MIG Welding, CC Inductor, and bypass thereof

I dont know much about welding, but I *do* know electronics.

You can *ONLY* cancel out the external effect of an inductor at a single frequency (i.e. for a single SINE WAVE signal). Any change in freqency requires you to change the capacitor value. Also that frequency is by definition resonance and there will be either massive circulating currents for the parallel case (looks like an open circuit externally) or massive voltage swings at the junction for the series case (looks like a piece of wire).

You are delivering a complex pulsed waveform with harmonics all over the place that in nio way can be treated as a single frequancy sine wave.

This means that switching in a cap will: (a) Not work as you need a DC circuit. (b) If it *could* work, it would overstress the existing inductor and need a high voltage, high current 'monster' cap to handle it. (c) Need a contactor with a *much* higher rating to switch it.

You are *NOT* going to save *any* space or parts!

Either go for a bypass contactor or fit a seperate terminal for the MIG wiregun that taps your output *before* the monster choke.