RE: Creepage/Clearance and Altitude
All, Paschen's Law is the result of two functions in the breakdown of gases. Both are related to the mean-free-path of ionized particles. As particles are ionized, they are then polarized and accelerate from one high voltage electrode to another. This can result the generation of secondary ionization by the collision of a highly accelerated ion into a neighboring particle. As pressure decreases the mean-free-path between any two adjacent air particles increases. Which results of a longer path for ions to accelerate and the energy of the resulting impact on a neighboring particle more easily removes an electron, creating another ion. Atmospheric pressure is approximately 760 Torr at sea level. In IEC 60664 minimum clearances are normalized for 2000 meters altitude, or about 600 Torr. For altitude higher than 2000 m, using the table in IEC 60664 for altitude correction, you simply adjust the clearance number (interpolation of the table is not prohibited). As Rich states, creepage cannot be less than clearance, so you may need to adjust this as well. This can be applied to any safety standard based on IEC 60664. There are many standards that do not take this into account and it might be prudent to factor this into your creepage and clearance allowances. As an exercise, if you were to take an electrical product to the highest point in Austria (3798 meters), you would need to increase your clearances to 126% of the calculated value of the safety standard. This would surely impact your creepage distances. It is interesting to note, as pressure continues to decrease, the number of available particles in a volume of air becomes fewer and therefore ions will begin to miss hitting their neighbors and ionization will once again decrease. This the insulating characteristic of a vacuum. The point at which low pressure begins to raise the voltage breakdown point above the IEC 60664 minimum is somewhere between 0.1 to and 1.0 Torr. This air pressure is not normally found on the surface of the earth is of no concern to IEC 60664. But it is of great interest to manufacturers of orbiting satellite equipment. -doug Douglas E. Powell Advanced Energy Industries, Inc. From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Richard Nute Sent: Friday, February 26, 2010 6:40 PM To: Petrie, Craig D Cc: emc-p...@ieee.org Subject: Re: Creepage/Clearance and Altitude Hi Craig: With regard to clearance, air is the insulator. As you go up in altitude, there is less air, so there is less insulation. And lower dielectric strength. So, to get the same amount of air (and the same dielectric strength) between the two conductors, you need more distance (clearance). Creepage is the interface between solid insulation and air insulation. Physically, creepage cannot be less than clearance. Degradation of the solid insulation surface (creepage) is a long-term effect largely due to deposition of foreign matter on the insulation surface. Best regards, Rich On 2/26/2010 04:12, Petrie, Craig D wrote: Hello, Can anyone tell me the link between creepage/clearance and altitude? Why do these values need increased at greater altitudes? Regards Craig *Craig D. Petrie **Product Safety Engineer * - 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 mailto:emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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...@socal.rr.com mailto:emcp...@socal.rr.com Mike Cantwell mcantw...@ieee.org mailto:mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org mailto:j.bac...@ieee.org David Heald dhe...@gmail.com mailto:dhe...@gmail.com - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com This message, including any attachments, may contain information that is confidential and
RE: [PSES] Toyota -- Comment on Software and Electronics for Safety
Yes, it is. And jet engines don’t spool up as quickly as piston engines. Ghery S. Pettit From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of ralph.mcdiar...@ca.schneider-electric.com Sent: Monday, March 01, 2010 4:49 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Toyota -- Comment on Software and Electronics for Safety I remember that video and it seemed to me, a layman, that the aircraft was in a flared attitude as it would be just before touchdown. It looked to me as if it intentionally landed well past the end of the runway, into the trees. To climb, isn't a large increase in thrust necessary? ___ _ Ralph McDiarmid | Schneider Electric | Renewable Energies Business | CANADA | From: Pettit, Ghery ghery.pet...@intel.com To: EMC-PSTC@LISTSERV.IEEE.ORG List-Post: emc-pstc@listserv.ieee.org List-Post: emc-pstc@listserv.ieee.org List-Post: emc-pstc@listserv.ieee.org Date: 03/01/2010 04:39 PM Subject: Re: [PSES] Toyota -- Comment on Software and Electronics for Safety This has been well discussed in aviation circles. The fly by wire systems in the Airbus will not allow the pilots direct control. The pilot tells the computer what he wants to do and the flight rules programmed into the computer limit the aircraft to a certain performance envelope. In the Paris incident the pilots tried to exceed the performance envelope to clear the trees and the computer wouldn't let them. I've seen video of the crash. Not good. Ghery S. Pettit From: emc-p...@ieee.org [mailto:emc-p...@ieee.org mailto:emc-p...@ieee.org ] On Behalf Of John M Woodgate Sent: Monday, March 01, 2010 4:26 PM To: EMC-PSTC Subject: Re: [PSES] Toyota -- Comment on Software and Electronics for Safety In message d500012385dca64883637ab4ccf491e30134c...@ms-cda-02.advanced-input.com, McInturff, Gary gary.mcintu...@esterline.com writes They got to the end of the pass saw the trees and tried to pull up, but the software looked at the flight envelope and said no because the low airspeed meant that they were at a critical point on the flight envelope and raising the nose at that speed would put it too close to the stall point of the aircraft. I certainly wasn't involved in the crash investigation rather having just read this is some journal somewhere - so I certainly could have this wrong - but like I said - as I understand it. Even so, if it is true, it shows that the software just wasn't intelligent, or, more likely, informed enough to cope with the situation. It didn't know about the trees, but if it did know, it should have allowed a low-angle climb to clear them. It must be a general principle that if a quasi-intelligent system does not know a key fact, it may implement a dangerous sequence of actions. What you don't know will kill you. -- This is my travelling signature, adding no superfluous mass. John M Woodgate - 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.ieeecommunities.org/emc-pstc http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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.ieeecommunities.org/emc-pstc http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com This email has been scanned for SPAM content and Viruses by the MessageL abs Email Security System.
