Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
In message OFE9DD0726.68368FB0-ON88257D15.007F7EB3-88257D15.007F95B3@US.Schneider-E lectric.com, dated Mon, 14 Jul 2014, ralph.mcdiar...@schneider-electric.com writes: Linear techniques these days are costly, heavy or just unfashionable. Or mysterious to some of the recent graduate engineers today? That's a consequence of 'unfashionable'. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Quid faciamus nisi sit? John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
On 7/15/2014 2:19 AM, John Woodgate wrote: Linear techniques these days are costly, heavy or just unfashionable. Or mysterious to some of the recent graduate engineers today? That's a consequence of 'unfashionable'. It's a consequence of efficiency standards. I may be fixing EMI problems until I'm NINETY -- if the pacemaker I'll need meets efficiency standards. Cortland Richmond, KA5S (70) - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
In message 53c53ed7.80...@earthlink.net, dated Tue, 15 Jul 2014, CR k...@earthlink.net writes: On 7/15/2014 2:19 AM, John Woodgate wrote: Linear techniques these days are costly, heavy or just unfashionable. Or mysterious to some of the recent graduate engineers today? That's a consequence of 'unfashionable'. It's a consequence of efficiency standards. That really only applies to linear power supplies and some amplifiers. A very great amount of linear stuff is low power, not within the scope of efficiency standards. I may be fixing EMI problems until I'm NINETY -- if the pacemaker I'll need meets efficiency standards. If you try to calculate the true efficiency (power out/power in) for things that include transducers you get silly answers. Take a TV set, for example. Electrical input 100 W, light output maybe 10 microwatts. Same for a hi-fi: the sound power output is typically less than 1 % of the electrical input power. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Quid faciamus nisi sit? John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
Linear techniques these days are costly, heavy or just unfashionable. Or mysterious to some of the recent graduate engineers today? ___ Ralph McDiarmid | Schneider Electric | Solar Business | CANADA | Regulatory Compliance Engineering From: John Woodgate j...@jmwa.demon.co.uk To: EMC-PSTC@LISTSERV.IEEE.ORG, Date: 06/04/2014 10:58 AM Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp In message a8f260b4d69943a6a1ef4c01b782b...@blupr01mb147.prod.exchangelabs.com, dated Wed, 4 Jun 2014, Rick Busche rick.bus...@qnergy.com writes: As a side note, do LED lamps create EMI concerns? Yes, or rather their feed circuits do: anything that uses switching technology does. Linear techniques these days are costly, heavy or just unfashionable. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Quid faciamus nisi sit? John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com __ This email has been scanned by the Symantec Email Security.cloud service. __ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
In message 538ea5c5.6070...@emcesd.com, dated Tue, 3 Jun 2014, Douglas Smith d...@emcesd.com writes: I just posted my latest Technical Tidbit a few hours ago using a class D stereo amplifier to illustrate a potential problem whereby emission test standards may understate the emissions from a digital device. Here goes: I wouldn't contest your results, but... Abstract: Radiated emissions measurements of table top equipment are usually made with the equipment placed on a non-conductive table. This is because the standards committees are primarily concerned with household products, used in very large numbers, unless they are specifically considering professional products (as defined). But such equipment is often used on conductive surfaces, like a metal desk, and can couple to the conductive surface to enhance emissions, essentially turning the conductive surface into part of an antenna structure. This is unlikely in the home but is much more likely in a commercial, light industrial or industrial environment. There is a move to reconsider how 'Class A or Class B' is working, but of course it is controversial. Nevertheless, it could be very relevant in this context. When this happens, standard testing of emissions can understate actual emissions. A Class D (actually labeled Class Z) stereo amplifier is used to illustrate this effect by measuring common mode current on its cables. I'm surprised that the maker stopped at Z: there's the whole Russian, or even Georgian, alphabet to explore. (;-) Link to the article: http://www.emcesd.com/tt2014/tt060114.htm Link to the whole site: http://www.emcesd.com (lots of new stuff) -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Quid faciamus nisi sit? John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
Hi Dough I am not sure that this increased current contributes to radiation, as it might be only a capacitive coupled local current that flows back from the cabling through the conductive table to EUT. By lifting the EUT that loop capacitance becomes smaller and so the current. It might even be so -and I suspect that to be true- that radiated emission reduce by placing the EUT on a conductive table. All that can't be evaluated correctly as long as the common mode impedance at the power supply and audio cabling is not defined...You might think of a CISPR16 set-up , or a set of CDN's or a lot of ferrite. In any way, not just put on the table. Regards, Ing. Gert Gremmen, BSc Hi Everyone, I just posted my latest Technical Tidbit a few hours ago using a class D stereo amplifier to illustrate a potential problem whereby emission test standards may understate the emissions from a digital device. Here goes: Abstract: Radiated emissions measurements of table top equipment are usually made with the equipment placed on a non-conductive table. But such equipment is often used on conductive surfaces, like a metal desk, and can couple to the conductive surface to enhance emissions, essentially turning the conductive surface into part of an antenna structure. When this happens, standard testing of emissions can understate actual emissions. A Class D (actually labeled Class Z) stereo amplifier is used to illustrate this effect by measuring common mode current on its cables. Link to the article: http://www.emcesd.com/tt2014/tt060114.htm Link to the whole site: http://www.emcesd.com (lots of new stuff) The class D amplifier I used to generate the data is a 20 Watt/channel stereo amp with preamp built-in, a Lepai LP-2020A+. It is a great little amp, if not a little noisy EMC wise, and makes a great EMC demo for those of you who run courses. I tried one at home and cannot tell the difference between it and a much larger amplifier. I plan to give one of these to all attendees in my public seminars. Doug -- University of Oxford Tutor Department for Continuing Education Oxford, Oxfordshire, United Kingdom -- ___ _Doug Smith \ / ) P.O. Box 60941 = Boulder City, NV 89006-0941 _ / \ / \ _TEL/FAX: 702-570-6108/570-6013 / /\ \ ] / /\ \ Mobile: 408-858-4528 | q-( ) | o | Email: d...@dsmith.org \ _ /]\ _ / Web: http://www.dsmith.org -- - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) http://www.ieee-pses.org/list.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
