[time-nuts] Mains Frequency

[Adrian Godwin]

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 <jim at luxfamily.com> 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.
>
>
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