Zenith Data Systems Corporation

Rayovac Corporation

Packard Bell Nec

Nec Corporation

Motorola Corporation

Upal Sengupta

Robert R Turnbull

Rajesh A Shah

Brian C Fritz

John Wendell Oglesbee

William C Hallowell

Peter A Ojeda

John P Wagner

Rodman S Brahman

Bruce Wang

Norman D Stobert

Russell S Uithoven

Larry L Jeffery

Steven R Ruth

Larry D Bailey

James G Pilarzyk

A battery charging circuit comprises a recharge input and a recharge output with a switching element electrically coupled in series between the recharge input and output. A recharge controller controls a conducting state of the switching element. When in a conducting state, recharge current can flow from the recharge input to the recharge output, thereby allowing a rechargeable battery coupled to the recharge output to be recharged. During periodically occurring intervals, the recharge controller switches the switching element to a non-conducting state such that the recharge current no longer flows to the recharge output. During the intervals, a battery voltage input is sampled to determine a charge state of the battery. The switching element is subsequently returned to a conducting state when further recharging is necessary, or left in a non-conducting state when sufficient recharging has occurred.

Method and apparatus for battery charging

An external flexible bay system includes an external flexible bay, a modular battery pack and a modular disk drive. The external flexible bay is adapted to receive either the modular battery pack or the modular disk drive to facilitate use of such devices with a portable PC. The external flexible bay includes a parallel port which enables an external I/O device, such as a printer, to be connected thereto. The external flexible bay contains circuitry to automatically sense whether a printer is connected and to determine whether a modular battery pack or modular disk drive has been inserted therein. In order to ensure proper configuration, the external flexible bay includes a mode switch for selecting between a floppy mode and a printer mode.

External modular bay for housing I/O devices

A power supply system, for example, for use with a portable personal computer, includes a smart battery pack and a charging system. The smart battery pack is provided with a dedicated microcontroller for controlling the charging level of the battery charger system. In particular, the status of the battery including the voltage and temperature of the battery is applied to the microcontroller along with a signal representative of the current load demand of the computer system. The micro controller, in turn, provides a control signal in the form of fixed frequency, variable duty cycle pulse width modulated (PWM) signal for controlling the charging level of the battery charger system. The duty cycle of the PWM signal is used to regulate the charging current supplied by the battery charger. In particular, the DC value of the PWM signal is used as a reference to control the charging current of the regulator to provide a variable output charging current with a relatively wide current range. As such, the battery charger is adapted to efficiently utilize the residual capacity of the battery charger system for optimizing charging of the battery packs during all operating conditions of the computer system. Moreover, the use of a PWM signal from the battery pack to control the battery charger enables a single type of battery charger to be utilized for various battery technologies.

System and apparatus for generating a continuosly variable reference

Method for generating a continuously variable reference signal for

A circuit and method for detecting and indicating the state of charge of an electrochemical cell or battery are disclosed. The invention finds particular application in the field of battery chargers for alkaline manganese dioxide cells, but may also be used in other types of chargers and electrochemical cells or batteries. In one preferred feature of the invention, a circuit low-pass filters or time-averages a charge enable control or transistor base drive signal, and provides the filtered or averaged signal as a first input to a comparator. The second input to the comparator is a predetermined reference voltage. When the voltage of the low-pass filtered or time-averaged signal becomes less than the reference voltage, the output of the comparator changes state. The change in state indicates that the cell has attained a full state of charge. Microprocessor means for accomplishing the same state of charge detection function are also disclosed.

Circuit and method for detecting and indicating the state of charge of a

In accordance with the present invention, a portable electrical device with a discriminating, rechargeable battery system is provided. The rechargeable battery system includes a load circuit connected to a discharge contact adapted to electrically couple to an electrical terminal on a battery to receive power therefrom whereby either a first battery having a predetermined feature or a second battery lacking the predetermined feature may be coupled thereto. The system further includes a charger circuit connected to a charging contact adapted to electrically couple to the same electrical terminal on the battery to provide a charging current to the battery from an outside power source. An inhibitor is associated with the charger circuit and is adapted to cooperate with the predetermined feature to only allow the coupling of the charging contact with the electrical terminal of the first battery thereby preventing the coupling of the charging contact with the electrical terminal of the second battery. As such, only a battery having the predetermined feature may receive the charging current.

Electrical device having a discriminating, rechargeable battery system

Computer power supply system

Computer power supply and battery recharging system

A power supply system, for example, for use with a portable personal computer, includes a smart battery pack and a charging system. The smart battery pack is provided with a dedicated microcontroller for controlling the charging level of the battery charger system. In particular, the status of the battery including the voltage and temperature of the battery is applied to the microcontroller along with a signal representative of the current load demand of the computer system. The microcontroller, in turn, provides a control signal in the form of fixed frequency, variable duty cycle pulse width modulated (PWM) signal for controlling the charging level of the battery charger system. The duty cycle of the PWM signal is used to regulate the charging current supplied by the battery charger. In particular, the DC value of the PWM signal is used as a reference to control the charging current of the regulator to provide a variable output charging current with a relatively wide current range. As such, the battery charger is adapted to efficiently utilize the residual capacity of the battery charger system for optimizing charging of the battery packs during all operating conditions of the computer system. Moreover, the use of a PWM signal from the battery pack to control the battery charger enables a single type of battery charger to be utilized for various battery technologies.

Growing community of inventors

St. Joseph, MI, United States of America

Upal Sengupta