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:
Jul. 10, 2007
Filed:
Aug. 18, 2005
Kenji Fujita, Tokyo, JP;
Yukihiro Nishikawa, Tokyo, JP;
Kenji Fujita, Tokyo, JP;
Yukihiro Nishikawa, Tokyo, JP;
Fuji Electric Device Technology Co., Ltd., Tokyo, JP;
Abstract
A control method for controlling a switching power supply circuit has a control circuit including a setting device that limits the exciting current of a transformer at the time of changeover from a switching delay to a switching period. The setting value set by the setting device is changed slowly to prevent the exciting current of transformer from changing rapidly and to reduce the excitation noise of transformer, and the setting value is changed gradually to prevent the output voltage from lowering even when the load becomes heavier than a certain value during the light load operation. The control method facilitates reducing the electric power consumption of the switching power supply circuit under a light load, reducing the transformer excitation noise and preventing the output voltage from lowering when the load is light.