Re: [PSES] Toyota -- Comment on Software and Electronics for Safety
I remember that video and it seemed to me, a layman, that the aircraft was in a flared attitude as it would be just before touchdown. It looked to me as if it intentionally landed well past the end of the runway, into the trees. To climb, isn't a large increase in thrust necessary? ___ _ Ralph McDiarmid | Schneider Electric | Renewable Energies Business | CANADA | From: Pettit, Ghery ghery.pet...@intel.com To: EMC-PSTC@LISTSERV.IEEE.ORG List-Post: emc-pstc@listserv.ieee.org List-Post: emc-pstc@listserv.ieee.org List-Post: emc-pstc@listserv.ieee.org Date: 03/01/2010 04:39 PM Subject:Re: [PSES] Toyota -- Comment on Software and Electronics for Safety This has been well discussed in aviation circles. The fly by wire systems in the Airbus will not allow the pilots direct control. The pilot tells the computer what he wants to do and the flight rules programmed into the computer limit the aircraft to a certain performance envelope. In the Paris incident the pilots tried to exceed the performance envelope to clear the trees and the computer wouldn't let them. I've seen video of the crash. Not good. Ghery S. Pettit From: emc-p...@ieee.org [mailto:emc-p...@ieee.org mailto:emc-p...@ieee.org ] On Behalf Of John M Woodgate Sent: Monday, March 01, 2010 4:26 PM To: EMC-PSTC Subject: Re: [PSES] Toyota -- Comment on Software and Electronics for Safety In message d500012385dca64883637ab4ccf491e30134c...@ms-cda-02.advanced-input.com, McInturff, Gary gary.mcintu...@esterline.com writes They got to the end of the pass saw the trees and tried to pull up, but the software looked at the flight envelope and said no because the low airspeed meant that they were at a critical point on the flight envelope and raising the nose at that speed would put it too close to the stall point of the aircraft. I certainly wasn't involved in the crash investigation rather having just read this is some journal somewhere - so I certainly could have this wrong - but like I said - as I understand it. Even so, if it is true, it shows that the software just wasn't intelligent, or, more likely, informed enough to cope with the situation. It didn't know about the trees, but if it did know, it should have allowed a low-angle climb to clear them. It must be a general principle that if a quasi-intelligent system does not know a key fact, it may implement a dangerous sequence of actions. What you don't know will kill you. -- This is my travelling signature, adding no superfluous mass. John M Woodgate - 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.ieeecommunities.org/emc-pstc http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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.ieeecommunities.org/emc-pstc http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com This email has been scanned for SPAM content and Viruses by the MessageL abs Email Security System. - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc.
RE: [PSES] Toyota -- Comment on Software and Electronics for Safety
This has been well discussed in aviation circles. The fly by wire systems in the Airbus will not allow the pilots direct control. The pilot tells the computer what he wants to do and the flight rules programmed into the computer limit the aircraft to a certain performance envelope. In the Paris incident the pilots tried to exceed the performance envelope to clear the trees and the computer wouldn't let them. I've seen video of the crash. Not good. Ghery S. Pettit From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of John M Woodgate Sent: Monday, March 01, 2010 4:26 PM To: EMC-PSTC Subject: Re: [PSES] Toyota -- Comment on Software and Electronics for Safety In message d500012385dca64883637ab4ccf491e30134c...@ms-cda-02.advanced-input.com, McInturff, Gary gary.mcintu...@esterline.com writes They got to the end of the pass saw the trees and tried to pull up, but the software looked at the flight envelope and said no because the low airspeed meant that they were at a critical point on the flight envelope and raising the nose at that speed would put it too close to the stall point of the aircraft. I certainly wasn't involved in the crash investigation rather having just read this is some journal somewhere - so I certainly could have this wrong - but like I said - as I understand it. Even so, if it is true, it shows that the software just wasn't intelligent, or, more likely, informed enough to cope with the situation. It didn't know about the trees, but if it did know, it should have allowed a low-angle climb to clear them. It must be a general principle that if a quasi-intelligent system does not know a key fact, it may implement a dangerous sequence of actions. What you don't know will kill you. -- This is my travelling signature, adding no superfluous mass. John M Woodgate - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Toyota -- Comment on Software and Electronics for Safety
In message d500012385dca64883637ab4ccf491e30134c...@ms-cda-02.advanced-input.com, McInturff, Gary gary.mcintu...@esterline.com writes They got to the end of the pass saw the trees and tried to pull up, but the software looked at the flight envelope and said no because the low airspeed meant that they were at a critical point on the flight envelope and raising the nose at that speed would put it too close to the stall point of the aircraft. I certainly wasn't involved in the crash investigation rather having just read this is some journal somewhere - so I certainly could have this wrong - but like I said - as I understand it. Even so, if it is true, it shows that the software just wasn't intelligent, or, more likely, informed enough to cope with the situation. It didn't know about the trees, but if it did know, it should have allowed a low-angle climb to clear them. It must be a general principle that if a quasi-intelligent system does not know a key fact, it may implement a dangerous sequence of actions. What you don't know will kill you. -- This is my travelling signature, adding no superfluous mass. John M Woodgate - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
