Patents by Inventor Gregory N. Stewart

Gregory N. Stewart has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5987613
    Abstract: A portable computer in which a single switch is positioned to be closed when the case is closed, and also to be readily operable by the user's finger. Software polls the switch. If the switch is briefly depressed, the software detects that the user is requesting entry into standby mode, and accordingly powers down certain input/output functions until new stimulus is received. If the switch is held down for a long time by the user closing the case cover, or manually holding the button down for a long time, the software causes the system to enter sleep mode (its lowest power mode).
    Type: Grant
    Filed: December 20, 1994
    Date of Patent: November 16, 1999
    Assignee: Dell Computer Corporation
    Inventors: John P. Busch, Gregory N. Stewart
  • Patent number: 5815706
    Abstract: A portable computer system with a special connector, on the motherboard, into which a field-installable boot card can be inserted. The special motherboard connector is wired so that the operator, by setting connections on the field-installable boot card, can bypass the boot memory on the motherboard and force the computer to boot from the memory on the boot card. This permits a technician, in the field, to temporarily override the internal nonvolatile memory which holds the basic system software. This permits recovery of a system in which the basic system software has been corrupted. Preferably the motherboard boot memory is a flash EPROM, and can be rewritten, by setting appropriate jumpers on the boot card, after the computer has booted from the boot card. The motherboard connector is preferably located on the motherboard, and is accessible through a removable cover. This connector can also preferably be used for temporary attachment of a diagnostic display card.
    Type: Grant
    Filed: September 20, 1995
    Date of Patent: September 29, 1998
    Assignee: Dell USA, L.P.
    Inventors: Gregory N. Stewart, Anthony Lynn Overfield, Mark T. Ellis
  • Patent number: 5566340
    Abstract: A portable electronic system which includes a smart power-management controller. The power-management controller is programmable to vary its operational parameters (such as the time without input which will send the system into a standby mode). The power-management controller also has the capability to self-program at least some of these parameters: thus, for example, if a user repeatedly demands a system power-up soon after the system had been placed into standby mode, the inactivity period required for entering standby mode will be increased.
    Type: Grant
    Filed: June 22, 1994
    Date of Patent: October 15, 1996
    Assignee: Dell USA L.P.
    Inventors: Gregory N. Stewart, N. Albert Sato, Warren W. Startup
  • Patent number: 5545935
    Abstract: A portable electronic system which has two electrically separate battery banks in a single removable battery pack. A power-management controller switches between the two banks in service--even when neither of the banks is exhausted--to provide optimal active and resting times for the batteries.
    Type: Grant
    Filed: May 18, 1995
    Date of Patent: August 13, 1996
    Assignee: Dell USA, L.P.
    Inventor: Gregory N. Stewart
  • Patent number: 5535371
    Abstract: A portable computer system wherein the printer port can be used, at the user's option, not only for connection to a printer, but also for connection to an external floppy disk drive. If the BIOS determines that there is an external floppy drive attached, the BIOS disables the normal operation of the parallel port in order to allow the external floppy to operate.
    Type: Grant
    Filed: June 22, 1994
    Date of Patent: July 9, 1996
    Assignee: Dell USA, L.P.
    Inventors: Gregory N. Stewart, Anthony L. Overfield
  • Patent number: 5523671
    Abstract: A system for controlling the rate and duration of battery charging. A microprocessor is connected in a battery current signal feedback loop and used to control the battery charge cycle. The rate of charge is gradually stepped up at the beginning of the charge cycle until the charging current reaches a defined maximum value, and thereafter maintained between the maximum and a defined minimum value for the duration of the charge cycle. The microcontroller terminates the charge cycle when the battery charging current begins to increase while the rate of charge remains constant, this being an indication that the battery is fully charged. Sensors input signals to the microcontroller to prevent or terminate charging if the battery cells are not within an appropriate temperature range, or if a short circuit or other adverse condition arises.
    Type: Grant
    Filed: July 23, 1993
    Date of Patent: June 4, 1996
    Assignee: Dell USA, L.P.
