Gert et al Can anyone provide a spec for the ferrite. For example, what is typically used in a CISPR 16 radiated power clamp? I am guessing when I say that I believe these were originally a Philips type ferrite ring. I have two of these clamps (Luthi MDS21 and Anritsu) and have found them to be quite different in terms of attenuation characteristics when used as loads in 61000-4-6 conducted immunity testing.
A short tutorial on the characteristics of ferrites as used in these clamps would be nice. Is anyone aware of a source, eg in a particular standard? Best Regards John Cronin >From: "Gert Gremmen" >Reply-To: "Gert Gremmen" >To: "Gordon,Ian" , >Subject: RE: EN55022:1998 + A1:2000 >Date: Wed, 29 Jan 2003 16:54:00 +0100 > > >Hi Group, > > >Proposals are on their way to specify >both transfer attenuation (first) and >input CM impedance of those clamps (later) >The radiation properties of the exposed wire will >vary widely depending on the CM load impedance. >The attenuation characteristic is to isolate >auxilary wire (and signal) from the test setup. > >Both will be published as an Amendment on CISPR 16 >document. >A controllable impedance clamp system can be >constructed using a current clamp system >with variable load . (like current clamp/transformer) >The first 1-5 rings can be loaded with a >screened wire that terminates into a variable ( or fixed) >impedance. Target CM impedance will probably be 150 Ohm >to be transferred to the load. > >This has best impact in the lower frequency range. >High loss ferrite will do better as low loss ferrite. >Attenuation is just a matter of quantity of rings. >Regards, > >Gert Gremmen >Manager > > >Ce-test, Qualified Testing >ce marking and more .. >EMCD LVD R&TTED MDD MD >www.cetest.nl >Electrical / Electronic Equipment > > > >-----Original Message----- >From: owner-emc-p...@majordomo.ieee.org >[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Gordon,Ian >Sent: Wednesday, January 29, 2003 11:51 AM >To: emc-p...@majordomo.ieee.org >Subject: RE: EN55022:1998 + A1:2000 > > > >All >I can see that my manager would prefer to use Neven's approach - it is >probably much cheaper than buying clamps. However, does anybody have any >practical experience of this? >A reply from an accredited test house would be welcomed! > >Thanks >Ian Gordon >-----Original Message----- >From: neve...@attbi.com [mailto:neve...@attbi.com] >Sent: 29 January 2003 05:22 >To: emc-p...@majordomo.ieee.org >Subject: Re: EN55022:1998 + A1:2000 > > > >Instead of paying big bucks for the clamps (I am not sure what the price is, > >but I'm sure it is too much anyway :), why not buying a bucket of ferrite >doughnuts that can be used over cables. Or, when possible, building in-line >adapters out of sections of cables (maybe 1m long) and lining them up with >ferrites. I'd select a combination of ferrites to cover 30 MHz to about 300 >MHz. The high frequencies will be radiated anyway by the segment of the >cables >close to the DUT. Taking a little more thorough approach, I'd check the >impedance with the lineup fixed over a defined height above a GND plane. >(Not >sure if that would make a big practical difference.) > > >Neven > > > > A1 to EN55022:1998 requires the use of ferrite clamps on all cables >leaving > > the table-top EUT for a connection outside the test site. Are there any > > other manufacturers of these clamps other than Fischer Custom > > Communications? > > > > Richard Woods > > Sensormatic Electronics > > Tyco International > > >_____________________________________________________________________ >This e-mail has been scanned for viruses by the WorldCom Internet Managed >Scanning Service - powered by MessageLabs. For further information visit >http://www.worldcom.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 > >Archive is being moved, we will announce when it is back on-line. >All emc-pstc postings are archived and searchable on the web at: > http://www.ieeecommunities.org/emc-pstc > > > > >------------------------------------------- >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 > >Archive is being moved, we will announce when it is back on-line. >All emc-pstc postings are archived and searchable on the web at: > http://www.ieeecommunities.org/emc-pstc _____ Stay in touch with absent friends. 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