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:
Mar. 30, 2004
Filed:
Sep. 16, 2002
Applicant:
Inventors:
Tomoyasu Yamada, Saitama, JP;
Masaaki Shimada, Saitama, JP;
Assignee:
Sanken Electric Co., Ltd., Niiza, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02M 3/335 ;
U.S. Cl.
CPC ...
H02M 3/335 ;
Abstract
In the switching power supply, a load state judgment circuit ( ) judges the state of a load ( ) according to a pulse signal VG to be used for ON/OFF control of a MOS transistor ( ) as a switching element in a DC—DC converter ( ). In order to reduce a power consumption of the switching power supply, a PFC ON/OFF switching circuit ( ) stops the operation of the power factor improving converter ( ) when the judgment result indicates a light load state, and starts the operation of the power factor improving converter ( ) when the judgment result indicates a heavy load state.