Re:
Hi Vijay, **reply below: Regards, Scott Wani, Vijay (V) wrote: Thank you all for your valuable input. i apologize for late reply. i ordered a copy of EN60950:2000. (thanks, Chris, George and constantin) and now, it is getting much clearer. however, i have some questions and would appreciate any comment. as per EN60950:2000, 4.7.2.1: 1. Except where method 2 of 4.7.1 is used exclusively, or as permitted in 4.7.2.2, the following parts are considered to have a risk of ignition and, therefore, require a FIRE ENCLOSURE: - components in PRIMARY CIRCUITS; So if i am interpreting Rich and Scott's e-mail right (great explanation), i do not need FIRE ENCLOSURE, if primary circuit is supplied by a Limited Power source. For an existing device, how do i know whether the primary circuit is supplied by a Limited Power source? are cell-phones, PDA's typically supplied by Limited Power Source? **Once you receive your EN60950, go to section 2.5 where LPS is discussed. LPS characteristics are broken down into two major types: 1) inherently limited (inherent in the circuit design-e.g. high impedance source), and 2) not inherently limited (requires an overcurrent protection device). Circuits must perform to the limits within tables 2B or 2C to be classified as LPS. as per 4.7.3.4 2. Inside FIRE ENCLOSURE, materials for components and other parts, (including MECHANICAL and ELECTRICAL ENCLOSURE located inside FIRE ENCLOSURS) shall comply with on of the following: - be of FLAMMABILITY CLASS V-2 OR FLAMMABILITY CLASS HF-2; OR - pass the flammability test described in clause A.2; or - meet flammability requirements of a relevant IEC component standard which includes such requirements. Does this mean; if i have an enclosure inside a FIRE ENCLOSURE, than it has to be V-2 eventhough there are no safety hazards resulting from complete disapperance of the enclosure? **Yes. In this scenario (assuming it does not serve as an electrical/mechanical enclosure), the key attribute of the internal enclosure you mention is not it's function as an enclosure, but it's fuel load. Therefore, once inside the fire enclosure, the internal enclosure is simply another internal component and must meet the flame rating for internal components or otherwise comply with the exemptions outlined in the standard. thank you. vijay wani --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: CNS Standards
Hi Fred, Is that an official translation of CNS 13438? By the way in visiting your website I notice that you stipulate that In-country testing is required for most equipment Under the APEC Mutual Recognition Arrangement, both Taiwan and the US being signatories, it is not required that testing be conducted in Taiwan. Testing may be conducted by a Conformity Assessment Body (CAB), in the U.S., that has been Nominated by NIST and confirmed by DGT. We are still in Phase 1 of the Arrangement so submission to DGT is still required. Once we move to Phase 2 the confirmed CABs under Phase 2 should be capable of certifying products for DGT. I'd be happy to discuss our capability with you off-line. Best Regards, Barbara ___ Barbara L. Judge Vice President Compliance Certification Services Designated TCB and CAB 561F Monterey Road Morgan Hill, CA 95037 408-463-0885 ext.104 Fax: 408-463-0888 e-mail: bju...@ccsemc.com http://www.ccsemc.com -Original Message- From: Fred Borda [mailto:fbo...@typeapproval.com] Sent: Monday, April 22, 2002 11:22 AM To: rehel...@mmm.com Cc: emc-p...@majordomo.ieee.org Subject: Re: CNS Standards Hello Bob, Compliance International can provide the CNS 13438 standard for you. Please contact me off-list for details. Best regards, -Fred Borda Compliance International www.typeapproval.com At PM 12:05 04/22/02 -0500, rehel...@mmm.com wrote: Can anyone provide a source to purchase Taiwan EMC standards (CNS) in English? Thank you, Bob Heller 3M Product Safety, 76-1-01 St. Paul, MN 55107-1208 Tel: 651- 778-6336 Fax: 651-778-6252 --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list Fred Borda Director Marketing Business Development Compliance International www.typeapproval.com -- The experts in telecommunications equipment type approval across the Asia-Pacific region -- 4713 First Street, Suite 280 Pleasanton, California 94566-7362 USA Tel +1.925.417.5571 (direct) Fax +1.925.417.5574 Mobile +1.650.740.5762 fbo...@typeapproval.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
(Thanks) Consultant - Class 1 Div 1
To all who responded to our clients need, thank you. I have passed on everyone's contact information to our client and they will advise us who they select. Sincerely, Robert R. Loop Engineering Supervisor - Product Safety ph: (256) 837-4411 x313 fax:(256) 721-0144 email: rl...@hnt.wylelabs.com This email transmission is confidential and intended for the addressee only. It may contain privileged and confidential information. If you are not the person or organization to whom it is addressed, you must not copy, distribute, or take any action in reliance upon it. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Decoupling - capacitor values
