I agree with Paul's take. One of the "trees" in the forest is keyboards. Do you have any keyboards attached to the DUT? I have personally seen an instance where EFT was coupling to a keyboard cable and causing all sorts of wierd effects.
I thought it was our design's fault, so I tried filtering, ferrites ... at our end of the keyboard cable. No use. It wasn't until I got to the test lab that they suggested a ferrite at the keyboard end of the cable.>>>>>> problem solved. Apparantly the keyboard itself was being upset and was sending garbage instructions to our unit. The keyboard was CE marked....but.... you never know. > -----Original Message----- > From: Hare, Paul [SMTP:ph...@pirus.com] > Sent: Wednesday, October 24, 2001 11:25 AM > To: 'alex.mcn...@ingenicofortronic.com'; emc-p...@majordomo.ieee.org > Subject: RE: EFT Failures..Update! > > > Alex, make sure you investigate whether or not energy is coupling to > other > cables of the EUT and causing problems. In other words, try to reduce > the > system (remove cables) and see if the EFT failures persist. If you > can't > remove a cable due to functionality, place ferrites on it instead > (near the > EUT). You may be surprised how a failure manifests itself. > Sometimes > you've got to back up and take a look at the forest... :) > > Good luck... > > Paul Hare e: ph...@pirus.com > Compliance Engineer w: 978.206.9179 > Pirus Networks f: 978.206.9199 > 43 Nagog Park c: 508.450.0376 > Acton, MA 01720 i: www.pirus.com > > > -----Original Message----- > From: am...@westin-emission.no [mailto:am...@westin-emission.no] > Sent: Wednesday, October 24, 2001 4:04 AM > To: emc-p...@majordomo.ieee.org > Subject: SV: EFT Failures..Update! > > > > Alex, > > What happened during the burst test ? Did the EUT break down or did > you only > have minor disturbances/faults during the test ? > > I assume that you know that EFT/bursts usually is a performance > criteria B > test, which means that temporary faults are accepted during the test, > as > long that the EUT is self-recoverable after the test. > > Amund > > -----Opprinnelig melding----- > Fra: owner-emc-p...@majordomo.ieee.org > [mailto:owner-emc-p...@majordomo.ieee.org]På vegne av Alex McNeil > Sendt: 23. oktober 2001 10:44 > Til: 'emc-p...@majordomo.ieee.org' > Emne: EFT Failures..Update! > > > > > Hi Group, > > THANKS for your very much appreciated responses!! I was in panic > mode!! > > I thought it would be appropriate to let you know the status. > > My product is a small all plastic enclosure Point if Sale (POS) Class > III > terminal. It has an external SMPS, Class II, no earth, supplying SELV, > 12Vdc > 1.5A to my product. The power supply works OK with some of our other > products, for EMC. The problem is with my product. > > I solved the problem at the test house by wrapping a few turns of the > DC PSU > cable through a "Large" Ferrite Clamp at the Product input (it did not > work > so well at the PSU I/P nor O/P). The fix cannot be considered final > due to > obvious reasons. > > I am now at my Lab, now the serious diagnostics begin. I have been > trying > various "quick fixes" to no avail i.e. Caps, TVS, MOV etc. > > If you have any further comments feel free to email me. > > THANKS again to all those who responded with their thoughts. I can > tell you > they were wide and varied just as you would expect to trying to > resolve an > EMC problem over the NET!! > > Best Regards > alex.mcn...@ingenicofortronic.com > > > > > > > > > > -----Original Message----- > > From: Alex McNeil > > Sent: 22 October 2001 11:23 > > To: emc-p...@majordomo.ieee.org > > Subject: EFT Failures..Help! > > > > Hi Guys, > > > > I am at an EMC test centre today and tomorrow. Unfortunately, my > product > > failed EFT testing on the AC power port at 1KV. This is for various > > combinations of Line, Neutral and Earth (L, N, E, LN, LE, NE and > LNE) > > > > My product is Class II, no Earth. It is supplied by an external > power > > supply. This supplies SELV to my product. The power supply > manufacturer > > has stated that his power supply meets EN61000-4-4 for 2KV and has > emailed > > me this report to verify this. > > > > Has anyone got a quick solution to my problem so that I can > implement here > > at the EMC test house? > > > > Kind Regards > > Alex McNeil > > Principal Engineer > > Tel: +44 (0)131 479 8375 > > Fax: +44 (0)131 479 8321 > > email: alex.mcn...@ingenicofortronic.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: > Michael Garretson: pstc_ad...@garretson.org > Dave Heald davehe...@mediaone.net > > 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: > No longer online until our new server is brought online and the > old > messages are imported into the new server. > > > > ------------------------------------------- > 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: > Michael Garretson: pstc_ad...@garretson.org > Dave Heald davehe...@mediaone.net > > 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: > No longer online until our new server is brought online and the > old > messages are imported into the new server. > > ------------------------------------------- > 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: > Michael Garretson: pstc_ad...@garretson.org > Dave Heald davehe...@mediaone.net > > 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: > No longer online until our new server is brought online and the > old messages are imported into the new server. ------------------------------------------- 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: Michael Garretson: pstc_ad...@garretson.org Dave Heald davehe...@mediaone.net 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: No longer online until our new server is brought online and the old messages are imported into the new server.
