Inverter welders are basically power inverters; they convert 120-volt AC power to DC electricity to power welding torches. Because you can plug one into a conventional 120-volt receptacle, it's more convenient to use than a stand-alone DC-current generator. The DC power passes through a transformer to step it up to the level needed for welding.
Frequency is Key
The on/off action of switches called IGBTs are the secret to increasing frequency of the primary power that reaches the welder’s transformer. This action simulates the increase and decrease of a magnetic field, similar to that of electrical alternating current but at a much higher frequency.
Inverter welders are much smaller than conventional welding units, making them portable, as they may be transported in a carrier instead of being rolled to jobs on a special dolly. Because of their small size, they are also ideal for do-it-yourselfers and for use in tight areas that cannot accommodate portable generators that are sometimes required to run traditional welders.
Because they run on household current, inverter welders use less electricity, making them more economical. Their design also makes welding more efficient thanks to a smooth arc, small spatter and stable welding current.