Doug, While this may be the case, the use of a non-conductive table provides a repeatable test setup from one lab to the next. Standardization of test methods is every bit as important. Besides, the problem the standards (FCC and CISPR) were designed to address was fixed a generation ago. While not perfect, the limits and methods of measurement have accomplished the goal that was set forth in the 1970s - solve a large interference problem. Ghery S. Pettit From: Douglas Smith [mailto:d...@emcesd.com] Sent: Tuesday, June 03, 2014 9:51 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Hi Everyone, I just posted my latest Technical Tidbit a few hours ago using a class D stereo amplifier to illustrate a potential problem whereby emission test standards may understate the emissions from a digital device. Here goes: Abstract: Radiated emissions measurements of table top equipment are usually made with the equipment placed on a non-conductive table. But such equipment is often used on conductive surfaces, like a metal desk, and can couple to the conductive surface to enhance emissions, essentially turning the conductive surface into part of an antenna structure. When this happens, standard testing of emissions can understate actual emissions. A Class D (actually labeled Class Z) stereo amplifier is used to illustrate this effect by measuring common mode current on its cables. Link to the article: http://www.emcesd.com/tt2014/tt060114.htm Link to the whole site: http://www.emcesd.com (lots of new stuff) The class D amplifier I used to generate the data is a 20 Watt/channel stereo amp with preamp built-in, a Lepai LP-2020A+. It is a great little amp, if not a little noisy EMC wise, and makes a great EMC demo for those of you who run courses. I tried one at home and cannot tell the difference between it and a much larger amplifier. I plan to give one of these to all attendees in my public seminars. Doug -- University of Oxford Tutor Department for Continuing Education Oxford, Oxfordshire, United Kingdom -- ___ _Doug Smith \ / ) P.O. Box 60941 = Boulder City, NV 89006-0941 _ / \ / \ _TEL/FAX: 702-570-6108/570-6013 / /\ \ ] / /\ \ Mobile: 408-858-4528 | q-( ) | o | Email: d...@dsmith.orgmailto:d...@dsmith.org \ _ /]\ _ / Web: http://www.dsmith.org -- - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.orgmailto:emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe)http://www.ieee-pses.org/list.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.netmailto:emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.orgmailto:mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.orgmailto:j.bac...@ieee.org David Heald dhe...@gmail.commailto:dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
Interference from digital devices has been solved, for all practical purposes (now). Class B limits are amazingly conservative, to which large populations of devices ascribe. Vigilance keeps us employed. If you ask (the FCC) about the numbers of interference problems that reported due to DIGITAL devices, the answer is, statistically nil. Engineers' Credo: If it ain't broke, don't fix it. The other part of the Credo: Electrons Happen. Mike Violette Washington Laboratories American Certification Body mi...@wll.com +1 240 401 1388 On Jun 4, 2014, at 10:56 AM, Pettit, Ghery wrote: Doug, While this may be the case, the use of a non-conductive table provides a repeatable test setup from one lab to the next. Standardization of test methods is every bit as important. Besides, the problem the standards (FCC and CISPR) were designed to address was fixed a generation ago. While not perfect, the limits and methods of measurement have accomplished the goal that was set forth in the 1970s – solve a large interference problem. Ghery S. Pettit From: Douglas Smith [mailto:d...@emcesd.com] Sent: Tuesday, June 03, 2014 9:51 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Hi Everyone, I just posted my latest Technical Tidbit a few hours ago using a class D stereo amplifier to illustrate a potential problem whereby emission test standards may understate the emissions from a digital device. Here goes: Abstract: Radiated emissions measurements of table top equipment are usually made with the equipment placed on a non-conductive table. But such equipment is often used on conductive surfaces, like a metal desk, and can couple to the conductive surface to enhance emissions, essentially turning the conductive surface into part of an antenna structure. When this happens, standard testing of emissions can understate actual emissions. A Class D (actually labeled Class Z) stereo amplifier is used to illustrate this effect by measuring common mode current on its cables. Link to the article: http://www.emcesd.com/tt2014/tt060114.htm Link to the whole site: http://www.emcesd.com (lots of new stuff) The class D amplifier I used to generate the data is a 20 Watt/channel stereo amp with preamp built-in, a Lepai LP-2020A+. It is a great little amp, if not a little noisy EMC wise, and makes a great EMC demo for those of you who run courses. I tried one at home and cannot tell the difference between it and a much larger amplifier. I plan to give one of these to all attendees in my public seminars. Doug -- University of Oxford Tutor Department for Continuing Education Oxford, Oxfordshire, United Kingdom -- ___ _Doug Smith \ / ) P.O. Box 60941 = Boulder City, NV 89006-0941 _ / \ / \ _TEL/FAX: 702-570-6108/570-6013 / /\ \ ] / /\ \ Mobile: 408-858-4528 | q-( ) | o | Email: d...@dsmith.org \ _ /]\ _ / Web: http://www.dsmith.org -- - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
On 6/4/2014 9:47 AM, Mike Violette wrote: Class B limits are amazingly conservative, to which large populations of devices ascribe. Try using an ordinary AM radio beside a compact fluorescent lamp as on a beside table. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
That's not what a commercial EMC standard is going to protect against. EN 55022 Class B is for domestic environment which is an environment where the use of broadcast radio and television receivers may be expected within a distance of 10m or the apparatus concerned. Regards Charlie -Original Message- From: Richard Nute [mailto:ri...@ieee.org] Sent: 04 June 2014 18:02 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp On 6/4/2014 9:47 AM, Mike Violette wrote: Class B limits are amazingly conservative, to which large populations of devices ascribe. Try using an ordinary AM radio beside a compact fluorescent lamp as on a beside table. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
Do we still have AM? Someone once called that was Ancient Modulation. :) I suspect that in a few years fluorescent lamps will give way to LED technology. As a side note, do LED lamps create EMI concerns? -Original Message- From: Richard Nute [mailto:ri...@ieee.org] Sent: Wednesday, June 04, 2014 11:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp On 6/4/2014 9:47 AM, Mike Violette wrote: Class B limits are amazingly conservative, to which large populations of devices ascribe. Try using an ordinary AM radio beside a compact fluorescent lamp as on a beside table. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
