Power supply apparatus
US5643475A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 8, 1995 |
| Grant date | Jul 1, 1997 |
| Priority date | — |
| Expiry date | Nov 8, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K10/00
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A power supply apparatus for a plasma arc cutter includes an inverter which converts DC power to high-frequency power. An output developing circuit rectifies and smooths the high-frequency power for application between a torch electrode and a workpiece which form together a plasma load. A current detecting unit detects current flowing through the plasma load. A reference signal generating unit generates a reference signal including a preset DC signal and a predetermined AC signal superposed on the DC signal. A control units control the inverter, in accordance with the difference between the output of the current detecting unit and the reference signal, so that the output current to be supplied between the electrode and the workpiece has a predetermined constant DC current and a predetermined AC current superposed on the DC current. The reference signal generating unit can vary the frequency and amplitude of the AC signal in the reference signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.