RE: Ferrites can increase emissions?
Yes, two chokes were the next step. That worked fine, but we had the room to build suppression into each box behind the connectors, so we didn't really end up with a cable with a lump at both ends. Ed -Original Message- From: Ralph Cameron [SMTP:ral...@igs.net] Sent: Thursday, December 02, 1999 5:39 PM To: Price, Ed; d...@dsmith.org Cc: emc-pstc Subject: Re: Ferrites can increase emissions? In such a case did you place a ferrite device at both ends of the cable? It has worked for me. Ralph - Original Message - From: Price, Ed ed.pr...@cubic.com To: 'Ralph Cameron' ral...@igs.net; d...@dsmith.org Cc: emc-pstc emc-p...@majordomo.ieee.org Sent: Thursday, December 02, 1999 12:29 PM Subject: RE: Ferrites can increase emissions? I have had the experience of putting ferrite chokes on a cable bundle which connected two parts of a system. Putting the choke close to Box A, some radiated emissions went down and some went up. It doesn't seem reasonable at first, until you remember that each box may be contributing some of the combined noise currents in the cable. The location of the choke affects the size of the loops oppositely. Ed -Original Message- From: Ralph Cameron [SMTP:ral...@igs.net] Sent: Thursday, December 02, 1999 12:10 PM To: d...@dsmith.org Cc: emc-pstc Subject: Re: Ferrites can increase emissions? Hi Doug: The term ground loop is misleading I agree. I meant to say coupling and by placing the ferrite remotely from the source of the emissions only serves to end load the conductors which will change the resonant length. In the case of placing the toroidal device on the power cord, right at the point of entry to the PCB, chassis, cabinet etc. the coupling loop as opposed to ground loop is generally broken and the harmful ffects( device malfunction) disappear. I guess the point I'm trying to make is why defeat the purpose of a suppression device by placing it on conductors remotely from the source of the emissions? Ralph - Original Message - From: Douglas C. Smith d...@dsmith.org To: Ralph Cameron ral...@igs.net Cc: emc-pstc emc-p...@majordomo.ieee.org Sent: Thursday, December 02, 1999 8:43 AM Subject: Re: Ferrites can increase emissions? Hi Ralph and all, Please define ground loop in your reply below. Normally, the term ground loop only has meaning at low frequencies (60 Hz and DC). At high frequencies an infinite number of loops exist and they do not require a conductor to complete them. You need to define exactly the effect for the particular case below. The special case in my article goes a level deeper than your discussion to show that ferrites at one end of a cable can either increase or decrease emissions from equipment at the opposite end by either causing an impedance match or mismatch. No ground loops needed to explain this phenomenon. Doug Ralph Cameron wrote: The purpose of a common mode choke whether it be of ferrite or powdered iron is to isolate the connecting conductors from the rest of the mainboard or chassis. If the toridal core is correctly placed as close to the source of the emissions i.e. the PCB, the conductors which carry the emitted noise are effectively isolated from high frequency noise currents to flow in common mode. The attenutaion will vary acording to the efficiency of the material selected and a permeability of a nominal 850 is useful over the range 3-40 Mhz. Some of the telphone companies use common mode chokes to attempt to suppress induced RF energy on phone lines and sometimes it works. They alsmot always specify placement of the in line encapsulated choke (ATT Z1000) at the wall socket. The amount of connecting cable from the phone to the wall socket is a good antenna too so picks up RF and bypasses any effect of the common mode choke. Although the problem is removing the condcuted current before it becomes a problem , the same principle applies to emitted noise. In some cases of suppressing consumer equipment there is a dramatic increase in sensitvity to conducted currents at different requencies( usually higher) and this requires that the ground loop provided by the power cord be isolated from the device. Inevitably this has cured the problem. Be aware that any cabling connected to a device can radiate as well as conduct undesireable energy into the device. Ferrites provide a simple, non intrusive, inexpensive solution to such problems. You will see them on all the better quality computer monitors and laptops. Ralph Cameron Independant EMC Consultant and
Re: Common Mode Choke
