RE: IEC 61000-4-2 ESD & 61000-4-5 Surge lower levels
David, I disagree with you here. As others have said, I have seen numerous failures at less than the maximum required test voltage while the same system passes at the max required voltage. It seems to me the intent was / is / should be to verify product performance up to a maximum level, not just at that level. The logic here would be that the "standards writing group" would make the test cover reasonable ground up to some limit because it is quite common that anything up to that limit could happen. The reason for the limit is because it is uncommon for things larger / higher than the limit to happen. Contact discharge is the only way to make reliable and repeatable tests for ESD. No approach speed issues, etc. So testing at low levels and working up to a maximum limit is a reasonable test method. On the other hand, I find air discharge to be a difficult and not very repeatable test to do which causes me to question its usefulness. Yes, I agree that people interacting with products will more often see air discharge rather than contact discharge. But I also find it impossible to reliably repeat air discharge test results. The old approach speed, distance and coordinates of contact point issue. Until someone can make an automated air discharge tester that keeps human interactions out of the process, I can't see it being corrected. That said, testing at lower levels is just as necessary here. Regards, Scott Douglas Senior Compliance Engineer Narad Networks 515 Groton Road Westford, MA 01886 office: 978 589-1869 cell: 978-239-0693 dougl...@naradnetworks.com www.naradnetworks.com At 08:36 AM 6/10/02 -0500, Pommerenke, David wrote: Dear Group, For most EUTs there is no need to do lower level testing in contact mode ESD. The time is better spend (meaning a better test results uncertainty is achieved) if the number of discharges is increased at the highest test level (hundreds is a good number). Although it is possible that a system fails at e.g., 2 kV contact mode (e.g., incomplete reset) and passes at 4 kV contact mode (full self-recovering quick reset) the likelyhood of that happening is not that large to require it in a standard. For air discharge lower level testing is needed, as the risetime is often much lower at lower voltages. Of course, if no discharge occurs, no further testing at even lower levels makes sense. I do know that what I am saying violates the present IEC 61000-4-2 standard. ut it reflects the coming version of IEC 61000-4-2. The standard does not intend to protect agains every possible ESD failure. I would like to receive your input, as I am one of the US-representatives in IEC TC77b WG-9 (ESD). David Pommerenke
Re: IEC 61000-4-2 ESD & 61000-4-5 Surge lower levels
Not to mention the vastly different current risetimes. Low voltage discharges actually have higher di/dt values than high voltage ones (and therefore higher interference potential). Doug don_borow...@selinc.com wrote: > > Let me add a bit on the air discharge side. > > You will want to do the lower voltage discharge tests because the path the > discharge takes may change with voltage. I have seen several instances where > connectors (sub-min D types, if I remember correctly) were mounted on metal > panels. At higher voltages, the path between the ESD gun and the grounded > shell > of the connector would break down first. At lower voltages, the connector pins > could be approached without breakdown to the shell, and the discharge would > occur to the connector pins. > > Don Borowski > Schweitzer Engineering Labs > Pullman, WA > > "Pommerenke, David" on 06/10/2002 06:36:46 AM > > Please respond to "Pommerenke, David" > > To: "Neil Helsby" , > emc-p...@majordomo.ieee.org > cc: kro...@yahoo.com (bcc: Don Borowski/SEL) > Subject: RE: IEC 61000-4-2 ESD & 61000-4-5 Surge lower levels > > Dear Group, > > For most EUTs there is no need to do lower level testing in contact mode ESD. > The time is better spend (meaning a better test results uncertainty is > achieved) > if the number of discharges is increased at the highest test level (hundreds > is > a good number). Although it is possible that a system fails at e.g., 2 kV > contact mode (e.g., incomplete reset) and passes at 4 kV contact mode (full > self-recovering quick reset) the likelyhood of that happening is not that > large > to require it in a standard. > > For air discharge lower level testing is needed, as the risetime is often much > lower at lower voltages. Of course, if no discharge occurs, no further testing > at even lower levels makes sense. > > I do know that what I am saying violates the present IEC 61000-4-2 standard. > ut > it reflects the coming version of IEC 61000-4-2. The standard does not intend > to > protect agains every possible ESD failure. > > I would like to receive your input, as I am one of the US-representatives in > IEC > TC77b WG-9 (ESD). > > David Pommerenke > > -Original Message- > From: Neil Helsby [mailto:nei...