HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  INDUSTRIES  |  FOCUS ON FUNDAMENTALS
REGISTER   |   LOGIN   |   HELP
Blogs
Sherlock Ohms

Failing Sensors Cause Consternation

NO RATINGS
2 saves
< Previous Page 2 / 2
View Comments: Newest First|Oldest First|Threaded View
Page 1/2  >  >>
Nancy Golden
User Rank
Platinum
Re: Doing the digging instead of the quick fix
Nancy Golden   5/18/2012 8:04:15 PM
NO RATINGS
It is interesting naperlou, and something I am always trying to get across. Often times folks don't think twice about changing something material or mechanical and don't expect it to have an impact on the electronics. This story certainly proves otherwise...

DanSchwartz
User Rank
Iron
Send this to Advanced Bionics
DanSchwartz   5/18/2012 4:06:20 PM
NO RATINGS
Somebody needs to forward this to cochlear implant maker Advanced Bionics, which has been struggling to seal their implanted electronics for over a decade, causing losses of upwards a half-billion dollars.

http://TinyURL.com/FailUgly

http://TinyURL.com/FailUgly2

William K.
User Rank
Platinum
Failing sensors mystery
William K.   5/17/2012 9:15:01 PM
NO RATINGS
It appears that on many occasions "epoxy" material is not suited for many kinds of electrical applications. I am aware of some antennas that don't work right when they are insulated with epoxy material, although one would think that they should. Moisture leaching out salts to short circuit a connector is a long way to go, though. It took good troubleshooting skills to find that problem.

ChasChas
User Rank
Gold
unusual
ChasChas   5/17/2012 10:27:32 AM
NO RATINGS
 

To find the cause first and then the failure process is truly unusual.

Tim
User Rank
Platinum
Moisture Absorption
Tim   5/17/2012 6:52:27 AM
NO RATINGS
The moisture absorption of polyamide is often overlooked in design.  We manufacture a polyamide product that is used on average two years before discard.  Consumers that were keeping the product over the two year mark complained of premature breakage of the product (non-safety related).  Investigation showed that the PA absorbed enough moisture to push out the plasitcizer on the product making it brittle.  As there was no other material available, we opted to put use by dates on the product to guide the consumer to when the products life was ending. 

dboccuti
User Rank
Iron
Re: Secondary or tertiary effects
dboccuti   5/16/2012 8:42:40 PM
NO RATINGS
Thanks for your insightful comment Charles. In this case the change was made for the right reasons (reliability; cost was a secondary benefit) by the system engineering folks, but it had an impact on a sub-system (the sensor) - an unintended consequence. Lesson learned - evaluate everything that might be affected by a change, not just how it affects "your own stuff."

Ann R. Thryft
User Rank
Blogger
Electrical problems are always a hassle
Ann R. Thryft   5/16/2012 6:46:16 PM
NO RATINGS
My only comment is that troubleshooting electrical problems are much harder to diagnose--or even to recognize as such--than mechanical problems.

Charles Murray
User Rank
Blogger
Re: Secondary or tertiary effects
Charles Murray   5/16/2012 6:12:34 PM
NO RATINGS
The interesting aspect of this is that the change was made, not just for cost reduction reasons, but for reliability purposes, as well. It makes me wonder if the original PTFE insulation had a problem, too. Was this a case of replacing something that wasn't working well with something that was even worse? Or was it a case of, "If it ain't broke, don't fix it?"

Jon Titus
User Rank
Blogger
Secondary or tertiary effects
Jon Titus   5/16/2012 12:00:02 PM
NO RATINGS
This story provides a good example of how a secondary effect (insulation change) caused a tertiary effect (shorted contacts).  New engineers must keep these types of problems in mind when they look for the root cause of a defect. That cause isn't always obvious. Nice work.

Rob Spiegel
User Rank
Blogger
Re: Doing the digging instead of the quick fix
Rob Spiegel   5/16/2012 11:08:49 AM
NO RATINGS
Yes, Naperlou, this is a good example of attention to detail. Something as simple as wire insulation made difference between sensors that worked and sensors that failed. This is excellent Sherlock sleuthing.

Page 1/2  >  >>
Partner Zone
More Blogs from Sherlock Ohms
Sherlock Ohms highlights stories told by engineers who have used their deductive reasoning and technical prowess to troubleshoot and solve the most perplexing engineering mysteries.
Sherlock Ohms highlights stories told by engineers who have used their deductive reasoning and technical prowess to troubleshoot and solve the most perplexing engineering mysteries.
Sherlock Ohms highlights stories told by engineers who have used their deductive reasoning and technical prowess to troubleshoot and solve the most perplexing engineering mysteries.
The problem with the engine light was not the usual sort. Only Sherlock Ohms could chase down the real problem.
Sherlock Ohms highlights stories told by engineers who have used their deductive reasoning and technical prowess to troubleshoot and solve the most perplexing engineering mysteries.
Design News Webinar Series
3/27/2014 11:00 a.m. California / 2:00 p.m. New York / 7:00 p.m. London
2/27/2014 11:00 a.m. California / 2:00 p.m. New York / 7:00 p.m. London
12/18/2013 Available On Demand
11/20/2013 Available On Demand
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Apr 21 - 25, Creating & Testing Your First RTOS Application Using MQX
SEMESTERS: 1  |  2  |  3  |  4  |  5


Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
Next Class: April 29 - Day 1
Sponsored by maxon precision motors
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
Copyright © 2014 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service