RTTE Directive Article 6.4 Notification Contact for Greece
Dear Colleagues, Has anyone has any success finding a contact to give notice to under Art 6.4 for Greece? Thanks Best Regards, Kevin Harris Manager, Approval Services Digital Security Controls 3301 Langstaff Road Concord, Ontario CANADA L4K 4L2 Tel: +1 905 760 3000 Ext. 2378 Fax +1 905 760 3020 Email: harr...@dscltd.com mailto:harr...@dscltd.com --- 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
Re: EN61000-3-2 -3
John, you may want to take a look at Schaffners offering, I really like their software and they are addressing A14. Call Greg Senko 603-642-4694 I believe HP are getting out of this market, so you may find some of their equipment going quite cheap. You may also find some other folks advertising in magazines like compliance design. Best regards, Derek. --- 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
Re:MoD Form 911 (Safety Assessment)
forwarded for wjack...@rfc.comm.harris.com Reply Separator Subject:MoD Form 911 (Safety Assessment) Author: Jackson; William wjack...@rfc.comm.harris.com List-Post: emc-pstc@listserv.ieee.org Date: 1/16/01 11:30 AM Greetings List, Can any tell me where I might find a copy of the subject document? Thanks, Bill Bill Jackson, CQE QA PrgmsEng/Product Safety Harris RF Communications Division (RFCD) (716)-242-3897 wjack...@harris.com --- 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
RE: Site Correlation
I have the feeling that different issues are mixed in this discussion. supposed that CE vs. RE methods is the issue, I can give you some historical information. The CE method is used as a simplified method for the radiation of the tested device. The CE method was used for devices which have to met several conditions 1. the cable length was long compared to the size of the device ( the longest side should not be longer than 80 cm) 2. the number of cable is limited to one or maximum 2 cables. 3. the frequencies produced in the equipment have to be low due the limitation of the method to 300 MHz. Reasons for 1. the cable should be the preferred antenna for the emission of the device 2. You can only made a correlation between CE and RE if all the radiated by the one cable. You will not be able to calculate the sum of different cables because you don't know the relation. 3. The method is only specified up to 300 MHz. At higher frequencies the cables act different. This method was used e. g. simple household devices and tools. I don't know if I got the real point because I didn't followed the whole discussion, but perhaps I can put in some more ideas. Best Regards Lothar Schmidt Technical Manager EMC/Bluetooth, BQB, Competent Body Cetecom Inc. 411 Dixon Landing Road Milpitas, CA 95035 Phone: +1 (408) 586 6214 Fax: +1 (408) 586 6299 -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Tuesday, January 16, 2001 7:45 AM To: Ralph Cameron; chris maxwell; dan kwok Cc: EMC-PCST (E-mail) Subject: Re: Site Correlation I am getting the distinct (but uncomfortable) feeling that was is being discussed by a lot of people on this thread is that cable cm CE need to be controlled to prevent either crosstalk to another bundle, or to prevent interference to equipment connected to the same bundle. Am I interpreting these comments correctly? For the record, I don't believe either of these is a real issue. The only traditional, and in my experience, legitimate purpose of controlling cable cm CE is to prevent coupling to the antennas connected to radio receivers. Ken Javor -- From: Ralph Cameron ral...@igs.net To: Chris Maxwell chris.maxw...@gnnettest.com, Ken Javor ken.ja...@emccompliance.com, dan kwok dk...@intetron.com Cc: EMC-PCST \(E-mail\) emc-p...@majordomo.ieee.org Subject: Re: Site Correlation Date: Tue, Jan 16, 2001, 9:01 AM What it boils down to Chris is the lack of immunity of the consumer equipment contributes to degradation of the intended function. Once the undesired energy reaches the consumer device there's no way to get rid of it. The rememdy is to prevent it from reaching the device and or isolating it from the source. At one time injection clamps were used for immunity testing- are they still? Ralph Cameron - Original Message - From: Chris Maxwell chris.maxw...@gnnettest.com To: 'Ralph Cameron' ral...@igs.net; Ken Javor ken.ja...@emccompliance.com; dan kwok dk...@intetron.com Cc: EMC-PCST (E-mail) emc-p...@majordomo.ieee.org Sent: Tuesday, January 16, 2001 8:38 AM Subject: RE: Site Correlation Seems like this thread has gotten into how to correlate common mode cable currents with their expected radiated emissions. For those interested, Fischer Custom Communications makes coupling and measuring clamps which can measure common mode surface currents on cables and surfaces. They used to publish some application notes regarding the usage of their clamps to measure surface/cable currents and how to correlate them to expected radiated emissions. I read them a couple of years ago. I never bought the clamps, but it did make for some very good technical reading. I do know of a table top power supply manufacturer that uses this method almost exclusively. They send one power supply to a calibrated OATS. They get it to pass. Then, when the sample comes back to the factory, they take clamp measurements of the common mode currents of the AC input and DC output cable. They then model the power supply as a dipole antenna with the AC input cable and DC output cable being the two poles. For future power supplies, they then use the clamp method in-house to measure the cable currents, if the currents pass, they assume the supply passes radiated emissions. This won't work for every product, but it does fit this application well. The power supply company could make more than 10 versions (3.3VDC, 5VDC, 9VDC, 12VDC ...) of a power supply with the same case and cabling so it can save them a great deal of time and money. The supplies only have two cables, which is easy to model. The supplies have clock speeds in the 100-500Khz range, meaning that most of thier harmonics will be dead over 230Mhz, which is the cutoff for most coupling clamps. I thought that this method would be difficult to use for our products since we have higher clock speeds and multiple cables. I guess many times the measurement
Beta Shipments
I am researching the stipulations for the shipping of Beta versions of ITE type equipment that is not yet compliant with the EU or FCC requirements. I hope I won't need to use this information, but just in case, I would like to know what my options are. Any help in these two arenas (i.e. Europe and US) would be much appreciated. Thanks, Brent Pahl --- 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