Tim, Here is the URL to Doug Smith's web page. http://www.emcesd.com/ Regards, Ahmad Fallah -Original Message- From: Wan Juang Foo [mailto:f...@np.edu.sg] Sent: Sunday, April 21, 2002 11:47 PM To: am...@westin-emission.no; ieee pstc list Subject: Re: Decoupling - capacitor values Amund, Thanks for the info, not having a copy of the standard, may I out of curiosity ask about the measurement bandwidth for the various bands? The way I see it, I suppose you have to test Radiated Emission down to 150 kHz which is very unusual because it will bring you into the near field. The units given are in E field units so am I missing on something here. BTY I take it that the units given is 'dBuV/m' and not 'dBmV/m'. Back to the original question of decoupling capacitors values. If 100 pF as a quick fix, proves to do no good, and AFAIK in all probability it may not work for all kinds of reason, then you may have to sniff around to identify the 'radiating element'. This can be done without a chamber and your probes need not be calibrated if it is 'only' used for debugging. As I have mention earlier, train your browser search engine on Douglas Smith or DIY 1 GHz probe and you may get something useful. Does anyone out there have the URLs? sincerely Tim Foo amund@westin-emission. no To: ieee pstc list emc-p...@ieee.org Sent by: cc: (bcc: Wan Juang Foo/ece/staff/npnet) owner-emc-pstc@majordo Subject: SV: Decoupling - capacitor values mo.ieee.org 04/20/02 03:45 PM Please respond to amund Tim, The standard is IEC/EN60945:1997, Maritime navigation and radio communication equipment and systems - General requirements- Methods of testing and required test results. Almost all ship classification societies as Lloyd's Register (LR), Germanischer Lloyd (GL), American Bureau of Shipping (ABS), Bureau Veritas (BV), Det Norske Veritas (DNV), Registro Italiano Navale (RINA), Korean Register of Shipping (KR), China Classification Society (CCS) refer to IEC60945. The limits are: 150kHz-300kHz80-52dBmV/m 300kHz - 30MHz 52-34dBmV/m 30M - 156MHz 54dBmV/m 156M -165MHz 24dBmV/m 165M - 1000MHz 54dBmV/m The 156M -165MHz band is used for marine radio communication, what's why they have stringent demands on radiated emission. Amund -Opprinnelig melding- Fra: Wan Juang Foo [mailto:f...@np.edu.sg] Sendt: 20. april 2002 06:30 Til: am...@westin-emission.no Kopi: ieee pstc list Emne: Re: Decoupling - capacitor values Amund, Cortland may be right, a chamber 'may not' be needed, high ambient considerations to be put aside for the moment, even if the emission is measured to be on the 24dBuV/m @ 3m, freq.band 155MHz-165MHz. I am just curious, what are the limits (or standards) are you trying to meet? From what I read here, is it CISPR22 (or EN 55022) or something like that (Class B) scaled back to 3 m? I note that it is about 20dB below FCC limits for class B (at 3m). If it is a single frequency line emission you can use a home made E or H field probe and work in the near field. Douglas Smith (who post frequently in this forum) have some good articles on DIY 1Ghz probes. You would need a E-field probe to 'sniff' out the CM portion of the emission and a H-field 'loop' to sniff out the offending loop before you can hug a 'return wire' to the offending signal line to cut the return loop down to size. I like to use the (thinisy, i.e. small gauge) wire-wraping wires for this. Good luck and hope that EMC don't always meant that it lead to Even More Coffee for the all nighter. Tim Foo Cortland Richmond 72146.373@compuserve. To: am...@westin-emission.no am...@westin-emission.no, ieee pstc com list emc-p...@ieee.org Sent by: cc: (bcc: Wan Juang Foo/ece/staff/npnet) owner-emc-pstc@majordo Subject: Decoupling - capacitor values (ESR, layout, CM filter) mo.ieee.org 04/20/02 05:39 AM Please respond to Cortland Richmond Cortland Richmond 72146@compuserve.com 04/20/02 05:39 AM Amund, You do not HAVE to be in a chamber to keep working on this. Since there is only one Vcc pin (which processor IS this? - be SURE there is only one Vcc pin; you may have an unfiltered, unconnected Vcc pin or two) you are limited in how many capacitors you can attach to it. This doesn't matter; if you filtered power, and got 7 dB, you've done there
Re: CNS Standards
Hello Bob, Compliance International can provide the CNS 13438 standard for you. Please contact me off-list for details. Best regards, -Fred Borda Compliance International www.typeapproval.com At PM 12:05 04/22/02 -0500, rehel...@mmm.com wrote: Can anyone provide a source to purchase Taiwan EMC standards (CNS) in English? Thank you, Bob Heller 3M Product Safety, 76-1-01 St. Paul, MN 55107-1208 Tel: 651- 778-6336 Fax: 651-778-6252 --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list Fred Borda Director Marketing Business Development Compliance International www.typeapproval.com -- The experts in telecommunications equipment type approval across the Asia-Pacific region -- 4713 First Street, Suite 280 Pleasanton, California 94566-7362 USA Tel +1.925.417.5571 (direct) Fax +1.925.417.5574 Mobile +1.650.740.5762 fbo...@typeapproval.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Decoupling - capacitor values
Tim, Here is the URL to Doug Smith's web page. http://www.emcesd.com/ Regards, Ahmad Fallah -Original Message- From: Wan Juang Foo [mailto:f...@np.edu.sg] Sent: Sunday, April 21, 2002 11:47 PM To: am...@westin-emission.no; ieee pstc list Subject: Re: Decoupling - capacitor values Amund, Thanks for the info, not having a copy of the standard, may I out of curiosity ask about the measurement bandwidth for the various bands? The way I see it, I suppose you have to test Radiated Emission down to 150 kHz which is very unusual because it will bring you into the near field. The units given are in E field units so am I missing on something here. BTY I take it that the units given is 'dBuV/m' and not 'dBmV/m'. Back to the original question of decoupling capacitors values. If 100 pF as a quick fix, proves to do no good, and AFAIK in all probability it may not work for all kinds of reason, then you may have to sniff around to identify the 'radiating element'. This can be done without a chamber and your probes need not be calibrated if it is 'only' used for debugging. As I have mention earlier, train your browser search engine on Douglas Smith or DIY 1 GHz probe and you may get something useful. Does anyone out there have the URLs? sincerely Tim Foo amund@westin-emission. no To: ieee pstc list emc-p...