Battery powered computer system wherein a power supply is selectively shut off when a low battery power is detected

• US 4,907,183 A
• Filed: 03/24/1988
• Issued: 03/06/1990
• Est. Priority Date: 03/25/1987
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Tanaka, Nobuyuki
• Primary Examiner(s): Clark, David L.
• Assistant Examiner(s): Shaw, Dale M.
• Application Number:
  US07/172,406
• Time in Patent Office: 712 Days
• Field of Search: 364/707, 364/200 MS File, 364/900 MS File, 365/229
• US Class Current: 713/340
• CPC Class Codes: G06F 1/30 Means for acting in the event of power-supply failure or interruption, e.g. power-supply fluctuations for resetting only G06F1/24

Abstract

A method and related apparatus for extending the battery life in a battery powered computer system having a high power consumption peripheral device, such as a hard disk. The energy state of the power supply battery is determined by a voltage detector. When the battery voltage drops to a level below which continued operation of the computer system will become unreliable or impossible, battery life is extended by de-energizing any high power consumption peripheral devices such as the hard disk, thereby providing an operator with additional time to store data or secure a backup power source. To prevent loss of data as it is being stored on a hard disk, one embodiment of the invention cuts off power to the hard disk only when the hard disk is operating in a standby mode, thereby improving data storage reliability.

Claims

1. A battery powered computer system comprising:

a computer unit having a first power consumption;

a peripheral device having a second, higher power consumption, and operating in an active mode and a standby mode;

a power supply having a battery power source, for supplying power corresponding to the energy state of the battery to said computer unit and said peripheral device; and

control means responsive to the energy state of said battery for shutting off power to said peripheral device at times when said peripheral device operates in the standby mode and the energy state of said battery drops below a predetermined level.

2. The computer system of claim 1 wherein said control means includes means for signalling said computer unit when power has been cut off to said peripheral device.

3. A battery powered computer system comprising:

a computer unit having a first power consumption;

a peripheral device having a second, higher power consumption, and operating in an active mode and a standby mode;

a power supply having a battery power source, for supplying power to said computer unit and said peripheral device;

a detector for detecting the energy state of said battery; and

control means responsive to said detector for shutting off power to said peripheral device at times when said peripheral device operates in the standby mode and the energy level of said battery drops below a predetermined level.

4. The computer system of claim 3 wherein said control means includes a transistor having a base connected to said detector, a collector connected to said power supply and an emitter connected to said peripheral device.

5. The computer system of claim 3 wherein said peripheral device is a hard disk data storage device.

6. A method of powering a computer system having a computer unit with a first, lower power consumption, and peripheral device with a second, higher power consumption, said peripheral device operating in an active mode and a standby mode, comprising the steps of:

supplying power to the computer unit and the peripheral device from a power supply having a battery power source;

detecting the energy state of said battery; and

shutting off power to the peripheral device at times when said peripheral device operates in the standby mode and the energy level of said battery drops below a predetermined level.

7. The method of claim 6 wherein said step of shutting off power includes signalling said computer unit when power to said peripheral device has been shut off.