    Inventor: Gregory N. Stewart
  • Patent number: 5519261
    Abstract: Method and apparatus for increasing the amount of power that may be extracted from a plurality of parallel connected battery banks by periodically effecting a switching between the banks for operative coupling to the power supply of an electronic or electrical device. The apparatus comprises at least two battery banks, a switching means, a microcontroller and a battery powered load. Upon each expiration of a predetermined time interval, the microcontroller monitors the voltage of the battery banks to determine which of the banks has the highest voltage. The microcontroller then positions the switch so that the bank with the highest voltage is coupled to the power supply of the load. In another embodiment, switching occurs upon a determination that the active bank has reached a specified power output.
    Type: Grant
    Filed: April 6, 1995
    Date of Patent: May 21, 1996
    Assignee: Dell U.S.A., L.P.
    Inventor: Gregory N. Stewart
  • Patent number: 5504907
    Abstract: A system for automatically adapting the power conservation functions of a personal computer (PC) to the work patterns of any user. A power control system of the PC monitors activity of I/O devices and if upon the elapse of a first time interval a particular I/O device or combination of devices has not been accessed, one or more I/O devices are powered-down. Following power-down, the first time interval is incrementally increased if I/O activity immediately occurs thereafter, prior to elapse of a second time interval. This process may repeat itself several times until the first time interval reaches a maximum value. Alternatively, if, following power-down, I/O activity does not occur until after elapse of a third time interval, the first time interval is incrementally decreased until the first time interval reaches a minimum value. The system thereby automatically adapts to maximize power conservation during periods of low activity while preventing user disruption during periods of increased activity.
    Type: Grant
    Filed: March 4, 1993
    Date of Patent: April 2, 1996
    Assignee: Dell USA, L.P.
    Inventors: Gregory N. Stewart, N. Albert Sato, Warren W. Startup
  • Patent number: 5471674
    Abstract: A portable computer system with a special connector, on the motherboard, into which a field-installable boot card can be inserted. The special motherboard connector is wired so that the operator, by setting connections on the field-installable boot card, can bypass the boot memory on the motherboard and force the computer to boot from the memory on the boot card. This permits a technician, in the field, to temporarily override the internal nonvolatile memory which holds the basic system software. This permits recovery of a system in which the basic system software has been corrupted. Preferably the motherboard boot memory is a flash EPROM, and can be rewritten, by setting appropriate jumpers on the boot card, after the computer has booted from the boot card. The motherboard connector is preferably located on the motherboard, and is accessible through a removable cover. This connector can also preferably be used for temporary attachment of a diagnostic display card.
    Type: Grant
    Filed: February 16, 1994
    Date of Patent: November 28, 1995
    Assignee: Dell USA, L.P.
    Inventors: Gregory N. Stewart, Anthony L. Overfield, Mark T. Ellis
  • Patent number: 5440448
    Abstract: A small computer having a card interface slot in a side of the computer. An inserted electronic card, the connector on its inserted end mates firmly with a connector at the inner end of the recess behind the slot. The user ejects an inserted card by sliding a slider which is positioned in a shallow recess on the bottom of the computer, near the slot. The slider is connected to an ejector which actually presses against the inner end of the card. By moving the slider with his thumb, the user can push the card out far enough to disengage the contacts of the card, and then can readily remove the card by hand or allow it to drop out.
    Type: Grant
    Filed: May 25, 1994
    Date of Patent: August 8, 1995
    Assignee: Dell USA, L.P.
    Inventors: Gregory N. Stewart, Christian G. Okonsky
  • Patent number: 5410711
    Abstract: A personal computer which a microcontroller, separate from the main processor, is used for power-management functions. Under certain conditions, this power-management microcontroller can take control of the system bus. This provide BIOS-independent power management, and permits sophisticated power management to be performed without placing any burden or constraints on the user's choice of operating system or application software.
    Type: Grant
    Filed: February 14, 1991
    Date of Patent: April 25, 1995
    Assignee: Dell USA, L.P.
    Inventor: Gregory N. Stewart
  • Patent number: 5408669
    Abstract: A computer system including an input/output (I/O) connector for connecting to an external data peripheral, where the computer includes circuitry for detecting the presence or absence of a load on a first pin and for providing power to the external data peripheral through a second pin of the I/O connector. In this manner, the external data peripheral need not include a separate power supply, but instead is sensed and powered by the computer itself through the I/O connector. In the preferred embodiment, the I/O connector is coupled to parallel port circuitry for interfacing to an external printer, and also to a floppy controller for interfacing with an external floppy drive, where the computer system further includes circuitry to switch from the printer controller to the floppy controller when an external floppy drive is connected to the I/O connector. In this manner, the same I/O port automatically serves either an external printer or an external floppy drive.