@ieee.org Sent by: cc: (bcc: Wan Juang Foo/ece/staff/npnet) owner-emc-pstc@majordo Subject: SV: Decoupling - capacitor values mo.ieee.org 04/20/02 03:45 PM Please respond to amund Tim, The standard is IEC/EN60945:1997, Maritime navigation and radio communication equipment and systems - General requirements- Methods of testing and required test results. Almost all ship classification societies as Lloyd's Register (LR), Germanischer Lloyd (GL), American Bureau of Shipping (ABS), Bureau Veritas (BV), Det Norske Veritas (DNV), Registro Italiano Navale (RINA), Korean Register of Shipping (KR), China Classification Society (CCS) refer to IEC60945. The limits are: 150kHz-300kHz80-52dBmV/m 300kHz - 30MHz 52-34dBmV/m 30M - 156MHz 54dBmV/m 156M -165MHz 24dBmV/m 165M - 1000MHz 54dBmV/m The 156M -165MHz band is used for marine radio communication, what's why they have stringent demands on radiated emission. Amund -Opprinnelig melding- Fra: Wan Juang Foo [mailto:f...@np.edu.sg] Sendt: 20. april 2002 06:30 Til: am...@westin-emission.no Kopi: ieee pstc list Emne: Re: Decoupling - capacitor values Amund, Cortland may be right, a chamber 'may not' be needed, high ambient considerations to be put aside for the moment, even if the emission is measured to be on the 24dBuV/m @ 3m, freq.band 155MHz-165MHz. I am just curious, what are the limits (or standards) are you trying to meet? From what I read here, is it CISPR22 (or EN 55022) or something like that (Class B) scaled back to 3 m? I note that it is about 20dB below FCC limits for class B (at 3m). If it is a single frequency line emission you can use a home made E or H field probe and work in the near field. Douglas Smith (who post frequently in this forum) have some good articles on DIY 1Ghz probes. You would need a E-field probe to 'sniff' out the CM portion of the emission and a H-field 'loop' to sniff out the offending loop before you can hug a 'return wire' to the offending signal line to cut the return loop down to size. I like to use the (thinisy, i.e. small gauge) wire-wraping wires for this. Good luck and hope that EMC don't always meant that it lead to Even More Coffee for the all nighter. Tim Foo Cortland Richmond 72146.373@compuserve. To: am...@westin-emission.no am...@westin-emission.no, ieee pstc com list emc-p...@ieee.org Sent by: cc: (bcc: Wan Juang Foo/ece/staff/npnet) owner-emc-pstc@majordo Subject: Decoupling - capacitor values (ESR, layout, CM filter) mo.ieee.org 04/20/02 05:39 AM Please respond to Cortland Richmond Cortland Richmond 72146@compuserve.com 04/20/02 05:39 AM Amund, You do not HAVE to be in a chamber to keep working on this. Since there is only one Vcc pin (which processor IS this? - be SURE there is only one Vcc pin; you may have an unfiltered, unconnected Vcc pin or two) you are limited in how many capacitors you can attach to it. This doesn't matter; if you filtered power, and got 7 dB, you've done there
RE: High Temp Caps and Inductors
Take a look at multi-layer ceramic capacitors from American Technical Ceramics. I used to buy 1.5 uF discoidal models (about 5/8 diameter by 1/8 thick) from them. I imagine that they now have rectangular surface-mount multi-layers capacitors now. Ed Ed Price ed.pr...@cubic.com Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military Avionics EMC Services Is Our Specialty Shake-Bake-Shock - Metrology - Reliability Analysis -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Friday, April 19, 2002 11:49 PM To: emc-p...@majordomo.ieee.org Subject: Re: High Temp Caps and Inductors I read in !emc-pstc that lfresea...@aol.com wrote (in 194.5bfc605.29f1e f...@aol.com) about 'High Temp Caps and Inductors', on Fri, 19 Apr 2002: I'm looking for Ceramics, 0.01 through 1 microfarad. Inductors, 1 to 100 microhenry, about 0.5 amps. You will not, I think, get ceramic capacitors in that value range that keep anything like their low-temperature value at 180 C. You probably need to look at glass-dielectric, but AFAIK a 1 uF glass cap would be physically very large. The normal core materials for inductors in that value range may well be near or above their Curie temperatures, too, so permeability values will be low and very temperature-sensitive. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
CNS Standards
Can anyone provide a source to purchase Taiwan EMC standards (CNS) in English? Thank you, Bob Heller 3M Product Safety, 76-1-01 St. Paul, MN 55107-1208 Tel: 651- 778-6336 Fax: 651-778-6252 --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Marking - Made in XXX
Amund, There are multiple countries that have Country of Origin (CoC) marking requirements. Probably all for the same reasons, i.e. tariffs, truth in advertising, etc. Many countries have their own lists of countries from whom they will not accept imported goods, usually for economic and/or political reasons. At one time, the U.S. would allow imports of products Made in... China, Taiwan, and Thailand, but the U.S. government would not purchase such products. I am sure there are corresponding laws in various other countries. George --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: High Temp Caps and Inductors
