EMI preamplifier
Group, Can anyone recommend an inexpensive preamplifier for the input to a spectrum analyser. BW requirement is 1MHz to 30mHz for conducted emmissions from an LISN tap. We need a noise floor below 1uV on the output, when fed with a 10dB attenuator. With a noise floor of 10dBu , theres no way we can troubleshoot for a customer's reported 6.5uV of interference. Removing the attenuator tends to overload the equipment due to LF content and the QA department won't stick a CAL sticker on home-brew stuff. Rob Legg Tectrol Inc. rl...@tectrol.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Equipment Rental 2
Bob Try EMC Hire on +44 1462 817111 or fax +44 1462 817444. I have no connection with the company other than as a satisfied customer. Best wishes Brian Jones EMC Consultant and Competent Body Signatory -Original Message- From: rehel...@mmm.com rehel...@mmm.com To: emc-p...@majordomo.ieee.org emc-p...@majordomo.ieee.org List-Post: emc-pstc@listserv.ieee.org Date: 11 July 2000 14:07 Subject: Equipment Rental 2 Thanks for everyone who sent me rental information but I did not word the question correctly. I would prefer not to take equipment with me from the U.S. to the U.K. I am looking to rent the equipment in England preferably near Darlington. Thanks, Bob Heller === -- Forwarded by Robert E. Heller/US-Corporate/3M/US on 07/11/2000 07:31 AM --- Robert E. Heller 07/10/2000 01:27 PM 3M Product Safety, St. Paul, MN 55107 76-1-01 EMC Laboratory Fax: 651-778-6252 To: emc-p...@majordomo.ieee.org cc: Subject: Equipment Rental I need to rent the following equipment (preferrably in Darlington, U.K.): * Antennas (EMC 30-1000 MHz) * Spectrum Analyzer/EMI Receiver * Pre-amp (30-1000 MHz) * 2M Tripod Anyone know of a company? Regards, Bob Heller --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Regulatory Compliance Engineer Wanted
Inter-Tel Inc. is looking for a qualified Regulatory Compliance Engineer. This individual will be responsible for the Safety, EMC and Telecom Compliance for PBX and Peripheral products. Products must comply with US, EU, Mexican and Japanese requirements. Familiarity with these regulations is required. An engineering degree or equivalent experience in the compliance field is also required. Inter-Tel is located in Chandler, (Phoenix), Arizona and offers competitive compensation and benefits. Send resume or call for more information. Joe Dwyer Manager of Product Validation Inter-Tel Inc. 7300 West Boston Street Chandler, AZ 85226 Tel:800-669-5858 x21235 Tel:480-961-9000 x21235 Fax: 480-961-6940 Email mailto: dw...@inter-tel.com Home Page http://www.inter-tel.com Employment http://www.nationjob.com/inter-tel Inter-Tel is the largest provider of business key telephone systems, voice processing systems and related software applications for the 40+ station key telephone system market in the United States. Inter-Tel is also a leading provider of IP telephony voice and data convergence products and operates an IP telephony-based long distance network. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Buying Environmental Chamber
Hi all, My company has been considering buying a walk-in chamber for some time. I'd appreciate any help in locating vendors of both used and new chambers. We are located just outside of Dallas so the nearer the better, but I'm open to all suggestions. Thanks in advance of any replies. Regards, Phil Godfrey Manager, Product Safety KTL Dallas, Inc. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Trying to locate CTS
Hello group, I am attempting to locate address and website information for a company called CTS or C.T.S. who does EMI/EMC consulting and manufactures EMI filters in the United Kingdom. thanks for the help, -doug --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Equipment Rental 2