    Type: Grant
    Filed: July 5, 1994
    Date of Patent: April 18, 1995
    Assignee: Dell USA, L.P.
    Inventors: Gregory N. Stewart, David Lunsford
  • Patent number: 5404546
    Abstract: Method and apparatus for effecting BIOS independent power management of a personal computer system having a processor complex connected via a system bus to at least one I/O device capable of operating in a reduced power consumption state. A power control system comprising a dedicated power management microcontroller monitors the activity of various I/O devices. When a particular device or combination of devices has remained inactive for the preselected time interval, the power control system issues a bus request to a processor complex. When the processor complex acknowledges the bus request, the power control system asserts control as master of the system bus and performs the operations necessary to cause at least one device to enter a reduced power consumption state. The power control system then surrenders control of the bus to the processor complex. In one aspect, a CPU clock controller is utilized to reduce the processing speed of the processor complex CPU.
    Type: Grant
    Filed: February 16, 1993
    Date of Patent: April 4, 1995
    Assignee: Dell USA
    Inventor: Gregory N. Stewart
  • Patent number: 5365453
    Abstract: A system for accurately predicting impending battery failure in battery powered electronic and electrical devices. The system continually monitors changes in battery voltage responsive to load changes and calculates a ratio of the change in voltage to the change in load. When the ratio exceeds a certain threshold value, indicating that the impedance of the battery has risen to near its final value, a user warning indication is generated.
    Type: Grant
    Filed: April 12, 1993
    Date of Patent: November 15, 1994
    Assignee: Dell USA, L.P.
    Inventors: Warren W. Startup, Gregory N. Stewart
  • Patent number: 5309031
    Abstract: A battery-powered lap-top computer has a main battery for ordinarily supplying power to the computer circuitry. A reserve battery is connected through a manual switch to the circuitry. When the main battery starts to lose its charge, the manual switch is operated to connect the reserve battery to the circuitry prior to removal of the main battery. A new main battery is installed and the switch is operated to disconnect the reserve battery from the circuitry. Provision is made for the main battery to slowly charge the reserve battery.
    Type: Grant
    Filed: April 22, 1991
    Date of Patent: May 3, 1994
    Assignee: Dell USA, L.P.
    Inventors: Gregory N. Stewart, John P. Busch
  • Patent number: 5268845
    Abstract: A portable electronic system, which can accurately predict impending battery failure, without using expensive comparators, by using voltage and current measurements to determine the source impedance of a battery. Preferably two banks of batteries are used, with a load-switching relay; the voltage and current of both banks is monitored, so that voltage drop under load can be monitored. Alternatively, the voltage variation of a single battery bank can simply be correlated to the current drawn by a changing load.
    Type: Grant
    Filed: February 14, 1991
    Date of Patent: December 7, 1993
    Assignee: Dell Corporate Services Corp.
    Inventors: Warren W. Startup, Gregory N. Stewart
  • Patent number: 5028806
    Abstract: A battery-powered lap-top computer has a main battery for ordinarily supplying power to the computer circuitry. A reserve battery is connected through an automatic switch to the circuitry. The circuitry is connected to a pair of contacts and the switch is connected to a contact. The main battery has positive and negative terminals, and a removal terminal which is shorter in length than the positive and negative terminals. When the main battery loses its charge, it is removed by a sliding action which slides the terminals past the contacts, the removal terminal being the first terminal to lose contact. This activates the automatic switch, connecting the reserve battery into the circuitry so that when the positive and negative terminals are no longer contacted, the reserve battery will have been supplying and will continue to supply power to the circuitry. A charged main battery is then installed, deactivating the switch, removing the reserve battery from the circuitry.
    Type: Grant
    Filed: April 14, 1989
    Date of Patent: July 2, 1991
    Assignee: Dell Corporate Services Corporation
    Inventors: Gregory N. Stewart, John P. Busch