Which device is used to change alternating current into direct current in welding equipment?

Which device is used to change alternating current into direct current in welding equipment?

• A. Inverter
• B. Rectifier
• C. Transformer
• D. Generator

Answer: (B)

Converting alternating current to direct current is done by a rectifier. A rectifier uses diodes (or thyristors) to steer current so it flows in only one direction, producing direct current. In welding, DC output provides a stable arc, smoother control, and more consistent penetration, which is why the power supply uses a rectifier to convert the incoming AC. The other devices don’t perform this single-step AC-to-DC conversion on their own: a transformer only changes AC voltage, a generator is a power source, and an inverter switches or shapes the output but relies on a rectified input to produce DC.

Converting alternating current to direct current is done by a rectifier. A rectifier uses diodes (or thyristors) to steer current so it flows in only one direction, producing direct current. In welding, DC output provides a stable arc, smoother control, and more consistent penetration, which is why the power supply uses a rectifier to convert the incoming AC. The other devices don’t perform this single-step AC-to-DC conversion on their own: a transformer only changes AC voltage, a generator is a power source, and an inverter switches or shapes the output but relies on a rectified input to produce DC.