Which of the following describes the volt-amp curve for constant current machines?

Which of the following describes the volt-amp curve for constant current machines?

• A. Flat volt-amp curve.
• B. Drooping volt-amp curve.
• C. Rising volt-amp curve.
• D. Constant amperage volt-amp curve.

Answer: (B)

Constant-current welding power sources regulate the current while allowing the arc voltage to swing with changing conditions. Because the current is kept near a set value, the source’s voltage response tends to fall off as load changes—so as current remains near the target, the available voltage “droops.” This creates a volt-amp curve with a downward slope, i.e., a drooping curve. In contrast, a constant-voltage machine holds voltage more consistently, giving a flatter curve. The other descriptions don’t match the typical CC behavior.

Constant-current welding power sources regulate the current while allowing the arc voltage to swing with changing conditions. Because the current is kept near a set value, the source’s voltage response tends to fall off as load changes—so as current remains near the target, the available voltage “droops.” This creates a volt-amp curve with a downward slope, i.e., a drooping curve. In contrast, a constant-voltage machine holds voltage more consistently, giving a flatter curve. The other descriptions don’t match the typical CC behavior.