RoHS list of Accredited Labs
I am looking for a list of accredited labs worldwide for RoHS testing. I have tried to find such a list from the IEC but was not lucky. Can anyone point me in the right direction? Thank you. Scott Griggs - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
RE: [PSES] Toyota -- Comment on Software and Electronics for Safety
Three rules of aviation relating to the Airbus – 1. Look what it's doing now! 2. It just did it again! 3. How do we make it stop doing that? Ghery S. Pettit From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of McInturff, Gary Sent: Monday, March 01, 2010 3:57 PM To: ralph.mcdiar...@ca.schneider-electric.com; EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: [PSES] Toyota -- Comment on Software and Electronics for Safety Ralph, When you get into designing things for the FAA, depending on the criticality of the system, it becomes almost impossible to use any CPU or von Nuemann architecture. Because of the V V requirements (verification and validation) requirements for those systems CPU’s are usually replaced with PALS, ASICS and the lot when ever possible simply because there are a finite number of input states in the PAL, (and I would presume ASICs etc) and one can write test vectors for all input states and then measure the all the output states. Software state machines are often replaced with shift registers that decode specific outputs to insure the input into the system gives you one and only one output. Writing simple software for earthbound control equipment might be 10’s of thousands of dollars for simple things, for aircraft the scale goes to 100’s of thousands. If you look at all of the work that goes on in trying to keep our bottom’s from bouncing off runways it becomes apparent why airplanes take the time they do to get out of development and why they cost big money. None of that keeps things from going wrong though. The Airbus crash at the Paris air show a few years go back was a case of the software being smarter than the pilots and having full authority to override pilot decisions. As I understand it The pilots made a pass over the crowd at low and slow speeds. They got to the end of the pass saw the trees and tried to pull up, but the software looked at the flight envelope and said no because the low airspeed meant that they were at a critical point on the flight envelope and raising the nose at that speed would put it too close to the stall point of the aircraft. I certainly wasn’t involved in the crash investigation rather having just read this is some journal somewhere – so I certainly could have this wrong – but like I said – as I understand it. Thoughts for what is worth. Gary McInturff 208 635 8306 From: Ralph McDiarmid [mailto:ralph.mcdiar...@ca.schneider-electric.com] Sent: Monday, March 01, 2010 2:42 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Toyota -- Comment on Software and Electronics for Safety It seems to me that the 'wrong position' is difficult to define and equally difficult to protect against. Would a watch-dog circuit always detect firmware departing from normal control flow into an unintended state?If the unintended state was caused by the instruction pointer fetching from the wrong address, then maybe a watchdog would always catch that error. In that state, I assume the microprocessor would begin executing instructions at random, never to return to its intended execution loop. ___ _ Ralph McDiarmid | Schneider Electric | Renewable Energies Business | CANADA | From: John Barnes jrbar...@iglou.com To: EMC-PSTC@LISTSERV.IEEE.ORG List-Post: emc-pstc@listserv.ieee.org List-Post: emc-pstc@listserv.ieee.org List-Post: emc-pstc@listserv.ieee.org Date: 03/01/2010 12:33 PM Subject: Re: [PSES] Toyota -- Comment on Software and Electronics for Safety Brian, Several years ago, in a workshop at one of the first Product Safety' Engineering Society (PSES) symposiums, the question came up: How can you certify software for safety-critical applications? One of the people in the audience answered Treat the software as a switch with two positions, ON or OFF. Then ask yourself, what will happen if the switch is in the wrong position? At that time our answer was that you need hardware to provide safety-- electronic, electrical, mechanical, or something. But don't trust software. With the advent of lead-free, RoHS-compliant electronics, I now don't trust electronics either. When it is *my* health or safety on the line, I ask: * What can happen if *any* one solder joint goes open? * What can happen if *any* two points within 10mm of each other-- that aren't separated by some kind of physical insulating barrier-- become shorted to one another? (But see conductive anodic filaments, CAF, where short circuits can develop inside of lead-free printed circuit boards.) Because of the conversion to lead-free electronics, I don't trust *any* electronic device, or item with a high electronic content, manufactured after 2005. I'm only buying new (built after 2005) electronics if: 1. I can't find
RE: [PSES] Toyota -- Comment on Software and Electronics for Safety
