Why not build an unregulated linear power supply out of parts from Radio Shack? Or buy a cheap 12 Volt lead-acid battery 1 or 2 Amp trickle charger and put a filter cap on the output.
As long as it is unregulated, it should not respond in any anomalous fashion to EMI. > From: Chris Chileshe <chris.chile...@ultronics.com> > Reply-To: Chris Chileshe <chris.chile...@ultronics.com> > Date: Wed, 24 Sep 2003 09:33:29 +0100 > To: "emc-p...@majordomo.ieee.org" <emc-p...@majordomo.ieee.org> > Subject: DC PSU for conducted immunity testing to EN61000-4-6 > > > Group, > > After quite a struggle to get a product through conducted immunity > tests (clamp method), I finally discovered that the weak link in the > chain was in fact my laboratory power supply which I have been > taking along with me to a nearby test house. > > The problem remained undetected for a number of reasons, not > least that I had used the same setup before at a different test > house using their PSU ( Solartron ASxxx) and had better results, > but mostly because we were using a small chamber dedicated to > conducted immunity tests and using a camera to monitor the > behaviour of the EUT behind closed doors and not keeping an eye > on the PSU. > > When we eventually tracked the anomalous behaviour of the > EUT to the PSU, we tried LISNs and a different PSU both of > which improved the test results significantly but the outcome > was still not good enough from a product compliance point of > view. > > Question 1: Is anyone aware of a power supply suitable for > this type of testing? The EUT draws a maximum of 30mA > at 12VDC. I have been unable to find any Solartron PSUs on > the web; probably long discontinued. > > Question 2: Has anyone tried to build a filter for this sort of > thing and would this be the way to go? > > Best regards > > - Chris Chileshe > - Ultronics Ltd > - UK > > (O.O.O.) > > > > ________________________________________________________________________ > This e-mail has been scanned for all viruses by Star Internet. The > service is powered by MessageLabs. For more information on a proactive > anti-virus service working around the clock, around the globe, visit: > http://www.star.net.uk > ________________________________________________________________________ > > ------------------------------------------- > 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: emc_p...@symbol.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: emc_p...@symbol.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