I do not want to speak for Mike Violette, but what I think he is referring to by interference is the fact that, while the FCC could care less if two part 15 devices interfered with each other, they do care if part 15 devices interfere with licensed services. And it is in this area that the 'issue has been solved' by the 'amazingly conservative' class B limits. Dennis Ward Senior Certification Engineer PCTEST This communication and its attachments contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient (s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachment(s) are free from computer virus or other defect. Thank you. -Original Message- From: Richard Nute [mailto:ri...@ieee.org] Sent: Wednesday, June 04, 2014 10:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp On 6/4/2014 9:47 AM, Mike Violette wrote: Class B limits are amazingly conservative, to which large populations of devices ascribe. Try using an ordinary AM radio beside a compact fluorescent lamp as on a beside table. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
I wake up to AM radio every morning. And I wouldn't be surprised to find that LED lamps make noise, too. Not causing any hate and discontent in my home at this time, however. Ghery S. Pettit -Original Message- From: Rick Busche [mailto:rick.bus...@qnergy.com] Sent: Wednesday, June 04, 2014 10:26 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Do we still have AM? Someone once called that was Ancient Modulation. :) I suspect that in a few years fluorescent lamps will give way to LED technology. As a side note, do LED lamps create EMI concerns? -Original Message- From: Richard Nute [mailto:ri...@ieee.org] Sent: Wednesday, June 04, 2014 11:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp On 6/4/2014 9:47 AM, Mike Violette wrote: Class B limits are amazingly conservative, to which large populations of devices ascribe. Try using an ordinary AM radio beside a compact fluorescent lamp as on a beside table. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
Dennis, Correct. In fact, the required notice on the product or in the manual explicitly states that your Part 15 device is not offered any protection against interference. Of course, it isn't supposed to cause any interference, either. The limits were designed to provide a reasonable level of protection against interference to radio services (and television is just radio with pictures). Protect your neighbor from you. Not you from yourself. And in this case the limits have been wildly successful. One could argue that the limits are overly conservative, but that's a fight I am not going to get involved in. I'm too old and will be long gone before that one would be remotely close to being resolved. :-) Ghery S. Pettit -Original Message- From: Dward [mailto:dw...@pctestlab.com] Sent: Wednesday, June 04, 2014 10:23 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp I do not want to speak for Mike Violette, but what I think he is referring to by interference is the fact that, while the FCC could care less if two part 15 devices interfered with each other, they do care if part 15 devices interfere with licensed services. And it is in this area that the 'issue has been solved' by the 'amazingly conservative' class B limits. Dennis Ward Senior Certification Engineer PCTEST This communication and its attachments contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient (s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachment(s) are free from computer virus or other defect. Thank you. -Original Message- From: Richard Nute [mailto:ri...@ieee.org] Sent: Wednesday, June 04, 2014 10:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp On 6/4/2014 9:47 AM, Mike Violette wrote: Class B limits are amazingly conservative, to which large populations of devices ascribe. Try using an ordinary AM radio beside a compact fluorescent lamp as on a beside table. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
Yes, thanks Dennis. The number of Part 15 interference complaints to Licensed Services from Part 15 device can be counted, maybe, on a few hands and feet. That works. Mike Violette Washington Laboratories American Certification Body mi...@wll.com +1 240 401 1388 On Jun 4, 2014, at 1:22 PM, Dward wrote: I do not want to speak for Mike Violette, but what I think he is referring to by interference is the fact that, while the FCC could care less if two part 15 devices interfered with each other, they do care if part 15 devices interfere with licensed services. And it is in this area that the 'issue has been solved' by the 'amazingly conservative' class B limits. Dennis Ward Senior Certification Engineer PCTEST This communication and its attachments contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient (s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachment(s) are free from computer virus or other defect. Thank you. -Original Message- From: Richard Nute [mailto:ri...@ieee.org] Sent: Wednesday, June 04, 2014 10:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp On 6/4/2014 9:47 AM, Mike Violette wrote: Class B limits are amazingly conservative, to which large populations of devices ascribe. Try using an ordinary AM radio beside a compact fluorescent lamp as on a beside table. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
In message 538f50f1.3090...@ieee.org, dated Wed, 4 Jun 2014, Richard Nute ri...@ieee.org writes: Class B limits are amazingly conservative, to which large populations of devices ascribe. Try using an ordinary AM radio beside a compact fluorescent lamp as on a beside table. IS a CFL a 'digital device'? Yes, well, this is the elephant in the room of radiated emissions. It's called 'separation distance', which is a bit tautological. Measurements made with very low separation are generally not reproducible, which for regulatory purposes is much more important that being realistic. So standards call for measurements at (mostly) 3 m and 10 m, where reproducibility is (if one is very careful) adequate. At 10 cm, you don't get results, you get options. (;-) -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Quid faciamus nisi sit? John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
In message a8f260b4d69943a6a1ef4c01b782b...@blupr01mb147.prod.exchangelabs.com, dated Wed, 4 Jun 2014, Rick Busche rick.bus...@qnergy.com writes: As a side note, do LED lamps create EMI concerns? Yes, or rather their feed circuits do: anything that uses switching technology does. Linear techniques these days are costly, heavy or just unfashionable. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Quid faciamus nisi sit? John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
Charlie, FCC Class B protection distance is 3m, where Class A is 10m. This establishes their relationship. Class B = X dBuV measured at 3m, and Class A = X dBuV @ 10m. (where X = X) EN 55022 Class B is for domestic environment which is an environment where the use of broadcast radio and television receivers may be expected within a distance of 10m or the apparatus concerned. --- Rick, AM is older than the FCC, but they are making noise (pun intended) about revitalizing it. https://apps.fcc.gov/edocs_public/attachmatch/DOC-323370A1.pdf While LEDs are quiet, any mains powered LED lamp involves some form of pulsed current and EMI. LED lamps are regulated under FCC Part 15. I tried to use them (LED floods) in my shielded enclosure with dismal results. For those interested; This article is mainly about visual flicker, but the same principles apply to noise generation. http://www.digikey.com/en-US/articles/techzone/2012/jul/characterizing-and-minimizing-led-flicker-in-lighting-applications Here's a discussion of the RFI problem more from a regulatory perspective. http://www.emcrules.com/2011/07/radio-interference-from-led-lighting.html -Bob Sykes -Original Message- From: Rick Busche [mailto:rick.bus...