Power supply apparatus
US7075032B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 2003 |
| Grant date | Jul 11, 2006 |
| Priority date | — |
| Expiry date | Feb 15, 2025 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K9/1062
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
An input-side rectifier (4), a smoothing capacitor (6), an inverter (8), a transformer (10) and an output-side rectifier (12) operate together to convert an AC voltage supplied from an AC power supply to a DC voltage. The DC voltage is coupled through a DC-to-AC converter (16) to a workpiece (18) and a torch (20). An auxiliary voltage supply (28) supplies the workpiece (18) and the torch (20) with a negative voltage for a short time following the transition of the AC voltage supplied to the workpiece (18) and the torch (20) from positive to negative. The negative voltage has a negative peak value larger than the negative peak value of the AC voltage supplied to the workpiece (18) and the torch (20), and rapidly changes from the negative peak value. The auxiliary voltage supply (28) produces a DC voltage having a negative peak value larger than the negative peak value of the AC voltage supplied to the workpiece (18) and the torch (20), by means of a transformer (30), a rectifier (32) and a smoothing capacitor (36). The smoothing capacitor (36) is coupled to the workpiece (18) and the torch (20) through a transistor (38) and a current-limiting resistor (40). A differentiating circuit…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.