The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 19, 2000
Filed:
Dec. 16, 1999
Oleg Siniaguine, San Jose, CA (US);
Patrick Halahan, Sunnyvale, CA (US);
Other;
Abstract
The present invention relates to ignition circuitry for a plasma generator. A discharge is created by application of a high frequency or high voltage dc ignition pulse between an electrode and a first nozzle. Following ignition, the discharge is redirected to a second nozzle for the purpose of moving the plasma flow from the ignition zone into the zone of application to the workpiece. The present invention is directed to plasma ignition circuitry for improving this performance. Positive thermal coefficient ('PTC') resistance is shown to be useful in reliably and reproducibly switching the arc. Alternative embodiments of the present invention relate to switching the plasma from a first nozzle to a second nozzle then sequentially to additional nozzles downstream in the flow of plasma gas in which PTC resistance is used to reliably and reproducibly effect the switching. Yet other embodiments of the present invention relate to the generation of two plasma jets directed so as to intersect, and switching current flow from the plasma-igniting nozzle electrodes to a direct flow of current from one electrode through the two plasma jets to the second electrode.