@qnergy.com] Sent: Wednesday, June 04, 2014 1:26 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Do we still have AM? Someone once called that was Ancient Modulation. :) I suspect that in a few years fluorescent lamps will give way to LED technology. As a side note, do LED lamps create EMI concerns? -Original Message- From: Richard Nute [mailto:ri...@ieee.org] Sent: Wednesday, June 04, 2014 11:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp On 6/4/2014 9:47 AM, Mike Violette wrote: Class B limits are amazingly conservative, to which large populations of devices ascribe. Try using an ordinary AM radio beside a compact fluorescent lamp as on a beside table. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com Please be advised that this email may contain confidential information. If you are not the intended recipient, please notify us by email by replying to the sender and delete this message. The sender disclaims that the content of this email constitutes an offer to enter into, or the acceptance of, any agreement; provided that the foregoing does not invalidate the binding effect of any digital or other electronic reproduction of a manual signature that is included in any attachment. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
Verily long gone, eventually, all of us, but the success of good EMI design reflects in good digital design reflects in good RF design reflects in good microwave design reflects in mm wave design reflects in good terrahertz design. Optical computation, someday. X-ray digital processors, eventually. Next? Storing information in the spin-states of electrons. Not unimaginable. Mike Violette Washington Laboratories American Certification Body mi...@wll.com +1 240 401 1388 On Jun 4, 2014, at 1:43 PM, Pettit, Ghery wrote: Dennis, Correct. In fact, the required notice on the product or in the manual explicitly states that your Part 15 device is not offered any protection against interference. Of course, it isn't supposed to cause any interference, either. The limits were designed to provide a reasonable level of protection against interference to radio services (and television is just radio with pictures). Protect your neighbor from you. Not you from yourself. And in this case the limits have been wildly successful. One could argue that the limits are overly conservative, but that's a fight I am not going to get involved in. I'm too old and will be long gone before that one would be remotely close to being resolved. :-) Ghery S. Pettit -Original Message- From: Dward [mailto:dw...@pctestlab.com] Sent: Wednesday, June 04, 2014 10:23 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp I do not want to speak for Mike Violette, but what I think he is referring to by interference is the fact that, while the FCC could care less if two part 15 devices interfered with each other, they do care if part 15 devices interfere with licensed services. And it is in this area that the 'issue has been solved' by the 'amazingly conservative' class B limits. Dennis Ward Senior Certification Engineer PCTEST This communication and its attachments contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient (s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachment(s) are free from computer virus or other defect. Thank you. -Original Message- From: Richard Nute [mailto:ri...@ieee.org] Sent: Wednesday, June 04, 2014 10:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp On 6/4/2014 9:47 AM, Mike Violette wrote: Class B limits are amazingly conservative, to which large populations of devices ascribe. Try using an ordinary AM radio beside a compact fluorescent lamp as on a beside table. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
Airplanes use AM for critical communications between airport and plane. A reliable connection may be the difference between a safe landing and a crash. Especially when flying low over LED lamps Gert -Oorspronkelijk bericht- Van: Rick Busche [mailto:rick.bus...@qnergy.com] Verzonden: woensdag 4 juni 2014 19:26 Aan: EMC-PSTC@LISTSERV.IEEE.ORG Onderwerp: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Do we still have AM? Someone once called that was Ancient Modulation. :) I suspect that in a few years fluorescent lamps will give way to LED technology. As a side note, do LED lamps create EMI concerns? -Original Message- From: Richard Nute [mailto:ri...@ieee.org] Sent: Wednesday, June 04, 2014 11:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp On 6/4/2014 9:47 AM, Mike Violette wrote: Class B limits are amazingly conservative, to which large populations of devices ascribe. Try using an ordinary AM radio beside a compact fluorescent lamp as on a beside table. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
The LED's themselves do not cause noise, but all of the high intensity LED's use a switching regulator to control LED current. And yes, they are capable of very strong emissions. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: Rick Busche [mailto:rick.bus...@qnergy.com] Sent: Wednesday, June 04, 2014 10:26 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Do we still have AM? Someone once called that was Ancient Modulation. :) I suspect that in a few years fluorescent lamps will give way to LED technology. As a side note, do LED lamps create EMI concerns? -Original Message- From: Richard Nute [mailto:ri...@ieee.org] Sent: Wednesday, June 04, 2014 11:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp On 6/4/2014 9:47 AM, Mike Violette wrote: Class B limits are amazingly conservative, to which large populations of devices ascribe. Try using an ordinary AM radio beside a compact fluorescent lamp as on a beside table. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
Bob I've always read it as being a measurement distance. The FCC/CISPR limits are (more or less) the same when extrapolated, and indeed the CISPR ones may be used instead. Regards Charlie -Original Message- From: Sykes, Bob [mailto:bob.sy...@gilbarco.com] Sent: 04 June 2014 18:58 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Charlie, FCC Class B protection distance is 3m, where Class A is 10m. This establishes their relationship. Class B = X dBuV measured at 3m, and Class A = X dBuV @ 10m. (where X = X) EN 55022 Class B is for domestic environment which is an environment where the use of broadcast radio and television receivers may be expected within a distance of 10m or the apparatus concerned. --- Rick, AM is older than the FCC, but they are making noise (pun intended) about revitalizing it. https://apps.fcc.gov/edocs_public/attachmatch/DOC-323370A1.pdf While LEDs are quiet, any mains powered LED lamp involves some form of pulsed current and EMI. LED lamps are regulated under FCC Part 15. I tried to use them (LED floods) in my shielded enclosure with dismal results. For those interested; This article is mainly about visual flicker, but the same principles apply to noise generation. http://www.digikey.com/en-US/articles/techzone/2012/jul/characterizing-and-minimizing-led-flicker-in-lighting-applications Here's a discussion of the RFI problem more from a regulatory perspective. http://www.emcrules.com/2011/07/radio-interference-from-led-lighting.html -Bob Sykes -Original Message- From: Rick Busche [mailto:rick.bus...@qnergy.com] Sent: Wednesday, June 04, 2014 1:26 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Do we still have AM? Someone once called that was Ancient Modulation. :) I suspect that in a few years fluorescent lamps will give way to LED technology. As a side note, do LED lamps create EMI concerns? -Original Message- From: Richard Nute [mailto:ri...@ieee.org] Sent: Wednesday, June 04, 2014 11:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp On 6/4/2014 9:47 AM, Mike Violette wrote: Class B limits are amazingly conservative, to which large populations of devices ascribe. Try using an ordinary AM radio beside a compact fluorescent lamp as on a beside table. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com Please be advised that this email may contain confidential information. If you are not the intended recipient, please notify us by email by replying to the sender and delete this message. The sender disclaims that the content of this email constitutes an offer to enter into, or the acceptance of, any agreement; provided that the foregoing does not invalidate the binding effect of any digital or other electronic reproduction of a manual signature that is included in any attachment
