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. 01, 2007
Filed:
Jun. 29, 2006
Yukinari Fukumoto, Niiza, JP;
Yukinari Fukumoto, Niiza, JP;
Sanken Electric Co., Ltd., , JP;
Abstract
A transformer has a primary winding connected to a pair of DC input terminals via an active switch, and a secondary winding connected to a pair of DC output terminals via a first rectifying and smoothing circuit. The active switch is driven constantly under normal load, and at intervals under light load, under the direction of a switch control circuit. This switch control circuit is powered with a control voltage fed from a second rectifying and smoothing circuit which is connected to a tertiary winding of the transformer. In order to preclude malfunctioning or nonoperation in the event of an abnormal drop of the control voltage during operation in light load mode, the switch control circuit is equipped to drive the active switch at shorter intervals in control voltage recovery mode when the control voltage falls below a predefined limit than the normal intervals of the light load mode.