Plasma torch starting circuit
AssigneeThermal Dynamics Corporation
InventorRaymond G. Wilkins
Life of this patent
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Abstract
A plasma torch system is provided which creates a pilot arc having high instantaneous power and low average power. The pilot arc ignition circuit reduces the pilot arc duty cycle by pulsing on the pilot arc and then extinguishing it. A plasma torch disclosed also reduces RF noise in the line by eliminating the additional spark gap typically used in the power supply circuit and by placing the triggering circuit on or adjacent the torch handle.
Claims8
A plasma torch unit of the type having a power supply, a torch assembly having an electrode, a welding tip and means for providing an ionizable gas therebetween, the improvement comprising a pilot arc ignition circuit comprising first means for periodically applying a sufficiently large voltage between said electrode and said tip to periodically ignite a pilot arc, and second means for extinguishing said pilot arc between said periodic ignitions of said pilot arc, whereby the instantaneous power of said pilot arc is much greater than the average power of the pilot arc, said second means comprising means for supplying a half wave rectified AC voltage between said electrode and said welding tip.
Dependencies are inferred from the claim text.