Browse Prior Art Database

Indicating Maintenance Aid

IP.com Disclosure Number: IPCOM000092025D
Original Publication Date: 1968-Aug-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 76K

Publishing Venue

IBM

Related People

McAdon, TM: AUTHOR [+2]

Abstract

This pluggable test fixture, employing indicating lamps and their associated drivers, augments the auto-diagnostic capabilities built into a computer system. Circuit card 1, shown at A, containing a plurality of lamp driver circuit modules 2, bears blocks 3 containing indicator lamps 4. Connector 5 at the opposite end is adapted to engage back pins 6 of circuit interconnection board 7. Interlock blocks 8 on card 1 assure protection of the wire wrap connections on pins 6 by limiting the amount of forward travel of connector 5 when engaging such pins. Power cable 9, fitted with connector block 10, couples card 1 to power supply pins 12 arranged along the outboard edges of board 7.

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Indicating Maintenance Aid

This pluggable test fixture, employing indicating lamps and their associated drivers, augments the auto-diagnostic capabilities built into a computer system. Circuit card 1, shown at A, containing a plurality of lamp driver circuit modules 2, bears blocks 3 containing indicator lamps 4. Connector 5 at the opposite end is adapted to engage back pins 6 of circuit interconnection board 7. Interlock blocks 8 on card 1 assure protection of the wire wrap connections on pins 6 by limiting the amount of forward travel of connector 5 when engaging such pins. Power cable 9, fitted with connector block 10, couples card 1 to power supply pins 12 arranged along the outboard edges of board 7.

Lamp driver circuit 15, shown at B, permits minimum loading of the networks on board 7 and can be used to check both saturating and nonsaturating ground to plus level switching mode circuit families. The condition of the indicator lights is checked prior to attaching the test fixture to a network when power is applied to the test fixture via block 10 and cable 9. With +V, -V, and ground potential applied to circuit 15, diode D1 and resistors R1 and R2 bias the base of transistor T1 positive. The output of emitter-follower T1, applied to the base of transistor T2, causes T2 to conduct, energizing lamp 4 at a high intensity.

When connector 5 is then secured to the appropriate pins, ground potential at a pin forming the input to circuit 15 causes a voltage shift at...