Re: [PSES] Compliance costs too much.
Anyone who has done this work more than a few years knows the liturgy; it starts with cost, moves to expense and ends with failure. I might be one of the EMC engineers you describe, because truly, following very simple design principles costs little, done at the outset, and averts much. But that is often overlooked. Why did a board layout route ALL the data and address lines all the way around a processor? The factory wanted all pin 1's in the same direction to better control wave soldering, or so they said. Why was a hard-drive cable run RIGHT across a chassis opening for its not-installed mate? Because it would disrupt production to rearrange wires on spools at each assembler's workspace. Why did I have to argue two hours with a mechanical engineering VP to get parts of a chassis to touch? Because an interference fit is mechanical blasphemy, tooling for the progressive die would have to be modified, and someone was sold on a labyrinth stopping EMI from getting out. Why did another company spend near half a million dollars testing and retesting equipment at an outside house when it already had enough equipment for pre-tests? Because there was no budget for the engineers who should have done it. I could go on, but I don't need to. Not here. We all know some sorry story of cost cutters who ruin budgets by overruling engineers. And you can't fool physics. Aunt Enna: Johnny! You put that electron back before it screams for its mother! That'll do, for a start. Cortland Richmond On 3/29/2012 2323, Richard Nute wrote: I once worked with an EMC engineer who measured the performance of himself and his time by the cost of the components that were used in the equipment solely for the purpose of EMC control. His objective was to reduce the cost of compliance by advising designers of careful layout so as to minimize the need for EMC components. Safety is a bit different because many safety components are also functional components. Nevertheless, a ground wire can be eliminated if double-insulation is employed. In this example, a cost trade-off between the power cord and the extra insulation. But, these days, most primary circuit designs are indeed double-insulated as transformers simply don't use internal shields. Enclosures... only needed for primary circuits and secondary circuits exceeding 30 V. (Yes, you still want an enclosure, but not for safety!) Etc. So, compliance should not cost too much. I look forward to your comments on compliance costing too much. Rich - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
[PSES] IATA regs for carriage of lithium batteries
Does anyone have a copy of the 2012 version for the IATA regs/guide for the carriage of lithium batteries by air, which they could e-mail me please? I've been trying to download it from the IATA site but it seems to have crashed, and I need a copy for Monday morning if at all possible. Nick. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Compliance costs too much.
I was once sent on a interference complaint a previous troubleshooter had attempted to fix with ferrites. *Forty-two* of them. Taking them off didn't change this more than 1 or 2 dB but a series termination resistor in the clock line substantially cut emissions in the lab. The real problem was a two layer board with no power or ground planes. FWIW department: If it was a few more than 15 years ago, Manny, I was involved with finding and fixing a similar problem. Two words: Nickel paint. Cortland Richmond On 3/30/2012 1623, Barron, Manny (IS) wrote: I used to manage an outside EMI test lab. About 15 years ago I remember one well known client who needed to pass FCC Class B but his product utilized a plastic case (not metalized nor conductive finish, but fully plastic). When his product failed he started adding [many] ferrite beads to the culprit internal I/O cable until his product was 10 dB below the limit. Then he started taking them off one by one until the product was about 2 dB below the limit. When I inquired why remove the beads and reduce margin his response was cost and that his management would not be pleased with him because he had added cost to the product. Just an interesting story. Manny Barron EMC/EMI Engineer Northrop Grumman Corp. San Jose, California - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Compliance costs too much.
You guys got me a job at Tandy a few years later. Thanks! (grin) Cortland Richmond On 3/30/2012 1524, Thomas Cokenias wrote: I used to work at FCC Lab and they have ways of getting your attention. One story as I remember it: Back in the mid 80's there was an IBM clone computer company named (I believe) Columbia Data - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] IATA regs for carriage of lithium batteries
Thanks to those who replied. I now have what I need. Regards Nick. On 31 Mar 2012, at 11:43, Nick Williams wrote: Does anyone have a copy of the 2012 version for the IATA regs/guide for the carriage of lithium batteries by air, which they could e-mail me please? I've been trying to download it from the IATA site but it seems to have crashed, and I need a copy for Monday morning if at all possible. Nick. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