@solid-state-logic.com] > Sent: Monday, June 10, 2002 4:56 AM > To: emc-p...@majordomo.ieee.org > Cc: kro...@yahoo.com > Subject: Re: IEC 61000-4-2 ESD & 61000-4-5 Surge lower levels > > I think there are two points here. > > 1) If you believe that in the environment in which it will be > used, your product may be subject to levels in excess of that defined > in the standard, you must test to that higher level. > > 2) Yes, failures can occur at mid range levels. We have just > recently experienced this problem with ESD. Below about 3.5 kV and > above about 4.5 kV the product worked fine. But at 4 kV we > experienced a failure mode. If we had only tested at 8 kV we would > have missed the problem. > > I also had a problem some years ago with mains voltage dips > to 0V. Having a test set that enabled the period to be varied in ms > increments, I discovered a problem affecting a voltage regulator. > When the mains dip was between about 16 ms and 35 ms, the regulator > went into a bistable mode switching on then off at each pulse. > Outside these periods, it worked satisfactorily, eventually losing > output when the period was extended. > > The problem with investigating these types of failure is determining > the size of step between measurements. Too short a step and you will > be testing forever, too long and you could miss a narrow band of > problem. > > Regards, > > Neil Helsby > > ** > This email and any files transmitted with it are confidential and > intended solely for the use of the individual or entity to whom they > are addressed. If you have received this email in error please notify > the system manager. > > This footnote also confirms that this email message has been swept by > MIMEsweeper for the presence of computer viruses. > > www.mimesweeper.com > ** > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Ron Pickard: emc-p...@hypercom.com > Dave Heald: davehe...@attbi.com > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > http://ieeepstc.mindcruiser.com/ > Click on "brows
Mutual inductance as a troubleshooting tool
Hi All, Mutual inductance can be a powerful debugging tool for problem circuits. It can also be either a friend or foe in the designs themselves. This month's Technical Tidbit at http://www.dsmith.org relates direct measurement of Ldi/dt voltage drop with Mdi/dt of the same voltage. Often direct measurement of a voltage drop is not possible. This article shows that Ldi/dt and Mdi/dt measurements can be equivalent. Yet another use for a probe made out of a paperclip! Doug -- --- ___ _ Doug Smith \ / ) P.O. Box 1457 = Los Gatos, CA 95031-1457 _ / \ / \ _ TEL/FAX: 408-356-4186/358-3799 / /\ \ ] / /\ \ Mobile: 408-858-4528 | q-( ) | o |Email: d...@dsmith.org \ _ /]\ _ / Website: http://www.dsmith.org --- --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
RE: DOC "Assembled from tested components"
Seems to me that the court could better use its time to nail some of the el-cheapo products from the far east made by manufacturers that just stick a CE mark on everything they make as part of the "graphics design". I have seen numerous such products that haven't a hope of getting CE approval, proudly wearing a CE mark. Bob Wilson TIR Systems Ltd. Vancouver. -Original Message- From: richwo...@tycoint.com [mailto:richwo...@tycoint.com] Sent: June 10, 2002 11:29 AM To: emc-p...@majordomo.ieee.org Subject: RE: DOC "Assembled from tested components" Ken, a UK court ruled that CE+CE does not equal CE. They fined at least one PC reseller because they integrated and sold PCs based upon the belief that CE+CE=CE. Obviously, the court thought otherwise. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: Gonzalez, Kenneth P (Rocky) [mailto:kpgon...@ingr.com] Sent: Monday, June 10, 2002 12:20 PM To: emc-p...@majordomo.ieee.org Subject: DOC "Assembled from tested components" All, Has anyone successfully issued a DOC using the "assembled from tested components" method for a personal computer? I have not been able to find a floppy disk drive manufacturer that has any DOC documentation for their device; even the ones marketing directly to home users. Have I just not found the right manufacturer? Best regards, Rocky -)-(- Kenneth P. Gonzalez (Rocky) Intergraph Solutions Group Integrated Products Division 170 Graphics Drive Madison, Alabama, USA 35758 phone (256) 730-2131 fax (256)730-2424 kpgon...@ingr.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list" --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list" --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
(off topic) Stirling cycle