Ralph, When you get into designing things for the FAA, depending on the criticality of the system, it becomes almost impossible to use any CPU or von Nuemann architecture. Because of the V V requirements (verification and validation) requirements for those systems CPU’s are usually replaced with PALS, ASICS and the lot when ever possible simply because there are a finite number of input states in the PAL, (and I would presume ASICs etc) and one can write test vectors for all input states and then measure the all the output states. Software state machines are often replaced with shift registers that decode specific outputs to insure the input into the system gives you one and only one output. Writing simple software for earthbound control equipment might be 10’s of thousands of dollars for simple things, for aircraft the scale goes to 100’s of thousands. If you look at all of the work that goes on in trying to keep our bottom’s from bouncing off runways it becomes apparent why airplanes take the time they do to get out of development and why they cost big money. None of that keeps things from going wrong though. The Airbus crash at the Paris air show a few years go back was a case of the software being smarter than the pilots and having full authority to override pilot decisions. As I understand it The pilots made a pass over the crowd at low and slow speeds. They got to the end of the pass saw the trees and tried to pull up, but the software looked at the flight envelope and said no because the low airspeed meant that they were at a critical point on the flight envelope and raising the nose at that speed would put it too close to the stall point of the aircraft. I certainly wasn’t involved in the crash investigation rather having just read this is some journal somewhere – so I certainly could have this wrong – but like I said – as I understand it. Thoughts for what is worth. Gary McInturff 208 635 8306 From: Ralph McDiarmid [mailto:ralph.mcdiar...@ca.schneider-electric.com] Sent: Monday, March 01, 2010 2:42 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Toyota -- Comment on Software and Electronics for Safety It seems to me that the 'wrong position' is difficult to define and equally difficult to protect against. Would a watch-dog circuit always detect firmware departing from normal control flow into an unintended state?If the unintended state was caused by the instruction pointer fetching from the wrong address, then maybe a watchdog would always catch that error. In that state, I assume the microprocessor would begin executing instructions at random, never to return to its intended execution loop. ___ _ Ralph McDiarmid | Schneider Electric | Renewable Energies Business | CANADA | From: John Barnes jrbar...@iglou.com To: EMC-PSTC@LISTSERV.IEEE.ORG List-Post: emc-pstc@listserv.ieee.org List-Post: emc-pstc@listserv.ieee.org List-Post: emc-pstc@listserv.ieee.org Date: 03/01/2010 12:33 PM Subject: Re: [PSES] Toyota -- Comment on Software and Electronics for Safety Brian, Several years ago, in a workshop at one of the first Product Safety' Engineering Society (PSES) symposiums, the question came up: How can you certify software for safety-critical applications? One of the people in the audience answered Treat the software as a switch with two positions, ON or OFF. Then ask yourself, what will happen if the switch is in the wrong position? At that time our answer was that you need hardware to provide safety-- electronic, electrical, mechanical, or something. But don't trust software. With the advent of lead-free, RoHS-compliant electronics, I now don't trust electronics either. When it is *my* health or safety on the line, I ask: * What can happen if *any* one solder joint goes open? * What can happen if *any* two points within 10mm of each other-- that aren't separated by some kind of physical insulating barrier-- become shorted to one another? (But see conductive anodic filaments, CAF, where short circuits can develop inside of lead-free printed circuit boards.) Because of the conversion to lead-free electronics, I don't trust *any* electronic device, or item with a high electronic content, manufactured after 2005. I'm only buying new (built after 2005) electronics if: 1. I can't find a suitable item manufactured before 2006 (maybe used, such as from E-bay). 2. I figure it will repay its purchase cost within 3 months (I believe that *most* lead-free electronics will last at least one year, versus 20+ years use that we can get from lead-based electronics). AND 3. It is not manufactured in Europe. If the only suitable product is manufactured in the European Union, which passed the RoHS Directive
Re: [PSES] Toyota -- Comment on Software and Electronics for Safety
It seems to me that the 'wrong position' is difficult to define and equally difficult to protect against. Would a watch-dog circuit always detect firmware departing from normal control flow into an unintended state?If the unintended state was caused by the instruction pointer fetching from the wrong address, then maybe a watchdog would always catch that error. In that state, I assume the microprocessor would begin executing instructions at random, never to return to its intended execution loop. ___ _ Ralph McDiarmid | Schneider Electric | Renewable Energies Business | CANADA | From: John Barnes jrbar...