Which machine type is associated with a drooping volt-amp curve?

Which machine type is associated with a drooping volt-amp curve?

• A. Constant Voltage Machine.
• B. Constant Current Machine.
• C. Rising Arc Voltage Machine.
• D. High Amperage Machine.

Answer: (B)

A drooping volt-amp curve shows the power source is regulating current, not voltage. In constant-current welding, the machine keeps the current roughly fixed, while the arc voltage can vary with arc length and other conditions. As you try to draw more current or shorten the arc, the source lowers the voltage to hold the current steady, producing a downward-sloping (drooping) V-A relationship. This is why the drooping curve is characteristic of a constant-current machine. In contrast, a constant-voltage machine aims to hold voltage steady, so the current rises with little change in voltage, yielding a more horizontal or slightly rising V-A trend rather than a droop.

A drooping volt-amp curve shows the power source is regulating current, not voltage. In constant-current welding, the machine keeps the current roughly fixed, while the arc voltage can vary with arc length and other conditions. As you try to draw more current or shorten the arc, the source lowers the voltage to hold the current steady, producing a downward-sloping (drooping) V-A relationship. This is why the drooping curve is characteristic of a constant-current machine. In contrast, a constant-voltage machine aims to hold voltage steady, so the current rises with little change in voltage, yielding a more horizontal or slightly rising V-A trend rather than a droop.