"Bob Paulin" wrote in message news:01c37eb7$51ce5ee0$b797c3d8@race...
DoN:

Any chance you know exactly what the electrical output is at the "jones
Plug" that goes into the magnetic chuck?

Volts, Amps, AC/DC?

With the rectifier bridge, it appears to be DC, but my limited
electrical/electronics knowledge keeps me from figuring out the
voltage/amperage.

I was considering maybe trying to operate the chuck on a separate
transformer/converter.

Thanks!

Bob Paulin - R.A.C.E.
Chassis Analysis Services

A small chuck might draw anywhere from 25 to 100 watts at a nominal
110V DC. That would be on the order of 1/4 to 1 amp. I don't know if
the 110V DC needs to be smooth, filtered or if it is just a simple
rectified but unfiltered 110/120V AC power line that averages out to
110V. (I'll go check if you ask me to but am not going to do that
just to post this text.) If it needs to be filtered, you'd need a
transformer on the order of 80 volts output, to get a rectfied
filtered output around 110V DC.

Anyway, I figure a variac (variable autotransformer, "variac",
"powerstat" etc.) and a bridge rectifier is the obvious way to
home-brew a control. Using that, you could wire a switch to bypass
the rectifier and also get variable AC, to demagnetize the chuck as
well, by slowly turning the variac up from zero and back down.