Try http://www.livingston.co.uk/rental.html rehel...@mmm.com wrote: Thanks for everyone who sent me rental information but I did not word the question correctly. I would prefer not to take equipment with me from the U.S. to the U.K. I am looking to rent the equipment in England preferably near Darlington. Thanks, Bob Heller === -- Forwarded by Robert E. Heller/US-Corporate/3M/US on 07/11/2000 07:31 AM --- Robert E. Heller 07/10/2000 01:27 PM 3M Product Safety, St. Paul, MN 55107 76-1-01 EMC Laboratory Fax: 651-778-6252 To: emc-p...@majordomo.ieee.org cc: Subject: Equipment Rental I need to rent the following equipment (preferrably in Darlington, U.K.): * Antennas (EMC 30-1000 MHz) * Spectrum Analyzer/EMI Receiver * Pre-amp (30-1000 MHz) * 2M Tripod Anyone know of a company? Regards, Bob Heller --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org -- Regards Dave Instone. Compliance Engineer Test Systems, MP24/22 Xyratex, Langstone Rd., Havant, Hampshire, P09 1SA, UK. Tel: +44 (0)23-92-496862 (direct line) Fax: +44 (0)23-92-496014 http://www.xyratex.com Tel: +44 (0)23-92-486363 --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Equipment Rental 2
Thanks for everyone who sent me rental information but I did not word the question correctly. I would prefer not to take equipment with me from the U.S. to the U.K. I am looking to rent the equipment in England preferably near Darlington. Thanks, Bob Heller === -- Forwarded by Robert E. Heller/US-Corporate/3M/US on 07/11/2000 07:31 AM --- Robert E. Heller 07/10/2000 01:27 PM 3M Product Safety, St. Paul, MN 55107 76-1-01 EMC Laboratory Fax: 651-778-6252 To: emc-p...@majordomo.ieee.org cc: Subject: Equipment Rental I need to rent the following equipment (preferrably in Darlington, U.K.): * Antennas (EMC 30-1000 MHz) * Spectrum Analyzer/EMI Receiver * Pre-amp (30-1000 MHz) * 2M Tripod Anyone know of a company? Regards, Bob Heller --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: RE: Notified Body Number
Cynthia, I am not familiar with Annex V of the Directive, however I do know that use of the NB number is not limited to that route of compliance. Annex IV requires a Notified Body assessment of the TCF and in so doing, the mfg. must identify, by use of the NB number, which NB was used. Also, it is my understanding that the NB number should be placed between the CE mark and the alert symbol, if required, otherwise just to the right of the CE mark(I have no basis for this position but it seems to be the accepted norm). ~ Sam Wismer RF Approvals Engineer LXE, Inc. (770) 447-4224 Ext. 3654 Visit Our Website at: http://www.lxe.com -Original Message- From: jim_bac...@mail.monarch.com [mailto:jim_bac...@mail.monarch.com] Sent: Tuesday, July 11, 2000 1:18 AM To: Cynthia Pleach; emc-p...@majordomo.ieee.org Subject: Re:RE: Notified Body Number Forwarding for Cynthia Reply Separator Subject:RE: Notified Body Number Author: Cynthia Pleach cynthia_ple...@digi.com List-Post: emc-pstc@listserv.ieee.org Date: 7/10/00 1:49 PM It was my understanding that only manufacturing using Annex V of the RTTE would use the CE and notified body number. All others would simply use the CE. -Original Message- From: wo...@sensormatic.com [mailto:wo...@sensormatic.com] Sent: Monday, July 10, 2000 9:56 AM To: emc-p...@majordomo.ieee.org; t...@world.std.com Subject: RE: Notified Body Number I just discovered the Commission's statement on marking in the Sept. 1999 publication Guide to the implementation of directives based upon the New Approach and the Global Approach. Section 7.3 says, A notified body may be involved in the design phase, the production phase, or both, depending on the conformity assessment procedures applied. The CE marking shall only be followed by the identification number of the notified body if it is involved in the production phase. Thus the identification number of a notified body involved in conformity assessment according to Module B does not follow the CE marking. Therefore, it appears that a product subject to Annex III or IV of the RTTE must have a NB marking but, according to the above, it cannot follow the CE marking since the NB is not involved in the production phase. Richard Woods -- From: prob...