Jan. 12, 2001 EMC/Telco/Product Safety Update Now Available
The Curtis-Straus Update for the week ending Jan. 12, 2001 is now available at: http://www.conformity-update.com This week's headlines are: WHAT A BUSH PRESIDENCY MAY MEAN FOR OSHA, FCC. NEW EMC SLIM DOCUMENT EMERGES AFTER MEETING. THE NEW FCC PART 68 RULES. WHAT'S NEW AT UL? ELECTROCUTION, AMPUTATION SPARKS OSHA ACTION. CPSC, DEWALT RECALL 1.7 MILLION BATTERY CHARGERS. REGULATORY BRIEFS: U.S. AND CANADA. U.S./MEXICO TELECOM DEAL HALTS WTO ACTION. WE HAVE THE ERO'S CATALOG. STANDARDS UPDATE. MEETINGS, SEMINARS, ETC. --- 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
EN61000-3-2 -3
Posted for John Linstrom. Q. If I may self-certify my ITE products and the A14, EN61000-3-2, -3 are in effect, how would I go about testing for -2 and -3 compliance? Can I make or rent this equipment? John Linstrom Computer Dynamics ph 864.672.4363 x266 fx 864.675.0106 john.linst...@cdynamics.com --- 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
RE: EN 61000-4-8
The issue is getting the required field strength: 1A (roughly) through a 1m coil will produce about 1A/m field in the center of the coil. Anything bigger than .3m in any dimension, won't be stressed adequately. For bigger stuff, you need a bigger coil, but the problem is you then need more current to get the same field strength: a 2m coil requires 2A, etc... Using multiple turns allows you to keep the current down. For a 1 meter coil, you can get 1A/m from a current of roughly 0.5A. The numbers don't exactly work because of losses in the coil: The coils we buy have a coil factor of about .85, which means they are 85% efficient and you need about 15% more current to get the correct fields. Other coils will have other factors, depending on their design. You can call Fischer Constant Communications -- I believe they've made some very big coils for some customers: FCC 2905 W. Lomita Blvd. Torrance, CA 90505 Tel: 310 891 0635 Fax: 310 891 0644 Hope this helps, Mike Hopkins KeyTek -Original Message- From: wo...@sensormatic.com [mailto:wo...@sensormatic.com] Sent: Tuesday, January 16, 2001 11:42 AM To: emc-p...@majordomo.ieee.org Subject: EN 61000-4-8 We will have to apply the magnetic field immunity test to some of our Generic and ITE products in order to comply with the new revisions of the standards. One of the tests is not clear to us. Consider a product whose width and depth are such that it fits correctly inside the standard 1 m loop, but also assume that the equipment height exceeds 0.5 m. On one hand, the standard tends to indicate that a two or more loops are required to ensure that the entire height of the equipment is immersed during a single test. But on the other hand, there is mention of moving a single loop over the height of the equipment. Do I understand correctly, that tall ( 0.5 m) equipment may be tested using a single 1 m loop that is moved along the height of the equipment? Richard Woods --- 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 --- 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
RE: European connectors
Go to: Panel Components Corporation P.O. Box 115, Oskaloosa, IA 52577 (U.S.A)E-mail: Phone: 641-673-5000 http://www.panelcomponents.com http://www.panelcomponents.com/scripts/wsisa.dll/P80FORM.p?w_part=88010200 For a picture of the connector: http://www.panelcomponents.com/scripts/wsisa.dll/P80FORM.p?w_part=88010200 http://www.panelcomponents.com/scripts/wsisa.dll/P80FORM.p?w_part=88010200 For a drawing: http://www.panelcomponents.com/drawings/88010120.pdf http://www.panelcomponents.com/drawings/88010120.pdf Tony Anton (Tony) Nikolassy Project Engineer, CB Scheme Coordinator Laboratory Qualification Program Factory Mutual Research Ph: 781-255-4819 Fx: 781-762-9375 Email: anton.nikola...@fmglobal.com -Original Message- From: Allen, John [mailto:john.al...@rdel.co.uk] Sent: Tuesday, January 16, 2001 10:01 AM To: daniel.fitzger...@apcc.com; emc-p...@ieee.org Subject:RE: European connectors Hi folks Not an EN60320 device - I think this is the 16A European 2-pin plug with dual (French pin in socket + German spring-loaded side) earthing contacts to Standard Sheet VII of the old CEE 7 standard. This plug is designed to fit almost all Continental European 2-pin sockets, and provides earthing in via the two different routes. Does not fit any British or some Danish, Swiss and Eastern European sockets. Regards John Allen. Thales Defence Ltd Bracknell -Original Message- From: jim_bac...@mail.monarch.com [mailto:jim_bac...@mail.monarch.com] Sent: 16 January 2001 16:37 To: daniel.fitzger...@apcc.com; emc-p...@ieee.org Subject: Re:European connectors forwarding for daniel.fitzger...@apcc.com Reply Separator Subject:European connectors Author: daniel.fitzger...@apcc.com Date: 1/12/01 3:22 PM Do anybody know what a Europe VIIG Plug - CEE (7) VII (16amp) is ? Is it similar too an IEC 320 ? * Daniel T. Fitzgerald Senior Regulatory Compliance Engineer American Power Conversion 978-670-2440 ext 17307 ** --- 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 --- 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 --- 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
EN 61000-4-8
We will have to apply the magnetic field immunity test to some of our Generic and ITE products in order to comply with the new revisions of the standards. One of the tests is not clear to us. Consider a product whose width and depth are such that it fits correctly inside the standard 1 m loop, but also assume that the equipment height exceeds 0.5 m. On one hand, the standard tends to indicate that a two or more loops are required to ensure that the entire height of the equipment is immersed during a single test. But on the other hand, there is mention of moving a single loop over the height of the equipment. Do I understand correctly, that tall ( 0.5 m) equipment may be tested using a single 1 m loop that is moved along the height of the equipment? Richard Woods --- 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
Re:European connectors
forwarding for daniel.fitzger...@apcc.com Reply Separator Subject:European connectors Author: daniel.fitzger...@apcc.com List-Post: emc-pstc@listserv.ieee.org Date: 1/12/01 3:22 PM Do anybody know what a Europe VIIG Plug - CEE (7) VII (16amp) is ? Is it similar too an IEC 320 ? * Daniel T. Fitzgerald Senior Regulatory Compliance Engineer American Power Conversion 978-670-2440 ext 17307 ** --- 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
