Short note on Basic arc Welding Circuit:

The fundamental arc-welding circuit is demonstrating in the image. An AC or DC power source, fixed with whatever controls may be wanted, is linked by a work wire to the work piece and by a "hot" cable to an electrode controller of a few type, which makes an electrical contact by the welding electrode.

An arc is formed across the gap when the energized circuit and the electrode tip touches the work part and is withdrawn, yet still with in close contact.

The arc creates a heat of about 6500ºF at the tip. This high temperature melts together the base metal and the welding electrode; creating a pool of molten metal sometimes called a "crater." The crater solidifies behind the electrode as it is moved along the joint. The outcome is a fusion bond.