The expert on this subject is Mark Nave (mark.n...@netapp.com). He has a book out (probably out-of-print now) on Power-Line Filtering for Switched Mode Power Supplies. Also a paper in the 1991 IEEE EMC Symposium record, On Modeling the CM Inductor. In that paper, he shows how to calculate the leakage inductance (dm component of cm inductance). It is this leakage inductance which causes saturation. -- From: Derek Walton l...@rols1.net To: IEEE EMC Discussion Group emc-p...@majordomo.ieee.org Subject: Common Mode Choke Date: Thu, Dec 2, 1999, 1:46 PM Good day all, I'm refining the input filter of a 150 watt SMPS. Nothing flashy, just a few caps and a common mode choke. The current is drawn by the supply in short bursts as the DC link cap is charged. I've shown that peak current reaches 6 amps for up to 2 ms. I've also demonstrated that the CM choke, while rated for the RMS current ( a 2 amp device ), does saturate when the current exceeds about 4 amps. I've been trying to find out from the vendors, what current it takes to saturate the CM choke. I've had answers from CM chokes can't saturate to that's not an important parameter, use the rms figure My question is, with over 20 potential vendors of this type of component, is there any way I can find out saturation performance without buying one of each type and testing it. I've played with 3 so far, the most expensive was NOT the best! I guess, I'm curious why more folks don't know about this effect also. Thanks, Derek Walton Owner L. F. Research EMC Design and Test Facility 12790 Route 76, Poplar Grove, IL 61065. www.lfresearch.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: Common Mode Choke
Well Fred, here's where we get to interesting discussions... Different folks use different core materials to achieve different goals. Knowing that in most cases a CM Choke will be faced with pulse current demands, you would think that cores would be made from materials with a large incremental current, i.e. a large current draw would result in only a small drop off in material perm. My point specifically is that CM chokes are being rated by: * wire current capability * core temp rise * anything else I've forgotten They are NOT rated for how they handle pulsed current, in fact there is no data sheet parameter that addresses this. However, as an EMC filter designer I want the best cost/performance compromise, so I need to know this. The 3 devices I've tested show dramatic differences in how they handle pulsed currents, even though they have the same rms current rating. If there are any CM Choke members on the list that would like to work on ( what I perceive to be ) this problem, please contact me directly.. It would make a good IEEE paper for the Chicago 2000 EMC Mini conference. Best regards, Derek. Fred Townsend wrote: I've read your message twice and I still don't get your point. Saturation is a disaster, EMI wise, (not to mention what it can do to the current in some semiconductor devices) so as a designer you have to make sure you never go there. If you have a 6 amp peak current then use a choke rated for 6 amps RMS. Using any device outside it's rated parameters is cruising for a bruising. Fred Townsend DC to Light Consulting Services Derek Walton wrote: Good day all, I'm refining the input filter of a 150 watt SMPS. Nothing flashy, just a few caps and a common mode choke. The current is drawn by the supply in short bursts as the DC link cap is charged. I've shown that peak current reaches 6 amps for up to 2 ms. I've also demonstrated that the CM choke, while rated for the RMS current ( a 2 amp device ), does saturate when the current exceeds about 4 amps. I've been trying to find out from the vendors, what current it takes to saturate the CM choke. I've had answers from CM chokes can't saturate to that's not an important parameter, use the rms figure My question is, with over 20 potential vendors of this type of component, is there any way I can find out saturation performance without buying one of each type and testing it. I've played with 3 so far, the most expensive was NOT the best! I guess, I'm curious why more folks don't know about this effect also. Thanks, Derek Walton Owner L. F. Research EMC Design and Test Facility 12790 Route 76, Poplar Grove, IL 61065. www.lfresearch.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). -- Derek Walton Owner L. F. Research EMC Design and Test Facility 12790 Route 76, Poplar Grove, IL 61065. www.lfresearch.com
Re: Common Mode Choke
Ken, well versed with Mark and his book. Excellent. not sure I totally agree with you on the leakage statement, but I agree it plays a big role. I had Marks phone number somewhere, but can't pull it to hand: would you still have it? Suggest you send it direct. Thanks, Derek. Ken Javor wrote: The expert on this subject is Mark Nave (mark.n...@netapp.com). He has a book out (probably out-of-print now) on Power-Line Filtering for Switched Mode Power Supplies. Also a paper in the 1991 IEEE EMC Symposium record, On Modeling the CM Inductor. In that paper, he shows how to calculate the leakage inductance (dm component of cm inductance). It is this leakage inductance which causes saturation. -- From: Derek Walton l...@rols1.net To: IEEE EMC Discussion Group emc-p...@majordomo.ieee.org Subject: Common Mode Choke Date: Thu, Dec 2, 1999, 1:46 PM Good day all, I'm refining the input filter of a 150 watt SMPS. Nothing flashy, just a few caps and a common mode choke. The current is drawn by the supply in short bursts as the DC link cap is charged. I've shown that peak current reaches 6 amps for up to 2 ms. I've also demonstrated that the CM choke, while rated for the RMS current ( a 2 amp device ), does saturate when the current exceeds about 4 amps. I've been trying to find out from the vendors, what current it takes to saturate the CM choke. I've had answers from CM chokes can't saturate to that's not an important parameter, use the rms figure My question is, with over 20 potential vendors of this type of component, is there any way I can find out saturation performance without buying one of each type and testing it. I've played with 3 so far, the most expensive was NOT the best! I guess, I'm curious why more folks don't know about this effect also. Thanks, Derek Walton Owner L. F. Research EMC Design and Test Facility 12790 Route 76, Poplar Grove, IL 61065. www.lfresearch.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). -- Derek Walton Owner L. F. Research EMC Design and Test Facility 12790 Route 76, Poplar Grove, IL 61065. www.lfresearch.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Common Mode Choke
