What's the deal with Pulsed MIG Power Supplies? What is the advantage over traditional CV Machines?
For aluminum, the goal of pulsing is to have the ability to use spray transfer while minimizing heat input. This makes pulsing especially suitable for thin aluminum – say ¼" or below. While it is not wrong to use pulse welding for much thicker aluminum, pulsing begins to lose its advantage.
Pulse welding out-of-position is also much easier than spray transfer out-of-position welding. And it is much easier to learn to weld aluminum using pulsed transfer because the arc is more controllable.
In pulsed spray transfer, we pulse the current between a "Peak Current" that is above the transition current and a much lower "Background Current". We have spray transfer when the arc is above the transition current. When the arc is at the Background Current, no droplets are transferred.
Pulsing occurs several hundred times per second. Therefore, we get spray transfer at a much lower average welding current so that we can easily weld thin aluminum.