@iglou.com To: EMC-PSTC@LISTSERV.IEEE.ORG List-Post: emc-pstc@listserv.ieee.org List-Post: emc-pstc@listserv.ieee.org List-Post: emc-pstc@listserv.ieee.org Date: 03/01/2010 12:33 PM Subject:Re: [PSES] Toyota -- Comment on Software and Electronics for Safety Brian, Several years ago, in a workshop at one of the first Product Safety' Engineering Society (PSES) symposiums, the question came up: How can you certify software for safety-critical applications? One of the people in the audience answered Treat the software as a switch with two positions, ON or OFF. Then ask yourself, what will happen if the switch is in the wrong position? At that time our answer was that you need hardware to provide safety-- electronic, electrical, mechanical, or something. But don't trust software. With the advent of lead-free, RoHS-compliant electronics, I now don't trust electronics either. When it is *my* health or safety on the line, I ask: * What can happen if *any* one solder joint goes open? * What can happen if *any* two points within 10mm of each other-- that aren't separated by some kind of physical insulating barrier-- become shorted to one another? (But see conductive anodic filaments, CAF, where short circuits can develop inside of lead-free printed circuit boards.) Because of the conversion to lead-free electronics, I don't trust *any* electronic device, or item with a high electronic content, manufactured after 2005. I'm only buying new (built after 2005) electronics if: 1. I can't find a suitable item manufactured before 2006 (maybe used, such as from E-bay). 2. I figure it will repay its purchase cost within 3 months (I believe that *most* lead-free electronics will last at least one year, versus 20+ years use that we can get from lead-based electronics). AND 3. It is not manufactured in Europe. If the only suitable product is manufactured in the European Union, which passed the RoHS Directive starting all of this mess, I will do without... For electronics manufactured since the beginning of 2006, I recommend to friends: * If it is AC powered. unplug it when it is not in use. * If it is battery powered, remove or disconnect the battery when it is not in use. I have been studying electronics for 49 years, and working fulltime in the electronics/computer industry for 37 years. I spent 2003 writing my books Robust Electronic Design Reference Book, Volumes I and II http://www.dbicorporation.com/book-out.htm http://www.dbicorporation.com/book-out.htm on how to design and develop electronic products and equipment. Since December 2004 I have been studying lead-free electronics, to see if there is a way to make high-quality, reliable, long-life electronics that are also RoHS-compliant. So far I haven't seen any way to meet both sets of requirements simultaneously... My 1,000+ page, nearly 4MB Bibliography for Designing Lead-Free, RoHS-Compliant, and WEEE-Compliant Electronics is at http://www.dbicorporation.com/rohsbib.htm http://www.dbicorporation.com/rohsbib.htm and covers over 250 books, over 220 PH. D. and Masters theses, and well over 15,875 papers, magazine articles, reports, web pages, etc. on these topics. John Barnes KS4GL, PE, NCE, NCT, ESDC Eng, ESDC Tech, PSE, SM IEEE dBi Corporation http://www.dbicorporation.com/ http://www.dbicorporation.com/ - 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.ieeecommunities.org/emc-pstc http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher:
Re: [PSES] Toyota (keynote speaker)
Hi Dan, If a keynote speaker is needed, I have a keynote talk that is both technically interesting and also will keep them laughing on the floor. The funny part is titled Funny Airport Stories and involves some interesting airport stores, a few of them acted out in a skit. This can be mixed with technical content or alone as a light talk with no thought required. Doug On 3/1/10 12:49 PM, Dan Roman wrote: Anybody know Dr. Griffin at SIU or have contacts at SIU? He might make a timely keynote speaker for the Boston Symposium or perhaps one of his students could do a paper at the Symposium. (See previous email with subject [PSES] FW: [LF] Expert recreates Toyota sudden acceleration) Dan -Original Message- From: Brian O'Connell [mailto:oconne...@tamuracorp.com] Sent: Monday, March 01, 2010 12:25 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Toyota Please ignore my earlier (snide) comments about s/w vs h/w reliability. This is an important topic that will probably become a recurring theme. Someone needs to give a seminar at a PSES symposium for testing microprocessor-controlled systems. And I am not talking about another standards conformity recipe class. It causes me great pain to say this, but we should probably look for an academic with applied experience to present this subject. We, as a community of safety and EMC professionals, should be concerned that that I continue to surprise and amaze safety agency/NCB assessment engineers with my test technique for a box with an embedded micro-controller. Perhaps the nature of the 'Toyota' discussion should have been the effect of hardware faults on a firmware-controlled system vs white box vs black box tests. Brian -Original Message- From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf Of Waterloo EMC Services Sent: Saturday, February 27, 2010 11:27 AM To: 'emc-p...@ieee.org' Subject: RE: [PSES] Toyota Group After reading this string, I tried putting my Camry Hybrid into neutral while accelerating with the result that the engine immediately dropped to idle and the car coasted freely. In this case the transmission (continuously Variable) is software controlled as is the throttle. John Mowbray Waterloo EMC Services 519 581 7170 email: waterloo...@gto.net Web: www.waterlooemcservices.ca From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Pettit, Ghery Sent: Thursday, February 18, 2010 11:06 AM To: d...@dsmith.org; Bob Richards Cc: emc-p...@ieee.org Subject: RE: [PSES] Toyota That's properly called a Dynaflush transmission. J I know, my first car was a 1954 Buick Special. J Ghery S. Pettit From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Doug Smith Sent: Wednesday, February 17, 2010 9:18 PM To: Bob Richards Cc: emc-p...