Derek, We stock a 16 amp line filter which we have used on lower current products specifically to prevent saturation of the choke when used as a protective device for external events such as EFT. I put one on a product containing an industrial computer supplied by a business partner to solve a problem with Ethernet communications during EFT testing. Interestingly, although the computer was CE marked, EN61000-4-4 was absent from the list on the compliance label. I had a tough time convincing the engineering manager that the larger device was needed. He wanted to use a smaller filter that replace the IEC cord inlet. The answer to your question is that, in the absence of reliable data from the vendors, you must either devise a quick test or deal directly with a good custom magnetics house that will build a part to your specs. Unfortunately, today we often find ourselves dealing with puppies after the old dog engineers have either retired or been laid off. A lot of these kids don't know, don't care, and think truthfulness is an impediment to sales. It can be difficult tell stupidity from malice as they both cause similar problems. Scott Lacey -Original Message- From: Derek Walton [SMTP:l...@rols1.net] Sent: Thursday, December 02, 1999 2:47 PM To: IEEE EMC Discussion Group Subject:Common Mode Choke Good day all, I'm refining the input filter of a 150 watt SMPS. Nothing flashy, just a few caps and a common mode choke. The current is drawn by the supply in short bursts as the DC link cap is charged. I've shown that peak current reaches 6 amps for up to 2 ms. I've also demonstrated that the CM choke, while rated for the RMS current ( a 2 amp device ), does saturate when the current exceeds about 4 amps. I've been trying to find out from the vendors, what current it takes to saturate the CM choke. I've had answers from CM chokes can't saturate to that's not an important parameter, use the rms figure My question is, with over 20 potential vendors of this type of component, is there any way I can find out saturation performance without buying one of each type and testing it. I've played with 3 so far, the most expensive was NOT the best! I guess, I'm curious why more folks don't know about this effect also. Thanks, Derek Walton Owner L. F. Research EMC Design and Test Facility 12790 Route 76, Poplar Grove, IL 61065. www.lfresearch.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: antenna and cable for 2.4GHz
I know it's impolite to answer a question with a question (let alone a host of questions), but... What is this for? Do you need gain (directivity)? If so, how much? How much bandwidth? A quarter wave stub gives you broadcast coverage, with little gain and relatively sharply tuned. A logperiodic can give a lot more gain and a lot of bandwidth. A horn gives sub-octave bandwidth, but potentially more gain. Does the 30 dB attenuation have to be inherent in the coax, or can you use an external pad? Answer these questions, and I can tell you exactly what to get. -- From: Muriel Bittencourt de Liz mur...@grucad.ufsc.br To: Lista de EMC da IEEE emc-p...@ieee.org Subject: antenna and cable for 2.4GHz Date: Fri, Dec 3, 1999, 10:51 AM Group, I need an antenna with impedance of 50ohms, for operating frequency of 2.4GHz. I also need a coaxial cable with 30dB attenuation, for operating at the same frequency (2.4GHz). Thanks in advance! Muriel -- 8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-) Muriel Bittencourt de Liz, M.Sc. - EMC Engineer GRUCAD - Group for Conception Analysis of Electromagnetic Devices Santa Catarina Federal University - UFSC PO Box: 476 ZIP: 88040-900 - Florianópolis - SC - BRAZIL Phone: +55.48.331.9649 - Fax: +55.48.234.3790 e-mail: mur...@grucad.ufsc.br ICQ#: 9089332 - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: LISN schematic for student in Belgium
Whoops! Looks like I forgot to attach the schematic. Here goes again. -- From: Ken Javor ken.ja...@emccompliance.com To: emc-p...@majordomo.ieee.org Cc: wde...@vt4.net Subject: LISN schematic for student in Belgium Date: Fri, Dec 3, 1999, 11:18 AM CISPR has updated the LISN to include a bleeder resistor between the EMI port and ground. It does NOT affect LISN impedance in any way. I have updated the previously drawn schematic to reflect the new LISN configuration. Also, if the addressee wishes to build one of these, he should be familiar with good rf design techniques. My experience in designing a LISN for commercial sale was that it took a little finessing. - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). CISPR 11 LISN schematic.doc Description: MS-Word document
RE: Cell Phone Hazards?
