I am somewhat familiar with this technology. We call it High Frequency Filtered Pulse Width Modulation. With this technology you can control the amplitude of the AC mains (commonly used in dimming lights) by controlling the duty cycle of a switching device at a frequency of tens, hundreds, or thousands of times per second.
It is much more complex than phase control but if done right very low harmonic emissions. Downsides are the large filters required to smooth the wave shape and filter out the switching emissions. It also takes up a lot more room than an SSR. High power light dimmers use this technology for many reasons other than harmonic emissions. The Other Brian ________________________________ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of ralph.mcdiar...@ca.schneider-electric.com Sent: Monday, April 26, 2010 1:45 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Harmonic Emissions Testing "sine wave technology" ? _______________________________________ _____________________________________________ Ralph McDiarmid | Schneider Electric | Renewable Energies Business | CANADA | Compliance Engineer From: John M Woodgate <j...@jmwa.demon.co.uk> To: EMC-PSTC@LISTSERV.IEEE.ORG List-Post: emc-pstc@listserv.ieee.org List-Post: emc-pstc@listserv.ieee.org List-Post: emc-pstc@listserv.ieee.org Date: 04/26/2010 09:57 AM Subject: Re: [PSES] Harmonic Emissions Testing ________________________________ In message <0ed66cd2c9bd0a459d54fb9119a605670168e...@mailserver.lecotc.com>, "Kunde, Brian" <brian_ku...@lecotc.com> writes >What other ?practical? furnace control methods are there that would >pass both the Harmonics and flicker emissions requirements? Theatrical dimmers using sine wave technology are available in power ratings up to at least 10 kW at acceptable cost. -- This is my travelling signature, adding no superfluous mass. John M Woodgate - 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 <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc <http://www.ieeecommunities.org/emc-pstc> Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ <http://www.ieee-pses.org/> Instructions: http://listserv.ieee.org/request/user-guide.html <http://listserv.ieee.org/request/user-guide.html> List rules: http://www.ieee-pses.org/listrules.html <http://www.ieee-pses.org/listrules.html> For help, send mail to the list administrators: Scott Douglas <emcp...@socal.rr.com> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com> ________________________________________________________________________ This email has been scanned for SPAM content and Viruses by the MessageLabs Email Security System. ________________________________________________________________________ - 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 <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc 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 <emcp...@socal.rr.com> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com> _________________________ 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 <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc 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 <emcp...@socal.rr.com> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com>