http://www.ieee-pses.org/symposium http://www.emc2004.org/ -------------------------------------------------- Chas,
my experience with ITE has been that folks SEEM to ignore it. In low power modes, some power supplies go discontinuous and that appears worse during the EMI test. As for lower clock frequencies, well, it depends where the radiating mechanism is most efficient: usually, but not always, the cables. If the clock is above that frequency, there will not be a great deal of noise radiated from cables say. However, if the frequency drops such cables may become a strong radiating mechanism. The philosophy that fastest clock is worst case is most definitely not true! Cheers, Derek. Grasso, Charles wrote on 6/1/2004, 1:03 PM: 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]; <ma lto:[email protected];%C2%A0> 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 -- Derek N. Walton L F Research Poplar Grove, IL 61065, USA ------------------------------------------- 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
