Hi All, I have just posted my latest video covering magnetic field emissions from switching power supplies. Such fields can cause unusual problems in systems such as data corruption with low enough probability to make finding it difficult. I have seen such emissions cause data corruption on a tape backup drive in a computer. It took about an hour for the spikes from a switching power supply about 12 cm away from the drive to line up with the data sampling in such a way as to cause a problem. About one read error was made per hour in a continuous write/read test. Such emissions can also cause noise in analog circuits and in some cases, as in my new video, even corrupt digital signals.
The video can be watched in two ways: Go to http://youtube.com and type dougcsmith in the search field. You will see my four videos there, this one being the latest. This video plays in Flash and is available in low and high resolution versions. Go to http://emcesd-podcast.com/weekly_podcasts/ and click on the "Latest Show" near the top. This video is in mp4 format, a popular format that has been around for several years but will not play in Windows Media Player (every video player I know of will play mp4 except WMP). Quicktime from Apple can play it as well as the free multi-platform VLC player from VideoLan.org. This video shows a great way to find, and even spec for design requirements, excessive magnetic emissions from switching power supplies that does not require expensive setups......sort of like the rest of my work on other problems. Doug -- ___ _ Doug Smith \ / ) P.O. Box 1457 ========= Los Gatos, CA 95031-1457 _ / \ / \ _ TEL/FAX: 408-356-4186/358-3799 / /\ \ ] / /\ \ Mobile: 408-858-4528 | q-----( ) | o | Email: [email protected] \ _ / ] \ _ / Website: http://www.dsmith.org - 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