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
We (pilots) even use it for less than critical communications. :-) Ghery S. Pettit -Original Message- From: ce-test, qualified testing bv - Gert Gremmen [mailto:g.grem...@cetest.nl] Sent: Wednesday, June 04, 2014 11:06 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Airplanes use AM for critical communications between airport and plane. A reliable connection may be the difference between a safe landing and a crash. Especially when flying low over LED lamps Gert -Oorspronkelijk bericht- Van: Rick Busche [mailto:rick.bus...@qnergy.com] Verzonden: woensdag 4 juni 2014 19:26 Aan: EMC-PSTC@LISTSERV.IEEE.ORG Onderwerp: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Do we still have AM? Someone once called that was Ancient Modulation. :) I suspect that in a few years fluorescent lamps will give way to LED technology. As a side note, do LED lamps create EMI concerns? -Original Message- From: Richard Nute [mailto:ri...@ieee.org] Sent: Wednesday, June 04, 2014 11:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp On 6/4/2014 9:47 AM, Mike Violette wrote: Class B limits are amazingly conservative, to which large populations of devices ascribe. Try using an ordinary AM radio beside a compact fluorescent lamp as on a beside table. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
While there is a distance difference between Class A and Class B, it is not the distance that defines the Class, it is the Class that defines the distance. The definition of a Class B is similar, but not exactly the same as for EN. Class B part 15 digital devices are defined as A digital device that is marketed for use in a residential environment notwithstanding use in commercial, business and industrial environments. A Class A digital device is A digital device that is marketed for use in a commercial, industrial or business environment, exclusive of a device which is marketed for use by the general public or is intended to be used in the home. This only means that a Class B can be approved for both residential and commercial environments, but a Class A is only approved for a commercial, industrial or business environment but not approved for residential. Currently the rules are very specific about the year of CISPR 22 that can be used. 15.38 specifically states that the reference to CISPR pub 22 only applies to the 1997 third edition version. Also, CFR47 does not recognize nor allow use of EN55022 in any year. While differences can be minute, it is only the legally referenced document that can be used to show compliance. Dennis Ward Senior Certification Engineer PCTEST This communication and its attachments contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient (s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachment(s) are free from computer virus or other defect. Thank you. -Original Message- From: Sykes, Bob [mailto:bob.sy...@gilbarco.com] Sent: Wednesday, June 04, 2014 10:58 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Charlie, FCC Class B protection distance is 3m, where Class A is 10m. This establishes their relationship. Class B = X dBuV measured at 3m, and Class A = X dBuV @ 10m. (where X = X) EN 55022 Class B is for domestic environment which is an environment where the use of broadcast radio and television receivers may be expected within a distance of 10m or the apparatus concerned. --- Rick, AM is older than the FCC, but they are making noise (pun intended) about revitalizing it. https://apps.fcc.gov/edocs_public/attachmatch/DOC-323370A1.pdf While LEDs are quiet, any mains powered LED lamp involves some form of pulsed current and EMI. LED lamps are regulated under FCC Part 15. I tried to use them (LED floods) in my shielded enclosure with dismal results. For those interested; This article is mainly about visual flicker, but the same principles apply to noise generation. http://www.digikey.com/en-US/articles/techzone/2012/jul/characterizing-and-m inimizing-led-flicker-in-lighting-applications Here's a discussion of the RFI problem more from a regulatory perspective. http://www.emcrules.com/2011/07/radio-interference-from-led-lighting.html -Bob Sykes -Original Message- From: Rick Busche [mailto:rick.bus...@qnergy.com] Sent: Wednesday, June 04, 2014 1:26 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Do we still have AM? Someone once called that was Ancient Modulation. :) I suspect that in a few years fluorescent lamps will give way to LED technology. As a side note, do LED lamps create EMI concerns? -Original Message- From: Richard Nute [mailto:ri...@ieee.org] Sent: Wednesday, June 04, 2014 11:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp On 6/4/2014 9:47 AM, Mike Violette wrote: Class B limits are amazingly conservative, to which large populations of devices ascribe. Try using an ordinary AM radio beside a compact fluorescent lamp as on a beside table. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
http://www.abcfoxmontana.com/story/25679777/plane-just-misses-sunbather-on-beach-in-low-landing Apparently Gert has been flying over the beach and was distracted by the LED lamp in this guy's back pocket! Gmac -Original Message- From: Pettit, Ghery [mailto:ghery.pet...@intel.com] Sent: Wednesday, June 04, 2014 11:15 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp We (pilots) even use it for less than critical communications. :-) Ghery S. Pettit -Original Message- From: ce-test, qualified testing bv - Gert Gremmen [mailto:g.grem...@cetest.nl] Sent: Wednesday, June 04, 2014 11:06 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Airplanes use AM for critical communications between airport and plane. A reliable connection may be the difference between a safe landing and a crash. Especially when flying low over LED lamps Gert -Oorspronkelijk bericht- Van: Rick Busche [mailto:rick.bus...@qnergy.com] Verzonden: woensdag 4 juni 2014 19:26 Aan: EMC-PSTC@LISTSERV.IEEE.ORG Onderwerp: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Do we still have AM? Someone once called that was Ancient Modulation. :) I suspect that in a few years fluorescent lamps will give way to LED technology. As a side note, do LED lamps create EMI concerns? -Original Message- From: Richard Nute [mailto:ri...