Yes Martin, Lets just know it for what it is Bad Science. People like John Stallcel? (I hope I didn't misspell his name too badly) with CBS has had several news shows on Bad Science. Now there is one, in the press, that understands. Those of us that were/are microwave engineers understand the risks. I have been exposed the microwave radiation many times, but I know the eyes go first. If people that use cell phones were getting cataracts, you bet I would pay attention. I better quit talking before I get upset. Al Patrick -Original Message- From: Martin Green [mailto:martin.gr...@iti.co.uk] Sent: Friday, December 03, 1999 4:09 AM To: 'Patrick, Al'; 'mkel...@es.com'; emc-p...@majordomo.ieee.org Subject:RE: Cell Phone Hazards? I agree, there has always been a knee jerk reaction by the press to anything bad. Mad cow disease is a typical example. We banned sales of beef on the bone in UK because someone suggested that there might be link with new form CJD. No proof, just a suggestion, and that gave rise to a ban on its sale in UK and a further drop in confidence about the safety of food. Now we have the bizarre situation where the UK government want to allow it to be sold again, but the Scottish and Welsh parliaments do not (they represent 15% of the total UK population), so the ban continues. And of course we now have a documented case of new form CJD in a young girl who has always been a vegetarian - bad science? And the press loved it all - they sold millions of papers and we killed millions of cows. The good news out today in UK is that a group of eminent researchers headed by the UK most prestigious epidemiologist, Sir Richard Doll from Oxford University, have concluded that there is no evidence of cancer being caused by electric power lines, so the heated blankets are OK. I have not read the report yet so there may be some stings in the tail. This is just hot off the morning news. Martin Green Technology International (Europe) Ltd. (44) 1793 783137 Fax (44) 1793 782310 -Original Message- From: Patrick, Al [SMTP:al.patr...@sciatl.com] Sent: 03 December 1999 07:34 To: 'mkel...@es.com'; emc-p...@majordomo.ieee.org Subject:RE: Cell Phone Hazards? Max, I remember seeing the same show and years later a show on PBS about that show. Bottom line: although the rate of cancer seemed high, it was still within the statistical norm for the population. Now many years ago, and I mean decades ago a statistical type was studying Leukemia rates among Line Men (High Tension Line works) for an insurance company, to find out why they had double the rate of Leukemia for the general population. His conclusion was? That the electrical fields somehow were the problem. He went on to conclude that all electrical workers and ham radio operators were being harmed. Bottom Line: Years later and with no fanfare in the press it was found that the PCB's which were in the wire insulation and transform oil (which were spilled all over the place) were the real cause of the Leukemia. By the time the Bad Science was over, even sleeping with an electric blanket would kill you. Did you throw yours away? (By the way, PCB's were banned after that Good Science). And the bottom of Boston harbor is still covered two feet deep in PCB's oils to this day. The press loves Bad Science because it could be true! and it sell newspapers or better ratings on the nightly news. There's my two cents and change for a dollar. Al Patrick Note! These opinions are my own and not of my employers. The names have been changes to protect the guilty. Batteries not included. -Original Message- From: mkel...@es.com [mailto:mkel...@es.com] Sent: Thursday, December 02, 1999 3:38 PM To: emc-p...@majordomo.ieee.org Subject:RE: Cell Phone Hazards? I remember seeing a television show quite a while ago
Common Mode Choke
On Thu, 2 Dec 1999, Derek Walton l...@rols1.net wrote: I'm refining the input filter of a 150 watt SMPS. Nothing flashy, just a few caps and a common mode choke. The current is drawn by the supply in short bursts as the DC link cap is charged. I've shown that peak current reaches 6 amps for up to 2 ms. I've also demonstrated that the CM choke, while rated for the RMS current ( a 2 amp device ), does saturate when the current exceeds about 4 amps. snip How did you determine this? By calculations or measurements. I've thought about this several times, but couldn't come up with a test setup I was satisfied with. -- Patrick Lawler plaw...@west.net - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: warning label overkill?