Re: Site Correlation
I am getting the distinct (but uncomfortable) feeling that was is being discussed by a lot of people on this thread is that cable cm CE need to be controlled to prevent either crosstalk to another bundle, or to prevent interference to equipment connected to the same bundle. Am I interpreting these comments correctly? For the record, I don't believe either of these is a real issue. The only traditional, and in my experience, legitimate purpose of controlling cable cm CE is to prevent coupling to the antennas connected to radio receivers. Ken Javor -- From: Ralph Cameron ral...@igs.net To: Chris Maxwell chris.maxw...@gnnettest.com, Ken Javor ken.ja...@emccompliance.com, dan kwok dk...@intetron.com Cc: EMC-PCST \(E-mail\) emc-p...@majordomo.ieee.org Subject: Re: Site Correlation Date: Tue, Jan 16, 2001, 9:01 AM What it boils down to Chris is the lack of immunity of the consumer equipment contributes to degradation of the intended function. Once the undesired energy reaches the consumer device there's no way to get rid of it. The rememdy is to prevent it from reaching the device and or isolating it from the source. At one time injection clamps were used for immunity testing- are they still? Ralph Cameron - Original Message - From: Chris Maxwell chris.maxw...@gnnettest.com To: 'Ralph Cameron' ral...@igs.net; Ken Javor ken.ja...@emccompliance.com; dan kwok dk...@intetron.com Cc: EMC-PCST (E-mail) emc-p...@majordomo.ieee.org Sent: Tuesday, January 16, 2001 8:38 AM Subject: RE: Site Correlation Seems like this thread has gotten into how to correlate common mode cable currents with their expected radiated emissions. For those interested, Fischer Custom Communications makes coupling and measuring clamps which can measure common mode surface currents on cables and surfaces. They used to publish some application notes regarding the usage of their clamps to measure surface/cable currents and how to correlate them to expected radiated emissions. I read them a couple of years ago. I never bought the clamps, but it did make for some very good technical reading. I do know of a table top power supply manufacturer that uses this method almost exclusively. They send one power supply to a calibrated OATS. They get it to pass. Then, when the sample comes back to the factory, they take clamp measurements of the common mode currents of the AC input and DC output cable. They then model the power supply as a dipole antenna with the AC input cable and DC output cable being the two poles. For future power supplies, they then use the clamp method in-house to measure the cable currents, if the currents pass, they assume the supply passes radiated emissions. This won't work for every product, but it does fit this application well. The power supply company could make more than 10 versions (3.3VDC, 5VDC, 9VDC, 12VDC ...) of a power supply with the same case and cabling so it can save them a great deal of time and money. The supplies only have two cables, which is easy to model. The supplies have clock speeds in the 100-500Khz range, meaning that most of thier harmonics will be dead over 230Mhz, which is the cutoff for most coupling clamps. I thought that this method would be difficult to use for our products since we have higher clock speeds and multiple cables. I guess many times the measurement method is somewhat defined by what you're measuring. Chris Maxwell Design Engineer GN Nettest 6 Rhoads Drive, Building 4 Utica,NY 13502 email: chris.maxw...@gnnettest.com phone: 315-266-5128 fax: 315-797-8024 -Original Message- From: Ralph Cameron [SMTP:ral...@igs.net] Sent: Monday, January 15, 2001 10:57 PM To: Ken Javor; dan kwok Cc: EMC-PCST (E-mail) Subject: Re: Site Correlation No, your message is clear, what I am saying is that the emissions below 30Mhz cause the majority of the interference problems to consumer electronics and that's not being addressed. Ralph Cameron - Original Message - From: Ken Javor ken.ja...@emccompliance.com To: Ralph Cameron ral...@igs.net; dan kwok dk...@intetron.com Cc: EMC-PCST (E-mail) emc-p...@majordomo.ieee.org Sent: Monday, January 15, 2001 10:34 PM Subject: Re: Site Correlation I must have been unclear in my previous message. The purpose of controlling cable cm CE is to control the resultant cable-induced RE, which are controlled to protect tunable antenna-connected radio receivers, period. There was never any other purpose for controlling CE or RE. Ken Javor -- From: Ralph Cameron ral...@igs.net To: Ken Javor ken.ja...@emccompliance.com, Dan Kwok dk...@intetron.com Cc: EMC-PCST \(E-mail\) emc-p...@majordomo.ieee.org Subject: Re: Site Correlation Date: Mon, Jan 15, 2001, 8:51 PM Perhaps what you state is correct Ken but there has been a supposition that RE , induced or
Re: Site Correlation
In a message dated 1/16/01 7:09:38 AM Pacific Standard Time, ral...@igs.net writes: What it boils down to Chris is the lack of immunity of the consumer equipment contributes to degradation of the intended function. Ralph, I've made this point to Art Wall of the FCC many times, he does not want to enforce immunity in the USA. I think that this is a mistake, considdering most companies are doing for Europe anyway. Derek. --- 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
Consumer Electronics Compatibility
Ralph: Would you provide a little more detail about the 30MHz Consumer Electronics compatibility problems that you have been addressing? Are you finding that the path is a direct galvanic connection, or is the problem caused primarily by radiation of energy off of the power lines? What are the most common emitting devices, and what types of devices are the most numerous victims? And of course, what's usually the best solution? Thanks, Ed -Original Message- From: Ralph Cameron [mailto:ral...@igs.net] Sent: Monday, January 15, 2001 7:57 PM To: Ken Javor; dan kwok Cc: EMC-PCST (E-mail) Subject: Re: Site Correlation No, your message is clear, what I am saying is that the emissions below 30Mhz cause the majority of the interference problems to consumer electronics and that's not being addressed. Ralph Cameron - Original Message - From: Ken Javor ken.ja...@emccompliance.com To: Ralph Cameron ral...@igs.net; dan kwok dk...@intetron.com Cc: EMC-PCST (E-mail) emc-p...@majordomo.ieee.org Sent: Monday, January 15, 2001 10:34 PM Subject: Re: Site Correlation I must have been unclear in my previous message. The purpose of controlling cable cm CE is to control the resultant cable-induced RE, which are controlled to protect tunable antenna-connected radio receivers, period. There was never any other purpose for controlling CE or RE. Ken Javor 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 --- 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
