Browse Prior Art Database

Battery Fail-Safe Mechanism for Personal Computer

IP.com Disclosure Number: IPCOM000119974D
Original Publication Date: 1991-Mar-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 3 page(s) / 94K

Publishing Venue

IBM

Related People

Fujita, N: AUTHOR [+2]

Abstract

Disclosed is a battery fail-safe mechanism for battery-powered personal computers without a backup battery, in which, at the time of lowering of the battery power, the clock frequency of the personal computer is reduced and necessary steps are taken to protect data and keep track of progress of the program steps.

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Battery

Fail-Safe Mechanism for Personal Computer

      Disclosed is a battery fail-safe mechanism for
battery-powered personal computers without a backup battery, in
which, at the time of lowering of the battery power, the clock
frequency of the personal computer is reduced and necessary steps are
taken to protect data and keep track of progress of the program
steps.

      Battery-powered personal computers will extend the utility of
personal computers and enable their use in any circumstances, such as
outdoors. The most straightforward way to deal with the problem of
battery down will be to use a backup battery.  However, a relatively
large backup battery is required to operate the personal computer
well, significantly increasing the weight and size of the personal
computer.  Thus, the use of a backup battery will not necessarily be
advantageous.  On the other hand, battery-powered personal computers
without a backup battery will suffer from different problems, such as
destruction of data and handling of the process stopped halfway.  The
present disclosure provides a battery fail-safe mechanism which is
useful to solve the problems encountered with battery-powered
personal computers without the provision of a backup bettery.

      In the figure, the personal computer system is powered by
battery 10. Battery voltage check circuit 12 monitors the voltage of
the battery 10.  Use time counter 14 accumlates power on time.  The
voltage of a new or fully charged battery is normally higher than a
nominal value of the battery.  When the check circuit 12 detects that
the voltage of the battery 10 lowers to its nominal value, it
requests a first interruption to CPU 22 to cause the current count of
the counter 14 to be stored in backup memory 26 powered by separate
backup battery 28.  When the personal computer is in a power- on
state, the counter 14 continues to accumulate power on time.  The
count of the counter 14 is periodically compared with the value
stored in the backup memory 26, and when the count reaches a first
predetermined state,...