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Personal Computer System Smartswitch Battery Backup Controller

IP.com Disclosure Number: IPCOM000036668D
Original Publication Date: 1989-Oct-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 3 page(s) / 60K

Publishing Venue

IBM

Related People

LeFranc, E: AUTHOR [+2]

Abstract

This article describes a circuit arrangement which allows the addition of a battery backup in a personal computer system without having to modify the existing power supply.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 52% of the total text.

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Personal Computer System Smartswitch Battery Backup Controller

This article describes a circuit arrangement which allows the addition of a battery backup in a personal computer system without having to modify the existing power supply.

Conventionally, in order to implement a battery backup circuit, the power supply had to be designed with the necessary components to support battery backup. The battery backup controller disclosed herein provides an isolation between the power supply and the system during power outages, provides for complete control over battery hook-up which eliminates the need to add a third pole for the battery to the main switch on the power supply, and completely de- energizes the power supply during power outages. The combination of this circuit with the battery backup circuit forms a single package which can be added easily to a personal computer system by a user of such a system.

During operation, the circuit shown in the drawing controls the operation of three electromechanical relays V1, V2 and V3. Relay V1 is used to connect the battery to the battery backup. V2 connects the existing power supply to the system, and V3 connects the power supply and the smartswitch AC sense to 120/240 VAC. Also contained in the circuit are six integrated circuit components with a host of supporting discrete components. U1, a quad comparator, is used to detect when AC is on as well as control the relay V2. U2 is a 74LS74 dual D flip- flop and is used with l/2 of U4, a 74LS00, to control the operation of the relay V3. U3 is also a 74LS74, and is used with the remaining half of U4 to control the relay V1. U6 a 555 timer, is used to generate a .6 Hz clock. The remaining U5 is a 74LS163 4-bit counter which is used to divide the .66 Hz clock into .33 Hz and
.083 Hz clocks.

Before the system's main power switch is turned to the on position, the control circuit is off with all relays in the resting position; the normally open relay V1 is in its open position, while the normally closed relay V3 is in the closed (no cu...