Chris, what is the Stirling cycle? short tongue in cheek reply: a well kept secret! in truth it is an external combustion engine which uses the thermal expansion and contraction of gas to produce motion. typically the system is sealed, there is a 'hot' end and a 'cold' end, The energy input in the form of the temperature differential can be extracted as work from a piston and crank. Alternatively put work into the shaft and you can maintain a temperature differential.. try searching the web for Stirling cycle the amount of information available has increased significantly in the past year or so there is hope :-) I believe people under estimate the incoming energy that penetrates the cloud cover. I don't have figures but I think long wave infrared reaches the ground through clouds. It can be focused by solar collectors. The oil/gas/electricity utilities and their PR departments would like us to believe we are helpless and dependant on their massive infrastructure. I believe they make sure we have the limitations of photovoltaic cells and rechargeable batteries rammed down our throats to discourage independent thinking. Electrolysis, fuel cells, flywheels, solar collectors, stirling engines, wind and wave power, all are coming and will be usable on a small scale by individual households. I plan to power/heat/cool my residence with solar energy and disconnect the utility lines in the foreseeable future. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
RE: 1kW per square meter.......free
Just a related thought here. I read last year in Science news weekly, that the world wide availble power from offshore wave action is about 72 terawatts. Its efficiently harvested in about 300 feet of water, before the waves dissapate on sandbars etc. The platform technology is based (ironically perhaps) on oil drilling rigs. The cost per kwhr is supposedly competitive with wind power (6 to 7 cents/kwhr if memory serves.) With that kind of steady supply of energy, one could convert water to hydrogen and oxygen, use the hydrogen to power cars and forget about oil, more or less. There are a few details of course. Regards George Stults -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Saturday, June 08, 2002 11:52 AM To: Scott Lacey; Ted Rook Cc: emc-p...@majordomo.ieee.org Subject: Re: 1kW per square meter...free More accurately, it is not energy efficiency but energy storage volumetric efficiency, or the ability to store large amounts of energy densely that is important in a vehicle. An electric motor is much more efficient than an internal combustion engine, but that is more than offset by the poor energy density (and mass) of batteries compared to gasoline or other chemical fuels. -- >From: "Scott Lacey" >To: "Ted Rook" >Cc: emc-p...@majordomo.ieee.org >Subject: Re: 1kW per square meter...free >Date: Sat, Jun 8, 2002, 12:15 PM > > > Ted, > > While most "alternative energy" schemes sound very promising, energy efficiency > problems make most of them impractical for real world use. Small solar charging > systems are great for maintaining a charge on a seldom used battery in a spare > automobile, or similar application, but the ratio of charge time to usage > has to be > large. The problems with a solar powered automobile would be: > > 1) Lots of expensive (and unsightly) solar panels plus the numerous serial and > parallel connections needed to make a usable system. Even then, the car would > have to be parked in the sunlight many more hours than it was driven. > > 2) An expensive buck/boost charge controller to compensate for the enormous > voltage variations due to weather. > > 3) A trunk full of heavy, expensive batteries, with their need to be eventually > replaced. > > 4) And finally, how would the batteries be charged if it rained for four or > five days > straight? > > The hybrid gas/electric vehicles seem to be the only practical electric > vehicles made > so far. And even these seem to be expensive enough that sales have to be > subsidized. > > I know people who have tried to use solar dc electrical systems at remote camps. > You have to strictly ration electrical usage even if you only use the place on > weekends after it has charged all week. Most people eventually revert to using > combinations of propane, gasoline, and kerosene for light and cooking. A gallon of > Coleman fuel will last a week running a stove and some lights. > > As to the energy efficiency of gasoline, years ago I watched a > demonstration where a > homemade mortar lobbed a sand-filled beer can hundreds of yards using a > SPOONFUL of gasoline! It graphically proved the point about why it is so hard to > replace the internal combution engine. > > Scott Lacey > On 7 Jun 2002 at 13:52, Ted Rook wrote: > >> >> sorry, off topic, mostly for US residents: >> >> just imagine everyone's car being coated with 'solar cell generator' >> material with a storage device in the trunk.. >> >> and how about air-conditioners that run on the Stirling cycle from a >> solar energy collector... >> >> lousy for the oil lobby but fantastic for the human race >> >> >> >> >> >> --- >> This message is from the IEEE EMC Society Product Safety >> Technical Committee emc-pstc discussion list. >> >> Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ >> >> To cancel your subscription, send mail to: >> majord...