@ieee.org Subject: Re: [PSES] Toyota The early 50s Buicks had a Dynaflow transmission with infinite gear ratios (variable pitch turbines instead of gears). You could shift into reverse at any speed. The more you pressed on the gas, the quicker the car stopped and then started in the opposite direction (backwards). Doug On 2/17/10 5:42 PM, Bob Richards wrote: I shifted from neutral to reverse once, while going about 60mph forward. (Non-intentional, I must add). It actually went into reverse. The rear tires locked up, but I was able to quickly shift back to neutral and coasted to a stop on the side of the road. I expected to see transmission fluid leaking out, a bent drive shaft, etc. Nothing wrong. Cranked back up and continued on my way. This was in a Plymouth Arrow (I believe it was a Mitsubishi product), circa 1980. Bob R. --- On Wed, 2/17/10, McInturff, Garygary.mcintu...@esterline.com wrote: Oh transmission aren't all that invulnerable. I thought it was impossible to get a transmission into part while doing about 60. An old girlfriend proved me wrong about that - *(*#REN#Y$I243()(@$)(@!! Anybody want some smooth gears and a pile of scrap metal Gary McInturff 208 635 8306 - 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 toemc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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 Douglasemcp...@socal.rr.com Mike Cantwellmcantw...@ieee.org For policy questions, send mail to: Jim Bacher:j.bac...@ieee.org David Heald:dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post
RE: [PSES] Toyota
Anybody know Dr. Griffin at SIU or have contacts at SIU? He might make a timely keynote speaker for the Boston Symposium or perhaps one of his students could do a paper at the Symposium. (See previous email with subject [PSES] FW: [LF] Expert recreates Toyota sudden acceleration) Dan From: Brian O'Connell [mailto:oconne...@tamuracorp.com] Sent: Monday, March 01, 2010 12:25 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Toyota Please ignore my earlier (snide) comments about s/w vs h/w reliability. This is an important topic that will probably become a recurring theme. Someone needs to give a seminar at a PSES symposium for testing microprocessor-controlled systems. And I am not talking about another standards conformity recipe class. It causes me great pain to say this, but we should probably look for an academic with applied experience to present this subject. We, as a community of safety and EMC professionals, should be concerned that that I continue to surprise and amaze safety agency/NCB assessment engineers with my test technique for a box with an embedded micro-controller. Perhaps the nature of the 'Toyota' discussion should have been the effect of hardware faults on a firmware-controlled system vs white box vs black box tests. Brian From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf Of Waterloo EMC Services Sent: Saturday, February 27, 2010 11:27 AM To: 'emc-p...@ieee.org' Subject: RE: [PSES] Toyota Group After reading this string, I tried putting my Camry Hybrid into neutral while accelerating with the result that the engine immediately dropped to idle and the car coasted freely. In this case the transmission (continuously Variable) is software controlled as is the throttle. John Mowbray Waterloo EMC Services 519 581 7170 email: waterloo...@gto.net Web: www.waterlooemcservices.ca From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Pettit, Ghery Sent: Thursday, February 18, 2010 11:06 AM To: d...@dsmith.org; Bob Richards Cc: emc-p...@ieee.org Subject: RE: [PSES] Toyota That's properly called a Dynaflush transmission. J I know, my first car was a 1954 Buick Special. J Ghery S. Pettit From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Doug Smith Sent: Wednesday, February 17, 2010 9:18 PM To: Bob Richards Cc: emc-p...@ieee.org Subject: Re: [PSES] Toyota The early 50s Buicks had a Dynaflow transmission with infinite gear ratios (variable pitch turbines instead of gears). You could shift into reverse at any speed. The more you pressed on the gas, the quicker the car stopped and then started in the opposite direction (backwards). Doug On 2/17/10 5:42 PM, Bob Richards wrote: I shifted from neutral to reverse once, while going about 60mph forward. (Non-intentional, I must add). It actually went into reverse. The rear tires locked up, but I was able to quickly shift back to neutral and coasted to a stop on the side of the road. I expected to see transmission fluid leaking out, a bent drive shaft, etc. Nothing wrong. Cranked back up and continued on my way. This was in a Plymouth Arrow (I believe it was a Mitsubishi product), circa 1980. Bob R. --- On Wed, 2/17/10, McInturff, Gary gary.mcintu...@esterline.com wrote: Oh transmission aren't all that invulnerable. I thought it was impossible to get a transmission into part while doing about 60. An old girlfriend proved me wrong about that - *(*#REN#Y$I243()(@$)(@!! Anybody want some smooth gears and a pile of scrap metal Gary McInturff 208 635 8306 - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Toyota -- Comment on Software and Electronics for Safety
Brian, Several years ago, in a workshop at one of the first Product Safety Engineering Society (PSES) symposiums, the question came up: How can you certify software for safety-critical applications? One of the people in the audience answered Treat the software as a switch with two positions, ON or OFF. Then ask yourself, what will happen if the switch is in the wrong position? At that time our answer was that you need hardware to provide safety-- electronic, electrical, mechanical, or something. But don't trust software. With the advent of lead-free, RoHS-compliant electronics, I now don't trust electronics either. When it is *my* health or safety on the line, I ask: * What can happen if *any* one solder joint goes open? * What can happen if *any* two points within 10mm of each other-- that aren't separated by some kind of physical insulating barrier-- become shorted to one another? (But see conductive anodic filaments, CAF, where short circuits can develop inside of lead-free printed circuit boards.) Because of the conversion to lead-free electronics, I don't trust *any* electronic device, or item with a high electronic content, manufactured after 2005. I'm only buying new (built after 2005) electronics if: 1. I can't find a suitable item manufactured before 2006 (maybe used, such as from E-bay). 