@ieee.org] Sent: Wednesday, June 04, 2014 11:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp On 6/4/2014 9:47 AM, Mike Violette wrote: Class B limits are amazingly conservative, to which large populations of devices ascribe. Try using an ordinary AM radio beside a compact fluorescent lamp as on a beside table. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: https://urldefense.proofpoint.com/v1/url?u=http://www.ieee-pses.org/emc-pstc.htmlk=b2vlTQszY8VIpYRvaG%2By2A%3D%3D%0Ar=wfHsZjj2K46njWikwK7lPtcx6a6MPoEnW107Er86quU%3D%0Am=gVIPyHtAyRIuLx3ToLXOGY0pmx5WBwUG0jO%2Bm4rr6Kk%3D%0As=a26679d5444f977b6d01b593a241dab0a311a5d6c65432925b54c734eac27ce3 Attachments are not permitted but the IEEE PSES Online Communities site at https://urldefense.proofpoint.com/v1/url?u=http://product-compliance.oc.ieee.org/k=b2vlTQszY8VIpYRvaG%2By2A%3D%3D%0Ar=wfHsZjj2K46njWikwK7lPtcx6a6MPoEnW107Er86quU%3D%0Am=gVIPyHtAyRIuLx3ToLXOGY0pmx5WBwUG0jO%2Bm4rr6Kk%3D%0As=6026dc93cfbdac62fb2e1b6e121759e344b72ad24119699951c93116fee7c4b5 can be used for graphics (in well-used formats), large files, etc. Website: https://urldefense.proofpoint.com/v1/url?u=http://www.ieee-pses.org/k=b2vlTQszY8VIpYRvaG%2By2A%3D%3D%0Ar=wfHsZjj2K46njWikwK7lPtcx6a6MPoEnW107Er86quU%3D%0Am=gVIPyHtAyRIuLx3ToLXOGY0pmx5WBwUG0jO%2Bm4rr6Kk%3D%0As=418a0690878641ef43e38ad56165859b12e896019488d2b53c265407f3a8d03a Instructions: https://urldefense.proofpoint.com/v1/url?u=http://www.ieee-pses.org/list.htmlk=b2vlTQszY8VIpYRvaG%2By2A%3D%3D%0Ar=wfHsZjj2K46njWikwK7lPtcx6a6MPoEnW107Er86quU%3D%0Am=gVIPyHtAyRIuLx3ToLXOGY0pmx5WBwUG0jO%2Bm4rr6Kk%3D%0As=16d7c3f31b2201fdf1afdf0620e5518075ea8bee500065b5dd6bfd82b4130c64 (including how to unsubscribe) List rules: https://urldefense.proofpoint.com/v1/url?u=http://www.ieee-pses.org/listrules.htmlk=b2vlTQszY8VIpYRvaG%2By2A%3D%3D%0Ar=wfHsZjj2K46njWikwK7lPtcx6a6MPoEnW107Er86quU%3D%0Am=gVIPyHtAyRIuLx3ToLXOGY0pmx5WBwUG0jO%2Bm4rr6Kk%3D%0As=c55e8432fc570f8e2d39264a5a2435c39fd3f1afc50f7c172e7b9fbf1f7cf529 For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: https://urldefense.proofpoint.com/v1/url?u=http://www.ieee-pses.org/emc-pstc.htmlk=b2vlTQszY8VIpYRvaG%2By2A%3D%3D%0Ar=wfHsZjj2K46njWikwK7lPtcx6a6MPoEnW107Er86quU%3D%0Am=gVIPyHtAyRIuLx3ToLXOGY0pmx5WBwUG0jO%2Bm4rr6Kk%3D%0As=a26679d5444f977b6d01b593a241dab0a311a5d6c65432925b54c734eac27ce3 Attachments are not permitted but the IEEE PSES Online Communities site at https://urldefense.proofpoint.com/v1/url?u=http://product-compliance.oc.ieee.org/k=b2vlTQszY8VIpYRvaG%2By2A%3D%3D%0Ar
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
No, I not German but Dutch ... This was me http://www.youtube.com/watch?v=zhnGIxrepEI Gert -Oorspronkelijk bericht- Van: Gary McInturff [mailto:gary.mcintu...@esterline.com] Verzonden: woensdag 4 juni 2014 20:44 Aan: EMC-PSTC@LISTSERV.IEEE.ORG Onderwerp: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp http://www.abcfoxmontana.com/story/25679777/plane-just-misses-sunbather- on-beach-in-low-landing Apparently Gert has been flying over the beach and was distracted by the LED lamp in this guy's back pocket! Gmac -Original Message- From: Pettit, Ghery [mailto:ghery.pet...@intel.com] Sent: Wednesday, June 04, 2014 11:15 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp We (pilots) even use it for less than critical communications. :-) Ghery S. Pettit -Original Message- From: ce-test, qualified testing bv - Gert Gremmen [mailto:g.grem...@cetest.nl] Sent: Wednesday, June 04, 2014 11:06 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Airplanes use AM for critical communications between airport and plane. A reliable connection may be the difference between a safe landing and a crash. Especially when flying low over LED lamps Gert -Oorspronkelijk bericht- Van: Rick Busche [mailto:rick.bus...@qnergy.com] Verzonden: woensdag 4 juni 2014 19:26 Aan: EMC-PSTC@LISTSERV.IEEE.ORG Onderwerp: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Do we still have AM? Someone once called that was Ancient Modulation. :) I suspect that in a few years fluorescent lamps will give way to LED technology. As a side note, do LED lamps create EMI concerns? -Original Message- From: Richard Nute [mailto:ri...@ieee.org] Sent: Wednesday, June 04, 2014 11:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp On 6/4/2014 9:47 AM, Mike Violette wrote: Class B limits are amazingly conservative, to which large populations of devices ascribe. Try using an ordinary AM radio beside a compact fluorescent lamp as on a beside table. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: https://urldefense.proofpoint.com/v1/url?u=http://www.ieee-pses.org/emc- pstc.htmlk=b2vlTQszY8VIpYRvaG%2By2A%3D%3D%0Ar=wfHsZjj2K46njWikwK7lPtcx 6a6MPoEnW107Er86quU%3D%0Am=gVIPyHtAyRIuLx3ToLXOGY0pmx5WBwUG0jO%2Bm4rr6K k%3D%0As=a26679d5444f977b6d01b593a241dab0a311a5d6c65432925b54c734eac27c e3 Attachments are not permitted but the IEEE PSES Online Communities site at https://urldefense.proofpoint.com/v1/url?u=http://product-compliance.oc. ieee.org/k=b2vlTQszY8VIpYRvaG%2By2A%3D%3D%0Ar=wfHsZjj2K46njWikwK7lPtcx 6a6MPoEnW107Er86quU%3D%0Am=gVIPyHtAyRIuLx3ToLXOGY0pmx5WBwUG0jO%2Bm4rr6K k%3D%0As=6026dc93cfbdac62fb2e1b6e121759e344b72ad24119699951c93116fee7c4 b5 can be used for graphics (in well-used formats), large files, etc. Website: https://urldefense.proofpoint.com/v1/url?u=http://www.ieee-pses.org/k=b 2vlTQszY8VIpYRvaG%2By2A%3D%3D%0Ar=wfHsZjj2K46njWikwK7lPtcx6a6MPoEnW107E r86quU%3D%0Am=gVIPyHtAyRIuLx3ToLXOGY0pmx5WBwUG0jO%2Bm4rr6Kk%3D%0As=418 a0690878641ef43e38ad56165859b12e896019488d2b53c265407f3a8d03a Instructions: https://urldefense.proofpoint.com/v1/url?u=http://www.ieee-pses.org/list .htmlk=b2vlTQszY8VIpYRvaG%2By2A%3D%3D%0Ar=wfHsZjj2K46njWikwK7lPtcx6a6M PoEnW107Er86quU%3D%0Am=gVIPyHtAyRIuLx3ToLXOGY0pmx5WBwUG0jO%2Bm4rr6Kk%3D %0As=16d7c3f31b2201fdf1afdf0620e5518075ea8bee500065b5dd6bfd82b4130c64 (including how to unsubscribe) List rules: https://urldefense.proofpoint.com/v1/url?u=http://www.ieee-pses.org/list rules.htmlk=b2vlTQszY8VIpYRvaG%2By2A%3D%3D%0Ar=wfHsZjj2K46njWikwK7lPtc x6a6MPoEnW107Er86quU%3D%0Am=gVIPyHtAyRIuLx3ToLXOGY0pmx5WBwUG0jO%2Bm4rr6 Kk%3D%0As=c55e8432fc570f8e2d39264a5a2435c39fd3f1afc50f7c172e7b9fbf1f7cf 529 For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: https://urldefense.proofpoint.com/v1/url?u=http://www.ieee-pses.org/emc- pstc.htmlk=b2vlTQszY8VIpYRvaG%2By2A%3D%3D%0Ar
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
I'm pretty sure that: The only reason the FAA is still using AM is they don't have the money to replace all the AM radios in use. Michael Sundstrom Garmin Compliance Engineer 2-2606 (913) 440-1540 Whatever your discipline, become a student of excellence in all things. Take every opportunity to observe people who manifest the qualities of mastery. These models of excellence will inspire you and guide you toward the fulfillment of your highest potential. -- Tony Buzan and Michael Gelb, authors -Original Message- From: ce-test, qualified testing bv - Gert Gremmen [mailto:g.grem...@cetest.nl] Sent: Wednesday, June 04, 2014 1:06 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Airplanes use AM for critical communications between airport and plane. A reliable connection may be the difference between a safe landing and a crash. Especially when flying low over LED lamps Gert -Oorspronkelijk bericht- Van: Rick Busche [mailto:rick.bus...@qnergy.com] Verzonden: woensdag 4 juni 2014 19:26 Aan: EMC-PSTC@LISTSERV.IEEE.ORG Onderwerp: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Do we still have AM? Someone once called that was Ancient Modulation. :) I suspect that in a few years fluorescent lamps will give way to LED technology. As a side note, do LED lamps create EMI concerns? -Original Message- From: Richard Nute [mailto:ri...@ieee.org] Sent: Wednesday, June 04, 2014 11:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp On 6/4/2014 9:47 AM, Mike Violette wrote: Class B limits are amazingly conservative, to which large populations of devices ascribe. Try using an ordinary AM radio beside a compact fluorescent lamp as on a beside table. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com CONFIDENTIALITY NOTICE: This email and any attachments are for the sole use of the intended recipient(s) and contain information that may be confidential and/or legally privileged. If you have received this email in error, please notify the sender by reply email
