http://www.ieee-pses.org/symposium http://www.emc2004.org/ -------------------------------------------------- Charles, Interesting question. Here is my view. In my product lines, there are dozens upon dozens of operational modes that could be exercised. I don't believe that it adds any value nor meets the intent of any EMC legislation to test them all. We apply engineer judgment to identify the worst-case and test it. In some situations, the analysis cannot be conclusive and we test more than one mode. So with that background and without knowing the details of your product, I suspect that your low-power mode is also a low-EMI mode (almost by definition) especially if the clock frequencies are less. (The Fourier transform peaks will all be reduced even if the rise time and pulse duration are the same.) Less overall energy + less high-frequency energy = Less EMI Any other opinions? Cheers, Marko
From: [email protected] mailto:[email protected]]On Behalf Of ext Grasso, Charles Sent: Tuesday, June 01, 2004 11:03 AM To: '[email protected]' Subject: Q on testing different power modes for PCs http://www.ieee-pses.org/symposium http://www.emc2004.org/ -------------------------------------------------- Greetings: Power saving modes becoming ubiquitous is consumer electronics and one of the techniques is to lower the clock frequency (while in low power mode). Heres the testing question: Given that different clock frequencies are used for power saving should we also be testing in standby modes? Best Regards Charles Grasso Senior Compliance Engineer Echostar Communications Corp. Tel: 303-706-5467 Fax: 303-799-6222 Cell: 303-204-2974 Email: [email protected]; <mailto:[email protected]; > Email Alternate: [email protected] From: Zhang Guoqing [mailto:[email protected]] Sent: Monday, May 31, 2004 10:29 PM To: [email protected] Cc: chendunli; Kelvin Shi Subject: a question http://www.ieee-pses.org/symposium http://www.emc2004.org/ -------------------------------------------------- Hi, I have a question on UL60950-1, in clause 2.6.4.2: "Equipment required to have protective earthing shall have a main protective earthing terminal.For equipment with a DETACHABLE POWER SUPPLY CORD, the earthing terminal in the appliance inlet is regarded as the main protective earthing terminal." in clause 2.3.2 "- for PLUGGABLE EQUIPMENT TYPE A, a separate protective earthing terminal shall be provided in addition to the main protective earthing terminal, if any (see 2.6.4.1)." My questions is how to mark the separate protective earthing terminal, do you think the symbol 60417-1-IEC-5019 is correct? For some equipment(for example, telecommunication centre equipment), seperate earthing terminal in the equipment may be a better way for connecting earth than earthing terminal in the appliance inlet. So my question is, if seperate earthing terminal is not required only from the standards UL60950-1, do you think the equipment which provide one seperate earthing terminal and indicated by symbol 60417-1-IEC-5019 do not comply with UL60950-1? Zhang Guoqing Huawei Technologies CO.,LTD. P.R. CHINA [email protected] Tel: +86-755-89653394 Fax: +86-755-89653384 Mobile: 13686493636 This e-mail and its attachments contain confidential information from HUAWEI, which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender by phone or email immediately and delete it! ------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. IEEE PSES Main Website: http://www.ieee-pses.org/ To post a message send your e-mail to [email protected] Instructions for use of the list server: 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: [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: http://www.ieeecommunities.org/emc-pstc ------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. IEEE PSES Main Website: http://www.ieee-pses.org/ To post a message send your e-mail to [email protected] Instructions for use of the list server: 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: [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: http://www.ieeecommunities.org/emc-pstc ------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. IEEE PSES Main Website: http://www.ieee-pses.org/ To post a message send your e-mail to [email protected] Instructions for use of the list server: 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: [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: http://www.ieeecommunities.org/emc-pstc