Re: Site Correlation
What it boils down to Chris is the lack of immunity of the consumer equipment contributes to degradation of the intended function. Once the undesired energy reaches the consumer device there's no way to get rid of it. The rememdy is to prevent it from reaching the device and or isolating it from the source. At one time injection clamps were used for immunity testing- are they still? Ralph Cameron - Original Message - From: Chris Maxwell chris.maxw...@gnnettest.com To: 'Ralph Cameron' ral...@igs.net; Ken Javor ken.ja...@emccompliance.com; dan kwok dk...@intetron.com Cc: EMC-PCST (E-mail) emc-p...@majordomo.ieee.org Sent: Tuesday, January 16, 2001 8:38 AM Subject: RE: Site Correlation Seems like this thread has gotten into how to correlate common mode cable currents with their expected radiated emissions. For those interested, Fischer Custom Communications makes coupling and measuring clamps which can measure common mode surface currents on cables and surfaces. They used to publish some application notes regarding the usage of their clamps to measure surface/cable currents and how to correlate them to expected radiated emissions. I read them a couple of years ago. I never bought the clamps, but it did make for some very good technical reading. I do know of a table top power supply manufacturer that uses this method almost exclusively. They send one power supply to a calibrated OATS. They get it to pass. Then, when the sample comes back to the factory, they take clamp measurements of the common mode currents of the AC input and DC output cable. They then model the power supply as a dipole antenna with the AC input cable and DC output cable being the two poles. For future power supplies, they then use the clamp method in-house to measure the cable currents, if the currents pass, they assume the supply passes radiated emissions. This won't work for every product, but it does fit this application well. The power supply company could make more than 10 versions (3.3VDC, 5VDC, 9VDC, 12VDC ...) of a power supply with the same case and cabling so it can save them a great deal of time and money. The supplies only have two cables, which is easy to model. The supplies have clock speeds in the 100-500Khz range, meaning that most of thier harmonics will be dead over 230Mhz, which is the cutoff for most coupling clamps. I thought that this method would be difficult to use for our products since we have higher clock speeds and multiple cables. I guess many times the measurement method is somewhat defined by what you're measuring. Chris Maxwell Design Engineer GN Nettest 6 Rhoads Drive, Building 4 Utica,NY 13502 email: chris.maxw...@gnnettest.com phone: 315-266-5128 fax: 315-797-8024 -Original Message- From: Ralph Cameron [SMTP:ral...@igs.net] Sent: Monday, January 15, 2001 10:57 PM To: Ken Javor; dan kwok Cc: EMC-PCST (E-mail) Subject: Re: Site Correlation No, your message is clear, what I am saying is that the emissions below 30Mhz cause the majority of the interference problems to consumer electronics and that's not being addressed. Ralph Cameron - Original Message - From: Ken Javor ken.ja...@emccompliance.com To: Ralph Cameron ral...@igs.net; dan kwok dk...@intetron.com Cc: EMC-PCST (E-mail) emc-p...@majordomo.ieee.org Sent: Monday, January 15, 2001 10:34 PM Subject: Re: Site Correlation I must have been unclear in my previous message. The purpose of controlling cable cm CE is to control the resultant cable-induced RE, which are controlled to protect tunable antenna-connected radio receivers, period. There was never any other purpose for controlling CE or RE. Ken Javor -- From: Ralph Cameron ral...@igs.net To: Ken Javor ken.ja...@emccompliance.com, Dan Kwok dk...@intetron.com Cc: EMC-PCST \(E-mail\) emc-p...@majordomo.ieee.org Subject: Re: Site Correlation Date: Mon, Jan 15, 2001, 8:51 PM Perhaps what you state is correct Ken but there has been a supposition that RE , induced or other wise when converted to conducted current does not effect other devices connected to those same conductors whether they be power, incoming TV or telephone cables etc. All these conductors intercept RE and their effects have been eliminated in 90% of cases( I have personally suppressed ) , by suppresseing the common mode signals.Over 300 successes is a significant statistic. Ralph Cameron . - Original Message - From: Ken Javor ken.ja...@emccompliance.com To: Dan Kwok dk...@intetron.com; Ralph Cameron ral...@igs.net Cc: EMC-PCST (E-mail) emc-p...@majordomo.ieee.org Sent: Monday, January 15, 2001 5:42 PM Subject: Re: Site Correlation Mr. Kwok's theories are logical and no doubt bear on the subject, but there is a historical angle that bears
RE: European connectors
Hi folks Not an EN60320 device - I think this is the 16A European 2-pin plug with dual (French pin in socket + German spring-loaded side) earthing contacts to Standard Sheet VII of the old CEE 7 standard. This plug is designed to fit almost all Continental European 2-pin sockets, and provides earthing in via the two different routes. Does not fit any British or some Danish, Swiss and Eastern European sockets. Regards John Allen. Thales Defence Ltd Bracknell -Original Message- From: jim_bac...@mail.monarch.com [mailto:jim_bac...@mail.monarch.com] Sent: 16 January 2001 16:37 To: daniel.fitzger...@apcc.com; emc-p...@ieee.org Subject: Re:European connectors forwarding for daniel.fitzger...@apcc.com Reply Separator Subject:European connectors Author: daniel.fitzger...@apcc.com List-Post: emc-pstc@listserv.ieee.org Date: 1/12/01 3:22 PM Do anybody know what a Europe VIIG Plug - CEE (7) VII (16amp) is ? Is it similar too an IEC 320 ? * Daniel T. Fitzgerald Senior Regulatory Compliance Engineer American Power Conversion 978-670-2440 ext 17307 ** --- 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 --- 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
Re:European connectors
Jim, Daniel, CEE 7-7, CEE 7/7, and CEE7 VII all refer to the 250V 16A Schuko plug commonly used in Europe. http://www.internationalconfig.com/config_chart/index.htmshows it at the very top. John Barnes Advisory Engineer Lexmark International --- 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
History Lesson - Pagers Cordless phones