Just to keep the record straight, Kapton is a polyimide, not a polyamide. They are vastly different. Polyamide is the general name for the family of polymers commonly referred to as Nylon. Bob Wilson TIR Systems Ltd. Vancouver. -Original Message- From: Scott Lacey [mailto:sco...@world.std.com] Sent: April 21, 2002 6:22 AM To: lfresea...@aol.com Cc: emc-p...@majordomo.ieee.org Subject: RE: High Temp Caps and Inductors Derek, You might try Texas Components (www.texascomponents.com) for high temperature capacitors. They claim usage up to 200 C. I suspect you will have to build (or have built) the inductors. You might check with Dupont to see if Kapton (a high-temperature polyamide) would be suitable for cores. You will also need to obtain magnet wire with suitable insulation, and I suspect that you will have to either weld or silver solder the interconnections. Once you have determined the materials choices any good custom magnetics house should be able to produce the inductors in quantity if needed. Good Luck, Scott Lacey -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of lfresea...@aol.com Sent: Friday, April 19, 2002 5:19 PM To: emc-p...@majordomo.ieee.org Subject: High Temp Caps and Inductors Hi all, I'm designing a filter that has to live and work with an Ambient temp of 180 C. Does anyone have suggestions as to component vendors that I could contact for parts? Thanks, Derek Walton. L F Research
Re:
Vijay, I have posted my opinions within brackets [ ] in your note below. Wani, Vijay (V) vwani%dow@interlock.lexmark.com on 04/20/2002 08:38:51 PM Thank you all for your valuable input. i apologize for late reply. i ordered a copy of EN60950:2000. (thanks, Chris, George and constantin) and now, it is getting much clearer. however, i have some questions and would appreciate any comment. as per EN60950:2000, 4.7.2.1: 1. Except where method 2 of 4.7.1 is used exclusively, or as permitted in 4.7.2.2, the following parts are considered to have a risk of ignition and, therefore, require a FIRE ENCLOSURE: - components in PRIMARY CIRCUITS; So if i am interpreting Rich and Scott's e-mail right (great explanation), i do not need FIRE ENCLOSURE, if primary circuit is supplied by a Limited Power source. For an existing device, how do i know whether the primary circuit is supplied by a Limited Power source? are cell-phones, PDA's typically supplied by Limited Power Source? [The type devices you list are typically battery powered. The output of batteries can often be totally unlimited, thus fire hazards. However, a current limiting device may be used to obtain a limited power source. One way to determine what is the case is to buy the product and test the battery power to the conditions for limited power source.] as per 4.7.3.4 2. Inside FIRE ENCLOSURE, materials for components and other parts, (including MECHANICAL and ELECTRICAL ENCLOSURE located inside FIRE ENCLOSURS) shall comply with on of the following: - be of FLAMMABILITY CLASS V-2 OR FLAMMABILITY CLASS HF-2; OR - pass the flammability test described in clause A.2; or - meet flammability requirements of a relevant IEC component standard which includes such requirements. Does this mean; if i have an enclosure inside a FIRE ENCLOSURE, than it has to be V-2 eventhough there are no safety hazards resulting from complete disapperance of the enclosure? [Simple answer is yes. There are exeptions listed immediately following the text you included above, e.g. parts mounted on materials of flammability class V-1.] thank you. vijay wani --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: High Temp Caps and Inductors
Derek, having previously worked for a filter manufacturer, I was involved with a feedthrough filter design for working up to 150C. A few comments based on the discussion so far: Working Voltage: this has not been mentioned, but considerable de-rating over room temperature ratings will probably be required. Low working voltages, a few Vdc, shouldn't be a problem. Inductor Core Materials: a glance at the Fair-Rite catalogue shows several materials with negligible change in room temp permeability up to 300C: e.g. materials 61, 65,67 68 Solders: somebody mentioned the need to weld, or silver solder. This shouldn't be necessary - 96S solder for example has a melting point of about 221C (96% tin, 4% silver), and is quite usable. Epoxy Seals: feedthroughs are commonly sealed with expoy encapsulants, and these are available with wide operating temperature ranges. BUT, temperature cycling has considerable effect, and can easily cause cracks in the sealant. So, it may be equally important to consider a) what is the minimum operating temperature, and b) how many times will the filter have to go from minimum temperature to 180C and back. The same consideration applies to an encapsulated inductor. Repeated temp cycling can be a real killer! Regards, Jeff Chambers - Dr Jeff Chambers Westbay Technology Ltd Suppliers of EMC Design Software Tel: +44 1229 869 108 Fax: +44 1229 869 108 http://www.westbay.ndirect.co.uk/westbay1.htm j.chamb...@ndirect.co.uk Main St Baycliff Ulverston Cumbria LA12 9RN England - - Original Message - From: lfresea...@aol.com To: emc-p...@majordomo.ieee.org Sent: 19 April 2002 21:19 Subject: High Temp Caps and Inductors Hi all, I'm designing a filter that has to live and work with an Ambient temp of 180 C. Does anyone have suggestions as to component vendors that I could contact for parts? Thanks, Derek Walton. L F Research --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: How to Minimize Global Approvals?