@ieee.org >> with the single line: >> unsubscribe emc-pstc >> >> For help, send mail to the list administrators: >> Ron Pickard: emc-p...@hypercom.com >> Dave Heald: davehe...@attbi.com >> >> For policy questions, send mail to: >> Richard Nute: ri...@ieee.org >> Jim Bacher: j.bac...@ieee.org >> >> All emc-pstc postings are archived and searchable on the web at: >> http://ieeepstc.mindcruiser.com/ >> Click on "browse" and then "emc-pstc mailing list" > > > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Ron Pickard: emc-p...@hypercom.com > Dave Heald: davehe...@att
RE: DOC "Assembled from tested components"
Richard, This was just for an FCC DOC. They (FCC) informed me that the floppy drive also had to have a DOC. This is the last document I need so if I can't find one then the "assembled from tested components" will not work for any ITE that have floppy disk drives in them! Rocky -)-(- -Original Message- From: richwo...@tycoint.com [mailto:richwo...@tycoint.com] Sent: Monday, June 10, 2002 1:29 PM To: emc-p...@majordomo.ieee.org Subject: RE: DOC "Assembled from tested components" Ken, a UK court ruled that CE+CE does not equal CE. They fined at least one PC reseller because they integrated and sold PCs based upon the belief that CE+CE=CE. Obviously, the court thought otherwise. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: Gonzalez, Kenneth P (Rocky) [mailto:kpgon...@ingr.com] Sent: Monday, June 10, 2002 12:20 PM To: emc-p...@majordomo.ieee.org Subject: DOC "Assembled from tested components" All, Has anyone successfully issued a DOC using the "assembled from tested components" method for a personal computer? I have not been able to find a floppy disk drive manufacturer that has any DOC documentation for their device; even the ones marketing directly to home users. Have I just not found the right manufacturer? Best regards, Rocky -)-(- Kenneth P. Gonzalez (Rocky) Intergraph Solutions Group Integrated Products Division 170 Graphics Drive Madison, Alabama, USA 35758 phone (256) 730-2131 fax (256)730-2424 kpgon...@ingr.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list" --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list" --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
RE: DOC "Assembled from tested components"
Ken, a UK court ruled that CE+CE does not equal CE. They fined at least one PC reseller because they integrated and sold PCs based upon the belief that CE+CE=CE. Obviously, the court thought otherwise. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: Gonzalez, Kenneth P (Rocky) [mailto:kpgon...@ingr.com] Sent: Monday, June 10, 2002 12:20 PM To: emc-p...@majordomo.ieee.org Subject: DOC "Assembled from tested components" All, Has anyone successfully issued a DOC using the "assembled from tested components" method for a personal computer? I have not been able to find a floppy disk drive manufacturer that has any DOC documentation for their device; even the ones marketing directly to home users. Have I just not found the right manufacturer? Best regards, Rocky -)-(- Kenneth P. Gonzalez (Rocky) Intergraph Solutions Group Integrated Products Division 170 Graphics Drive Madison, Alabama, USA 35758 phone (256) 730-2131 fax (256)730-2424 kpgon...@ingr.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list" --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
RE: DOC "Assembled from tested components"
Fred, I have asked both Sony and Teac for DOC's and haven't received a positive response. Where may one find the DOC information? I have searched the web sites and sent them email too! Did I not get the right people? Best Regards, Rocky -)-(- -Original Message- From: Fred Townsend [mailto:f...@poasana.com] Sent: Monday, June 10, 2002 12:29 PM To: Gonzalez, Kenneth P (Rocky) Cc: emc-p...@majordomo.ieee.org Subject: Re: DOC "Assembled from tested components" Rocky: It is not clear what information you are looking for. Are you looking for hook-up information or trying to write a driver? If you want to know how to hook it up, both Sony and Teac have such documents. If you are writing a driver, the data sheet on the old NEC 765 controller chip may be of some help. No one uses the 765 any more because they use multifunction chips but the data sheet is still the most comprehensive for the driver writer. Fred Townsend "Gonzalez, Kenneth P (Rocky)" wrote: > All, > Has anyone successfully issued a DOC using the "assembled from tested > components" method for a personal computer? I have not been able to find a > floppy disk drive manufacturer that has any DOC documentation for their > device; even the ones marketing directly to home users. Have I just not > found the right manufacturer? > > Best regards, > > Rocky > -)-(- > > Kenneth P. Gonzalez (Rocky) > Intergraph Solutions Group > Integrated Products Division > 170 Graphics Drive > Madison, Alabama, USA 35758 > phone (256) 730-2131 > fax (256)730-2424 > kpgon...