While I don't personally care for 'spam' messages, I thought the group would find this interesting . . . a brief history lesson about pagers, walkie-talkies and cordless phones (as well as a lesson to be learned - don't let your patents expire!) It is actually an obituary about the inventor that was written by the Los Angeles Times and noted in the Long Island Newsday yesterday. *** Al Gross' ideas took decades to catch on. And by the time they gained wide-spread popularity, he had suffered the fate of a legion of inspired inventor: his patents had expired. But what a difference Gross' gizmos made. Gross, who died Dec. 21 in Sun City, Arizona at 82, invented the walkie-talkie, the wireless pager, and the cordless telephone. He also pioneered Citizen's Band radio. His patents led to technological developments that have become icons of the late 20th century, such as the cellular phone. Gross also inspired the wristwatch radio, tha twas indespensable to a 1950's cartoon-strip detective named Dick Tracy. Half a century ago, however, when Gross tried to market his pager at a medical convention, doctors smirked at the device. It would, they complained, ruin afternoons at the golf course. By the end of the 20th Century, 300 million pocket pagers wre in use around the world. I was born 35 years too soon, he once told The Arizona Republic. If I still had the patents on my inventions, Bill Gates would have to stand aside for me. Gross was born in Toronto. By 1937 he had built a hand-held radio that could transmit messages across town. He called it a 'walkie-talkie.' In 1949, he devised the first wireless pager, and in 1951 the wireless telephone. in 1958 he came up with the first battery-operated calculatory, developed for the military. Gross held about a dozen patents, all of which had expired around 1971. Last year Gross was honored with a $500,000 Lemelson-Massachusetts Institute of Technology Lifetime Acheivement Award for Invention. Along the way, he earned a degree in electrical engineering from what is now Case Western Reserve University in Cleveland. He also studied under Albert Einstein at Princeton. GRoss is survived by his wife Ethel Stanka Gross of Sun City. ** That man could've been very wealthy . . . don't let your patents expire! John Juhasz Fiber Options Bohemia, NY
RE: Site Correlation
Seems like this thread has gotten into how to correlate common mode cable currents with their expected radiated emissions. For those interested, Fischer Custom Communications makes coupling and measuring clamps which can measure common mode surface currents on cables and surfaces. They used to publish some application notes regarding the usage of their clamps to measure surface/cable currents and how to correlate them to expected radiated emissions. I read them a couple of years ago. I never bought the clamps, but it did make for some very good technical reading. I do know of a table top power supply manufacturer that uses this method almost exclusively. They send one power supply to a calibrated OATS. They get it to pass. Then, when the sample comes back to the factory, they take clamp measurements of the common mode currents of the AC input and DC output cable. They then model the power supply as a dipole antenna with the AC input cable and DC output cable being the two poles. For future power supplies, they then use the clamp method in-house to measure the cable currents, if the currents pass, they assume the supply passes radiated emissions. This won't work for every product, but it does fit this application well. The power supply company could make more than 10 versions (3.3VDC, 5VDC, 9VDC, 12VDC ...) of a power supply with the same case and cabling so it can save them a great deal of time and money. The supplies only have two cables, which is easy to model. The supplies have clock speeds in the 100-500Khz range, meaning that most of thier harmonics will be dead over 230Mhz, which is the cutoff for most coupling clamps. I thought that this method would be difficult to use for our products since we have higher clock speeds and multiple cables. I guess many times the measurement method is somewhat defined by what you're measuring. Chris Maxwell Design Engineer GN Nettest 6 Rhoads Drive, Building 4 Utica,NY 13502 email: chris.maxw...@gnnettest.com phone: 315-266-5128 fax: 315-797-8024 -Original Message- From: Ralph Cameron [SMTP:ral...@igs.net] Sent: Monday, January 15, 2001 10:57 PM To: Ken Javor; dan kwok Cc: EMC-PCST (E-mail) Subject: Re: Site Correlation No, your message is clear, what I am saying is that the emissions below 30Mhz cause the majority of the interference problems to consumer electronics and that's not being addressed. Ralph Cameron - Original Message - From: Ken Javor ken.ja...@emccompliance.com To: Ralph Cameron ral...@igs.net; dan kwok dk...@intetron.com Cc: EMC-PCST (E-mail) emc-p...@majordomo.ieee.org Sent: Monday, January 15, 2001 10:34 PM Subject: Re: Site Correlation I must have been unclear in my previous message. The purpose of controlling cable cm CE is to control the resultant cable-induced RE, which are controlled to protect tunable antenna-connected radio receivers, period. There was never any other purpose for controlling CE or RE. Ken Javor -- From: Ralph Cameron ral...@igs.net To: Ken Javor ken.ja...@emccompliance.com, Dan Kwok dk...@intetron.com Cc: EMC-PCST \(E-mail\) emc-p...@majordomo.ieee.org Subject: Re: Site Correlation Date: Mon, Jan 15, 2001, 8:51 PM Perhaps what you state is correct Ken but there has been a supposition that RE , induced or other wise when converted to conducted current does not effect other devices connected to those same conductors whether they be power, incoming TV or telephone cables etc. All these conductors intercept RE and their effects have been eliminated in 90% of cases( I have personally suppressed ) , by suppresseing the common mode signals.Over 300 successes is a significant statistic. Ralph Cameron . - Original Message - From: Ken Javor ken.ja...@emccompliance.com To: Dan Kwok dk...@intetron.com; Ralph Cameron ral...@igs.net Cc: EMC-PCST (E-mail) emc-p...@majordomo.ieee.org Sent: Monday, January 15, 2001 5:42 PM Subject: Re: Site Correlation Mr. Kwok's theories are logical and no doubt bear on the subject, but there is a historical angle that bears inspection. About the time FCC limits for IT equipment were being drawn up (late '70s) PCs were not yet on everyone's desktop. Most of the business equipment that would have been envisioned to be qualified to USC Title 47, Part 15, Subpart J would have been stand-alone items such a copier, with the only cable connection being ac power. The report which documents the development of the CE and RE limits/test methods found in the above mentioned FCC limits specifically states that 30 MHz was picked as the cutoff between CE and RE for the reason of radiation efficiency per Mr. Kwok's surmise, but also because 30 MHz was the lowest frequency at which a 3 m OATS measurement would provide the desired accuracy. Ken Javor
