Patent ID: 8575516

Claim:
An arc welding power source that supplies a start current, a welding current and a crater current as an output current in accordance with an activating signal supplied from outside, the power source comprising: a start period setting unit that is configured to set a start period; a crater period setting unit that is configured to set a crater period; a current control unit that is configured to control the output current; a repeated welding period setting unit that is configured to set a repeated welding period; and a repetition number setting unit that is configured to set a repetition number of crater periods; wherein the current control unit is configured to cause the power source to supply the start current and the welding current consecutively while the activating signal is in an on-state, the start current being supplied for the start period, the welding current being supplied for a period following the start period, wherein the current control unit is configured to cause the power source to supply the crater current as a constant current after the activating signal is turned off, the crater current being supplied for a first crater period; wherein the current control unit is configured to cause the power source to supply a welding current for the repeated welding period following the first crater period, and to supply the crater current for a second crater period following the repeated welding period, the current control unit is configured to cause repetition of supplied current, and wherein the current control unit is configured to cause the power source to stop the supplying of the output current to terminate welding when a number of repeated crater periods, including the first crater period and the second crater period, reaches the repetition number of crater periods set by the repetition number setting unit.