Control of computer AC adapter output voltage via battery pack feedback

摘要

A computer system including circuitry for accurately and economically controlling the charge voltage and charge current at the terminals of its rechargeable battery. During a battery recharge, sensor circuitry coupled to the battery provides accurate data to a battery microcontroller regarding the charge voltage and charge current present at the battery terminals. A battery microcontroller relays this information to a multipurpose microcontroller. The battery microcontroller also provides the desired charging voltage and current as determined by the battery pack's charging algorithm. The multipurpose microcontroller uses the battery status information to program an addressable potentiometer. In turn, the potentiometer generates an adjustment signal that controls the output voltage of the computer's AC adapter. Preferably, the AC adapter is capable of being operated in a constant-power mode. Adjustment of the potentiometer allows the output of the AC adapter to be dithered up or down as needed to provide the desired charging voltage and charging current to the battery.