@ingr.com > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Ron Pickard: emc-p...@hypercom.com > Dave Heald: davehe...@attbi.com > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > http://ieeepstc.mindcruiser.com/ > Click on "browse" and then "emc-pstc mailing list" --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
Re: PCB layout question for good EMC performance
Thanks to all who replied on this question. Ken Javor -- >From: emccom...@aol.com >To: dave.clem...@motorola.com, ken.ja...@emccompliance.com, emc-p...@majordomo.ieee.org >Subject: Re: PCB layout question for good EMC performance >Date: Fri, Jun 7, 2002, 6:00 PM > > Hi Ken, > > "Rent's Rule" (spelled as in Howard and Graham's book) with a worked example > is on pages 216-217. > > Good Luck with your problem, > > Thurman J. (Bill) Ritenour > EMC Compliance LLC > 4575 Sioux Drive #303 > Boulder, CO 80303 > 303-543-7404 > emccom...@aol.com > --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
Re: DOC "Assembled from tested components"
Rocky: It is not clear what information you are looking for. Are you looking for hook-up information or trying to write a driver? If you want to know how to hook it up, both Sony and Teac have such documents. If you are writing a driver, the data sheet on the old NEC 765 controller chip may be of some help. No one uses the 765 any more because they use multifunction chips but the data sheet is still the most comprehensive for the driver writer. Fred Townsend "Gonzalez, Kenneth P (Rocky)" wrote: > All, > Has anyone successfully issued a DOC using the "assembled from tested > components" method for a personal computer? I have not been able to find a > floppy disk drive manufacturer that has any DOC documentation for their > device; even the ones marketing directly to home users. Have I just not > found the right manufacturer? > > Best regards, > > Rocky > -)-(- > > Kenneth P. Gonzalez (Rocky) > Intergraph Solutions Group > Integrated Products Division > 170 Graphics Drive > Madison, Alabama, USA 35758 > phone (256) 730-2131 > fax (256)730-2424 > kpgon...@ingr.com > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Ron Pickard: emc-p...@hypercom.com > Dave Heald: davehe...@attbi.com > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > http://ieeepstc.mindcruiser.com/ > Click on "browse" and then "emc-pstc mailing list" --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
RE: IEC 61000-4-2 ESD & 61000-4-5 Surge lower levels
Let me add a bit on the air discharge side. You will want to do the lower voltage discharge tests because the path the discharge takes may change with voltage. I have seen several instances where connectors (sub-min D types, if I remember correctly) were mounted on metal panels. At higher voltages, the path between the ESD gun and the grounded shell of the connector would break down first. At lower voltages, the connector pins could be approached without breakdown to the shell, and the discharge would occur to the connector pins. Don Borowski Schweitzer Engineering Labs Pullman, WA "Pommerenke, David" on 06/10/2002 06:36:46 AM Please respond to "Pommerenke, David" To: "Neil Helsby" , emc-p...@majordomo.ieee.org cc: kro...@yahoo.com (bcc: Don Borowski/SEL) Subject: RE: IEC 61000-4-2 ESD & 61000-4-5 Surge lower levels Dear Group, For most EUTs there is no need to do lower level testing in contact mode ESD. The time is better spend (meaning a better test results uncertainty is achieved) if the number of discharges is increased at the highest test level (hundreds is a good number). Although it is possible that a system fails at e.g., 2 kV contact mode (e.g., incomplete reset) and passes at 4 kV contact mode (full self-recovering quick reset) the likelyhood of that happening is not that large to require it in a standard. For air discharge lower level testing is needed, as the risetime is often much lower at lower voltages. Of course, if no discharge occurs, no further testing at even lower levels makes sense. I do know that what I am saying violates the present IEC 61000-4-2 standard. ut it reflects the coming version of IEC 61000-4-2. The standard does not intend to protect agains every possible ESD failure. I would like to receive your input, as I am one of the US-representatives in IEC TC77b WG-9 (ESD). David Pommerenke -Original Message- From: Neil Helsby [mailto:nei...