Yes, these are conducted emissions. I used a pair of 50 uH, 50 Ohm LISNs designed as far as I know to CISPR 16. A spectrum analyzer swept from 0.5 - 3.5 MHz using a 9 kHz rbw with no video averaging (initially). I did not check what the quasi-peak detector read. The set-up did not perfectly replicate CISPR 22 or ANSI C63 methods, but at these frequencies I judged the discrepancies to be insignificant.
> From: John Woodgate <j...@jmwa.demon.co.uk> > Date: Fri, 26 Nov 2004 20:36:01 +0000 > To: emc-p...@ieee.org > Subject: Re: fluorescent lamp rfi > > In article <bdcbdbe5.19b9d%ken.ja...@emccompliance.com>, Ken Javor > <ken.ja...@emccompliance.com> writes >> I made some AM band measurements, peak detection: >> >> Freq Ampl. >> MHz dBuV >> 0.45 98 >> 0.55 94 >> 0.63 92 >> 0.75 90 >> 0.83 86 >> 0.88 83 >> 0.94 82 >> 1 78 >> 1.2 73 >> 1.4 72 >> 1.54 70 >> 1.61 68 >> 1.68 67 >> 1.73 69 >> >> These were rectification harmonics. If I turned on video averaging, >> they went away and left a nice spectrum of some cw switching activity at >> a much lower level. It is the rectification harmonics, not the >> switcher, that causes the problem. BTW, the noise was pure differential >> mode - there was no common mode component, which is to be expected for >> this two wire topology. > > I suppose these are conducted emissions, measured according to CISPR 15. > But these lamps are subject only to the 'insertion loss' measurement > described in clause 7. > > Someone has left out the capacitors across the rectifier diodes, or used > cheap diodes instead of the special ones that don't produce as much r.f. > -- > Regards, John Woodgate, OOO - Own Opinions Only. > The good news is that nothing is compulsory. > The bad news is that everything is prohibited. > http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk > > ---------------------------------------------------------------- > This message is from the IEEE Product Safety Engineering Society > emc-pstc discussion list. Website: http://www.ieee-pses.org/ > > To post a message to the list, send your e-mail to emc-p...@ieee.org > > Instructions: http://listserv.ieee.org/listserv/request/user-guide.html > > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > > Ron Pickard: emc-p...@hypercom.com > Scott Douglas emcp...@ptcnh.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: > > http://www.ieeecommunities.org/emc-pstc > This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Scott Douglas emcp...@ptcnh.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: http://www.ieeecommunities.org/emc-pstc
