Pieter-Tjerk, Now that is exactly what I had pictured in my head yesterday, and the day before. The chart will give a comparison, over a long time period, of any deviation. We do the same with calibrations, when we're looking for the deviation on voltage and resistance, over a month to a year. It's really similar to the old paper chart recorders on the OCXO and Rubidium WWVB standards. This is a job well done!
If you don't want to mess with the full line voltage, use a step-down type isolation transformer, and drive a LED to phottransistor IC, or just use a 1:1 isolation xformer, and use a neon like here. I think Chris mentioned using the fluorescent lights in his shop as the drive. For accuracy sake, I'd still compare the line freq. to a standard, but that's just me. Best, Will *********** REPLY SEPARATOR *********** On 7/1/2011 at 7:58 PM Pieter-Tjerk de Boer wrote: >Hello 50 & 60 Hz nuts, > >The recent discussions here on measuring the mains frequency and >phase prompted me to revive an experiment I set up some 3 years ago. >Live data about the phase and frequency of the 50 Hz mains here in >the Netherlands can now be viewed at: > http://websdr.ewi.utwente.nl:8901/lichtnet/ > >The system consists of a simple circuit to feed the mains signal >safely into an RS232 port (using a neon bulb and a phototransistor; >the schematic is on the web page), and some cobbled-together >software running under Linux. > >Regards, > Pieter-Tjerk > > >_______________________________________________ >time-nuts mailing list -- time-nuts@febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. > >__________ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __________ > >The message was checked by ESET Smart Security. > >http://www.eset.com _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.