Browse Prior Art Database

Automatic Restart Facility

IP.com Disclosure Number: IPCOM000092231D
Original Publication Date: 1968-Oct-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 31K

Publishing Venue

IBM

Related People

Chupay, JJ: AUTHOR [+2]

Abstract

Power systems contain over and under voltage and current protection circuits. These cause a power shutdown when a variation exceeds the built-in threshold level of the circuits. The threshold level is set so that expected noise and ripple variations do not cause a power shutdown. Nevertheless, a large percentage of the power shutdowns of computers is caused by intermittent variations. This restart facility automatically brings the power back up when a power failure occurs to determine whether the shutdown is caused by an intermittent error variation.

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Automatic Restart Facility

Power systems contain over and under voltage and current protection circuits. These cause a power shutdown when a variation exceeds the built-in threshold level of the circuits. The threshold level is set so that expected noise and ripple variations do not cause a power shutdown. Nevertheless, a large percentage of the power shutdowns of computers is caused by intermittent variations. This restart facility automatically brings the power back up when a power failure occurs to determine whether the shutdown is caused by an intermittent error variation.

The power retry arrangement includes battery 12 to power the recovery management logic. A power drop in power supply 13, detected at the beginning of a power shutdown, is used to trigger single-shot 14. This has a two millisecond delay before it signals the contacts in control circuitry 16 to start bringing the power up. This delay provides time for the cause of the power failure to quiesce. The delay must necessarily be short as the power must be brought up as rapidly as possible before the contacts in circuitry 16 are fully opened.

Single-shot 18 is energized by the detected power drop which has a ten to thirty-five millisecond delay which is equal to the maximum time it takes to sequence power back up to normal. Also, counter 20 is energized each time single-shot 14 is fired which can be preset to insure that an endless retry loop does not result from a solid power failure. Since battery...