On Oct 7, 5:51*pm, Winston wrote:
Bill Janssen wrote:
Transformer Iron cores depend on Iron with a Oxide surface (black). I
don't know if your
MIG wire is suitable for that treatment.

The MIG wire is 97% iron so I'm hoping that will be sufficient.
I suppose the oxide surface acts as an electrical insulator to limit
eddy current flow between laminations. *For the prototype, varnish
would take that role.

Thanks!

--Winston

--

I'm still waiting for another sublime, transcendent flash of adequacy.

And steel is 99.9-99% iron. It's the little details that will get
you. My old, OLD electrical how-to from the teens and twenties shows
them using iron, not steel, wire for solenoid cores. The reason being
is that soft iron, not steel, wire will have little or no remaining
field once the current is turned off. You want it magnetized only
when the current is on. And eddy currents are only there if you're
running AC through it, which sounds like some kind of choke, if that's
what you're doing. In which case you might want to rethink your
choice of magnetic core. At 60 Hz or so you can salvage the silcon
iron out of old transformer cores. Insulate with varnish, the induced
voltages are low. For higher frequencies, hit one of the remaining
ham radio supplier sites and look for powdered iron or ferrite cores,
they have much better properties at higher frequencies. Then you need
a book to tell you the formulas to get the performance out that you
want with the magnet parameters of those cores.

Stan