@solid-state-logic.com] Sent: Monday, June 10, 2002 4:56 AM To: emc-p...@majordomo.ieee.org Cc: kro...@yahoo.com Subject: Re: IEC 61000-4-2 ESD & 61000-4-5 Surge lower levels I think there are two points here. 1) If you believe that in the environment in which it will be used, your product may be subject to levels in excess of that defined in the standard, you must test to that higher level. 2) Yes, failures can occur at mid range levels. We have just recently experienced this problem with ESD. Below about 3.5 kV and above about 4.5 kV the product worked fine. But at 4 kV we experienced a failure mode. If we had only tested at 8 kV we would have missed the problem. I also had a problem some years ago with mains voltage dips to 0V. Having a test set that enabled the period to be varied in ms increments, I discovered a problem affecting a voltage regulator. When the mains dip was between about 16 ms and 35 ms, the regulator went into a bistable mode switching on then off at each pulse. Outside these periods, it worked satisfactorily, eventually losing output when the period was extended. The problem with investigating these types of failure is determining the size of step between measurements. Too short a step and you will be testing forever, too long and you could miss a narrow band of problem. Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept by MIMEsweeper for the presence of computer viruses. www.mimesweeper.com ** --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list" --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hyperco
DOC "Assembled from tested components"
All, Has anyone successfully issued a DOC using the "assembled from tested components" method for a personal computer? I have not been able to find a floppy disk drive manufacturer that has any DOC documentation for their device; even the ones marketing directly to home users. Have I just not found the right manufacturer? Best regards, Rocky -)-(- Kenneth P. Gonzalez (Rocky) Intergraph Solutions Group Integrated Products Division 170 Graphics Drive Madison, Alabama, USA 35758 phone (256) 730-2131 fax (256)730-2424 kpgon...@ingr.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
RE: IEC 61000-4-2 ESD & 61000-4-5 Surge lower levels
Dear Group, For most EUTs there is no need to do lower level testing in contact mode ESD. The time is better spend (meaning a better test results uncertainty is achieved) if the number of discharges is increased at the highest test level (hundreds is a good number). Although it is possible that a system fails at e.g., 2 kV contact mode (e.g., incomplete reset) and passes at 4 kV contact mode (full self-recovering quick reset) the likelyhood of that happening is not that large to require it in a standard. For air discharge lower level testing is needed, as the risetime is often much lower at lower voltages. Of course, if no discharge occurs, no further testing at even lower levels makes sense. I do know that what I am saying violates the present IEC 61000-4-2 standard. ut it reflects the coming version of IEC 61000-4-2. The standard does not intend to protect agains every possible ESD failure. I would like to receive your input, as I am one of the US-representatives in IEC TC77b WG-9 (ESD). David Pommerenke -Original Message- From: Neil Helsby [mailto:nei...@solid-state-logic.com] Sent: Monday, June 10, 2002 4:56 AM To: emc-p...@majordomo.ieee.org Cc: kro...@yahoo.com Subject: Re: IEC 61000-4-2 ESD & 61000-4-5 Surge lower levels I think there are two points here. 1) If you believe that in the environment in which it will be used, your product may be subject to levels in excess of that defined in the standard, you must test to that higher level. 2) Yes, failures can occur at mid range levels. We have just recently experienced this problem with ESD. Below about 3.5 kV and above about 4.5 kV the product worked fine. But at 4 kV we experienced a failure mode. If we had only tested at 8 kV we would have missed the problem. I also had a problem some years ago with mains voltage dips to 0V. Having a test set that enabled the period to be varied in ms increments, I discovered a problem affecting a voltage regulator. When the mains dip was between about 16 ms and 35 ms, the regulator went into a bistable mode switching on then off at each pulse. Outside these periods, it worked satisfactorily, eventually losing output when the period was extended. The problem with investigating these types of failure is determining the size of step between measurements. Too short a step and you will be testing forever, too long and you could miss a narrow band of problem. Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept by MIMEsweeper for the presence of computer viruses. www.mimesweeper.com ** --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list" --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