Hi Ron: In the interest of safety, why place the onus on the consumer when he/she had nothing to do with the design? Ralph Cameron - Original Message - From: ron_du...@agilent.com To: emc-p...@majordomo.ieee.org; sobe...@fdanews.com Sent: Friday, December 03, 1999 6:40 AM Subject: RE: warning label overkill? I agree. I question the warning on champagne bottles. I mean anybody that reaches legal drinking age knows a champagne cork can become a projectile. This is a prime example of shifting the responsibility from the responsible person to the manufacturer. Ron Duffy Product Safety Engineer Aiglent Technologies -Original Message- From: sobe...@fdanews.com [mailto:sobe...@fdanews.com] Sent: Thursday, 02 December, 1999 14:14 To: emc-p...@majordomo.ieee.org Subject: FW: warning label overkill? Serious question even though this involves a non-electrical product: at what point do warning labels undermine themselves? I was surprised to find this warning label on a 20 oz bottle of Dr. Pepper. It seems to be unique to that brand -- Coke, Pepsi and whatnot don't seem to carry it. ! WARNING (exclamation point is inside a triangle) CONTENTS UNDER PRESSURE. CAP MAY BLOW OFF CAUSING EYE OR OTHER SERIOUS INJURY. POINT AWAY FROM FACE AND PEOPLE, ESPECIALLY WHILE OPENING. It didn't seem to be any more carbonated than the Cokes I usually buy. I can see the point of such labels on Champaign with the corks that often become projectiles. But the physics of a screw-off soda bottle cap just doesn't seem to have the same ballistic potential. (I know, I know, the GC made them do it. But still.) -- Sean Oberle Vice President of New Products Washington Business Information, Inc. 1117 N 19th St, Ste 200, Arlington, VA 22209 Voice: 703/247-3429; Fax: 703/247-3421 - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: RE: Minnesota and Vermont Mercury labeling law
Try the following site: http://www.revisor.leg.state.mn.us/stats/115A/9651.html Title: Listed Metals In Specified Products (Minnesota) I didn't see anything about product labeling, but there is a process to submit products for re-sale containing listed metals Good Luck -Original Message- From: jim_bac...@mail.monarch.com [mailto:jim_bac...@mail.monarch.com] Sent: Friday, December 03, 1999 7:03 AM To: emc-p...@majordomo.ieee.org Cc: tom_bec...@perkinelmer.com Subject: Fwd:RE: Minnesota and Vermont Mercury labeling law forwarded for: tom_bec...@perkinelmer.com Forward Header_ Subject:RE: Minnesota and Vermont Mercury labeling law Author: Becker; Tom tom_bec...@perkinelmer.com List-Post: emc-pstc@listserv.ieee.org Date: 12/02/99 5:26 PM Hi All, We use some mercury wetted relays that fall under these laws. Does anyone know of any standard labels available that can be put on an instrument so that it complies with these laws? What does the label wording have to say? Thanks, Tom Becker tom_bec...@perkinelmer.com -Original Message- From: ron_well...@agilent.com [SMTP:ron_well...@agilent.com] Sent: Wednesday, November 03, 1999 11:48 AM To: emc-p...@ieee.org Subject: Minnesota and Vermont Mercury labeling law Hello all, This message is directed at the non-ITE folk regarding labeling of products that contain Mercury for the States of Vermont and Minnesota. First of all, are you ISM folk aware of these laws? If you are, are you doing anything about them regarding compliance? For Minnesota, check out: http://www.revisor.leg.state.mn.us/stats/116/92.html For Vermont, check out: http://www.anr.state.vt.us/dec/ead/mercury/manufact.htm Regards, Ron Wellman ron_well...@agilent.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: AC Mains Color Coding
Hi Robert: But what about permanently connected products? For the purposes of Article 400-22(c), the NEC does not distinguish between permanently-connected and plug-and-socket-connected appliances. The rule is: Specifically, 400-22(c): For jacketed cords furnished with appliances, one conductor having its insulation colored light blue... So, if the cord is furnished with the appliance, then the neutral may employ a light blue insulation. Many industrial appliances are permanently connected by means of a jacketed cord that is permanently connected at the appliance end. My interpretation is that such a cord could have its neutral colored light blue. Best regards, Rich - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: AC Mains Color Coding
