Mark Nave of EMC Services patented such a device clear back around 1989. He presented a paper at the '89 Denver EMC Symposium, entitled, "A Novel..." I don't recall the whole title. That device discriminated against dm emissions, he called it a dmrn, dm rejection network and trade-named it LISNMATE. It attenuated dm emissions by 50 dB up to 30 MHz. Later he built and patented its sibling, a cmrn. I have one of each and they are very useful devices when troubleshooting a filter design! I built a combination unit that did either at the flick of a switch and used it to inject pure cm and dm into a LISN pair to show that radios are much more susceptible to cm than dm noise, which implies that CE limits ought to take that into account. These days Mark works in Silicon Valley. I doubt he is in production but you could try him out at:
[email protected] Good Luck. Ken Javor on 2/4/02 10:37 PM, Muriel Bittencourt de Liz at [email protected] wrote: > > Hello Group, > > > I am looking for a device that will differentiate the dominant component > (either > common-mode or differential-mode current) in the total conducted noise > emission > current of a product measuring through its' power cord using a LISN. > > > This device can be called "common/differential mode current separator". In > conducted > noise emission measurement, both common-mode and differential mode noise > current are measured by LISN and the LISN can't tell which mode is the > dominant > current. > > > I came across a paper by Clayton Paul and Keith Hardin which explain the > usefulness of a separator like this that would identified the dominant > current > from the total current. Hence, the correct capacitor value(either X-caps or > Y-caps) can be changed accordingly so to reduce the overall conducted noise. > The book by Clayton Paul "Introduction to Eletromagnetic Compatibility" has > also mention about this device. > > > I have contacted a few persons trying to look for the person who have > actually > built this separator himself and I am also looking for any vendor who have > this > product for sale. So far, my effort has yield no results. > > > Can anybody point me to the right person so that i can try to built this > separator myself. Any other suggestion and comments are greatly appreciated. > > > Best Regards, > > ************************************************************** > > Muriel Bittencourt de Liz > > Ph.D. Student > > Federal University at Santa Catarina > > Florianópolis, SC > > Brazil > > > > > ------------------------------------------- > 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: > Michael Garretson: [email protected] > Dave Heald [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] > Jim Bacher: [email protected] > > All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the old messages > are imported into the new server. > ------------------------------------------- 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: Michael Garretson: [email protected] Dave Heald [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
