B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
B23K9/00—Arc welding or cutting
B23K9/06—Arrangements or circuits for starting the arc, e.g. by generating ignition voltage, or for stabilising the arc
B23K9/067—Starting the arc
B23K9/0672—Starting the arc without direct contact between electrodes
B23K9/0673—Ionisation of the arc gap by means of a tension with a step front (pulses or high frequency tensions)