Hien T Le

US Patent:

56252757, Apr 29, 1997

Filed:

May 24, 1995

Appl. No.:

8/449534

Inventors:

Roy Tanikawa - Irvine CA
Hien Le - Garden Grove CA

Assignee:

AST Research, Inc. - Irvine CA

International Classification:

H02J 700

US Classification:

320 32

Abstract:

A power supply for a rechargeable battery in a portable computer system is disclosed which adjusts the level of charging current depending upon the current drawn by the portable computer system. The power supply includes an AC adapter which supplies input current for operating the computer system and for charging the battery. Sensors are connected to the AC adapter, the battery, and an output of the power supply to detect the level of input current from the AC adapter, the level of charging current supplied to the battery, and the output voltage level of the power supply. A controller is connected to each of the sensors and monitors the input current level, the charging current level, and the output voltage level. The controller generates a control signal which indicates whether any one of the levels has exceeded a respective predetermined maximum value. A charging current control circuit is connected to the controller and to the battery and controls current flow between the AC adapter and the battery based upon the control signal generated by the controller.