A constant current machine produces a volt-amp curve that is

A constant current machine produces a volt-amp curve that is

• A. Flat.
• B. Drooping.
• C. Rising.
• D. Variable.

Answer: (B)

When a welding machine is set to constant current, it keeps the current essentially fixed while the arc voltage can vary with arc length and other conditions. If you plot voltage versus current for the arc under this mode, you get a downward-sloping, or drooping, curve. That shape reflects how the arc voltage changes as conditions move within the current range used by the CC source. A flat line would indicate constant voltage (current varying), and a rising line would imply voltage increases with current—both of which don’t describe a constant-current setup. The drooping curve best matches the behavior of a CC power source.

When a welding machine is set to constant current, it keeps the current essentially fixed while the arc voltage can vary with arc length and other conditions. If you plot voltage versus current for the arc under this mode, you get a downward-sloping, or drooping, curve. That shape reflects how the arc voltage changes as conditions move within the current range used by the CC source. A flat line would indicate constant voltage (current varying), and a rising line would imply voltage increases with current—both of which don’t describe a constant-current setup. The drooping curve best matches the behavior of a CC power source.