1. Power Source:
- Alternator: An alternator is a synchronous machine that converts mechanical energy into alternating current (AC) electrical energy. It requires an external source of mechanical power, such as an engine or turbine, to rotate its rotor.
- Generator: A generator is also a synchronous machine that converts mechanical energy into electrical energy. However, unlike an alternator, a generator produces direct current (DC) electrical energy. It has a commutator or rectifier that converts the generated AC current into DC.
2. Output Current Type:
- Alternator: An alternator produces alternating current (AC) welding current. The output current continuously reverses direction, with the polarity changing from positive to negative and back.
- Generator: A generator produces direct current (DC) welding current. The output current flows in one consistent direction, maintaining a constant polarity throughout.
3. Arc Stability:
- Alternator: AC welding current produced by an alternator creates an arc that is less stable compared to DC welding current. The alternating nature of the current can cause the arc to flicker and produce spatter.
- Generator: DC welding current generated by a generator provides a more stable arc. It reduces the flickering effect and produces a smoother weld bead with less spatter.
4. Electrode Type:
- Alternator: AC welding current is suitable for welding with alternating current (AC) welding electrodes. These electrodes are designed to handle the reversing polarity of the alternating current.
- Generator: DC welding current is compatible with direct current (DC) welding electrodes. These electrodes are specifically designed for use with DC current and provide better arc stability and penetration.
5. Welding Applications:
- Alternator: AC welding current is commonly used in industrial applications where AC power is readily available. It is suitable for welding various metals, including mild steel, stainless steel, and aluminum.
- Generator: DC welding current is often preferred for welding applications that require high precision, such as in construction, automotive, and shipbuilding industries. It provides better control over the welding process and produces higher-quality welds.
In summary, the main differences between welding current produced by an alternator and a generator lie in the type of output current (AC vs. DC), arc stability, electrode compatibility, and their suitability for different welding applications.