In a message dated 4/19/2002, you write: My summarized Analogue Modem Requirements TBR21 + EG 201 121 (Europe) FCC Pt 68 (Mexico and Canada acceptance?) TS002 (Australasia, no PTC 200?) Hi Alex: As Ron Pickard has already pointed out, Mexico's telecom requirements are not fully harmonized with FCC Part 68, so there is a separate test and approval process for Mexico. I just wanted to add a couple comments about other aspects of your proposed plan: 1) As you know, TBR 21 and EG 201 121 are strictly voluntary, so if you are seeking to cut testing costs this is something you should look at. If you have good confidence in your modem design and you do not expect your customers to insist on this testing, it is an avoidable expense. I typically perform internal testing for those parts of TBR 21 and EG 201 121 that are relevant, but the formal testing at an outside lab is now of questionable value. 2) You use the term Australasia in reference to TS 002. Some people use this term to refer to Australia and the entire Asian region. Please keep in mind that a TS 002 report will only get you approval in Australia. Other countries, such as New Zealand, China, Taiwan, and Singapore each have their own requirements that are not identical to TS 002. Fortunately, there is considerable overlap in the requirements of the different countries, so a carefully designed modem can meet the requirements of all these countries. Other than a few software-controlled characteristics related to dialing and such, the only hardware related parameter where there is a conflict is return loss (Australia and Singapore can not both be addressed with a single compromise impedance). 3) It's not clear whether your plan for worldwide approvals implies that you have a single, worldwide modem design, but you may want to give some thought to how you will address the various worldwide requirements. With some advance planning it is possible to have a single design that can be used worldwide, but without such planning you will likely be forced to have multiple versions of your modem. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 http://www.randolph-telecom.com
RE: Suitable CDN for IEC61000-4-6 ethernet 10/100
LINK LOSS Complete link loss is likely from the collision-detect circuitry (EUT or AE); it interprets the induced RF + signal as a collision. Hubs typically 'partition' ports having high collision rates (remaining ports function normally if the noisy node is disconnected). Some hubs 'unpartition' a noisy port if it is quiet for several minutes. In my opinion, a partitioned port is a failure. BIT ERROR Ethernet is designed for a 1E-10 to 1E-14 bit-error-rate environment. Higher rates clog the network with resent packets. See M. Shooman, The Reliability of Error Correcting Code Implementations. Proc RAMS:1996. IEEE, p148,ff. IEC61000-4-6 acceptance criteria do not require theoretical bit-error rates during screening. Consider your customer: evaluate competitive product and set your goal at equal or better performance. TEST VALIDITY In light of the above, it is important that the immunity test configuration be close to real world. 1) Preserve the IEEE802.3 transmission line - avoid short cables (especially with F-E) and do not attach probes to the line (possible antenna) 2) Cat-5 is required for Ethernet/F-E; 10/100 should also be tested at 10Mb on Cat-3 3) 'band-aid' fixes for EN55022 can reduce immunity; ferrited RJ-45's increase back pressure causing cable-length sensitivites (very bad - customer complaints - no fault found). 4) Field strength is high near the RF input end of the EM clamp. Keep unrelated AE cables away from this area; 300mm clamp-EUT separationmay be required (which you should note on the data sheet). TECHNICAL A good starting point is Application Note 8.7 by T. Greene and P. Brandt on SMSC's website http://www.smsc.com David Original Message- From: Chris Maxwell [mailto:chris.maxw...@nettest.com] Sent: Friday, April 19, 2002 1:35 PM To: emc-p...@majordomo.ieee.org Subject: RE: Suitable CDN for IEC61000-4-6 ethernet 10/100 Maybe there's the rub. We have usually tried to test a device to device link using a crossover cable. We haven't had to worry about small errors. I considered a link loss to be failure; and that's what I was seeing...a complete link loss. Perhaps using a bridge or other type of LAN driving device would make our Ethernet link seem more robust during the test. What do you mean by a lxia box? Chris -Original Message- From: Gary McInturff [SMTP:gary.mcintu...@worldwidepackets.com] Sent: Friday, April 19, 2002 1:18 PM To: Pommerenke, David; Chris Maxwell; emc-p...@majordomo.ieee.org Subject: RE: Suitable CDN for IEC61000-4-6 ethernet 10/100 Yup, when we do immunity testing - we see the occassional crc error or the ilk, but I've never seen a problem with the link. We use an Ixia box to cram data down the lines. There are probably many other traffic generators that will work just fine but none of them are pocket change. Gary -Original Message- --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Consultant - Class 1 Div 1 Locations
