A constant current welding power source primarily maintains a steady level of which parameter?

• A. Current
• B. Voltage
• C. Power output
• D. Electrode size

Answer: (A)

A constant current welding power source keeps the welding current steady. This stabilizes the heat delivered to the weld, which helps produce a consistent penetration and bead shape. With the current fixed, the voltage automatically adjusts to accommodate changes in arc length or arc resistance. If the arc length increases, the source raises voltage to maintain the same current; if the arc shortens, voltage drops while current stays the same. Since power is the product of current and voltage, the input power will vary with arc conditions rather than stay constant. The electrode size isn’t controlled by the power source, and the goal isn’t to hold power constant.