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
Thanks Charlie, My use of the protection distance concept stems FCC docket 20780, an museum piece which was replaced by Part 15. I guess I know what that makes me :-) Best Regards, Bob Sykes -Original Message- From: Charlie Blackham [mailto:char...@sulisconsultants.com] Sent: Wednesday, June 04, 2014 2:12 PM To: Sykes, Bob; EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Bob I've always read it as being a measurement distance. The FCC/CISPR limits are (more or less) the same when extrapolated, and indeed the CISPR ones may be used instead. Regards Charlie -Original Message- From: Sykes, Bob [mailto:bob.sy...@gilbarco.com] Sent: 04 June 2014 18:58 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Charlie, FCC Class B protection distance is 3m, where Class A is 10m. This establishes their relationship. Class B = X dBuV measured at 3m, and Class A = X dBuV @ 10m. (where X = X) EN 55022 Class B is for domestic environment which is an environment where the use of broadcast radio and television receivers may be expected within a distance of 10m or the apparatus concerned. --- Rick, AM is older than the FCC, but they are making noise (pun intended) about revitalizing it. https://apps.fcc.gov/edocs_public/attachmatch/DOC-323370A1.pdf While LEDs are quiet, any mains powered LED lamp involves some form of pulsed current and EMI. LED lamps are regulated under FCC Part 15. I tried to use them (LED floods) in my shielded enclosure with dismal results. For those interested; This article is mainly about visual flicker, but the same principles apply to noise generation. http://www.digikey.com/en-US/articles/techzone/2012/jul/characterizing-and-minimizing-led-flicker-in-lighting-applications Here's a discussion of the RFI problem more from a regulatory perspective. http://www.emcrules.com/2011/07/radio-interference-from-led-lighting.html -Bob Sykes -Original Message- From: Rick Busche [mailto:rick.bus...@qnergy.com] Sent: Wednesday, June 04, 2014 1:26 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Do we still have AM? Someone once called that was Ancient Modulation. :) I suspect that in a few years fluorescent lamps will give way to LED technology. As a side note, do LED lamps create EMI concerns? -Original Message- From: Richard Nute [mailto:ri...@ieee.org] Sent: Wednesday, June 04, 2014 11:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp On 6/4/2014 9:47 AM, Mike Violette wrote: Class B limits are amazingly conservative, to which large populations of devices ascribe. Try using an ordinary AM radio beside a compact fluorescent lamp as on a beside table. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com Please be advised that this email may contain
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
In message 000a01cf8024$494154b0$dbc3fe10$@pctestlab.com, dated Wed, 4 Jun 2014, Dward dw...@pctestlab.com writes: Currently the rules are very specific about the year of CISPR 22 that can be used. 15.38 specifically states that the reference to CISPR pub 22 only applies to the 1997 third edition version. Only available as engraved stone tablets. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Quid faciamus nisi sit? John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
I thought that version was available on papyrus scrolls also. Ted Eckert Compliance Engineer Microsoft Corporation ted.eck...@microsoft.com The opinions expressed are my own and do not necessarily reflect those of my employer. -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Wednesday, June 4, 2014 12:40 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp In message 000a01cf8024$494154b0$dbc3fe10$@pctestlab.com, dated Wed, 4 Jun 2014, Dward dw...@pctestlab.com writes: Currently the rules are very specific about the year of CISPR 22 that can be used. 15.38 specifically states that the reference to CISPR pub 22 only applies to the 1997 third edition version. Only available as engraved stone tablets. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Quid faciamus nisi sit? John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
Didn't have time to get there while we were on St. Maarten last summer. It's on my bucket list, however. :-) Ghery S. Pettit -Original Message- From: ce-test, qualified testing bv - Gert Gremmen [mailto:g.grem...@cetest.nl] Sent: Wednesday, June 04, 2014 12:02 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp No, I not German but Dutch ... This was me http://www.youtube.com/watch?v=zhnGIxrepEI Gert -Oorspronkelijk bericht- Van: Gary McInturff [mailto:gary.mcintu...@esterline.com] Verzonden: woensdag 4 juni 2014 20:44 Aan: EMC-PSTC@LISTSERV.IEEE.ORG Onderwerp: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp http://www.abcfoxmontana.com/story/25679777/plane-just-misses-sunbather- on-beach-in-low-landing Apparently Gert has been flying over the beach and was distracted by the LED lamp in this guy's back pocket! Gmac -Original Message- From: Pettit, Ghery [mailto:ghery.pet...@intel.com] Sent: Wednesday, June 04, 2014 11:15 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp We (pilots) even use it for less than critical communications. :-) Ghery S. Pettit -Original Message- From: ce-test, qualified testing bv - Gert Gremmen [mailto:g.grem...@cetest.nl] Sent: Wednesday, June 04, 2014 11:06 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Airplanes use AM for critical communications between airport and plane. A reliable connection may be the difference between a safe landing and a crash. Especially when flying low over LED lamps Gert -Oorspronkelijk bericht- Van: Rick Busche [mailto:rick.bus...@qnergy.com] Verzonden: woensdag 4 juni 2014 19:26 Aan: EMC-PSTC@LISTSERV.IEEE.ORG Onderwerp: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Do we still have AM? Someone once called that was Ancient Modulation. :) I suspect that in a few years fluorescent lamps will give way to LED technology. As a side note, do LED lamps create EMI concerns? -Original Message- From: Richard Nute [mailto:ri...@ieee.org] Sent: Wednesday, June 04, 2014 11:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp On 6/4/2014 9:47 AM, Mike Violette wrote: Class B limits are amazingly conservative, to which large populations of devices ascribe. Try using an ordinary AM radio beside a compact fluorescent lamp as on a beside table. