If you want to monitor the waveform with a scope use a 2' long x 1" wide x 1/16" thick piece of steel and lay it on an insulating surface. Connect your ground clamp to one one end and short your torch to the other end. Set the current to 70A. Connect your scope ground to the ground clamp and the scope probe about 1" to 2" from the ground clamp. This is a cheap current shunt and can be used to see the wafeform but is not accurate for current measurement. To increase the signal seen on the scope move the probe closer to the shorted torch, or to decrease the signal move the probe closer to the ground clamp. Its simple and you can measure the frequency and balance easily.
Reply With Quote