RE: Transient Surge Suppressor
John, Another source to consider is Protek. I only have a catalog, which doesn't list a website. They probably have one by now. Their phone number is 602-431-8101. They are located in Arizona, so they'll be a couple of hours behind Eastern Time. (Arizona sort of has thier own time zone, something about they don't buy into the daylight savings time theory). Their product line is similar to Semtech. Sometimes their part availability is better. Best Regards, Chris Maxwell Design Engineer GN Nettest 6 Rhoads Drive, Building 4 Utica,NY 13502 email: chris.maxw...@gnnettest.com phone: 315-266-5128 fax: 315-797-8024 -Original Message- From: j...@aol.com [SMTP:j...@aol.com] Sent: Monday, January 15, 2001 3:16 PM To: jjuh...@fiberoptions.com; emc-p...@ieee.org Subject: Re: Transient Surge Suppressor In a message dated 1/15/01, John Juhasz writes: I am trying to find a second-source for a TVS (Transient Voltage Suppressor) that I now use to meet the 61000-4-5 1.2/50us 1kV transient. Hi John: To finalize the requirements on the surge suppressor you need, you will have to determine the short circuit current of the surge, the required standoff voltage of the TVS device, the required clamping voltage, and the allowable capacitance. With these parameters in mind, some vendors to consider are Teccor (http://www.teccor.com), ST Microelectronics (http://www.st.com), and Semtech (http://www.semtech.com). All of these vendors have some very nice surface mount crowbar type devices, some of which are in packages common to two or more vendors. For instance, the Teccor sidactor in the DO-214 package is similar to some ST Microelectronics parts. If the surge is not very high energy, you could also consider using surge suppressor zener diodes such as the devices in the SMA, SMB, and SMC packages that many manufacturers of discrete components make. Some of these can handle up to 1500 watts for one millisecond. Motorola (now On Semiconductor, http://onsemi.com), General Semiconductor (http://www.gensemi.com), and Central Semiconductor (http://www.centralsemi.com) all make these devices. Examples from the Motorola family of 600 watt TVS diodes are the 1SMB series and the P6SMB series. For high energy surges, I prefer the crowbar type devices such as teh Teccor sidactor. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 http://www.randolph-telecom.com --- 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
Re: AC Adapters in Australia
Richard, Yes, most likely the adapter will require a safety approval. EMC is also required unless the unit ONLY comes with its powered product, and is not to be commercially available independently. George woods%sensormatic@interlock.lexmark.com on 01/15/2001 04:41:45 PM Please respond to woods%sensormatic@interlock.lexmark.com To: emc-pstc%majordomo.ieee@interlock.lexmark.com cc:(bcc: George Alspaugh/Lex/Lexmark) Subject: AC Adapters in Australia The subject is an AC adapter imported into Australia as part of non-telecom ITE for business use only. Is the AC Adapter for this particular application considered to be declared and thus subject to safety approval? Richard Woods --- 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
Re: Site Correlation
No, your message is clear, what I am saying is that the emissions below 30Mhz cause the majority of the interference problems to consumer electronics and that's not being addressed. Ralph Cameron - Original Message - From: Ken Javor ken.ja...@emccompliance.com To: Ralph Cameron ral...@igs.net; dan kwok dk...@intetron.com Cc: EMC-PCST (E-mail) emc-p...@majordomo.ieee.org Sent: Monday, January 15, 2001 10:34 PM Subject: Re: Site Correlation I must have been unclear in my previous message. The purpose of controlling cable cm CE is to control the resultant cable-induced RE, which are controlled to protect tunable antenna-connected radio receivers, period. There was never any other purpose for controlling CE or RE. Ken Javor -- From: Ralph Cameron ral...@igs.net To: Ken Javor ken.ja...@emccompliance.com, Dan Kwok dk...@intetron.com Cc: EMC-PCST \(E-mail\) emc-p...@majordomo.ieee.org Subject: Re: Site Correlation Date: Mon, Jan 15, 2001, 8:51 PM Perhaps what you state is correct Ken but there has been a supposition that RE , induced or other wise when converted to conducted current does not effect other devices connected to those same conductors whether they be power, incoming TV or telephone cables etc. All these conductors intercept RE and their effects have been eliminated in 90% of cases( I have personally suppressed ) , by suppresseing the common mode signals.Over 300 successes is a significant statistic. Ralph Cameron . - Original Message - From: Ken Javor ken.ja...@emccompliance.com To: Dan Kwok dk...@intetron.com; Ralph Cameron ral...@igs.net Cc: EMC-PCST (E-mail) emc-p...@majordomo.ieee.org Sent: Monday, January 15, 2001 5:42 PM Subject: Re: Site Correlation Mr. Kwok's theories are logical and no doubt bear on the subject, but there is a historical angle that bears inspection. About the time FCC limits for IT equipment were being drawn up (late '70s) PCs were not yet on everyone's desktop. Most of the business equipment that would have been envisioned to be qualified to USC Title 47, Part 15, Subpart J would have been stand-alone items such a copier, with the only cable connection being ac power. The report which documents the development of the CE and RE limits/test methods found in the above mentioned FCC limits specifically states that 30 MHz was picked as the cutoff between CE and RE for the reason of radiation efficiency per Mr. Kwok's surmise, but also because 30 MHz was the lowest frequency at which a 3 m OATS measurement would provide the desired accuracy. Ken Javor P.S. Said report also demonstrated that the CE limit below 30 MHz sufficed to control RE from the power cable to levels sufficient to protect against cable radiation-induced rfi. -- From: Dan Kwok dk...@intetron.com To: Ralph Cameron ral...@igs.net Cc: EMC-PCST (E-mail) emc-p...