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. 17, 2007
Filed:
Apr. 14, 2003
Minehiro Nemoto, Hitachi, JP;
Akihiko Kanouda, Hitachinaka, JP;
Fumikazu Takahashi, Hitachi, JP;
Masahiro Hamaogi, Odawara, JP;
Yoshihide Takahashi, Odawara, JP;
Takashi Tanabe, Nakai, JP;
Takao Gotou, Kawasaki, JP;
Masato Isogai, Mito, JP;
Toshikatsu Miyata, Suita, JP;
Minehiro Nemoto, Hitachi, JP;
Akihiko Kanouda, Hitachinaka, JP;
Fumikazu Takahashi, Hitachi, JP;
Masahiro Hamaogi, Odawara, JP;
Yoshihide Takahashi, Odawara, JP;
Takashi Tanabe, Nakai, JP;
Takao Gotou, Kawasaki, JP;
Masato Isogai, Mito, JP;
Toshikatsu Miyata, Suita, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi Maxell, Ltd., Ibaraki-Shi, JP;
Hitachi Computer Peripherals Co., Ltd., Ashigarakami-Gun, Kanagawa-Ken, JP;
Abstract
A reliable uninterruptible DC power supply device. The DC backup power supply device includes an AC/DC converter, a DC/DC converter, voltage step-up/down choppers and a battery connected to a DC path of a main circuit connected with a load via a switch, and a microcomputer. In the device, under control of the microcomputer, the voltage step-up/down choppers are first operated under a condition that the MOS FET was turned OFF for self diagnosis of the backup power supply device. Next, the switch is turned ON to execute the remaining self diagnosis. The DC backup power supply device can execute its self diagnosis with a reduced likelihood of danger of exerting an adverse effect on the main circuit and also can exhibit a reliable uninterruptible power supply function.