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:
Dec. 25, 2007
Filed:
Jul. 31, 2006
Wataru Nakahori, Tokyo, JP;
Yasuhiro Murai, Tokyo, JP;
Wataru Nakahori, Tokyo, JP;
Yasuhiro Murai, Tokyo, JP;
TDK Corporation, Tokyo, JP;
Abstract
The present invention provides a switching power supply unit capable of suppressing a surge voltage generated in a rectifier element more effectively. A first resonance circuit is constructed by capacitors in a surge voltage suppressing circuit and an inductor, and resonance time of the first resonance circuit is set to be longer than recovery time of a diode in a rectifier circuit. According to at least one of a DC input voltage and an output current, either a first bridge circuit or a second bridge circuit is selectively allowed to perform switching operation. At the time of forward-direction operation, the first resonance circuit is formed by the capacitors in the surge voltage circuit and the inductor on the high voltage side. At the time of reverse-direction operation, a second resonance circuit is formed by the capacitors and an inductor on the low voltage side.