RE: Measurement below 30MHz
KC, Allow me to make one additional comment regarding your final statement. You asked ". . . which one should I use?" The FCC will never have a problem with you using linear (20 dB/decade) roll-off. This is more restrictive than is sometimes called for. They allow the use of 40 dB/decade below 30 MHz. You will not have a rejection of an application for using a provision that is allowed. Similarly, if you choose, the FCC allows you to use other roll-off factors as long as you use at least 2 points to establish the roll-off and provide the calculation that showed how you arrived at your results. So which to use? That is up to you. Personally, I generally use 2 points and provide the roll-off calculated. Good luck, Don Umbdenstock > -- > From: djumbdenst...@tycoint.com[SMTP:djumbdenst...@tycoint.com] > Reply To: djumbdenst...@tycoint.com > Sent: Friday, June 07, 2002 5:34 PM > To: emc-p...@majordomo.ieee.org; kcc...@hkpc.org > Subject: RE: Measurement below 30MHz > > > Hello KC, > > I cannot comment on the Japanese standard; I can comment on the FCC > regulations. The FCC does allow 40 dB/decade below 30 MHz; they also > allow > a different roll-off established by measuring at 2 points along a radial. > The resultant may be different than 40 dB/decade, depending on the > frequency > and the antenna. A basic loop antenna at 13 MHz will likely produce less > than 40 dB/decade. If the antenna is wound in a field canceling manor, > you > might measure something greater than 40/dB per decade. > > Best regards, > > Don Umbdenstock > Tyco Safety Products > Sensormatic > > > -- > > From: KC CHAN [PDD][SMTP:kcc...@hkpc.org] > > Reply To: KC CHAN [PDD] > > Sent: Thursday, June 06, 2002 10:36 PM > > To: emc-p...@majordomo.ieee.org > > Subject:Measurement below 30MHz > > > > > > To all > > > > I just came across a Japanese standard about a RFID product at 13.5 MHZ, > > it says that measurement of FCC from 30m to 3m will need to take the > 20dB > > conversion(ie 20dB/decade) into account. > > > > But I found a statement from FCC part 15.31(f)(2) that at frequency > below > > 30 MHZ, 40/decade extrapolation factor shall be used. > > > > I just want to clarify which we should use for measurement below 30MHz, > > 20dB/decade or 40/decade? > > > > Thank you > > KC Chan > > > > > > --- > > This message is from the IEEE EMC Society Product Safety > > Technical Committee emc-pstc discussion list. > > > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > > > To cancel your subscription, send mail to: > > majord...@ieee.org > > with the single line: > > unsubscribe emc-pstc > > > > For help, send mail to the list administrators: > > Ron Pickard: emc-p...@hypercom.com > > Dave Heald: davehe...@attbi.com > > > > For policy questions, send mail to: > > Richard Nute: ri...@ieee.org > > Jim Bacher: j.bac...@ieee.org > > > > All emc-pstc postings are archived and searchable on the web at: > > http://ieeepstc.mindcruiser.com/ > > Click on "browse" and then "emc-pstc mailing list" > > > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Ron Pickard: emc-p...@hypercom.com > Dave Heald: davehe...@attbi.com > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > http://ieeepstc.mindcruiser.com/ > Click on "browse" and then "emc-pstc mailing list" > --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
Re: IEC 61000-4-2 ESD & 61000-4-5 Surge lower levels
I think there are two points here. 1) If you believe that in the environment in which it will be used, your product may be subject to levels in excess of that defined in the standard, you must test to that higher level. 2) Yes, failures can occur at mid range levels. We have just recently experienced this problem with ESD. Below about 3.5 kV and above about 4.5 kV the product worked fine. But at 4 kV we experienced a failure mode. If we had only tested at 8 kV we would have missed the problem. I also had a problem some years ago with mains voltage dips to 0V. Having a test set that enabled the period to be varied in ms increments, I discovered a problem affecting a voltage regulator. When the mains dip was between about 16 ms and 35 ms, the regulator went into a bistable mode switching on then off at each pulse. Outside these periods, it worked satisfactorily, eventually losing output when the period was extended. The problem with investigating these types of failure is determining the size of step between measurements. Too short a step and you will be testing forever, too long and you could miss a narrow band of problem. Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept by MIMEsweeper for the presence of computer viruses. www.mimesweeper.com ** --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
