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:
Feb. 08, 2011
Filed:
May. 17, 2007
Tetsuro Hashimoto, Kyoto, JP;
Isao Yamamoto, Kyoto, JP;
Tetsuro Hashimoto, Kyoto, JP;
Isao Yamamoto, Kyoto, JP;
Rohm Co., Ltd., , JP;
Abstract
A battery charging circuit is used by being connected to a direct-current power source. The battery charging circuit includes a control transistor, a backflow prevention transistor and a charging controller. The control transistor is disposed in a charging path between the direct-current power source and a battery, and is configured to control a direct-current voltage from the direct-current power source, and to output controlled direct-current voltage as a charging voltage. The backflow prevention transistor is disposed in the charging path, and is configured to output the charging voltage to the battery, and to be turned off when an electric current flows backward from the battery to the direct-current power source. The charging controller is configured to turn on the backflow prevention transistor when charging of the battery starts, and to turn on the control transistor after a fixed period of time elapses from a start of the charging.