Equations for twisted-pair (was Re: Zo)
** Virus Warning Message (on gemini2.ieee.org) Found virus TROJ_NAVIDAD.E in file Emanuel.exe The file is deleted. If you have questions, contact virus-ad...@ieee.org * Hi! Robert: I'm very interested in the emperical equations that you have for twisted-pair. Do you mind sharing this with me ? Thanks in advance Perry Qu Robert Macy wrote: Did you find out what you need? Somewhere around here I have the equations that closely approximate twisted pair for 26 Awg and 28 Awg wire from DC to 10MHz. They were derived from empirical modeling. You can make various approximations to simplify their use. That includes impedance, loss per length vs frequency, etc. I don't think they take into account being close to conductors, like a shield, or crosstalk between pairs, because that's another analysis, but they're *extremely* useful for predicting attenuation versus frequency for analyzing the expected performance one will get from DSL modems. - Robert - Robert A. Macy, PEm...@california.com 408 286 3985 fx 408 297 9121 AJM International Electronics Consultants 619 North First St, San Jose, CA 95112 -Original Message- From: William D'Orazio dora...@cae.ca To: EMC Posting (E-mail) emc-p...@majordomo.ieee.org Date: Thursday, January 11, 2001 7:20 AM Subject: Zo Does anybody know the characteristic impedance of a twisted pair? Thanks in advance, ...OLE_Obj... William D'Orazio CAE Electronics Ltd. Electrical System Designer Phone: (514) 341-2000 (X4555) Fax: (514)340-5552 Email: dora...@cae.ca ** Virus Warning Message (on gemini2.ieee.org) Emanuel.exe is removed from here because it contains a virus. *
New Guide on EMC and Functional Safety
** Virus Warning Message (on gemini2.ieee.org) Found virus TROJ_NAVIDAD.E in file Emanuel.exe The file is deleted. If you have questions, contact virus-ad...@ieee.org * Dear Group The Institution of Electrical Engineers (IEE, London, UK) have recently published a new professional guidance document on EMC and Functional Safety, a much neglected and misunderstood area which is becoming very important as more and more safety-related functions are controlled by electronics or software. Their new Guide has a Core, plus nine Industry Annexes. You can download them all for free, in Word or PDF format, from http://www.iee.org.uk/PAB/EMC/core.htm. (Please note: this URL may be case-sensitive.) This new Guide makes the point that meeting EMC standards (e.g. under Europe's EMC directive) may well be inadequate for safety-related applications, and that these need a proper hazards and risk assessment using EMC and safety personnel who are competent to perform this task. (Engineers experienced only in safety or only in EMC will usually need more training if they are to deal with emc-related functional safety.) Everyone involved with EMC or safety should at least read the first few pages of the Core, and copy its Executive Summary widely to their colleagues and managers, so that even more people aren't put at risk by poor design or inadequate testing. If companies follow this new Guide it should help them show due diligence with European CE marking safety directives, and should also help them to achieve a 'state of the art' defence under European Product Liability and General Product Safety directives. (Many companies aren't aware of these latter two directives, because they don't require CE marking or declarations of conformity, but their possible penalties are very much higher than CE marking directives, and the defence they require is much more difficult to achieve.) Although this guide mentions European legislation on EMC and on Safety, it will be of relevance anywhere in the world where functional safety is an issue for electronic equipment or systems. Keith Armstrong Partner, Cherry Clough Consultants, www.cherryclough.com Cherry Clough House, Rochdale Road, Denshaw, OL3 5UE, Great Britain phone: +44 (0)1457 871 605, fax: +44 (0)1457 820 145 E-mail: keith.armstr...@cherryclough.com ** Virus Warning Message (on gemini2.ieee.org) Emanuel.exe is removed from here because it contains a virus. *
RE: Safety test your EMC test sample?
