A motor or machine that converts mechanical energy into electric energy, used as a power source for arc welding processes. The mechanical power can be from an internal combustion engine, an electric motor, or from a power take-off from other equipment. For welding, two basic types of rotating power sources are used: the generator, which produces direct current, and the alternator type, which produces alternating current, and is capable of producing low d-c power. Both have a rotating member, called a rotor or an armature, and a stationary member, called a stator. A system of excitation is needed for both types.

Welding power sources are available that produce both constant current and constant voltage. These units are used for field applications where either may be needed at the job site and utility power is not available. In many designs, electronic solid-state circuitry is integrated to produce a variety of volt-ampere characteristics. See Power Source under specific process; i.e., GAS METAL ARC WELDING.

X