Group, We have a client in Orange County, California that needs a consultant for a product intended to be used in a Class 1 Div 1 location. They would prefer someone to work with them on a one-to-one basis and time is of the essence. If anyone with the proper credentials in UL 1203 or FM 3610 would like to contract to assist them, please contact me off line and I will put you in contact with them. Sincerely, Robert R. Loop Engineering Supervisor - Product Safety ph: (256) 837-4411 x313 fax:(256) 721-0144 email: rl...@hnt.wylelabs.com This email transmission is confidential and intended for the addressee only. It may contain privileged and confidential information. If you are not the person or organization to whom it is addressed, you must not copy, distribute, or take any action in reliance upon it. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Varistor to Ground
Hi John, I read your quote below regarding the safety implications of placing MOVs between AC power and ground: Some ban it already: others will in due course, AFAIK. What about sidactors? (essentially a specialized Silicon Controlled Rectifier). We have used them on Telecom circuits with good success with hipot and surge testing. They are more reliable than MOV's as they don't degrade with every activation. Are sidactors banned? Will they be banned? If not, they are an excellent alternative to MOVs. I know of two manufacturers: Teccor and Raychem. Small quantities of the Raychem parts are available from Digi-Key (www.digikey.com). Chris Maxwell | Design Engineer - Optical Division email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | -Original Message- From: John Woodgate [SMTP:j...@jmwa.demon.co.uk] Sent: Friday, April 19, 2002 4:31 PM To: emc-p...@majordomo.ieee.org Subject: Re: Varistor to Ground I read in !emc-pstc that Dan Kwok dk...@intetron.com wrote (in 3cc06a29.e6198...@intetron.com) about 'Varistor to Ground', on Fri, 19 Apr 2002: Is it generally permissible to put a varistor (MOV) across the 120 Vac line and ground for surge suppression/line conditioning products? I can see some potential safety implications here if the MOV shorts but I am interested in how this is addressed in the relevant safety standards. Some ban it already: others will in due course, AFAIK. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: Marking - Made in XXX
On this subject some countries also insist Made in XXX in there own language, i.e. China. regards Darren Pearson Radio Telecom Approval Services Genesys Singleton Court, Wonastow Road Monmouth, NP25 5JA UK Tel: +44 1600 710300 Fax: +44 1600 710301 email: dar...@genesysibs.com web: www.genesysibs.com - Original Message - From: Jacob Schanker schan...@frontiernet.net To: am...@westin-emission.no; emc-p...@majordomo.ieee.org Sent: Sunday, April 21, 2002 5:46 PM Subject: Re: Marking - Made in XXX Amund: I looked into this a few years ago, and for the United States, the answer was yes: country of origin is required to be marked on imported goods. Actually, this was a function of the percentage of foreign material/labor incorporated nto the product, but the short anwswer was yes. I believe the US rules are the responsibility of the Department of Commerce www.doc.gov As a US consumer, I always check for country of origin, and almost always find it marked (more and more these days, it is China). By the way, I believe that if the goods are made in the USA, they do not need to be so marked. But most manufacturers will mark them Made in the U.S.A. anyways, both as an indication to domestic consumers, and for export reasons. Hope this helps. Regards, Jacob Z. Schanker, P.E. 65 Crandon Way Rochester, NY 14618 Phone: 585 442 3909 Fax: 585 442 2182 j.schan...@ieee.org - Original Message - From: am...@westin-emission.no To: emc-p...@majordomo.ieee.org Sent: Saturday, April 20, 2002 5:54 PM Subject: Marking - Made in XXX | | Is it necessary to describe where a product is manufactured, as in Made in | XXX. I have see this statement/label on many products, but is it only | voluntary ? | | Best regards | Amund Westin, Oslo/Norway | | | | --- | This message is from the IEEE EMC Society Product Safety | Technical Committee emc-pstc discussion list. | | Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ | | 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: | Ron Pickard: emc-p...@hypercom.com | Dave Heald: davehe...@attbi.com | | For policy questions, send mail to: | Richard Nute: ri...@ieee.org | Jim Bacher: j.bac...@ieee.org | | All emc-pstc postings are archived and searchable on the web at: | http://ieeepstc.mindcruiser.com/ | Click on browse and then emc-pstc mailing list | --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: FCC Class measuring distance 3 meters vs 10 meters
Hello Cecil, Although it is common practice to extrapolate test distances using a linear scale (20 dB/dec) you need to be warned about the theory behind it that suggest different. Using an OATS type of measurement , the reflected wave by the ground plane does at 10 meters distance fully cancel the direct wave at low antenna heights. Therefore one needs to rise the antenna to find a point where the direct and indirect wave sum up to get twice the amplitude. This is never the case however in normal test set ups. Normally antenna height goes to 4 meters max height and at this point both reflected and direct wave still attenuate. At 30 Mhz this is -25 dB approx. This is valid for horizontal polarization. Vertical the situation is much less critical. At 3 meters however, the situation if fully different. Of course this analysis is theory and valid for small radiators only and for using dipole antennas instead of wideband antenna's, but one must make sure to well understand that this effect will heavily impact the measurement results in many cases. For those who have MathCad , I can send you a Matcad sheet that shows the required test height distance per frequency / OATS size / EUT height. Regards, Gert Gremmen Manager Ce-test, Qualified Testing ce marking and more .. EMCD LVD RTTED MDD MD www.ce-test.nl Electrical / Electronic Equipment -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of cecil.gitt...