Hi Brian, I have no experience in your subject, but...
If the problem is (as other suggest) estimating the zero crossing points with immunity to noise I suppose instead of PLL you can use any 8-bit microcontroller to do the job. It can analyse some past zero crossing points and estimate the future ones. The current decision can be based ignoring the last 4 zero crossings which are still under noise analyse. I assume AC phase is enough stable during 2 periods (I have no knowledge if it is true). Based on like-this solution we have done PSK demodulation of 62.5kHz signal. Small 8-bit was able to follow slow phase shifts, and detect faster phase shifts (with immune to some noise level and short periods of signal loses made by 180 degree phase shift). For 1000 times slower signal 1000 times more analysis can be done. Best Regards Piotr Galka ----- Original Message ----- From: "Kunde, Brian" <brian_ku...@lecotc.com> To: "David Cuthbert" <dcuthb...@linear.com>; <emc-p...@ieee.org> Sent: Wednesday, November 08, 2006 5:42 PM Subject: RE: Worst Case AC Power Conditions > Dave, > > Thanks for the reply. > > I should have explained further. Our equipment is designed to work only > in the 230V nominal voltage range at both 50 and 60 hz. Our equipment > has furnaces that we must regulate the temperature within a very tight > spec. To do this we must fire control relays (SSRs) either at the zero > crossing or use phase control method. These methods require us to > monitor the AC line so to fire the SSR properly. As you can image, such > methods would be susceptible to AC line noise, harmonics, dips, etc.. So > we design immunity to such noise into our products, but sometimes it is > not enough. > > The other Brian > > > > -----Original Message----- > From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of David > Cuthbert > Sent: Wednesday, November 08, 2006 11:30 AM > To: Kunde, Brian; emc-p...@ieee.org > Subject: RE: Worst Case AC Power Conditions > > Brian, > > When I worked for a well-known instrumentation company our universal > power line requirement was, if I remember correctly, 80 to 270 VAC. If > one could achieve more it was good. I designed one that would reliably > operate from 75 to 280 VAC. This covered 100 V Japan on up with margin. > Our products were sometimes used in the field with generators and I > believe the extra margin built in helped us avoid field complaints. Our > off-line bulk capacitance, as well as the DC output capacitance was > unusually large to allow for long line dropouts. > > Of course building in extra margin can raise the cost of design and > manufacturing. In our case it was reflected in higher capacitor cost and > lower power density. The upside was a slow but steady improvement in our > reputation and the ability to continue to command a price premium for > our products. > > > Dave Cuthbert > Senior Test Engineer > NARTE Certified EMC Engineer > Linear Technology Corporation > > *******************Internet e-mail Confidentiality > Footer******************* This e-mail transmission, and any documents, > files or previous e-mail messages attached to it may contain > confidential information that is legally privileged. If you are not the > intended recipient, or a person responsible for delivering it to the > intended recipient, you are hereby notified that any disclosure, > copying, distribution or use of any of the information contained in or > attached to this transmission is STRICTLY PROHIBITED. If you have > received this transmission in error, please immediately notify me by > reply e-mail, or by telephone at (719) 593-1579, extension 261 and > destroy the original transmission and its attachments without reading or > saving in any manner. Thank you. > ======================================================= > > > -----Original Message----- > From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Kunde, > Brian > Sent: Wednesday, November 08, 2006 7:15 AM > To: emc-p...@ieee.org > Subject: Worst Case AC Power Conditions > > Greetings, > > 1. Can anyone provide specifications for a "worst case" real world AC > power line condition in which an apparatus is expected to operate > properly in (pass/criteria A)? This would encompass a combination of > harmonics, voltage variations, frequency variations, etc.. > > 2. Also, if anyone has a program for a California Instrument CTS > system with a 5000ix power supply that could test for a "worst case" AC > line condition, that would be helpful. I have heard that some companies > have developed such a custom program to simulate poor power conditions > from different parts of the world. Such a program would operate with the > the provided CIgui32 program. > > 3. Can anyone recommend an AC Power Line analyzer that we can just > plug-in and it will analyze the AC power conditions at different > customer locations? Then we could take the results and program our > 5000ix power supply to simulate those conditions in our lab. > > The reason I'm asking is that from time to time we have experienced > problems in the field due to with poor AC power line conditions at some > customer locations even though we test and comply with the standard > tests that are required for CE (surge, burst, dips, etc). We want to > develop an internal test standard that will minimize problems in the > field. > > Thank for any help or advice you can offer. > > The Other Brian. > > - > ---------------------------------------------------------------- > 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 emc-p...@ieee.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...@ptcnh.net > Mike Cantwell mcantw...@ieee.org > > For policy questions, send mail to: > > Jim Bacher: j.bac...@ieee.org > David Heald: emc-p...@daveheald.com > > 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. Website: http://www.ieee-pses.org/ > > To post a message to the list, send your e-mail to emc-p...@ieee.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...@ptcnh.net > Mike Cantwell mcantw...@ieee.org > > For policy questions, send mail to: > > Jim Bacher: j.bac...@ieee.org > David Heald: emc-p...@daveheald.com > > 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. Website: http://www.ieee-pses.org/ > > To post a message to the list, send your e-mail to emc-p...@ieee.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...@ptcnh.net > Mike Cantwell mcantw...@ieee.org > > For policy questions, send mail to: > > Jim Bacher: j.bac...@ieee.org > David Heald: emc-p...@daveheald.com > > 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. 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