Plasma torch with power supply for equalizing wear to prolong the lifespan of an electrode of the torch

Plasma torch (10) comprising two coaxial tubular electrodes (11, 12) between which an arc is established, a chamber (13) which separates said electrodes (11, 12) and into which a plasma-generating gas is injected, at least one magnetic field coil (14) which locally surrounds an electrode, preferably the upstream electrode (11) identified with respect to the direction of outflow of the plasma, an electrical power supply (20) for supplying energy to the arc and to the coil, and means (30) for controlling the displacement of the foot of the arc on the electrode in such a way as to make the foot described an alternating longitudinal course in order to equalise the wear, and to prolong the life span, of the electrode, characterised in that the electrical power supply (20) comprises an arc circuit (21) and a coil circuit (22), in that this arc circuit (21) and this coil circuit (22) are mounted in series, and in that these means (30) comprise, connected in parallel with the coil (14), at least one chopper consisting of at least one capacitor (31) and of at least one electronic power switch (32) placed distant from the coil.