Plasma torch pilot arc circuit
US5990443A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 12, 1998 |
| Grant date | Nov 23, 1999 |
| Priority date | — |
| Expiry date | Mar 12, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K10/00
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A pilot arc circuit for a plasma torch establishes a pilot arc current in the channel between the torch electrode and torch tip at a first target level which is greater than a predetermined minimum current sufficient to maintain a stable pilot arc. After a period of time following pilot arc initiation, the pilot arc current is reduced to a second target level which is greater than or equal to the predetermined minimum current so that damage to the torch is reduced by minimizing wear on the parts. The pilot arc current is established and maintained as a function of a pilot arc reference signal. Pulsing the pilot arc current assists in main arc transfer and enhances pilot arc stability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.