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:
Apr. 29, 1997
Filed:
Jun. 29, 1995
Applicant:
Inventors:
Assignee:
Fujitsu Limited, Kawasaki, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02J / ;
U.S. Cl.
CPC ...
307 48 ; 307 64 ; 307 66 ; 320-5 ; 320-9 ; 320 30 ; 320 32 ; 320 43 ; 320 48 ; 320 53 ; 364483 ; 364492 ;
Abstract
A power source device capable of using both an external DC power source and a battery contained therein, and an electronic device using this power source device. A circuit is provided to measure the battery voltage, to calculate the remaining capacity of the battery and to indicate the remaining capacity. Means is provided which detects the state where no battery is mounted in the power source device, and short-circuits the input side of the battery voltage-measuring circuit. When no battery is mounted, therefore, a voltage leaking from the external DC power source is not erroneously measured as the battery voltage, and the remaining amount of power of the battery is correctly calculated.