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Apparatus for Raising and Lowering Voltage on Circuit Card as Card is Plugged into Circuit Board and Unplugged

IP.com Disclosure Number: IPCOM000037690D
Original Publication Date: 1989-May-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Corcoran, PM: AUTHOR [+4]

Abstract

A circuit board has signal pins and power pins and circuit cards that are plugged into the board have corresponding pin sockets. When a card is to be removed from the board or replaced, the power to the board is conventionally disconnected to avoid transient electrical signals on the power conductors that could interfere with the operating circuits.

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Apparatus for Raising and Lowering Voltage on Circuit Card as Card is Plugged into Circuit Board and Unplugged

A circuit board has signal pins and power pins and circuit cards that are plugged into the board have corresponding pin sockets. When a card is to be removed from the board or replaced, the power to the board is conventionally disconnected to avoid transient electrical signals on the power conductors that could interfere with the operating circuits.

This board has long pins for power and short pins for signals, as is conventional for disconnecting power last when a card is removed and for applying power first when a card is plugged in, as is conventional. The card has a slide potentiometer and the board has a post that actuates the potentiometer as a card is plugged in. A spring returns the potentiometer to its high resistance position when the card is unplugged. Power from the pin sockets on the card is supplied to the card circuits through a semiconductor linear circuit. The potentiometer controls this circuit to apply power gradually as the card is plugged in and to remove power gradually as the card is unplugged.

Disclosed anonymously.

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