** Virus Warning Message (on gemini2.ieee.org) Found virus TROJ_NAVIDAD.E in file Emanuel.exe The file is deleted. If you have questions, contact virus-ad...@ieee.org * I definitely opt for option 2 in combination with 3. Apart from safety AFTER Emc tests there exist also EMC tests for safety itself. This is a hot topic at the moment in Europe. Currently the ideas go into the direction of two suites of EMC-tests, one for the EMC-directive evaluating spectrum protection and functional immunity, and the second suite for the LVD, MDD or MD, evaluating the safety of the product while undergoing EMC stresses. The initial idea was to use higher levels of the same tests phenomena and that was it and this second suite could be done in the same test lab as the first one (but not the same session) Safety people emphasize however, that safety evaluation is definitely something else as emc testing. Not all safety problems need to show up during functional tests. A IEC technical report will be published in the near future about this topic and it is currently known as 77/231/CDV Regards, Gert Gremmen, (Ing) ce-test, qualified testing === Web presence http://www.cetest.nl CE-shop http://www.cetest.nl/ce_shop.htm /-/ Compliance testing is our core business /-/ === -Original Message- From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf Of eric.lif...@ni.com Sent: Thursday, September 28, 2000 9:02 PM To: IEEE EMC and Product Safety Discussion List Subject: Safety test your EMC test sample? Equipment shall not become dangerous or unsafe as a result of the application of the tests defined in this section of IEC 1000-4. That statement appears in (with only slight variations) -2, -3, -4, -5 and -6. Dangerous or unsafe is not defined. There are no links to any safety standards or other criteria to apply. So, which one of the following would apply? 1. No smoke, no fire, the cover didn't fly off, dogs still hate cats, so it's safe! 2. The usual standards-driven safety qualification is done on another sample, the EMC sample is not safety tested unless something very obvious has happened. 3. Take the EMC sample(s) to the safety lab for validating key parameters like dielectric withstand and leakage current. 4. Take the EMC sample(s) to the safety lab for a full safety evaluation. Regards, Eric Lifsey Compliance Manager National Instruments --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org ** Virus Warning Message (on gemini2.ieee.org) Emanuel.exe is removed from here because it contains a virus. *
Equations for twisted-pair (was Re: Zo)
** Virus Warning Message (on gemini2.ieee.org) Found virus TROJ_NAVIDAD.E in file Emanuel.exe The file is deleted. If you have questions, contact virus-ad...@ieee.org * Hi! Robert: I'm very interested in the emperical equations that you have for twisted-pair. Do you mind sharing this with me ? Thanks in advance Perry Qu Robert Macy wrote: Did you find out what you need? Somewhere around here I have the equations that closely approximate twisted pair for 26 Awg and 28 Awg wire from DC to 10MHz. They were derived from empirical modeling. You can make various approximations to simplify their use. That includes impedance, loss per length vs frequency, etc. I don't think they take into account being close to conductors, like a shield, or crosstalk between pairs, because that's another analysis, but they're *extremely* useful for predicting attenuation versus frequency for analyzing the expected performance one will get from DSL modems. - Robert - Robert A. Macy, PEm...@california.com 408 286 3985 fx 408 297 9121 AJM International Electronics Consultants 619 North First St, San Jose, CA 95112 -Original Message- From: William D'Orazio dora...@cae.ca To: EMC Posting (E-mail) emc-p...@majordomo.ieee.org Date: Thursday, January 11, 2001 7:20 AM Subject: Zo Does anybody know the characteristic impedance of a twisted pair? Thanks in advance, ...OLE_Obj... William D'Orazio CAE Electronics Ltd. Electrical System Designer Phone: (514) 341-2000 (X4555) Fax: (514)340-5552 Email: dora...@cae.ca ** Virus Warning Message (on gemini2.ieee.org) Emanuel.exe is removed from here because it contains a virus. *
New Guide on EMC and Functional Safety
** Virus Warning Message (on gemini2.ieee.org) Found virus TROJ_NAVIDAD.E in file Emanuel.exe The file is deleted. If you have questions, contact virus-ad...@ieee.org * Dear Group The Institution of Electrical Engineers (IEE, London, UK) have recently published a new professional guidance document on EMC and Functional Safety, a much neglected and misunderstood area which is becoming very important as more and more safety-related functions are controlled by electronics or software. Their new Guide has a Core, plus nine Industry Annexes. You can download them all for free, in Word or PDF format, from http://www.iee.org.uk/PAB/EMC/core.htm. (Please note: this URL may be case-sensitive.) This new Guide makes the point that meeting EMC standards (e.g. under Europe's EMC directive) may well be inadequate for safety-related applications, and that these need a proper hazards and risk assessment using EMC and safety personnel who are competent to perform this task. (Engineers experienced only in safety or only in EMC will usually need more training if they are to deal with emc-related functional safety.) Everyone involved with EMC or safety should at least read the first few pages of the Core, and copy its Executive Summary widely to their colleagues and managers, so that even more people aren't put at risk by poor design or inadequate testing. If companies follow this new Guide it should help them show due diligence with European CE marking safety directives, and should also help them to achieve a 'state of the art' defence under European Product Liability and General Product Safety directives. (Many companies aren't aware of these latter two directives, because they don't require CE marking or declarations of conformity, but their possible penalties are very much higher than CE marking directives, and the defence they require is much more difficult to achieve.) Although this guide mentions European legislation on EMC and on Safety, it will be of relevance anywhere in the world where functional safety is an issue for electronic equipment or systems. Keith Armstrong Partner, Cherry Clough Consultants, www.cherryclough.com Cherry Clough House, Rochdale Road, Denshaw, OL3 5UE, Great Britain phone: +44 (0)1457 871 605, fax: +44 (0)1457 820 145 E-mail: keith.armstr...@cherryclough.com ** Virus Warning Message (on gemini2.ieee.org) Emanuel.exe is removed from here because it contains a virus. *
RE: Safety test your EMC test sample?
