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. 02, 2002
Filed:
Sep. 23, 1998
Fujitsu Limited, Kawasaki, JP;
Abstract
A power unit having a built-in battery to supply voltage from the battery over a long period of time by utilizing fully the capabilities of the built-in battery. The power unit supplies electric power to a load even when a battery with a higher battery voltage than the external power source voltage is used by charging the battery from an external power source even when the external power source voltage is lower than the battery voltage. By charging the battery when electric power is supplied to a load from an external power source, the power unit supplies electric power to the load from the battery when the supply of electricity from an external power source is cut off. The power unit includes a having converter to boost output voltage from the battery and to supply the voltage to the load when the battery is discharged and the external power source voltage is higher than the battery voltage. Alternatively, the power unit includes a converter to boost the external power source voltage and to charge the battery when using the battery with a voltage lower than the external power source voltage.