few years ago new (made in China) for
less than $20 [if you need the company name ..., e-mail me privately and
I will look it up at home].  This soldering gun is basically a
transformer with a single winding on the secondary.  Replace the
soldering "tip" with the wire you are trying to test, plus a current
meter -- you probably will get a LOT of current -- maybe even too
much.  But you can do things to reduce that.

Dave Reinagel
cisco Systems, Inc.