Patent · US Expired

Power supply unit and an electronic apparatus having same

US5818203A · kind A · utility

14Cited by
7References
14Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 10, 1997
Grant dateOct 6, 1998
Priority date
Expiry dateSep 10, 2017

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02E60/10
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

Disclosed is an electronic apparatus which includes a power supply unit and a constant voltage rechargeable battery. The power supply unit activates a dedicated charging circuit, which is located near the battery, only at the charging end stage after the terminal voltage of the battery has attained a predetermined value, and provides constant voltage control for a charge current by using the charging circuit. The charging circuit, however, is not employed at the initial charging stage, where precise constant voltage control is not required. The output current, for which constant current control is performed by the AC adaptor, is employed unchanged as a charge current, with which quick charging is performed. That is, since a transformer in the charging circuit is not activated at the initial charging stage, a power loss, which accompanies the operation of the transformer, and heat generation and the occurrence of magnetic noise in the electronic apparatus can be reduced to a minimum.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.