** Virus Warning Message (on gemini3.ieee.org) Found virus TROJ_NAVIDAD.E in file Emanuel.exe The file is deleted. If you have questions, contact virus-ad...@ieee.org * I definitely opt for option 2 in combination with 3. Apart from safety AFTER Emc tests there exist also EMC tests for safety itself. This is a hot topic at the moment in Europe. Currently the ideas go into the direction of two suites of EMC-tests, one for the EMC-directive evaluating spectrum protection and functional immunity, and the second suite for the LVD, MDD or MD, evaluating the safety of the product while undergoing EMC stresses. The initial idea was to use higher levels of the same tests phenomena and that was it and this second suite could be done in the same test lab as the first one (but not the same session) Safety people emphasize however, that safety evaluation is definitely something else as emc testing. Not all safety problems need to show up during functional tests. A IEC technical report will be published in the near future about this topic and it is currently known as 77/231/CDV Regards, Gert Gremmen, (Ing) ce-test, qualified testing === Web presence http://www.cetest.nl CE-shop http://www.cetest.nl/ce_shop.htm /-/ Compliance testing is our core business /-/ === -Original Message- From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf Of eric.lif...@ni.com Sent: Thursday, September 28, 2000 9:02 PM To: IEEE EMC and Product Safety Discussion List Subject: Safety test your EMC test sample? Equipment shall not become dangerous or unsafe as a result of the application of the tests defined in this section of IEC 1000-4. That statement appears in (with only slight variations) -2, -3, -4, -5 and -6. Dangerous or unsafe is not defined. There are no links to any safety standards or other criteria to apply. So, which one of the following would apply? 1. No smoke, no fire, the cover didn't fly off, dogs still hate cats, so it's safe! 2. The usual standards-driven safety qualification is done on another sample, the EMC sample is not safety tested unless something very obvious has happened. 3. Take the EMC sample(s) to the safety lab for validating key parameters like dielectric withstand and leakage current. 4. Take the EMC sample(s) to the safety lab for a full safety evaluation. Regards, Eric Lifsey Compliance Manager National Instruments --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org ** Virus Warning Message (on gemini3.ieee.org) Emanuel.exe is removed from here because it contains a virus. *
RE: Safety test your EMC test sample?
** Virus Warning Message (on gemini3.ieee.org) Found virus TROJ_NAVIDAD.E in file Emanuel.exe The file is deleted. If you have questions, contact virus-ad...@ieee.org * I definitely opt for option 2 in combination with 3. Apart from safety AFTER Emc tests there exist also EMC tests for safety itself. This is a hot topic at the moment in Europe. Currently the ideas go into the direction of two suites of EMC-tests, one for the EMC-directive evaluating spectrum protection and functional immunity, and the second suite for the LVD, MDD or MD, evaluating the safety of the product while undergoing EMC stresses. The initial idea was to use higher levels of the same tests phenomena and that was it and this second suite could be done in the same test lab as the first one (but not the same session) Safety people emphasize however, that safety evaluation is definitely something else as emc testing. Not all safety problems need to show up during functional tests. A IEC technical report will be published in the near future about this topic and it is currently known as 77/231/CDV Regards, Gert Gremmen, (Ing) ce-test, qualified testing === Web presence http://www.cetest.nl CE-shop http://www.cetest.nl/ce_shop.htm /-/ Compliance testing is our core business /-/ === -Original Message- From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf Of eric.lif...@ni.com Sent: Thursday, September 28, 2000 9:02 PM To: IEEE EMC and Product Safety Discussion List Subject: Safety test your EMC test sample? Equipment shall not become dangerous or unsafe as a result of the application of the tests defined in this section of IEC 1000-4. That statement appears in (with only slight variations) -2, -3, -4, -5 and -6. Dangerous or unsafe is not defined. There are no links to any safety standards or other criteria to apply. So, which one of the following would apply? 1. No smoke, no fire, the cover didn't fly off, dogs still hate cats, so it's safe! 2. The usual standards-driven safety qualification is done on another sample, the EMC sample is not safety tested unless something very obvious has happened. 3. Take the EMC sample(s) to the safety lab for validating key parameters like dielectric withstand and leakage current. 4. Take the EMC sample(s) to the safety lab for a full safety evaluation. Regards, Eric Lifsey Compliance Manager National Instruments --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org ** Virus Warning Message (on gemini3.ieee.org) Emanuel.exe is removed from here because it contains a virus. *