@nmi.nl [SMTP:prob...@nmi.nl] Sent: Monday, July 10, 2000 10:52 AM To: wo...@sensormatic.com Cc: emc-p...@majordomo.ieee.org; t...@world.std.com Subject: Re: Notified Body Number Richard, Directive 93/68/EC (Article 5), which linked the CE marking to the EMC directive, states that the minimum height of the CE marking must be 5 mm. The Maritime Directive requires a CE marking which also includes the NB number. From the example drawing in the directive it shows that the height of the NB number is identical to the height of the CE marking. The distance of the NB number to the CE marking is based on the distance between the characters C and E. The marking for the RTTE Directive would then look like: CE XXX, where XXX is the NB number. Best regards, NMi Certin B.V. Pieter Robben Department of EMC, Telecommunications and Electrical Safety Web: www.nmicertin.com / www.nmicertin.nl wo...@sensormatic.com on 10/07/2000 14:54:46 Please respond to wo...@sensormatic.com To: emc-p...@majordomo.ieee.org, t...@world.std.com cc:(bcc: Pieter Robben/Nmi) Subject: Notified Body Number Neither the LV nor the RTTE Directive indicates the minimal size for the Notified Body number nor do they indicate the placement of the number relative to the CE marking. Do any of the other directives or any other documents from the Commission indicate the proper way to size and place the Notified Body number? Richard Woods Received: from ruebert.ieee.org ([199.172.136.3]) by mail.monarch.com with SMTP (IMA Internet Exchange 3.14) id FAD1; Mon, 10 Jul 2000 14:50:21 -0700 Received: by ruebert.ieee.org (8.9.3/8.9.3)id OAA08207 Received: from gemini.ieee.org by ruebert.ieee.org (8.9.3/8.9.3) with ESMTP id OAA08181; Mon, 10 Jul 2000 14:50:32 -0400 (EDT) Received: from gopostal.digi.com (gopostal.digi.com [204.221.110.15]) by gemini.ieee.org (8.9.3/8.9.3) with ESMTP id OAA15958 for emc-p...@majordomo.ieee.org; Mon, 10 Jul 2000 14:50:27 -0400 (EDT) Received: by gopostal.digi.com with Internet Mail Service (5.5.2650.21) id 3GBTYFCJ; Mon, 10 Jul 2000 13:50:26 -0500 Message-ID: 415a9f6dcfa0d211b78d0008c7a42fb302fc6...@gopostal.digi.com From: Cynthia Pleach cynthia_ple...@digi.com To: 'wo...@sensormatic.com' wo...@sensormatic.com, emc-p...@majordomo.ieee.org, t...@world.std.com Subject: RE: Notified Body Number
Dialers
DEAR ALL, DOES ANYONE KNOW THE REQUIREMENTS FOR ASFETY AND EMC FOR DIALERS INTENDED FOR THE US AND EUROPE? Peter Merguerian Managing Director Product Testing Division I.T.L. (Product Testing) Ltd. Hacharoshet 26, POB 211 Or Yehuda 60251, Israel Tel: 972-3-5339022 Fax: 972-3-5339019 e-mail: pmerguer...@itl.co.il website: http://www.itl.co.il --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
R: Voltage Breakdown
Hi, what about relative humidity of air ? I believe breakdown voltage depends also on humidity content of air. One thing anybody can experience is the much higher frequency of ESD jolts one gets in dry weather vs. humid weather. Anyone knows a quantitative relation or formula ? my penny's worth... Regards Paolo Roncone -Messaggio originale- Da: bogdan matoga [SMTP:bogda...@pacbell.net] Inviato:sabato 8 luglio 2000 22.57 A: Rich Nute Cc: allen_tu...@pairgain.com; emc-p...