Which of the following best describes the volt-amp curve produced by constant voltage power sources?

Which of the following best describes the volt-amp curve produced by constant voltage power sources?

• A. Relatively flat volt-amp curve.
• B. Drooping volt-amp curve.
• C. Rising volt-amp curve.
• D. Constantly changing volt-amp curve.

Answer: (A)

Constant voltage power sources regulate arc voltage so it stays nearly the same as current changes. On a volt-amp curve (voltage vs current), that means the voltage remains essentially constant across a range of welding currents, producing a relatively flat line. This stability makes arc characteristics predictable because the operator can change current (via wire feed, arc length, or other factors) while the voltage stays steady. A drooping curve would mean voltage falls as current increases, which isn’t how a well-regulated CV source behaves. A rising curve would imply voltage increases with current, which also isn’t typical of a constant voltage setup. A constantly changing curve isn’t the stable, defined response you expect from a CV power source.

Constant voltage power sources regulate arc voltage so it stays nearly the same as current changes. On a volt-amp curve (voltage vs current), that means the voltage remains essentially constant across a range of welding currents, producing a relatively flat line. This stability makes arc characteristics predictable because the operator can change current (via wire feed, arc length, or other factors) while the voltage stays steady. A drooping curve would mean voltage falls as current increases, which isn’t how a well-regulated CV source behaves. A rising curve would imply voltage increases with current, which also isn’t typical of a constant voltage setup. A constantly changing curve isn’t the stable, defined response you expect from a CV power source.