Plasma generator ignition circuit
US6121571A · kind A · utility
Inventors
Key dates
| Filing date | Dec 16, 1999 |
| Grant date | Sep 19, 2000 |
| Priority date | — |
| Expiry date | Dec 16, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05H1/3452
- WIPO fieldChemical engineering
- WIPO sectorChemistry
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.