What type of power source is typically used for GTAW?

The correct response, which identifies constant current power sources as typically used for Gas Tungsten Arc Welding (GTAW), is grounded in the fundamental requirements of the welding process. Constant current power sources provide a stable arc during welding, which is crucial for the precision required in GTAW. This stability ensures that the current remains relatively constant despite slight variations in arc length caused by changes in the operator's technique or adjustments in the welding equipment.

In GTAW, it is essential to maintain a suitable arc length to produce a consistent weld bead and to avoid issues such as arc blow or unstable arcs. The constant current characteristic allows the welder to focus on manipulating the torch and filler material without needing to adjust the power source continuously.

While alternating current can be used in specific applications, particularly for welding aluminum, it is the constant current power sources that fundamentally define the operation of GTAW, as this is the primary type in carrying out most applications effectively.