Re: variac amperage control??

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

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <Tesla729-at-cs-dot-com>

In a message dated 2/11/01 10:18:02 AM Pacific Standard Time, 
tesla-at-pupman-dot-com writes:

<< "Ed Phillips wrote:
< Cutting a
< thin slot through the core would probably cure the saturation and turn
< it into a linear reactor, but have never sacrificed a variac to find
< out.  Cutting through that silicon steel ribbon would be a pretty tough
< proposition, but think some have reported it.

Hi Ed, Un-Terry,
Yep, I can testify to what both of you are saying. I had a 28 amp/240 volt
variac that I was using as a current limiter for my a coil a while back and
I ended up burning the windings up on a very small area of the variac (< 1").
It was enough to riun the variac, though. Then I decided to take it apart and
salvage the donut core. I then thought about cutting the slot in the variac 
core for an extra reactor ballast. I first tried with a hacksaw (lol). Not! 
We're 
talikng about appr. 2" x 2.5" of solid silicon steel. Then I bought a metal 
cut-
ting blade and installed it on my circular saw and proceeded to cut thru it.
By now, it was more of the challenge of actually cutting thru the core than
actually being able to get something useful out of it. After about 10 minutes
of a shower of sparks, I finally cut clean thru it, although the edges were
rather ragged. Anyway, the core kind of "spring" opened once the cut was 
completely thru and it left a gap about 2" wide. Also, the lamenations 
spread out pretty bad around the cut, so I don't know if it's even usuable 
now and it's pretty doggone ugly :-(

David Rieben