But what about permanently connected products? -Original Message- From: Rich Nute [mailto:ri...@sdd.hp.com] Sent: Friday, December 03, 1999 8:53 AM To: Mavis, Robert Cc: emc-p...@majordomo.ieee.org Subject: Re: AC Mains Color Coding Hi Robert: Yes certain UL standards have accepted the Lt Blue for the neutral. But therein lies the conflict. The NEC states that the neutral (grounded conductor) must be white or nat. Gray. Has there been an acceptance by the NEC for the blue neutral?? Yes, the NEC does indeed accept blue for the neutral color for cords, but not for building wiring. See: Cords: NEC Articles 200(c), 400-22(c), 400-23. Buildings: NEC Articles 200-7, 210-5. Specifically, 400-22(c): For jacketed cords furnished with appliances, one conductor having its insulation colored light blue... (UL would not accept blue unless the NEC first accepted blue.) Best regards, Rich - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). Note: If you are not the intended recipient of this e-mail, contact administra...@pelco.com or call (559) 292-1981. Information contained may be confidential. Dissemination, distribution or copying of this e-mail is prohibited if you are not the intended recipient.
antenna and cable for 2.4GHz
Group, I need an antenna with impedance of 50ohms, for operating frequency of 2.4GHz. I also need a coaxial cable with 30dB attenuation, for operating at the same frequency (2.4GHz). Thanks in advance! Muriel -- 8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-) Muriel Bittencourt de Liz, M.Sc. - EMC Engineer GRUCAD - Group for Conception Analysis of Electromagnetic Devices Santa Catarina Federal University - UFSC PO Box: 476 ZIP: 88040-900 - Florianópolis - SC - BRAZIL Phone: +55.48.331.9649 - Fax: +55.48.234.3790 e-mail: mur...@grucad.ufsc.br ICQ#: 9089332 - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: An informative, compact article about FCC requirements
Well written article! This is a must read for those that are new to compliance engineering. -John Juhasz- Fiber Options Bohemia, NY -Original Message- From: wo...@sensormatic.com [mailto:wo...@sensormatic.com] Sent: Friday, December 03, 1999 9:48 AM To: emc-p...@majordomo.ieee.org Subject: An informative, compact article about FCC requirements http://www.wirelessdesignmag.com/exec/relpgm.exe?RPTID=SHOWPR?ACCT=100?I SSUE=9911?RELTYPE=FE?PRODCODE=0?PRODLETT=A http://www.wirelessdesignmag.com/exec/relpgm.exe?RPTID=SHOWPR?ACCT=100? ISSUE=9911?RELTYPE=FE?PRODCODE=0?PRODLETT=A - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: An informative, compact article about FCC requirements
The URL is longer than one line. When it wrapped, the text printed but is not in HTML format. You will have to type in the balance of the URL. Richard Woods -- From: John Juhasz [SMTP:jjuh...@fiberoptions.com] Sent: Friday, December 03, 1999 12:58 PM To: 'wo...@sensormatic.com' Subject: RE: An informative, compact article about FCC requirements Richard, I got this error on these URLs Error in Product Search No Company, rel type, issue or product number selected -John Juhasz- Fiber Options Bohemia, NY -Original Message- From: wo...@sensormatic.com [ mailto:wo...@sensormatic.com mailto:wo...@sensormatic.com ] Sent: Friday, December 03, 1999 9:48 AM To: emc-p...@majordomo.ieee.org Subject: An informative, compact article about FCC requirements http://www.wirelessdesignmag.com/exec/relpgm.exe?RPTID=SHOWPR?ACCT=100?I http://www.wirelessdesignmag.com/exec/relpgm.exe?RPTID=SHOWPR?ACCT=100? I SSUE=9911?RELTYPE=FE?PRODCODE=0?PRODLETT=A http://www.wirelessdesignmag.com/exec/relpgm.exe?RPTID=SHOWPR?ACCT=100 http://www.wirelessdesignmag.com/exec/relpgm.exe?RPTID=SHOWPR?ACCT=100 ? ISSUE=9911?RELTYPE=FE?PRODCODE=0?PRODLETT=A - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: Common Mode Choke