@majordomo.ieee.org Subject: Re: Site Correlation Date: Mon, Jan 15, 2001, 2:49 PM Hello Ralph: That's a good question. At one time, I pondered the same question myself. There are obviously plenty of communication systems operating under 30 MHz. I suppose there are reasons why CISPR or CISPR 22 does not specify radiated emissions below 30 MHz. I can suggest one possibility. Perhaps others here will come up with more. For a fixed cable of length L, the ratio of L/lambda gets progressively small for frequencies much less than 30 MHz with most commercial EUTs. If we consider the cable part of dipole antenna, the reduction in frequency has a diminishing effect on the antenna's radiation resistance. Given a constant current, the radiated power would decrease with decreasing radiation resistance. At 550 KHz (bottom of the AM broadcast band in North America), the 1/4 wavelength is 136 meters. Even if the antenna's reactance is ignored, one would need very long cables driven by a significant CM noise voltage at this frequency to radiate much energy. -- Daniel Kwok Principal EMC Engineer Intetron Consulting, Inc. Vancouver, Canada Phone (604) 432-9874 Email dk...@intetron.com Web http://www.intetron.com; Ralph Cameron wrote: Ken: I like the idea of setting a limit to common mode currents on attaching cables but mI wonder why CISPR has chosen to start such measurements at 30Mhz when most of the common mode currents are the result of switching products and are generated harmonically from the fundamental and as such propagate from the low Khz range up through 30Mhz. is there no consideration for those who occupy the spectrum below 30Mhz? --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To
RE: AC Adapters in Australia
Richard, If by AC Adapter you mean a plug-pack stand-alone SELV type power supply (i.e. an Extra-Low Voltage Power Supply Unit) then it is a Declared Article and requires electrical approval (by one of the Australian State Electricity Authorities etc). I notice you picked up on for business use only. Although the Declared Articles listing does say that such devices only fall under the Declared Articles listing if they are of a household type, the Electricity Authorities consider all such devices can be of a household type unless they have a very unique means of connection between the AC Adapter and the equipment it supplies (i.e. most have relatively common means of connection enabling them to be used to power many other types of equipment, including household type equipment. My advice is - approval required Richard. Best regards, Kevin Richardson Stanimore Pty Limited Compliance Advice Solutions for Technology Products and Services (Legislation/Regulations/Standards) Ph: 02-4329-4070 (Int'l: +61-2-4329-4070) Fax: 02-4328-5639 (Int'l: +61-2-4328-5639) Mobile: 04-1224-1620 (Int'l: +61-4-1224-1620) Email:k...@compuserve.com kevin.richard...@ieee.org k...@technologist.com (alternate internet) -Original Message- From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf Of wo...@sensormatic.com Sent: Tuesday, 16 January 2001 8:42 AM To: emc-p...@majordomo.ieee.org Subject: AC Adapters in Australia The subject is an AC adapter imported into Australia as part of non-telecom ITE for business use only. Is the AC Adapter for this particular application considered to be declared and thus subject to safety approval? Richard Woods --- 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 --- 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
Re: Site Correlation
I must have been unclear in my previous message. The purpose of controlling cable cm CE is to control the resultant cable-induced RE, which are controlled to protect tunable antenna-connected radio receivers, period. There was never any other purpose for controlling CE or RE. Ken Javor -- From: Ralph Cameron ral...@igs.net To: Ken Javor ken.ja...@emccompliance.com, Dan Kwok dk...@intetron.com Cc: EMC-PCST \(E-mail\) emc-p...@majordomo.ieee.org Subject: Re: Site Correlation Date: Mon, Jan 15, 2001, 8:51 PM Perhaps what you state is correct Ken but there has been a supposition that RE , induced or other wise when converted to conducted current does not effect other devices connected to those same conductors whether they be power, incoming TV or telephone cables etc. All these conductors intercept RE and their effects have been eliminated in 90% of cases( I have personally suppressed ) , by suppresseing the common mode signals.Over 300 successes is a significant statistic. Ralph Cameron . - Original Message - From: Ken Javor ken.ja...@emccompliance.com To: Dan Kwok dk...@intetron.com; Ralph Cameron ral...@igs.net Cc: EMC-PCST (E-mail) emc-p...@majordomo.ieee.org Sent: Monday, January 15, 2001 5:42 PM Subject: Re: Site Correlation Mr. Kwok's theories are logical and no doubt bear on the subject, but there is a historical angle that bears inspection. About the time FCC limits for IT equipment were being drawn up (late '70s) PCs were not yet on everyone's desktop. Most of the business equipment that would have been envisioned to be qualified to USC Title 47, Part 15, Subpart J would have been stand-alone items such a copier, with the only cable connection being ac power. The report which documents the development of the CE and RE limits/test methods found in the above mentioned FCC limits specifically states that 30 MHz was picked as the cutoff between CE and RE for the reason of radiation efficiency per Mr. Kwok's surmise, but also because 30 MHz was the lowest frequency at which a 3 m OATS measurement would provide the desired accuracy. Ken Javor P.S. Said report also demonstrated that the CE limit below 30 MHz sufficed to control RE from the power cable to levels sufficient to protect against cable radiation-induced rfi. -- From: Dan Kwok dk...@intetron.com To: Ralph Cameron ral...@igs.net Cc: EMC-PCST (E-mail) emc-p...@majordomo.ieee.org Subject: Re: Site Correlation Date: Mon, Jan 15, 2001, 2:49 PM Hello Ralph: That's a good question. At one time, I pondered the same question myself. There are obviously plenty of communication systems operating under 30 MHz. I suppose there are reasons why CISPR or CISPR 22 does not specify radiated emissions below 30 MHz. I can suggest one possibility. Perhaps others here will come up with more. For a fixed cable of length L, the ratio of L/lambda gets progressively small for frequencies much less than 30 MHz with most commercial EUTs. If we consider the cable part of dipole antenna, the reduction in frequency has a diminishing effect on the antenna's radiation resistance. Given a constant current, the radiated power would decrease with decreasing radiation resistance. At 550 KHz (bottom of the AM broadcast band in North America), the 1/4 wavelength is 136 meters. Even if the antenna's reactance is ignored, one would need very long cables driven by a significant CM noise voltage at this frequency to radiate much energy. -- Daniel Kwok Principal EMC Engineer Intetron Consulting, Inc. Vancouver, Canada Phone (604) 432-9874 Email dk...@intetron.com Web http://www.intetron.com; Ralph Cameron wrote: Ken: I like the idea of setting a limit to common mode currents on attaching cables but mI wonder why CISPR has chosen to start such measurements at 30Mhz when most of the common mode currents are the result of switching products and are generated harmonically from the fundamental and as such propagate from the low Khz range up through 30Mhz. is there no consideration for those who occupy the spectrum below 30Mhz? --- 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 --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail
