Forum: Reliability & Maintainability Questions and Answers
Posted by: John S. Hoegbraathen (firstname.lastname@example.org )
Organization:Kongsberg Defence & Aerospace
Date posted: Wed Jul 14 7:00:11 US/Eastern 1999
Subject: Dudding of EEDīs
I am a system safety/reliability engineer working in an
AEROSPACE company. I am looking into the possibility of including a bridgewire conductivity test for some of the EEDīs (Electro Explosive Device) in a new system which is currently under development. This test will perhaps be a part of a built in test. The proposed test current is 1 - 2 mA over a 10 to 100 msec interval. The EED tested will all be of 1A/1W type (hot bridgewire devices), pr MIL-I-23659C. Could this testing lead to dudding (fails to operate when called upon) of the EEDīs if the test is frequently used? What are the test limitations concerning the possibility of dudding? Are there anyone who could answer these questions or direct me to relevant l
Posted by: Xiangping,Wu (email@example.com )
Date posted: Sun Jul 11 23:40:44 US/Eastern 1999
Subject: Reliability of Telecommunication
I'm a reliability engineer of a telecommunication corp.of China,but I have little experience on reliability of telecommunication products.I would be very glad if someone can tell me something about how other telecommunication or electronics corp.s(e.g.,Motorola,IBM,Nokia,etc.) conduct reliability.Thank you,very much.
Posted by: Daniel Mahoney (firstname.lastname@example.org )
Date posted: Thu Jul 8 15:13:03 US/Eastern 1999
Subject: Relay reliability
MIL-39016/13 Relays have a life requirement of 100,000 cycles at high level (1 ampere at 28 V dc) and 1,000,000 cycles at low level (10 to 50 milli amperes).
Question 1: Can an operational usage at .85 amperes be extrapolated to arrive at a life of 200,000 hours (i.e., a straight line fit of the two requirements above)? Question 2: Is it the load at opening/closing of the relay that is driving this requirement or is it the load while the relay is sitting there in the opened/closed position? A quick response would be grately appreciated.
Posted by: Clay Davis
Date posted: Wed Jul 7 14:16:55 US/Eastern 1999
Subject: Component Reliability (Belcore vs Supplier Data)
I am starting to use the Belcore (Part Stress / Method 1 Case 3) to predict the reliability for various components (esp ICs) but I can also use the supplier's FIT data from their internal demonstration test. Does anybody have any experience on which which method would provide a better result?
Posted by: Eugene L. Neuliep (email@example.com )
Date posted: Tue Jul 6 14:52:00 US/Eastern 1999
Subject: Reuse of Removed Electronic Components
Is there any information about the reuse of Electronic components that have been removed from a CCA (Circuit Card Assembly)? Is it risky to reuse Diodes, Transistors, I.C.'s and etc. that have been put in backwards? Both those that have been powered up and those that have not been powered up. I need to know of any company policies and any industry standard recommendations.
Thank you much, GeneN.