Question

The voltage - current characteristics of constant current power source for the arc welding must be

Answer 1

The constant current curve shows that the welding power source pro­duces maximum output voltage with no load, and as the load increases, the output voltage decreases. The maximum no load or open circuit voltage is usually 100 volts.

A constant current type power source may have dc or ac, output. Apart from SMAW it is used for carbon arc welding, gas tungsten arc welding, plasma arc welding and stud welding. It can also be used for continuous wire processes when relatively large diameter wires arc used, for example, sub­merged arc welding.

The constant current type welding power sources can also be used for some automatic welding processes. This necessitates the use of wire feeder and controls to duplicate the motions of the welder to initiate and maintain arc which is normally achieved by complex feedback system to monitor arc voltage to control arc length.

Answer 2

Answer:

the voltage current graph is a straight line