Arc welding appts.

摘要

Arc welding appts. includes a fully controlled inverse rectifier (12) whose output is connected to the welding current circuit (16) containing an electrode (14), a workpiece (15) and inductive elements (17,18,19) and to the trigger input (27) of a high-voltage ignition unit (26) supplying ignition pulses to the welding current circuit. The adjacent (+,-) voltage pulses produced by the inverse rectifier are sepd. by a dead time. The output of the inverse rectifier is connected to a voltage limiting circuit (30) whose limit voltage is higher than the output voltage of the inverse rectifier, but is lower than the voltage peaks produced by the inductive (and possibly capacitative) elements (17,18,19) in the welding current circuit.