Tim:
Again, I’m guessing at what your “problem” is, but following Ari’s supposition, here’s another tip. I have sometimes encountered devices that try to start by drawing a heavy current surge, but then, either due to ohmic or inductive voltage drop across the LISN, refuse to start. I simply connect a wire jumper from the LISN source to load terminals, start the EUT, and then remove the jumper. Sometimes, a “watchdog” circuit in the EUT will not allow starting if the input voltage is too low, You might get around this just by setting the power supply voltage to the EUT’s maximum input voltage, starting the EUT, and then setting the voltage to nominal. OTOH, sometimes the maximum and minimum watchdog set points are so close together that you wonder how the gadget ever works in real life. Ed Price [email protected] <blocked::mailto:[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 From: [email protected] [mailto:[email protected]] On Behalf Of Honkala, Ari (Espoo) Sent: Monday, August 30, 2010 10:33 PM To: [email protected] Subject: RE: Alternative Conducted EMI method for CISPR 22 Hi, If the problem is that EUT does not start due to series inductance, you may try to use LISN in parallel, as a voltage probe. The principle is explained in CISPR 16-2-1 Annex A.5 Ari Honkala SGS Fimko Oy ________________________________ From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: 31. elokuuta 2010 1:20 To: [email protected] Subject: Alternative Conducted EMI method for CISPR 22 Hello Group, Does anyone know if there is an alternative conducted EMI power line measurement method for CISPR 22? I'm having trouble testing a DC powered unit with a traditional CISPR 16 LISN. Someone mentioned that a current measurement can be made on power lines using a current clamp instead. I could not find anything about measuring power lines with a current clamp. What limits would be used? The only reference to current clamp measurements in CISPR 22 is for telecommunication ports. I know ANSI C63.4 mentions you can make measurements using a current clamp, however CISPR 22 does not. Any information would be helpful. Thanks, Tim Pierce TAP Engineering, LLC. Information in this email and any attachments is confidential and intended solely for the use of the individual(s) to whom it is addressed or otherwise directed. Please note that any views or opinions presented in this email are solely those of the author and do not necessarily represent those of the Company. Finally, the recipient should check this email and any attachments for the presence of viruses. The Company accepts no liability for any damage caused by any virus transmitted by this email. All SGS services are rendered in accordance with the applicable SGS conditions of service available on request and accessible at http://www.sgs.com/terms_and_conditions.htm - - 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]>