Scott, It looks like I agree with you, but I'm just trying to see if I can get filter vendors to publish critical data about their parts. As we say in England ( and possibly elsewhere too ), It's like flogging a dead horse Best regards, Derek. Lacey,Scott wrote: Derek, We stock a 16 amp line filter which we have used on lower current products specifically to prevent saturation of the choke when used as a protective device for external events such as EFT. I put one on a product containing an industrial computer supplied by a business partner to solve a problem with Ethernet communications during EFT testing. Interestingly, although the computer was CE marked, EN61000-4-4 was absent from the list on the compliance label. I had a tough time convincing the engineering manager that the larger device was needed. He wanted to use a smaller filter that replace the IEC cord inlet. The answer to your question is that, in the absence of reliable data from the vendors, you must either devise a quick test or deal directly with a good custom magnetics house that will build a part to your specs. Unfortunately, today we often find ourselves dealing with puppies after the old dog engineers have either retired or been laid off. A lot of these kids don't know, don't care, and think truthfulness is an impediment to sales. It can be difficult tell stupidity from malice as they both cause similar problems. Scott Lacey -Original Message- From: Derek Walton [SMTP:l...@rols1.net] Sent: Thursday, December 02, 1999 2:47 PM To: IEEE EMC Discussion Group Subject:Common Mode Choke Good day all, I'm refining the input filter of a 150 watt SMPS. Nothing flashy, just a few caps and a common mode choke. The current is drawn by the supply in short bursts as the DC link cap is charged. I've shown that peak current reaches 6 amps for up to 2 ms. I've also demonstrated that the CM choke, while rated for the RMS current ( a 2 amp device ), does saturate when the current exceeds about 4 amps. I've been trying to find out from the vendors, what current it takes to saturate the CM choke. I've had answers from CM chokes can't saturate to that's not an important parameter, use the rms figure My question is, with over 20 potential vendors of this type of component, is there any way I can find out saturation performance without buying one of each type and testing it. I've played with 3 so far, the most expensive was NOT the best! I guess, I'm curious why more folks don't know about this effect also. Thanks, Derek Walton Owner L. F. Research EMC Design and Test Facility 12790 Route 76, Poplar Grove, IL 61065. www.lfresearch.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). -- Derek Walton Owner L. F. Research EMC Design and Test Facility 12790 Route 76, Poplar Grove, IL 61065. www.lfresearch.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
UL1459
UL was talking about integrating 1459 (telephone equip.) into UL1950 (ITE) can anyone update me as to status? Product will be ADSL combining digital data and digital voice, then sent over public networks and leased line for eventual distibution to residences. Does equipment like this have to be evaluated to 1459 and 1950 or what? thanks bruce benzie - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
An informative, compact article about FCC requirements
http://www.wirelessdesignmag.com/exec/relpgm.exe?RPTID=SHOWPR?ACCT=100?I SSUE=9911?RELTYPE=FE?PRODCODE=0?PRODLETT=A http://www.wirelessdesignmag.com/exec/relpgm.exe?RPTID=SHOWPR?ACCT=100? ISSUE=9911?RELTYPE=FE?PRODCODE=0?PRODLETT=A - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Fwd:RE: Minnesota and Vermont Mercury labeling law
forwarded for: tom_bec...@perkinelmer.com Forward Header_ Subject:RE: Minnesota and Vermont Mercury labeling law Author: Becker; Tom tom_bec...@perkinelmer.com List-Post: emc-pstc@listserv.ieee.org Date: 12/02/99 5:26 PM Hi All, We use some mercury wetted relays that fall under these laws. Does anyone know of any standard labels available that can be put on an instrument so that it complies with these laws? What does the label wording have to say? Thanks, Tom Becker tom_bec...@perkinelmer.com -Original Message- From: ron_well...@agilent.com [SMTP:ron_well...@agilent.com] Sent: Wednesday, November 03, 1999 11:48 AM To: emc-p...@ieee.org Subject: Minnesota and Vermont Mercury labeling law Hello all, This message is directed at the non-ITE folk regarding labeling of products that contain Mercury for the States of Vermont and Minnesota. First of all, are you ISM folk aware of these laws? If you are, are you doing anything about them regarding compliance? For Minnesota, check out: http://www.revisor.leg.state.mn.us/stats/116/92.html For Vermont, check out: http://www.anr.state.vt.us/dec/ead/mercury/manufact.htm Regards, Ron Wellman ron_well...@agilent.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: Cell Phone Hazards?