@kodak.com Sent: Sunday, April 21, 2002 8:12 PM To: emc-p...@majordomo.ieee.org Subject: FCC Class measuring distance 3 meters vs 10 meters Hi All, While reading subpart B I saw that section 15.31 Measurement Standards section (f) (1)states: At frequencies at or above 30 Mhz, measurements may be performed at a distance other than what is specified provided: measurements are not made in the near field... When performing measurements at a distance other than that specified, the results shall be extrapolated to the specified distance using an extrapolation factor of 20dB/decade... Is 3 meters distance testing acceptable for testing to FCC Class A? Cecil --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
SV: Decoupling - capacitor values
Hi Tim, Yes, it's dBuV/m. The bandwidths and limits : 150kHz-300kHz 9kHz 80-52dBuV/m 300kHz - 30MHz 9kHz 52-34dBuV/m 30M - 156MHz 120kHz 54dBuV/m 156M -165MHz 9kHz24dBuV/m 165M - 1000MHz 120kHz 54dBuV/m The standard is under revision and the band 150kHz-30MHz is not included in the new standard. We have now made some sniffers and we will search for 'hot spots'. Regards Amund -Opprinnelig melding- Fra: Wan Juang Foo [mailto:f...@np.edu.sg] Sendt: 22. april 2002 08:47 Til: am...@westin-emission.no; ieee pstc list Emne: Re: Decoupling - capacitor values Amund, Thanks for the info, not having a copy of the standard, may I out of curiosity ask about the measurement bandwidth for the various bands? The way I see it, I suppose you have to test Radiated Emission down to 150 kHz which is very unusual because it will bring you into the near field. The units given are in E field units so am I missing on something here. BTY I take it that the units given is 'dBuV/m' and not 'dBmV/m'. Back to the original question of decoupling capacitors values. If 100 pF as a quick fix, proves to do no good, and AFAIK in all probability it may not work for all kinds of reason, then you may have to sniff around to identify the 'radiating element'. This can be done without a chamber and your probes need not be calibrated if it is 'only' used for debugging. As I have mention earlier, train your browser search engine on Douglas Smith or DIY 1 GHz probe and you may get something useful. Does anyone out there have the URLs? sincerely Tim Foo amund@westin-emission. no To: ieee pstc list emc-p...@ieee.org Sent by: cc: (bcc: Wan Juang Foo/ece/staff/npnet) owner-emc-pstc@majordo Subject: SV: Decoupling - capacitor values mo.ieee.org 04/20/02 03:45 PM Please respond to amund Tim, The standard is IEC/EN60945:1997, Maritime navigation and radio communication equipment and systems - General requirements- Methods of testing and required test results. Almost all ship classification societies as Lloyd's Register (LR), Germanischer Lloyd (GL), American Bureau of Shipping (ABS), Bureau Veritas (BV), Det Norske Veritas (DNV), Registro Italiano Navale (RINA), Korean Register of Shipping (KR), China Classification Society (CCS) refer to IEC60945. The limits are: 150kHz-300kHz80-52dBmV/m 300kHz - 30MHz 52-34dBmV/m 30M - 156MHz 54dBmV/m 156M -165MHz 24dBmV/m 165M - 1000MHz 54dBmV/m The 156M -165MHz band is used for marine radio communication, what's why they have stringent demands on radiated emission. Amund -Opprinnelig melding- Fra: Wan Juang Foo [mailto:f...@np.edu.sg] Sendt: 20. april 2002 06:30 Til: am...@westin-emission.no Kopi: ieee pstc list Emne: Re: Decoupling - capacitor values Amund, Cortland may be right, a chamber 'may not' be needed, high ambient considerations to be put aside for the moment, even if the emission is measured to be on the 24dBuV/m @ 3m, freq.band 155MHz-165MHz. I am just curious, what are the limits (or standards) are you trying to meet? From what I read here, is it CISPR22 (or EN 55022) or something like that (Class B) scaled back to 3 m? I note that it is about 20dB below FCC limits for class B (at 3m). If it is a single frequency line emission you can use a home made E or H field probe and work in the near field. Douglas Smith (who post frequently in this forum) have some good articles on DIY 1Ghz probes. You would need a E-field probe to 'sniff' out the CM portion of the emission and a H-field 'loop' to sniff out the offending loop before you can hug a 'return wire' to the offending signal line to cut the return loop down to size. I like to use the (thinisy, i.e. small gauge) wire-wraping wires for this. Good luck and hope that EMC don't always meant that it lead to Even More Coffee for the all nighter. Tim Foo Cortland Richmond 72146.373@compuserve. To: am...@westin-emission.no am...@westin-emission.no, ieee pstc com list emc-p...@ieee.org Sent by: cc: (bcc: Wan Juang Foo/ece/staff/npnet) owner-emc-pstc@majordo Subject: Decoupling - capacitor values (ESR, layout, CM filter) mo.ieee.org 04/20/02 05:39 AM Please respond to Cortland Richmond Cortland Richmond 72146@compuserve.com 04/20/02 05:39 AM Amund, You do not HAVE to be in a chamber to keep working on this. Since there is only one Vcc pin (which processor IS this? - be SURE
