Patent ID: 7288741

Claim:
An arc welder having: a rectifier circuit which rectifies an alternating current to a direct current; an inverter circuit which converts an output of said rectifier circuit to a high-frequency alternating current; a transformer which converts an output of said inverter circuit to a voltage suitable for arc welding; a second rectifier circuit which rectifies an output of said transformer to a direct current; and a first DC reactor which is connected to said second rectifier circuit, wherein said arc welder comprises a current circuit which is connected in parallel to said second rectifier circuit with a reactance that is larger than a reactance of said first DC reactor, a voltage that is applied to the current circuit from the transformer is higher than a voltage that is applied to the second rectifier circuit from the transformer, an output voltage of the current circuit is higher than an output voltage of the second rectifier circuit, and said current circuit comprises: a current controlling circuit which controls a current that is outputted from said transformer, a third rectifier circuit which rectifies said controlled current, and a second DC reactor which is connected to said third rectifier circuit.