Compaq Computer Corporation, Inc.

Michael E Schneider

David S Lin

Richard A Faulk

Thomas P Sawyers

William C Hallowell

Dean P Perkins

Brian C Fritz

Norman D Stobert

Robert K Watts

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.

Control of computer AC adapter output voltage via battery pack feedback

A battery pack for a computer system including static memory to maintain battery operating parameters and charge information, a real time clock (RTC) for measuring periods of non-use of the battery and a communication means to exchange the battery information with a microcontroller located in the computer system. The static memory, RTC and communication means is preferably in the form of a single RAM/RTC chip. The battery pack also includes circuitry to maintain power to the RAM/RTC from the battery if AC power is not available. The microcontroller detects the presence of the battery and retrieves the present time from the RTC, a timestamp indicating time or removal of the battery and other operating parameters and charge information from the battery pack, and controls the charging functions of the battery accordingly. The microcontroller also updates the charge information of the battery pack while performing other housekeeping functions of a DC-DC converter. The microcontroller further controls a switch located in the charge path of the battery to control fast charging. Trickle charge is simulated by pulsing the switch at a predetermined duty cycle and period. The microcontroller may be placed in standby to conserve energy, while also monitoring the standby switch to pull the computer system out of standby mode if the standby switch is pressed. This allows the keyboard controller 21 to be shut off during standby mode to conserve energy.

Pulse charge technique to trickle charge a rechargeable battery

A battery pack for a computer system including static memory to maintain battery operating parameters and charge information, a real time clock (RTC) for measuring periods of non-use of the battery and a communication circuit to exchange the battery information with a microcontroller located in the computer system. The static memory, RTC and communication circuit is preferably in the form of a single RAM/RTC chip. The battery pack also includes circuitry to maintain power to the RAM/RTC from the battery if AC power is not available. The microcontroller detects the presence of the battery and retrieves the present time from the RTC, a timestamp indicating time or removal of the battery and other operating parameters and charge information from the battery pack, and controls the charging functions of the battery accordingly. The microcontroller also updates the charge information of the battery pack while performing other housekeeping functions of a DC--DC converter. The microcontroller further controls a switch located in the charge path of the battery to control fast charging. Trickle charge is simulated by pulsing the switch at a predetermined duty cycle and period. The microcontroller may be placed in standby to conserve energy, while also monitoring the standby switch to pull the computer system out of standby mode if the standby switch is pressed. This allows the keyboard controller to be shut off during standby mode to conserve energy.

Battery pack including static memory and a timer for charge management

An automatic line monitor for use in conjunction with a power supply for electronic components automatically accommodates either of two voltage ranges. Since the power supply may operate in domestic voltage ranges of about 100 volts or in international voltage ranges of about 120, the automatic line monitor senses and automatically switches to a voltage-doubling mode for the domestic range or a non-voltage-doubling mode for the higher international range. A latch may latch the line monitor in a non-voltage doubling mode once the higher voltage range is sensed. A monitor of a preferred embodiment eliminates almost all of the high-power-handling elements of the switch so that almost all of the operative elements of the switch may be incorporated on a single integrated circuit chip.

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Conroe, TX, United States of America

Michael E Schneider