2. I figure it will repay its purchase cost within 3 months (I believe that *most* lead-free electronics will last at least one year, versus 20+ years use that we can get from lead-based electronics). AND 3. It is not manufactured in Europe. If the only suitable product is manufactured in the European Union, which passed the RoHS Directive starting all of this mess, I will do without... For electronics manufactured since the beginning of 2006, I recommend to friends: * If it is AC powered. unplug it when it is not in use. * If it is battery powered, remove or disconnect the battery when it is not in use. I have been studying electronics for 49 years, and working fulltime in the electronics/computer industry for 37 years. I spent 2003 writing my books Robust Electronic Design Reference Book, Volumes I and II http://www.dbicorporation.com/book-out.htm on how to design and develop electronic products and equipment. Since December 2004 I have been studying lead-free electronics, to see if there is a way to make high-quality, reliable, long-life electronics that are also RoHS-compliant. So far I haven't seen any way to meet both sets of requirements simultaneously... My 1,000+ page, nearly 4MB Bibliography for Designing Lead-Free, RoHS-Compliant, and WEEE-Compliant Electronics is at http://www.dbicorporation.com/rohsbib.htm and covers over 250 books, over 220 PH. D. and Masters theses, and well over 15,875 papers, magazine articles, reports, web pages, etc. on these topics. John Barnes KS4GL, PE, NCE, NCT, ESDC Eng, ESDC Tech, PSE, SM IEEE dBi Corporation http://www.dbicorporation.com/ - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Translation sought for CENELEC-Speak
Reviewing the following link, I see that for EN 60204-33 the Stage code deadline is 1 March 10. It also shows the Target date for vote as 30 June 10. http://tinyurl.com/FprEN60204-33-2009 1. What do these two dates imply? 2. When will the Dor, Dav...Dow dates be set? 3. Historically, what is the timeline for Member States to make the standard available with respect to the two dates mentioned? Any help is appreciated. Thanks and best regards, Steve -- Steve Baldwin 408 838-2667 baldwin...@gmail.com - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com
RE: [PSES] Toyota
Please ignore my earlier (snide) comments about s/w vs h/w reliability. This is an important topic that will probably become a recurring theme. Someone needs to give a seminar at a PSES symposium for testing microprocessor-controlled systems. And I am not talking about another standards conformity recipe class. It causes me great pain to say this, but we should probably look for an academic with applied experience to present this subject. We, as a community of safety and EMC professionals, should be concerned that that I continue to surprise and amaze safety agency/NCB assessment engineers with my test technique for a box with an embedded micro-controller. Perhaps the nature of the 'Toyota' discussion should have been the effect of hardware faults on a firmware-controlled system vs white box vs black box tests. Brian From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf Of Waterloo EMC Services Sent: Saturday, February 27, 2010 11:27 AM To: 'emc-p...@ieee.org' Subject: RE: [PSES] Toyota Group After reading this string, I tried putting my Camry Hybrid into neutral while accelerating with the result that the engine immediately dropped to idle and the car coasted freely. In this case the transmission (continuously Variable) is software controlled as is the throttle. John Mowbray Waterloo EMC Services 519 581 7170 email: waterloo...@gto.net Web: www.waterlooemcservices.ca From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Pettit, Ghery Sent: Thursday, February 18, 2010 11:06 AM To: d...@dsmith.org; Bob Richards Cc: emc-p...@ieee.org Subject: RE: [PSES] Toyota That's properly called a Dynaflush transmission. J I know, my first car was a 1954 Buick Special. J Ghery S. Pettit From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Doug Smith Sent: Wednesday, February 17, 2010 9:18 PM To: Bob Richards Cc: emc-p...@ieee.org Subject: Re: [PSES] Toyota The early 50s Buicks had a Dynaflow transmission with infinite gear ratios (variable pitch turbines instead of gears). You could shift into reverse at any speed. The more you pressed on the gas, the quicker the car stopped and then started in the opposite direction (backwards). Doug On 2/17/10 5:42 PM, Bob Richards wrote: I shifted from neutral to reverse once, while going about 60mph forward. (Non-intentional, I must add). It actually went into reverse. The rear tires locked up, but I was able to quickly shift back to neutral and coasted to a stop on the side of the road. I expected to see transmission fluid leaking out, a bent drive shaft, etc. Nothing wrong. Cranked back up and continued on my way. This was in a Plymouth Arrow (I believe it was a Mitsubishi product), circa 1980. Bob R. --- On Wed, 2/17/10, McInturff, Gary gary.mcintu...@esterline.com wrote: Oh transmission aren't all that invulnerable. I thought it was impossible to get a transmission into part while doing about 60. An old girlfriend proved me wrong about that - *(*#REN#Y$I243()(@$)(@!! Anybody want some smooth gears and a pile of scrap metal Gary McInturff 208 635 8306 - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
RE: Screened room move.