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: https://urldefense.proofpoint.com/v1/url?u=http://www.ieee-pses.org/emc- pstc.htmlk=b2vlTQszY8VIpYRvaG%2By2A%3D%3D%0Ar=wfHsZjj2K46njWikwK7lPtcx 6a6MPoEnW107Er86quU%3D%0Am=gVIPyHtAyRIuLx3ToLXOGY0pmx5WBwUG0jO%2Bm4rr6K k%3D%0As=a26679d5444f977b6d01b593a241dab0a311a5d6c65432925b54c734eac27c e3 Attachments are not permitted but the IEEE PSES Online Communities site at https://urldefense.proofpoint.com/v1/url?u=http://product-compliance.oc. ieee.org/k=b2vlTQszY8VIpYRvaG%2By2A%3D%3D%0Ar=wfHsZjj2K46njWikwK7lPtcx 6a6MPoEnW107Er86quU%3D%0Am=gVIPyHtAyRIuLx3ToLXOGY0pmx5WBwUG0jO%2Bm4rr6K k%3D%0As=6026dc93cfbdac62fb2e1b6e121759e344b72ad24119699951c93116fee7c4 b5 can be used for graphics (in well-used formats), large files, etc. Website: https://urldefense.proofpoint.com/v1/url?u=http://www.ieee-pses.org/k=b 2vlTQszY8VIpYRvaG%2By2A%3D%3D%0Ar=wfHsZjj2K46njWikwK7lPtcx6a6MPoEnW107E r86quU%3D%0Am=gVIPyHtAyRIuLx3ToLXOGY0pmx5WBwUG0jO%2Bm4rr6Kk%3D%0As=418 a0690878641ef43e38ad56165859b12e896019488d2b53c265407f3a8d03a Instructions: https://urldefense.proofpoint.com/v1/url?u=http://www.ieee-pses.org/list .htmlk=b2vlTQszY8VIpYRvaG%2By2A%3D%3D%0Ar=wfHsZjj2K46njWikwK7lPtcx6a6M PoEnW107Er86quU%3D%0Am=gVIPyHtAyRIuLx3ToLXOGY0pmx5WBwUG0jO%2Bm4rr6Kk%3D %0As=16d7c3f31b2201fdf1afdf0620e5518075ea8bee500065b5dd6bfd82b4130c64 (including how to unsubscribe) List rules: https://urldefense.proofpoint.com/v1/url?u=http://www.ieee-pses.org/list rules.htmlk=b2vlTQszY8VIpYRvaG%2By2A%3D%3D%0Ar=wfHsZjj2K46njWikwK7lPtc x6a6MPoEnW107Er86quU%3D%0Am=gVIPyHtAyRIuLx3ToLXOGY0pmx5WBwUG0jO%2Bm4rr6 Kk%3D%0As=c55e8432fc570f8e2d39264a5a2435c39fd3f1afc50f7c172e7b9fbf1f7cf 529 For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
AM holds other advantages over FM, as well. No capture effect, so it's easier to tell if another station was transmitting at the same time. And it wouldn't just be the FAA's radios that would have to be replaced. No payback for such a change. Ghery S. Pettit -Original Message- From: Sundstrom, Mike [mailto:mike.sundst...@garmin.com] Sent: Wednesday, June 04, 2014 12:11 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp I'm pretty sure that: The only reason the FAA is still using AM is they don't have the money to replace all the AM radios in use. Michael Sundstrom Garmin Compliance Engineer 2-2606 (913) 440-1540 Whatever your discipline, become a student of excellence in all things. Take every opportunity to observe people who manifest the qualities of mastery. These models of excellence will inspire you and guide you toward the fulfillment of your highest potential. -- Tony Buzan and Michael Gelb, authors -Original Message- From: ce-test, qualified testing bv - Gert Gremmen [mailto:g.grem...@cetest.nl] Sent: Wednesday, June 04, 2014 1:06 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Airplanes use AM for critical communications between airport and plane. A reliable connection may be the difference between a safe landing and a crash. Especially when flying low over LED lamps Gert -Oorspronkelijk bericht- Van: Rick Busche [mailto:rick.bus...@qnergy.com] Verzonden: woensdag 4 juni 2014 19:26 Aan: EMC-PSTC@LISTSERV.IEEE.ORG Onderwerp: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp Do we still have AM? Someone once called that was Ancient Modulation. :) I suspect that in a few years fluorescent lamps will give way to LED technology. As a side note, do LED lamps create EMI concerns? -Original Message- From: Richard Nute [mailto:ri...@ieee.org] Sent: Wednesday, June 04, 2014 11:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp On 6/4/2014 9:47 AM, Mike Violette wrote: Class B limits are amazingly conservative, to which large populations of devices ascribe. Try using an ordinary AM radio beside a compact fluorescent lamp as on a beside table. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
Some of us have been around long enough to have it on PDF. As well as the CISPR I documents that lead up to its publication. Ghery S. Pettit -Original Message- From: Ted Eckert [mailto:ted.eck...@microsoft.com] Sent: Wednesday, June 04, 2014 12:55 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp I thought that version was available on papyrus scrolls also. Ted Eckert Compliance Engineer Microsoft Corporation ted.eck...@microsoft.com The opinions expressed are my own and do not necessarily reflect those of my employer. -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Wednesday, June 4, 2014 12:40 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp In message 000a01cf8024$494154b0$dbc3fe10$@pctestlab.com, dated Wed, 4 Jun 2014, Dward dw...@pctestlab.com writes: Currently the rules are very specific about the year of CISPR 22 that can be used. 15.38 specifically states that the reference to CISPR pub 22 only applies to the 1997 third edition version. Only available as engraved stone tablets. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Quid faciamus nisi sit? John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
In message a6c794aac3df43f79e3a96a2a8754...@bl2pr03mb372.namprd03.prod.outlook.com , dated Wed, 4 Jun 2014, Ted Eckert ted.eck...@microsoft.com writes: I thought that version was available on papyrus scrolls also. Only the French text. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Quid faciamus nisi sit? John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
Ted, you are correct. However, the papyrus scrolls are encrypted so to read them one must first unlock with the engraved scarab encoder stone. Chet Summers Compliance Engineering Pelco by Schneider Electric -Original Message- From: Ted Eckert [mailto:ted.eck...@microsoft.com] Sent: Wednesday, June 04, 2014 12:55 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp I thought that version was available on papyrus scrolls also. Ted Eckert Compliance Engineer Microsoft Corporation ted.eck...@microsoft.com The opinions expressed are my own and do not necessarily reflect those of my employer. -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Wednesday, June 4, 2014 12:40 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp In message 000a01cf8024$494154b0$dbc3fe10$@pctestlab.com, dated Wed, 4 Jun 2014, Dward dw...@pctestlab.com writes: Currently the rules are very specific about the year of CISPR 22 that can be used. 15.38 specifically states that the reference to CISPR pub 22 only applies to the 1997 third edition version. Only available as engraved stone tablets. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Quid faciamus nisi sit? John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com __ This email has been scanned by the Symantec Email Security.cloud service. __ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp
I have a paper copy somewhere in my standards dead file. Dennis Ward Senior Certification Engineer PCTEST This communication and its attachments contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient (s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachment(s) are free from computer virus or other defect. Thank you. -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Wednesday, June 04, 2014 12:40 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp In message 000a01cf8024$494154b0$dbc3fe10$@pctestlab.com, dated Wed, 4 Jun 2014, Dward dw...@pctestlab.com writes: Currently the rules are very specific about the year of CISPR 22 that can be used. 15.38 specifically states that the reference to CISPR pub 22 only applies to the 1997 third edition version. Only available as engraved stone tablets. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Quid faciamus nisi sit? John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
