Power supply apparatus for welder
US6797922B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 2003 |
| Grant date | Sep 28, 2004 |
| Priority date | — |
| Expiry date | Apr 25, 2023 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K9/092
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A power supply apparatus for a welder includes a rectifier (104) and a smoothing reactor (106) which operate together to convert a commercial AC supply voltage to a DC voltage. The DC voltage is converted to a high-frequency voltage by an inverter (108), which, in turn, is voltage-transformed by a voltage-transformer (110). The voltage-transformed, high-frequency voltage is converted to a DC voltage by a rectifying diode (112) and a smoothing reactor (114), and the resulting DC voltage is applied to a workpiece (118a) and a torch (118b). A current detector (120) develops a load current representative signal, and a control circuit (122) so controls a drive circuit (126) which drives the inverter (108) that the load current representative signal becomes equal to a reference current signal provided by a reference source (124). When a small load current is used, a pulse forming switch (140) is repetitively turned on and off to produce a pulse current from a pulse current setting source (139). The pulse current is superposed on a control signal from the control circuit (122).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.