| 摘要 |
PURPOSE:To maintain the output voltage of a rectifier circuit which rectifies AC to DC always constant despite the fluctuation in the primary voltage of a transformer for welding by using phase controlling elements such as thyristors as rectifying elements for said rectifier circuit. CONSTITUTION:In a DC arc welding device which drops a commercial electric power source to prescribed voltage with a transformer 1 for welding, further rectifies the AC to DC with a rectifier circuit 13, flows the same to a transistor 4 and flows the welding current to between base materials 7 and a wire 6 thereby generating an arc 8, the circuit 13 consists of diodes 13a, 13b, 13c and thyristors 13d, 13e, 13f for controlling the phases of conduction angles as rectifying elements. When the primary voltage of said transformer 1 rises or drops, a thyristor controlling circuit (not shwon) detects this and decreases or increases the conduction angles of the thyristors 13d, 13e, 13f, thereby preventing the rise or drop of the output voltage of the circuit 13. |
