Hi Chet, There are many other standard electronic equipment that qualify them for these tests; possibly not in the phase of compliance seeking, but at least when looking for simple quality.
Magnetic fields tend to build up low value EMF sources in series with loops and have extremely low impedances. When any electronic circuit contains loops, at a low impedance level, this circuit will almost certainly be affected by the test's field. You may think of low impedance wheathstone bridges, audio output amplifiers; virtual ground sink input in opamps and many other applications. Also, in high end, low level or high dynamic range equipment , the EMF value induced by the field may directly cause performance issues . For this to happen one does not need a low impedanc e path. Finally any equipment containing air coils, or any other non closed magnetic field loop coil may pick up EMF voltages from this test. If these EMF source that buil up in the coil cause a performance problem is entirely dependent of the design, of course. It's for this reason that for professional audio systems EN 55103 the application of a magnetic field source test is prescribed for the full audio frequency range. Looking just at VDU and Hall sensors is a bit restricted, although i definitely agree that for power frequency issues they are the vast majority. Regards, Gert Gremmen Ing. ce-test, qualified testing ce-marking & more http://www.cetest.nl Want to get started quick with ce marking ? http://www.cetest.nl/ce-shop.htm ---------------------------------------------------------------------- This email and any files transmitted with it may be of confidential nature and are intended solely for the use of the individual or entity to whom they are addressed. If you think you have received this email in error please notify me immediately. ---------------------------------------------------------------------- -----Original Message----- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Jim Ericson Sent: woensdag 27 maart 2002 4:18 To: emcpost Subject: Scope of EN 61000-4-8 (Power Frequency Magnetic Testing) >From experience, what type of electronic equipment other than Visual Display Units has been found particularly susceptible to power frequency and pulsed magnetic fields? Thank you, Chet Summers Pelco Chet, EN 61000-4-8 applies if the equipment under test contains devices that are potentially sensitive to magnetic fields. CRTs and other electron beam devices are obvious candidates. Not so obvious (without reviewing the equipment design) are Hall Effect devices. The test is relatively simple, and doesn't take long to perform. A good approach is, when in doubt ... just do it. Jim Ericson Acme Testing Company Acme, WA ------------------------------------------- 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: From - Sun Mar 31 04:57:38 2002 Return-Path: <owner-emc-p...@majordomo.ieee.org> Received: from ruebert.ieee.org ([140.98.193.10]) by mtiwgwc26.worldnet.att.net (InterMail vM.4.01.03.27 201-229-121-127-20010626) with ESMTP id <20020327035346.jueg27913.mtiwgwc26.worldnet.att....@ruebert.ieee.org>; Wed, 27 Mar 2002 03:53:46 +0000 Received: () by ruebert.ieee.org (Switch-2.1.0/Switch-2.1.0) id g2R3mQg02070 for emc-pstc-resent; Tue, 26 Mar 2002 22:48:26 -0500 (EST) From: nickjro...@cs.com Message-ID: <188.5832857.29d29...@cs.com> List-Post: emc-pstc@listserv.ieee.org Date: Tue, 26 Mar 2002 22:48:16 EST Subject: Re: Scope of EN 61000-4-8 (Power Frequency Magnetic Testing) To: jde...@nas.com CC: emc-p...@majordomo.ieee.org MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_188.5832857.29d29b00_boundary" X-Mailer: CompuServe 2000 6.0 for Windows UK sub 10507 Sender: owner-emc-p...@majordomo.ieee.org Precedence: bulk Reply-To: nickjro...@cs.com X-Resent-To: Multiple Recipients <emc-p...@majordomo.ieee.org> X-Listname: emc-pstc X-Info: Help requests to emc-pstc-requ...@majordomo.ieee.org X-Info: [Un]Subscribe requests to majord...@majordomo.ieee.org X-Moderator-Address: emc-pstc-appro...@majordomo.ieee.org X-Mozilla-Status: 8011 X-Mozilla-Status2: 00000000 X-UIDL: <188.5832857.29d29...@cs.com> --part1_188.5832857.29d29b00_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Hello Chet, Hall effect based current senors as used in most motor drives, Nick Rouse --part1_188.5832857.29d29b00_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: 7bit <HTML><FONT FACE=arial,helvetica><FONT SIZE=2>Hello Chet, <BR>Hall effect based current senors as used in <BR>most motor drives, <BR>Nick Rouse <BR></FONT></HTML> --part1_188.5832857.29d29b00_boundary-- ------------------------------------------- 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"