@ieee.org Oggetto:Re: Voltage Breakdown Gentlemen: Let me add my penny's worth to Rich's information. a. Parallel plates provide a homogenous field only in their center, the field fringes at the edges. (One could configure the plates according to Rogowski form). b. The breakdown voltage is not a linear function, even for spherical electrodes. What applies is Paschen's law, which gives the voltage as a function of distance x atmospheric pressure. Have fun! Regards, Bogdan. Rich Nute wrote: Hi Allen: The voltage breakdown of air is presented in IEC 664. There is no fixed number (i.e., mm/kV) that describes or predicts voltage breakdown of air. The principle factor that affects voltage breakdown is the shape of the electrodes (degree of homogeneousness of the electric field between the two electrodes). The more homogeneous the field, the higher the breakdown voltage, and vice versa. For example, at 2 mm, the breakdown of an inhomogeneous field is about 2.5 kV, while the breakdown of an homogeneous field is almost 8 kv! An homogeneous field is created by two parallel planes. An inhomogeneous field is created by a needle-point and a plane. The second factor that affects voltage breakdown of air is the voltage waveshape. The more impulse-type waveshape, the higher the breakdown voltage; the more sinusoidal-type waveshape, the lower the breakdown voltage. The third factor that affects voltage breakdown of air is the air pressure. The higher the air pressure, the higher the breakdown voltage, and vice-versa (Paschen's Law). There are still other factors such as temperature, but these are minor effects compared to the first three. If you are interested, I can send a Powerpoint 4.0 file of the voltage-distance curves of the homogeneousness effect. It covers the distance range from 0 to 2 mm for both homogeneous and inhomogeneous fields for sinsoidal waveforms. The data is taken from IEC 664. Best regards, Rich --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re:RE: Notified Body Number
Forwarding for Cynthia Reply Separator Subject:RE: Notified Body Number Author: Cynthia Pleach cynthia_ple...@digi.com List-Post: emc-pstc@listserv.ieee.org Date: 7/10/00 1:49 PM It was my understanding that only manufacturing using Annex V of the RTTE would use the CE and notified body number. All others would simply use the CE. -Original Message- From: wo...@sensormatic.com [mailto:wo...@sensormatic.com] Sent: Monday, July 10, 2000 9:56 AM To: emc-p...@majordomo.ieee.org; t...@world.std.com Subject: RE: Notified Body Number I just discovered the Commission's statement on marking in the Sept. 1999 publication Guide to the implementation of directives based upon the New Approach and the Global Approach. Section 7.3 says, A notified body may be involved in the design phase, the production phase, or both, depending on the conformity assessment procedures applied. The CE marking shall only be followed by the identification number of the notified body if it is involved in the production phase. Thus the identification number of a notified body involved in conformity assessment according to Module B does not follow the CE marking. Therefore, it appears that a product subject to Annex III or IV of the RTTE must have a NB marking but, according to the above, it cannot follow the CE marking since the NB is not involved in the production phase. Richard Woods -- From: prob...@nmi.nl [SMTP:prob...@nmi.nl] Sent: Monday, July 10, 2000 10:52 AM To: wo...@sensormatic.com Cc: emc-p...@majordomo.ieee.org; t...@world.std.com Subject: Re: Notified Body Number Richard, Directive 93/68/EC (Article 5), which linked the CE marking to the EMC directive, states that the minimum height of the CE marking must be 5 mm. The Maritime Directive requires a CE marking which also includes the NB number. From the example drawing in the directive it shows that the height of the NB number is identical to the height of the CE marking. The distance of the NB number to the CE marking is based on the distance between the characters C and E. The marking for the RTTE Directive would then look like: CE XXX, where XXX is the NB number. Best regards, NMi Certin B.V. Pieter Robben Department of EMC, Telecommunications and Electrical Safety Web: www.nmicertin.com / www.nmicertin.nl wo...@sensormatic.com on 10/07/2000 14:54:46 Please respond to wo...