The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 11, 2006
Filed:
Nov. 21, 2003
Kunio Karino, Osaka, JP;
Toshikazu Fujiyoshi, Osaka, JP;
Kenzo Danjo, Osaka, JP;
Hideo Ishii, Osaka, JP;
Kunio Karino, Osaka, JP;
Toshikazu Fujiyoshi, Osaka, JP;
Kenzo Danjo, Osaka, JP;
Hideo Ishii, Osaka, JP;
Sansha Electric Manufacturing Company, Limited, Osaka, JP;
Abstract
An input-side rectifier (), a smoothing capacitor (), an inverter (), a transformer () and an output-side rectifier () 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 () to a workpiece () and a torch (). An auxiliary voltage supply () supplies the workpiece () and the torch () with a negative voltage for a short time following the transition of the AC voltage supplied to the workpiece () and the torch () 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 () and the torch (), and rapidly changes from the negative peak value. The auxiliary voltage supply () produces a DC voltage having a negative peak value larger than the negative peak value of the AC voltage supplied to the workpiece () and the torch (), by means of a transformer (), a rectifier () and a smoothing capacitor (). The smoothing capacitor () is coupled to the workpiece () and the torch () through a transistor () and a current-limiting resistor (). A differentiating circuit () is coupled in parallel with the current-limiting resistor (), and includes a resistor () having a smaller resistance value than the current-limiting resistor ().