Power supply for electric arc gas heater

Abstract

This invention concerns power supplies suitable for electric arc gas heaters such a plasma torches. It more particularly relates to the dimensioning of the inductor in the switched-mode DC to DC converter used for feeding the torch. The invention concerns in particular a DC power supply for driving a non-transferred electric arc gas heater, comprising: an AC to DC rectifier providing a potential U0; a DC to DC switching converter having a switching frequency fs; a current control loop having a latency τ; and, a ballast inductor having an inductance L; characterized in that inductance L is such that L > ( U 0 1  5  0  0 )  τ , and   L < 1 f s  ( U 0 2  0  0 ) . Such a design ensures the stability of the current control loop, while also ensuring a sufficient amount of current ripple to spread out the erosion zone on the electrodes of the torch.

Dependencies are inferred from the claim text.