Colleagues, Has anyone out there designed power supplies based on the Vicor 2nd generation converters? I have a design based on the Vicor "FARM" (Filter And Rectification Module) with two Vicor V300 series DC-DC converters behind it.
I can't get this design through surge testing at 500V/250V, even though the data sheets for all of the modules claim immunity to 2KV/1KV. I'm not taking issue with the data sheets, Vicor makes good stuff. I just can't figure out what's up with this design. I have followed the spec sheet protection recommendations to the letter. I have suspected the Corcom 6ED8 filter in front could be causing "ringing" of the surge; but found that the failure occurs with or without the filter. The failure is very strange in that it: -Is load dependent. It seems that a higher load makes failure more likely -It happens at a random time, up to 17seconds after the surge. -Is characterized by the FARM's enable signal (which controls the V300s behind it) going low. -I can get some improvment (pass 500/250 but fail 1000/500) if I remove chassis ground from the FARM heatsink. It almost seems as though the surge is passing through the FARM to its grounded heatsink, along the way, maybe it is heating up some components, perhaps this heat takes a little while to get to the FARM's thermal shutdown circuit, which then dumps the enable signal (I know, really far fetched.) Maybe a layout problem? I'd appreciate any experience that others could share with this. Thanks, Chris Maxwell | Design Engineer - Optical Division email [email protected] | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | 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: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] 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