Further to the items regarding Luekaemia and power lines the following press release was given today. Friday December 3, 8:37 AM Child Cancer And Pylons 'Not Linked' A Department of Health-supported study says there are no links between child cancers and electricity pylons. The independent UK Childhood Cancer Study found no evidence to link childhood cancer with exposure to magnetic fields from electricity supply after examining more than 2,200 cases. The report says: This study provides no evidence that exposure to magnetic fields associated with the electricity supply in the UK increases risks for childhood leukaemia, cancers of the central nervous system or any other childhood cancer. The independent study was supported by the Department of Health and the UK's main cancer charities. Its management committee chairman and leading epidemiologist is Sir Richard Doll, who is credited with discovering the link between smoking and lung cancer. He concluded after the study: I believe there is now no justification for further epidemiological studies on exposure to magnetic fields and childhood cancer in Britain. The new report follows the publication of research by Bristol University scientists who said that people living and working near high voltage lines were up to three times more at risk from airborne cancer-causing pollutants being deposited on the skin. The researchers, who made some 2,000 measurements in fields near the city, said ionisation of the air around the cables spread the increased-risk effect up to several hundred metres from the lines. Presenting two papers published in the International Journal of Radiation Biology, the scientists suggested that this might explain the well-chronicled association between power lines and childhood leukaemia. But electricity industry chiefs welcomed the findings of the UK Childhood Cancer team and said other surveys should now be carried out to establish what is linked to childhood cancers. RCIC - http://www.rcic.com Regulatory Compliance Information Center - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
FDA Laser Regulations
Group, In one of our products we use a certified laser transmitter. The unit is class 1, is internally protected so it cannot exceed this limit and it has an FDA ascession number i.e. a report on the product is filed with the FDA. The other day whilst searching the FDA website I found laser notice number 42 which states that 'the CDRH will consider firms incorperating certified class 1 laser products into another product as distributors of laser products certified and reported by other manufacturers.' It goes on to give some conditions, mostly regarding the labeling. Earlier on in the same document examples of such situations were given as 'disc drive units incorperated into computers, CD players installed into home entertainment centres and CD players installed into automobiles' The laser we use is in a drop in DIL package and is an approved laser product in its own right. The main question is how applicable is this? In words it would seem that we are 'incorperating a certified class 1 laser product' but there is a big difference between a CD player as a hi fi seperate and a CD player as a component module that is then built into a Hi Fi seperate. The main difference being that the seperate is a 'laser system' i.e. it has a power supply and the CD module is not and therefore cannot be used unless it is installed in another unit. The car CD player or the PC CD ROM would also need to be installed before they could be used. The main question here is does the relaxation in the CRDH laser reporting requirements for incorperated certified class 1 laser products cover 'laser systems' laser components or both? Many thanks in advance, Duncan. - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
AW: Question about EN55024
Hi Sandy, The EN 50082-1 is an Generic Standard. If a Product Standard like EN 55024 is available this standard have the preference. Lothar Schmidt -Ursprüngliche Nachricht- Von: Sandy Mazzola [mailto:mazzo...@symbol.com] Gesendet am: Mittwoch, 1. Dezember 1999 23:26 An: emc-p...@majordomo.ieee.org Betreff: Question about EN55024 To All, EN 55024 (Immunity Characteristics-Information Technology Equipment- Product Specific) does not address industrial/Heavy industrial ITE equipment. All of the levels for the most part match the levels of EN50082-1 (Generic Immunity -Light Industrial). Is EN 55024 a license to release any and all ITE equipment to the formerly light industrial levels? I would appreciate any opinions as to how to specify/release industrial/heavy industrial ITE. Sandy Mazzola - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Mil-Std-202
Does anyone know a website where I can download a copy of Mil-Std-202. Preferably at no charge. Daniel W. Mitchell Product Safety Engineer Condor DC Power Supplies, Inc. P: (805) 486-4565 x323 F: (805) 483-4307 - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