@sensormatic.com To: emc-p...@majordomo.ieee.org, t...@world.std.com cc:(bcc: Pieter Robben/Nmi) Subject: Notified Body Number Neither the LV nor the RTTE Directive indicates the minimal size for the Notified Body number nor do they indicate the placement of the number relative to the CE marking. Do any of the other directives or any other documents from the Commission indicate the proper way to size and place the Notified Body number? Richard Woods Received: from ruebert.ieee.org ([199.172.136.3]) by mail.monarch.com with SMTP (IMA Internet Exchange 3.14) id FAD1; Mon, 10 Jul 2000 14:50:21 -0700 Received: by ruebert.ieee.org (8.9.3/8.9.3)id OAA08207 Received: from gemini.ieee.org by ruebert.ieee.org (8.9.3/8.9.3) with ESMTP id OAA08181; Mon, 10 Jul 2000 14:50:32 -0400 (EDT) Received: from gopostal.digi.com (gopostal.digi.com [204.221.110.15]) by gemini.ieee.org (8.9.3/8.9.3) with ESMTP id OAA15958 for emc-p...@majordomo.ieee.org; Mon, 10 Jul 2000 14:50:27 -0400 (EDT) Received: by gopostal.digi.com with Internet Mail Service (5.5.2650.21) id 3GBTYFCJ; Mon, 10 Jul 2000 13:50:26 -0500 Message-ID: 415a9f6dcfa0d211b78d0008c7a42fb302fc6...@gopostal.digi.com From: Cynthia Pleach cynthia_ple...@digi.com To: 'wo...@sensormatic.com' wo...@sensormatic.com, emc-p...@majordomo.ieee.org, t...@world.std.com Subject: RE: Notified Body Number List-Post: emc-pstc@listserv.ieee.org Date: Mon, 10 Jul 2000 13:49:03 -0500 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2650.21) Content-Type: text/plain; X-Resent-To: emc-pstc-ad...@ieee.org Precedence: bulk --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re[2]: Notified Body Number
Forwarding for Pieter Robben Reply Separator Subject:Re: Notified Body Number Author: prob...@nmi.nl List-Post: emc-pstc@listserv.ieee.org Date: 7/10/00 3:51 PM Richard, Directive 93/68/EC (Article 5), which linked the CE marking to the EMC directive, states that the minimum height of the CE marking must be 5 mm. The Maritime Directive requires a CE marking which also includes the NB number. From the example drawing in the directive it shows that the height of the NB number is identical to the height of the CE marking. The distance of the NB number to the CE marking is based on the distance between the characters C and E. The marking for the RTTE Directive would then look like: CE XXX, where XXX is the NB number. Best regards, NMi Certin B.V. Pieter Robben Department of EMC, Telecommunications and Electrical Safety Web: www.nmicertin.com / www.nmicertin.nl wo...@sensormatic.com on 10/07/2000 14:54:46 Please respond to wo...@sensormatic.com To: emc-p...@majordomo.ieee.org, t...@world.std.com cc:(bcc: Pieter Robben/Nmi) Subject: Notified Body Number Neither the LV nor the RTTE Directive indicates the minimal size for the Notified Body number nor do they indicate the placement of the number relative to the CE marking. Do any of the other directives or any other documents from the Commission indicate the proper way to size and place the Notified Body number? Richard Woods Received: from ruebert.ieee.org ([199.172.136.3]) by mail.monarch.com with SMTP (IMA Internet Exchange 3.14) id F6F7; Mon, 10 Jul 2000 09:49:11 -0700 Received: by ruebert.ieee.org (8.9.3/8.9.3)id JAA05230 Received: from gemini.ieee.org by ruebert.ieee.org (8.9.3/8.9.3) with ESMTP id JAA05189; Mon, 10 Jul 2000 09:49:19 -0400 (EDT) From: prob...@nmi.nl Received: from gate.nmi.nl (gate.nmi.nl [194.178.88.1]) by gemini.ieee.org (8.9.3/8.9.3) with ESMTP id JAA02184 for emc-p...@majordomo.ieee.org; Mon, 10 Jul 2000 09:49:00 -0400 (EDT) Received: (from fwmaster@localhost) by gate.nmi.nl (8.9.1a/8.6.12) id PAA25725; Mon, 10 Jul 2000 15:48:13 +0200 (MET DST) Received: by gate.nmi.nl via smap (V1.3) id sma025689; Mon, 10 Jul 00 15:48:07 +0200 Received: by gwmail.nmi.nl(Lotus SMTP MTA v4.6.3 (778.2 1-4-1999)) id 41256918.005082BD ; Mon, 10 Jul 2000 15:39:23 +0100 X-Lotus-FromDomain: NMI To: wo...@sensormatic.com cc: emc-p...@majordomo.ieee.org, t...@world.std.com Message-ID: 41256918.00508295...@gwmail.nmi.nl List-Post: emc-pstc@listserv.ieee.org Date: Mon, 10 Jul 2000 15:51:57 +0100 Subject: Re: Notified Body Number Mime-Version: 1.0 Content-type: text/plain; charset=us-ascii Content-Disposition: inline X-Resent-To: emc-pstc-ad...@ieee.org Precedence: bulk --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Are NTCs Safe to Use in Electrical Equipment
