Does pushing the control to the bottom position always yield maximum welding power?

• A. Yes
• B. No
• C. Sometimes
• D. Only when using AC

Answer: (A)

On most welding power controls, the bottom position is the highest current setting. The welding power you get is basically current times voltage, and the line voltage is fairly constant. When you push the control toward the bottom, the circuit resistance drops and more current can flow to the arc. More current means more heat at the weld, i.e., more welding power. This mapping holds for both AC and DC operation in typical machines, so the bottom position indeed yields the maximum power.