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:
Oct. 08, 2002
Filed:
Aug. 29, 2001
Applicant:
Inventors:
Masahiro Watanabe, Hitachi, JP;
Kazuo Kato, Mito, JP;
Kenji Ogawa, Hitachi, JP;
Isao Ueno, Hitachiohta, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
H02H 3/20 ;
U.S. Cl.
CPC ...
H02H 3/20 ;
Abstract
A power supply apparatus is disclosed comprising a voltage detection circuit connected to a smoothing circuit and an AC switch having a low ON-resistance with no offset voltage at current-buildup. The AC switch is further connected to a secondary winding of a current transformer. When an output voltage of the smoothing circuit increases up to a predetermined value, the output voltage is detected by the voltage detection circuit and the AC switch is turned on by an output signal of the voltage detection circuit, whereby the secondary winding of the current transformer is short-circuited.