Re: Decoupling - capacitor values
Amund, Thanks for the info, not having a copy of the standard, may I out of curiosity ask about the measurement bandwidth for the various bands? The way I see it, I suppose you have to test Radiated Emission down to 150 kHz which is very unusual because it will bring you into the near field. The units given are in E field units so am I missing on something here. BTY I take it that the units given is 'dBuV/m' and not 'dBmV/m'. Back to the original question of decoupling capacitors values. If 100 pF as a quick fix, proves to do no good, and AFAIK in all probability it may not work for all kinds of reason, then you may have to sniff around to identify the 'radiating element'. This can be done without a chamber and your probes need not be calibrated if it is 'only' used for debugging. As I have mention earlier, train your browser search engine on Douglas Smith or DIY 1 GHz probe and you may get something useful. Does anyone out there have the URLs? sincerely Tim Foo amund@westin-emission. no To: ieee pstc list emc-p...@ieee.org Sent by: cc: (bcc: Wan Juang Foo/ece/staff/npnet) owner-emc-pstc@majordo Subject: SV: Decoupling - capacitor values mo.ieee.org 04/20/02 03:45 PM Please respond to amund Tim, The standard is IEC/EN60945:1997, Maritime navigation and radio communication equipment and systems - General requirements- Methods of testing and required test results. Almost all ship classification societies as Lloyd's Register (LR), Germanischer Lloyd (GL), American Bureau of Shipping (ABS), Bureau Veritas (BV), Det Norske Veritas (DNV), Registro Italiano Navale (RINA), Korean Register of Shipping (KR), China Classification Society (CCS) refer to IEC60945. The limits are: 150kHz-300kHz80-52dBmV/m 300kHz - 30MHz 52-34dBmV/m 30M - 156MHz 54dBmV/m 156M -165MHz 24dBmV/m 165M - 1000MHz 54dBmV/m The 156M -165MHz band is used for marine radio communication, what's why they have stringent demands on radiated emission. Amund -Opprinnelig melding- Fra: Wan Juang Foo [mailto:f...@np.edu.sg] Sendt: 20. april 2002 06:30 Til: am...@westin-emission.no Kopi: ieee pstc list Emne: Re: Decoupling - capacitor values Amund, Cortland may be right, a chamber 'may not' be needed, high ambient considerations to be put aside for the moment, even if the emission is measured to be on the 24dBuV/m @ 3m, freq.band 155MHz-165MHz. I am just curious, what are the limits (or standards) are you trying to meet? From what I read here, is it CISPR22 (or EN 55022) or something like that (Class B) scaled back to 3 m? I note that it is about 20dB below FCC limits for class B (at 3m). If it is a single frequency line emission you can use a home made E or H field probe and work in the near field. Douglas Smith (who post frequently in this forum) have some good articles on DIY 1Ghz probes. You would need a E-field probe to 'sniff' out the CM portion of the emission and a H-field 'loop' to sniff out the offending loop before you can hug a 'return wire' to the offending signal line to cut the return loop down to size. I like to use the (thinisy, i.e. small gauge) wire-wraping wires for this. Good luck and hope that EMC don't always meant that it lead to Even More Coffee for the all nighter. Tim Foo Cortland Richmond 72146.373@compuserve. To: am...@westin-emission.no am...@westin-emission.no, ieee pstc com list emc-p...@ieee.org
Re: FCC Class measuring distance 3 meters vs 10 meters
The following answer represents my thoughts on the technical aspects - I don't know if there are any rules/regulations which govern when you can test at three vs. ten meters. The key issue is that the measurement separation represent the far field, since the FCC scaling represents far field behavior, and there are two parameters involved which need to be logically ANDed to determine whether three meter testing is justified: the far field of the measurement antenna, as well as the far field of the test item. If you were using tuned dipoles, three meters would be in the near field of the measurement antenna at 30 MHz. Most people use biconicals below 200 MHz, or the biconical portion of a biconical-logperiodic combination, so there isn't a problem at low frequencies like there used to be a long time ago. The other issue is the size of the test item. A large test item may not achieve a far field pattern at three meters, and if so the FCC linear scaling doesn't work. I would say that a rule of thumb would be that: if the test item resides comfortably on the 80 cm tall table AND you are using biconicals and logperiodics above 200 MHz then: a three meter test should correlate well with ten meter results. -- Ken Javor EMC Compliance Huntsville, Alabama 256/650-5261 on 4/21/02 1:11 PM, cecil.gitt...@kodak.com at cecil.gitt...@kodak.com wrote: Hi All, While reading subpart B I saw that section 15.31 Measurement Standards section (f) (1)states: At frequencies at or above 30 Mhz, measurements may be performed at a distance other than what is specified provided: measurements are not made in the near field... When performing measurements at a distance other than that specified, the results shall be extrapolated to the specified distance using an extrapolation factor of 20dB/decade... Is 3 meters distance testing acceptable for testing to FCC Class A? Cecil --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
