Patent ID: 8664566
Filing Date: 2014-03-04
Classification: B23K

Abstract:
1. An apparatus for performing an arc welding process by passing a welding arc current through a welding torch and a base material, the apparatus comprising: a main power supply circuit for outputting a high voltage for creating a welding arc between the welding torch and the base material to pass the welding arc current therethrough; a high-frequency voltage generating circuit for generating a high-frequency voltage; an operation switch operated by a user for providing an arc start instruction to create a welding arc at a start of whenever the welding arc current is to be passed through the welding torch and the base material; and a control circuit for controlling the main power supply circuit to pass a pilot arc current from the main power supply circuit through the welding torch and the base material until an arc start instruction is provided through the operation switch, the pilot arc current having a smaller value than the welding arc current, wherein the control circuit controls the pilot arc current to have insufficient heat for arc welding but sufficient radiation for illuminating a welding point on the base material to allow the user to view the welding point; wherein upon a first arc start instruction provided through the operation switch since the apparatus is powered on, the control circuit controls the main power supply circuit to generate a high voltage, controls the high-frequency voltage generating circuit to generate a high-frequency voltage such that the high-frequency voltage is superimposed on the high voltage, and controls the high-frequency voltage generating circuit to deactivate after creation of the welding arc; wherein upon an arc start instruction provided through the operation switch for a second time and thereafter after the arc welding with the first arc start instruction is completed, the control circuit controls the main power supply circuit to generate a high voltage without activating the high-frequency voltage generating circuit such that the high-frequency voltage is not superimposed on the high voltage; and wherein the control circuit enables the arc welding by allowing arc transition from the pilot arc current passing through the welding torch and the base material to the welding arc current with no high-frequency voltage generated by the high-frequency voltage generating circuit superimposed on the high voltage when the arc start instruction for the second time and thereafter is provided through the operation switch.