Browse Prior Art Database

Printed Circuit Card Redundant Etched Fuse Implementation Method

IP.com Disclosure Number: IPCOM000109101D
Original Publication Date: 1992-Jul-01
Included in the Prior Art Database: 2005-Mar-23
Document File: 2 page(s) / 70K

Publishing Venue

IBM

Related People

Jordan, RC: AUTHOR [+3]

Abstract

Disclosed is a method for providing redundant overcurrent protection on printed circuit cards using etched wires as fuse elements in secondary power circuits. The method disclosed provides designers with a low-cost or no-cost choice for repair or replacement of traditional circuit protection devices. The method described uses a secondary fuse repair element when the primary fuse element becomes damaged or opened by excessive fault current.

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This is the abbreviated version, containing approximately 58% of the total text.

Printed Circuit Card Redundant Etched Fuse Implementation Method

       Disclosed is a method for providing redundant overcurrent
protection on printed circuit cards using etched wires as fuse
elements in secondary power circuits.  The method disclosed provides
designers with a low-cost or no-cost choice for repair or replacement
of traditional circuit protection devices.  The method described uses
a secondary fuse repair element when the primary fuse element becomes
damaged or opened by excessive fault current.

      The redundant fuse protection design method is shown in the
figure.

      When an overcurrent fault condition occurs as a result of
misregistered component carrier plane(s) or card-mounted component
failure, the primary fuse element between plated holes 1 and 2 will
open.  The secondary fuse element is then installed by adding the
appropriate size solid wire jumper between plated holes 3 and 4.
Plated holes 1 and 2 may be optionally jumped first before actuating
the secondary fuse element.  This approach protects the secondary
fuse element from damage while repairing or determining the reason
for the original overcurrent fault condition.  Power supply current
limiting should be used during failure analysis and may eliminate the
optional jumper procedure between plated holes 1 and 2.  Any number
of redundant fuse elements can be built into a circuit design using
the disclosed method.

      There are several design considerations that f...