Jim, Replacing the switch with a toggle type dimmer will greatly lengthen the service life of bulbs. I have them in bedrooms and the bathroom. The main intent was to prevent being jolted awake by bright lights if it were necessary to get up at night. Because they look like ordinary light switches, visitors have no trouble operating them. As to using NTC thermistors, I would recommend that you NOT use them inside of an electrical box. They do get quite hot, and even if they did not damage wire insulation, you might be risking your insurance coverage in the event of a fire. I have used them in the past to reduce inrush currents in power supplies, but these were forced air cooled. Without forced cooling, they provide almost no protection if power is re-applied almost immediately after shutoff. By the way, mechanical vibration may be the real culprit. I used to work in a place where the bulbs failed with alarming frequency in our old shield room. Leaving the ventilation blower off reduced the failure rate. Fragile filaments hate to be shaken. Scott Lacey -Original Message- From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf Of Jim Eichner Sent: Monday, July 10, 2000 2:35 PM To: emc-p...@majordomo.ieee.org Subject: RE: Are NTCs Safe to Use in Electrical Equipment On the subject of NTC's, please allow me a slight detour from the compliance world to the real world. I have a circuit in my house that blows light bulbs far more often than any other. I can't determine any reason for this - the voltage seems normal and there aren't any transient-producers on that same circuit (that I'm aware of). Long life and rural-duty bulbs make little or no difference. Instead of figuring out the root cause, I'm considering resorting to trying to deal with the symptom (blown bulbs) by putting an NTC in series with the light fixture somewhere. My thinking is that the mechanism that blows an incandescent bulb filament is related to the high inrush current into the cold (and therefore low R) filament, and the physical and thermal stresses that that inrush causes. Any comments on how likely this is to help, and whether or not I can safely put an NTC in an junction box full of wires? I'd check the NTC's temperature under load (they get hot) and compare that the the temp. rating of the wires in the box. I'd also insulate the bare legs of the NTC and try to make sure it isn't touching anything else. Anyone familiar with the failure modes of these things? Thanks, Jim -Original Message- From: Peter Merguerian [mailto:pmerguer...@itl.co.il] Sent: Monday, July 10, 2000 7:58 AM To: emc-p...@majordomo.ieee.org Subject: Are NTCs Safe to Use in Electrical Equipment Dear All, I have seen some design where NTCs are used to limit inrush currents in motion controllers. Q. Are NTCs safe and reliable as means to limit inrush currents? Q. Are there safety considerations to consider for circuits employing NTCs? Q. Are there any Approved (previously evaluated) NTC components out there? I appreciate all of your comments and/or links regarding the use of NTCs in electrical equipment. Thanks Peter Merguerian Managing Director Product Testing Division I.T.L. (Product Testing) Ltd. Hacharoshet 26, POB 211 Or Yehuda 60251, Israel Tel: 972-3-5339022 Fax: 972-3-5339019 e-mail: pmerguer...@itl.co.il website: http://www.itl.co.il --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
