I love that demo. The best one I saw was done with an old metal minnow bucket. The presenter had a small circuit that interfered with a small radio, then placed the circuit inside the minnow bucket and closed the top lid to show how the interference went away. Then pulled the inner bucket out from the outer bucket to show how the RF did not get out through the holes (cooling holes). Then he ran a wire through one of the holes and powered the circuit by a 9 volt battery outside the minnow bucket and showed how the RF coupled out through the wire showing the importance of decoupling or shielding of external wires. I bet a ferrite bead would also have a noticeable affect.
The Other Brian From: [email protected] [mailto:[email protected]] On Behalf Of Ken Wyatt Sent: Thursday, September 29, 2011 12:42 PM To: [email protected] Cc: [email protected] Subject: Re: [PSES] EMC Demonstration I've built up a number of demos for me EMC seminars, but maybe the simplest and easiest to understand for non-EEs is to place a breadboarded (battery-operated) 20 MHz crystal oscillator in a "leaky" metal enclosure (could be a simple cookie tin) and tune an FM radio to a station near 100 MHz. The oscillator should provide "full quieting" (capture effect) to any stations that are heard. You can also probe the harmonics with a spectrum analyzer and/or copper tape the seams to demonstrate the fix. You could also get fancier and power it with a wall wart and measure the harmonic currents on the cable. Cheers, Ken _______________________ Kenneth Wyatt Wyatt Technical Services LLC Woodland Park, CO Email Me! <mailto:[email protected]> | Web Site <http://www.emc-seminars.com> | Blog < ttp://www.emc-seminars.com/Blog/Blog.php> Subscribe to Newsletter <http://www.emc seminars.com/Newsletter/Newsletter.html> Connect with me on LinkedIn <http://www.linkedin.com/in/kennethwyatt> On Sep 29, 2011, at 3:47 AM, Robert Heller wrote: I have been tasked with the opportunity to provide a short EMC demonstration for non-EMC people. I am having some difficulty coming up with something and I wonder if anyone else has been in this situation in the past. The demo and talk should be about 5 minutes. The basic premise is 'what does an EMC facility do and why do they do it'? I though what I might do is set up an antenna and receiver and show the ambients the need protection: radio, TV, fire, police, cell phones, etc. Then I thought about using a piece of equipment and a hand probe and show the various frequencies coming off the equipment that may interfere with these services and in general terms talk about the various means of reducing this energy to acceptable limits. I really don't have time to "teach" anything and I don't want to get into immunity. Anyone been there before? I would appreciate any suggestions. Thanks, Bob Heller 3M EMC Laboratory, 76-1-01 St. Paul, MN 55107-1208 Tel: 651-778-6336 Fax: 651-778-6252 - ---------------------------------------------------------------- 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://product-compliance.oc.ieee.org/ http://product-compliance.oc.ieee.org/> 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]> - ---------------------------------------------------------------- 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://product-compliance.oc.ieee.org/ http://product-compliance.oc.ieee.org/> 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]> ________________________________ LECO Corporation Notice: This communication may contain confidential information intended for the named recipient(s) only. If you received this by mistake, please destroy it and notify us of the error. Thank you. - ---------------------------------------------------------------- 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://product-compliance.oc.ieee.org/ 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]>
