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:
May. 15, 2007
Filed:
Sep. 28, 2004
Masayuki Yasumura, Kanagawa, JP;
Masayuki Yasumura, Kanagawa, JP;
Sony Corporation, , JP;
Abstract
A switching power supply circuit is disclosed which can achieve a high power conversion efficiency and besides achieve reduction of the circuit scale and the cost by simplification in circuit configuration. The switching power supply circuit includes a synchronous rectification circuit of the winding voltage detection system on the secondary side of a resonance converter. The coupling coefficient of an insulating converter transformer or the induced voltage level per one turn of the secondary winding is set so that the magnetic flux density of the insulating converter transformer may be lower than a fixed level thereby to maintain the secondary side rectification current in a continuous mode even in a heavy load condition. An inductor is inserted in series in a path along which rectification current is to be supplied to a secondary side smoothing capacitor so that reverse current appearing on the rectification current is suppressed by counter electromotive force generated in the inductor to further reduce the reactive power. A dc superposition characteristic of the inductor is set so that abnormal oscillation in a very light load condition (for example, 12.5 W or less) is prevented.