"whit3rd" wrote in message
...
On Tuesday, March 17, 2020 at 11:06:10 AM UTC-7,
wrote:
On Sat, 14 Mar 2020 21:25:20 +0000 (UTC), Cydrome Leader

The alnico
magnets in old and/or inexpensive mag bases were/are magnetized
after
assembly. This takes a LOT of current. I have seen the setups for
doing this and they are not trivial.

There's a two-part magnetization process for alnico, you have to
observe the
built-in (at ceramic-firing time) polarity when you apply current.
It WILL magnetize one direction, not the other.

Usually, metalworkers have access to high DC current sources from
Lincoln, Miller,
Hobart, etc. and that's what it'll take.

Arc welders inherently limit short circuit current by designed-in self
inductance, core saturation, etc and can't easily be tweaked to
deliver higher current in a short pulse. Also their rated current is
at 20-25V which doesn't allow for much wire resistance. At 20V the 0.1
Ohm resistance of a coil wound with 100' of 10AWG copper wire would
limit the current to around 200A. Unless you can reuse the wire in a
solar system it's cheaper to replace the magnetic base.

Perhaps a motor shop can repolarize it.