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Forum: Reliability & Maintainability Questions and Answers

Topic: Reliability & Maintainability Questions and Answers

Topic Posted by: Reliability & Maintainability Forum (src_forum@alionscience.com )
Organization: System Reliability Center
Date Posted: Mon Aug 31 12:47:36 US/Eastern 1998

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Original Message:

Posted by: Terry McCrossan
Date posted: Mon Jul 5 17:24:19 US/Eastern 1999
Subject: Component Derating
Message:
Does anyone have any new quantifiable data on the use of component parameter derating (thermal, power etc). I am used to the usual "margin of ignorance" type arguments, package glass transition temperatures and the junction/channel type Arrhenius relationships (generally with assumed activation energies). However, is there any more recent quantifiable data available to convince a sceptical design engineer and to what extent is derating used?


Reply:

Subject: Derating information/Data.
Reply Posted by: Eugene L. Neuliep (neuliep.eugene@orbital-lsg.com )
Organization: ORBITAL
Date Posted: Tue Jul 6 14:37:41 US/Eastern 1999
Message:
In our business we use ELV-JC-002(D)"PARTS, MATERIALS, AND PROCESSES CONTROL PROGRAM FOR EXPENDABLE LAUNCH VEHICLES." We do not have the time to dig into every specific component and determine the potential "EXCEPTIONS" to these "Blind" rules. To do so would make each piece part a research project. We can not afford anything like that. These are not really arguments. They are basic rules that have and are being followed to design high reliability electronics where Human Life and Much finacial Gain or Loss could or would be at risk. Also try NASA 311-INST-001 (I have A) "INSTRUCTIONS FOR EEE PARTS SELECTION, SCREENING, AND QUALIFICATION. I hope that I have helped. Regards, GeneN. Regards, GeneN.


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