I'll also agree about "positioning" of the power supply and the filter module. The two little bricks should be placed as physically close as possible, as the interconnecting traces are carrying some really nasty noise. I came across an installation where three power supply modules were separated by about 10" from the three filter modules, with each module mounted to a separate chassis panel. It failed CE02 (I told you it was long ago!) spectacularly. The fix was to consolidate each supply / filter pair onto a single heat sink, positioned to absolutely minimize the length of interconnecting leads. I believe that we later found that Vicor had a small cautionary note in their literature (pre-web, remember) to the effect that separation was a bad idea.
Another thing to remember is that Vicor's design allows the switching frequency to shift quite a bit with power supply loading, so be sure you are testing it with typical operating loads. When mounted properly, the Vicor modules worked pretty well. OTOH, we did have to add doghouse filtering, but IIRC, it was more to fix our other sins than necessary for the power supply. Ed Price [email protected] WB6WSN NARTE Certified EMC Engineer Electromagnetic Compatibility Lab Cubic Defense Applications San Diego, CA USA 858-505-2780 Military & Avionics EMC Is Our Specialty > -----Original Message----- > From: [email protected] [mailto:[email protected]] On Behalf > Of Brian O'Connell > Sent: Tuesday, March 10, 2009 3:34 PM > To: [email protected] > Subject: RE: Filter module > > From: [email protected] [mailto:[email protected]]On Behalf > Of Ken Javor > Sent: Tuesday, March 10, 2009 2:18 PM > To: Untitled > Subject: Re: Filter module > > > Full list reply; no negative criticism here. > > and I, for one, am disappointed... > > I have also experienced the same as Mr Javor (with similar > modules) that the physical placement/attachment can effect > device characteristics. > > > > From: Derek Walton <[email protected]> > > Date: Tue, 10 Mar 2009 16:57:07 -0500 > > To: IEEE EMC Discussion Group <[email protected]> > > Subject: Filter mofdule > > > > Good day folks, > > > > I'm using a Vicor filter module designed to make it's range of > SMPS > > power supplies 461 compliant. > > > > The module appears to do a great job on conducted noise, but > diminishes > > in effectiveness as we go higher in frequency: thus radiated > noise is > > not as well suppressed.. > > > > Can anyone share their experiences of these modules and how > they perform > > over 30 MHz. Off list replies may be better. > > > > Thanks in anticipation, > > > > Derek Walton - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
