I wouldn't be surprised to find that streetlight clocks use the same old Sangamo or Venner electromechanical timers that they've always used, and are far more of a problem to correct than domestic clocks.
Andy, what equipment do you use to monitor the cycle count ? On Fri, Feb 12, 2021 at 2:55 PM Lux, Jim <[email protected]> wrote: > On 2/12/21 3:12 AM, Andy Talbot wrote: > > I maintain a real time display of mains frequency, and the cumulative > > timing offset from real time. It was last reset 10 days ago when we > had a > > brief power outage (HV fault a mile or so away). > > > > Since then, for the first few days the timing discrepancy kept within > > plus/minus perhaps 20 seconds. But in the last couple of days is has > crept > > up and is now sitting at +48 seconds. On average the frequency will > have > > been running about 0.013Hz high to give that. > > > > Given Nat. Grid still aim to average out to exactly 50Hz, does anyone > know > > if there is a time scale associated with that long-term average? > > > I would think they try to hold it over 1 day, so that mains driven > clocks don't run slow or fast. That being said, I wonder how many > clocks are still being built using a synchronous motor drive? Given that > all the clocks on appliances in my kitchen have drifted apart, I'll bet > they use their internal microcontroller crystal as a reference. > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