Re: Site Correlation
Perhaps what you state is correct Ken but there has been a supposition that RE , induced or other wise when converted to conducted current does not effect other devices connected to those same conductors whether they be power, incoming TV or telephone cables etc. All these conductors intercept RE and their effects have been eliminated in 90% of cases( I have personally suppressed ) , by suppresseing the common mode signals.Over 300 successes is a significant statistic. Ralph Cameron . - Original Message - From: Ken Javor ken.ja...@emccompliance.com To: Dan Kwok dk...@intetron.com; Ralph Cameron ral...@igs.net Cc: EMC-PCST (E-mail) emc-p...@majordomo.ieee.org Sent: Monday, January 15, 2001 5:42 PM Subject: Re: Site Correlation Mr. Kwok's theories are logical and no doubt bear on the subject, but there is a historical angle that bears inspection. About the time FCC limits for IT equipment were being drawn up (late '70s) PCs were not yet on everyone's desktop. Most of the business equipment that would have been envisioned to be qualified to USC Title 47, Part 15, Subpart J would have been stand-alone items such a copier, with the only cable connection being ac power. The report which documents the development of the CE and RE limits/test methods found in the above mentioned FCC limits specifically states that 30 MHz was picked as the cutoff between CE and RE for the reason of radiation efficiency per Mr. Kwok's surmise, but also because 30 MHz was the lowest frequency at which a 3 m OATS measurement would provide the desired accuracy. Ken Javor P.S. Said report also demonstrated that the CE limit below 30 MHz sufficed to control RE from the power cable to levels sufficient to protect against cable radiation-induced rfi. -- From: Dan Kwok dk...@intetron.com To: Ralph Cameron ral...@igs.net Cc: EMC-PCST (E-mail) emc-p...@majordomo.ieee.org Subject: Re: Site Correlation Date: Mon, Jan 15, 2001, 2:49 PM Hello Ralph: That's a good question. At one time, I pondered the same question myself. There are obviously plenty of communication systems operating under 30 MHz. I suppose there are reasons why CISPR or CISPR 22 does not specify radiated emissions below 30 MHz. I can suggest one possibility. Perhaps others here will come up with more. For a fixed cable of length L, the ratio of L/lambda gets progressively small for frequencies much less than 30 MHz with most commercial EUTs. If we consider the cable part of dipole antenna, the reduction in frequency has a diminishing effect on the antenna's radiation resistance. Given a constant current, the radiated power would decrease with decreasing radiation resistance. At 550 KHz (bottom of the AM broadcast band in North America), the 1/4 wavelength is 136 meters. Even if the antenna's reactance is ignored, one would need very long cables driven by a significant CM noise voltage at this frequency to radiate much energy. -- Daniel Kwok Principal EMC Engineer Intetron Consulting, Inc. Vancouver, Canada Phone (604) 432-9874 Email dk...@intetron.com Web http://www.intetron.com; Ralph Cameron wrote: Ken: I like the idea of setting a limit to common mode currents on attaching cables but mI wonder why CISPR has chosen to start such measurements at 30Mhz when most of the common mode currents are the result of switching products and are generated harmonically from the fundamental and as such propagate from the low Khz range up through 30Mhz. is there no consideration for those who occupy the spectrum below 30Mhz? --- 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 --- 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 --- 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
Re: Battery Requirement
Dear Koh Nai Ghee, Hong Kong There is no EMI requirement in Hong Kong. Though there is a voluntry Mark: Hong Kong Safety Mark with EMC requirment. China EMI requirement on 6 types of products according to CISPR, one of which is Switching Mode Power Supply. If your external AC/DC adaptor is so, CCIB EMC require. Otherwise no requirements on Power Supply in China. Best Regards Paul Chan Hong Kong Standards and Testing Centre - Original Message - From: Koh Nai Ghee koh...@cyberway.com.sg To: EMC-PSTC emc-p...@majordomo.ieee.org Sent: Monday, January 15, 2001 10:32 PM Subject: Battery Requirement Hi all, I was being asked a question regarding battery regulatory requirement for a portable analog amplifier speaker. This speaker has built in an internal chargeable battery. This battery is Lead Acid Battery. This speaker is being powered up, as well as battery charging, by an external AC/DC adaptor. The country of concern is as follows, Hong Kong Taiwan Japan Australia/New Zealand China. The EMI requirement are : Taiwan = BSMI, Australia/NZ = C-Tick, Japan =VCCI.. As I'm no expert on batteries, can anyone advice on the battery requirement for the above countries. Your reply is much appreciated. Regards Koh --- 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 --- 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
RE: AC Adapters in Australia
Richard, Will need more details of the AC adaptor, but generally, will need a safety approval and may also need EMC approvals. Praveen -Original Message- From: wo...@sensormatic.com [mailto:wo...@sensormatic.com] Sent: Tuesday, 16 January 2001 8:42 AM To: emc-p...@majordomo.ieee.org Subject: AC Adapters in Australia The subject is an AC adapter imported into Australia as part of non-telecom ITE for business use only. Is the AC Adapter for this particular application considered to be declared and thus subject to safety approval? Richard Woods --- 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 --- 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
