Has anyone else noticed the tendency of modern switch mode power supply designers to save manufacturing costs at the expense of harmonic and conducted emissions measurements?
EN 61000-3-2:2000 has introduced the concept of Partial Odd Harmonics for the 21st and above. While this adds extra functions to the spread-sheet results check, I wonder if it also has an unhelpful side effect. With conducted emissions, new power supply designs generate peak emissions at frequencies below 200 KHz that increase in level inversely to the frequency. These out-of-band emissions result in overloading the front-end of a Spectrum Analyser that consequently requires either a pre-selector or calibrated filter to function correctly. There is, of course, the alternative of purchasing a new receiver! Neil Helsby ********************************************************************** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept by MIMEsweeper for the presence of computer viruses. www.mimesweeper.com ********************************************************************** This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc 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] Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
