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INTERACTIVE CHARGING ARRANGEMENT FOR BATTERY OPERATED PORTABLE COMPUTER PERIPHERALS

IP.com Disclosure Number: IPCOM000006488D
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2002-Jan-08
Document File: 2 page(s) / 112K

Publishing Venue

Motorola

Related People

Morris Moore: AUTHOR [+3]

Abstract

This article describes an approach to charging the battery of battery operated peripherals attached to port- able computers. Provision is made for the peripheral to request a charging cycle to be initiated by the computer via the lines normally used for data communications to the peripheral. This provides a means by which the bat- tery ofthe peripheral becomes a secondaty storage means so that the peripheral never fails to have access to a power supply when connected to a computer which has battery power remaining.

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MOTOROLA INC. Technical Developments Volume 16 August 1992

INTERACTIVE CHARGING ARRANGEMENT FOR BATTERY OPERATED PORTABLE COMPUTER PERIPHERALS

by Morris Moore, Greg Fuller, and Dave Petreye

  This article describes an approach to charging the battery of battery operated peripherals attached to port- able computers. Provision is made for the peripheral to request a charging cycle to be initiated by the computer via the lines normally used for data communications to the peripheral. This provides a means by which the bat- tery ofthe peripheral becomes a secondaty storage means so that the peripheral never fails to have access to a power supply when connected to a computer which has battery power remaining.

  The example below describes how this arrangement might be used for an RF modem designed to attach to a laptop, palmtop, portable computer, etc. via the serial

port. The idea here is that when the RF modem senses that its battery is low, it would use the capability to wake up the computer (needed anyway for the data capture function) and send a message indicating the need to receive charge. The data line from the computer to the RF modem would then be held high by the computer. The RF modem would drive an internal chalging arrange- ment from this data line until it sensed that the battery was suitably charged. At this point, the RF modem would use the data line back to the computer to signal that charging has completed and the computer would reset the serial port to its normal state and go back to sleep, if appropriate. Figure 1 illustrates the components.

r

BATTERY POWERED PERIPHERAL

I I SWITCH I

LAPTOP PALMTOP of3 PORTABLE SERIAL PORT

FIGURE

1

  Figures 2 and 3 are flow charts of the controller functions of the RF modem (or other serially connected peripheral) and portable computer, respectively, as they apply to the interactive charging arrangement. Assume, for now, that the host computer is inactive, in an idle (perhaps battery save) mode. The peripheral would sense a battery low condition and would signal the host to "wake up" by sending a "break" signal (long space) on the peripheral transmit (host receive) line. The host would acknowledge its return to an active conditi...