Hi Ian Charles, When we put in our chamber (Boston area, MA), we used dielectric breaks to all connections and mounting, isolated the power to the chamber and test equipment and then used a dedicated ground from ground rods. We were required to drive 3 rods, 6 ft down, we ended up driving a 4th because # 3 only went down 4 ft. Regards, Charlie Martin From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Grasso, Charles Sent: Friday, February 26, 2010 6:07 PM To: 'Ian White (UK)'; 'IEEE Forum (emc-p...@ieee.org)' Subject: RE: Screened room move. Hello Ian, A single ground rod should suffice – but it all depended on building codes! Best Regards Charles Grasso From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Ian White (UK) Sent: Friday, February 26, 2010 2:24 AM To: IEEE Forum (emc-p...@ieee.org) Subject: Screened room move. We are due to move our EMC screened room within the next year to a new site. It is planned to be placed in a much larger building of steel and concrete construction. We have planned it to be placed close to an outside wall so we can pick up an outside earth which will be bonded in to the mass of the earth for safety reasons Could l hear your ideas on the best solution for earthing the screened room as l feel the present arrangement may be far from ideal. For example is it better to use a number of rod earth electrodes or some sort of steel mesh arrangement buried in the earth for a good RF performance. Thanks for your help. Regards Ian White (Project Engineer - Electronics) - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com
EU power transmission ?
A colleague of mine is looking for guidance on this EU specific question(s): Is CE Mark required for equipment installed in power transmission facilities, power plants, hydroelectric plants, substations and transmission towers? If the answer is yes, is self-declaration acceptable, or is certification required? Also- what standards should be applied during assessment? Thanks in advance. Thx! Patrick Conway, NCE. - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com
RE: [PSES] EuP EC 643 Household refrigerator/freezer requirements
This is just a definition not a requirement. Best regards Andy Andy Clifford Conformance Ltd - Product safety, approvals and CE-marking consultants, The Old Methodist Chapel, Great Hucklow, Buxton, SK17 8RG England Tel. +44 1298 873800, Fax. +44 1298 873801, www.conformance.co.uk Registered in England, Company No. 3478646 From: Scott Xe [mailto:scott...@gmail.com] Sent: 27 February 2010 14:50 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] EuP EC 643 Household refrigerator/freezer requirements In this regulation, the wine cooler is required to have an active or passive control of the compartment humidity in the range from 50 % to 80 %. In the previous requirements, it does not have this requirement. Can someone share what is reason behind to have this control for EuP requirements. Most likely to add an active control of humidity generator in order to meeet this requirement and causes more energy consumption. It sounds contradiction to EuP requirements. Thanks and regards, Scott - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: Screened room move.
Hi Ian, Hans makes some great points. I installed a grid system under my entire building and all metal building structure is bonded to that around the periphery. The shield room is bonded all four corners to this mesh. Power for the chamber is supplied from a dedicated power supply, which itself is Transformer isolated from grid power. The goals were: 1) to make sure all metal stayed at the same potential in the event of a lightning strike for safety. 2) to make all RF potentials on and near the shield room effectively zero. All emissions instrument green wires use the room ground. I have seen a number of cases where noise on the building structure ingresses to the measurement through a ground connection. In thoese cases an inductor has helped. There are loads of compromises to be worked out. You may want to seek advice from a facilities guy, I suggest Wally Pilat of EMC Lab Services, but he's located in the USA. John Dearing of Teseq (UK) may know of someone local. Cheers, Derek Walton L F Research On 2/26/2010 12:44 PM, Hans Mellberg wrote: It depends if you want a single point ground or a distributed ground. For some applications there is a recommendation to use a “ufer” grounding scheme which is essentially a buried grounding grid. At our building, we were able to drill through our concrete floor and install grounding rods about 8feet or about 2.5m deep into earth. No need to place the shield room near the building’s side (unless you are above ground on a multi-story building) Our EMC semi-anechoic chambers were intentionally isolated from ground and only grounded at key locations per the manufacturer’s instructions. It would seem that a multiple distributed grounding scheme might have been better. Best Regards Hans T Mellberg Vice President of Engineering Bay Area Compliance Laboratories www.baclcorp.com 1274 Anvilwood Avenue Sunnyvale, CA 94089, USA (408)732 9162 x 3601 fax: (408) 732 9164 From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Ian White (UK) Sent: Friday, February 26, 2010 1:24 AM To: IEEE Forum (emc-p...@ieee.org) Subject: Screened room move. We are due to move our EMC screened room within the next year to a new site. It is planned to be placed in a much larger building of steel and concrete construction. We have planned it to be placed close to an outside wall so we can pick up an outside earth which will be bonded in to the mass of the earth for safety reasons Could l hear your ideas on the best solution for earthing the screened room as l feel the present arrangement may be far from ideal. For example is it better to use a number of rod earth electrodes or some sort of steel mesh arrangement buried in the earth for a good RF performance. Thanks for your help. Regards Ian White (Project Engineer - Electronics) - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com -
China Quality Inspector
My company would like to start manufacturing in China so I am looking for a local Shenzhen company who specializes in quality inspections /audits Mechanical /electrical sub assemblies e . Joel Mandel Manager Quality Assurance Environmental Testing Teledata Networks Tel: +972.9.9591850 Fax: +972.9.9601171 Mobile: +972.54.7743272 Email: joel.man...@teledata-networks.com mailto:joel.man...@teledata-networks.com Teledata Networks - Access the Future - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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...@socal.rr.com Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com
