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:
Sep. 28, 2004
Filed:
Apr. 16, 2003
Masao Katooka, Osaka, JP;
Kenzo Danjo, Osaka, JP;
Takeshi Morimoto, Osaka, JP;
Hideo Ishii, Osaka, JP;
Sansha Electric Manufacturing Company, Limited, Osaka, JP;
Abstract
A power supply apparatus for a welder includes a rectifier ( ) and a smoothing reactor ( ) 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 ( ), which, in turn, is voltage-transformed by a voltage-transformer ( ). The voltage-transformed, high-frequency voltage is converted to a DC voltage by a rectifying diode ( ) and a smoothing reactor ( ), and the resulting DC voltage is applied to a workpiece ( ) and a torch ( ). A current detector ( ) develops a load current representative signal, and a control circuit ( ) so controls a drive circuit ( ) which drives the inverter ( ) that the load current representative signal becomes equal to a reference current signal provided by a reference source ( ). When a small load current is used, a pulse forming switch ( ) is repetitively turned on and off to produce a pulse current from a pulse current setting source ( ). The pulse current is superposed on a control signal from the control circuit ( ).