The important thing to keep in mind is that Uo in Figure 2a is the open circuit potential. That means the power source needs to be able to deliver:
20 Volts rms* 1.8 = 36 Vrms open circuit, which means 18 Vrms into 50 Ohms, which is 6.5 Watts. Then of course you have to place the 100 Ohm load in series with the signal generator output, further limiting the power delivered, while not affecting open circuit Uo. I don't see where Figure 2a or 2b imply a conductive enclosure at all. Figure 2b shows the case isolated above ground. The only grounding provision would be that supplied by the installation. I don't see where this impacts test execution. I can see where it might cause susceptibilities, depending on the circuitry inside... From: "Price, Ed" <[email protected]> List-Post: [email protected] Date: Tue, 21 Feb 2006 07:12:57 -0800 To: [email protected] Subject: EN61000-4-6:1996 I have been asked to do a Conducted Immunity test per BS EN61000-4-6:1996 on a gadget that mounts on the inside wall of a bus (and is accessible to the passengers). First, I think this isn't the latest version of this specification, but it is what the customer requested. This device has a completely non-conductive outer case. The only conductive point is on it's rear, where a 15-pin "D" connector supplies vehicle power through a shielded, twisted-pair cable. The customer asked for a "direct connection" test, as shown in Figure 2a, with a test level of 20 Volts. It seems to me that I will need to be able to generate about 100 Vpp and 200 Watts from my RF amplifier. Does the requested test level seem a bit extreme for a passenger bus application? Further, I don't understand how to measure the voltage Uo. Is this the voltage across the output of my 50-ohm RF source, or the voltage from the test specimen injection point to ground? And finally, Figure 2a implies a conductive test specimen case. How do you do this test for a non-conductive case, where the only conductive surface available is the length of the shielded power cable? I'd appreciate any comments or guidance. Regards, Ed Price [email protected] WB6WSN NARTE Certified EMC Engineer & Technician Electromagnetic Compatibility Lab Cubic Defense Applications San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military & Avionics EMC Is Our Specialty - ---------------------------------------------------------------- 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 [email protected] 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] 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 [email protected] 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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
