I need to monitor a plasma cutter's DC voltage. I selected the AD629 from Analog Devices and have a schematic and layout that works on a test bench.
Admittedly, my talents are in software and what I know about EE just makes me dangerous. :)
My concern is that welders and plasma cutters emit a high-frequency AC signal in order to start the arc. Not knowing any better, it seems to me that signal would fry my board. Although I've seen torch-height controllers and similar and see no obvious technique for "shielding" the PCB from this.
I am assuming that a 5K volt AC signal would happily create arcs anywhere the POS and NEG lines are very close -- such as on a PCB.
How is this working?