In article ,
Grant Erwin wrote:

Wild Bill wrote:

What's in this welder described below, a couple of resistors?

Everyone had better hope that utility system current is not passing through
the welder's output leads.

Obviously it is not.

WB

(snicker) Wow what a goober I hacked up that time! I have to laugh at the fact
that electrical engineers are capable of the dumbest things sometimes. OK, let's
amend it: current flows down one leg, through the primary of the transformer
and back through the other leg. Point is, the same current flows in both legs.

Don't laugh. I've done it. The "resistor" was a 100-watt light bulb in
series with 110-volt power (AC and DC), the welding "stick" was a carbon
rod liberated from a carbon-zinc "D" size battery, and the flux was
twenty mule team borax. We were welding chromel-alumel thermocouples
(with AC and flux) and 3mm diameter platinum capsules (with DC and no
flux aside from the carbon monoxide and hydrogen from the carbon rod and
moisture in the air), all in the 1970s. Simple, cheap, and worked well.

In those days, the University had its own powerplant, and supplied
110/220 volt DC to the labs. When AC power came, all but the labs
converted. In the sub-basement of the lab building there was a four by
six foot 1900s-era open-face power panel carrying the 220 volt DC power,
controlled by huge bare-metal knife switches and cylinder fuses, all
bolted to the front surface of a massive sheet of some kind of black
thermoset plastic, perhaps a bakelite composition. A terrifying
contraption if there ever was - one stumble or slip, and your goose was
*really* cooked. Especially if you were wearing any jewelry.

Joe Gwinn