[time-nuts] Blackout in Europe and power line frequency jump

[Normand Martel]

--- Tom Van Baak <tvb at leapsecond.com> wrote:

> > Your report, though, inspires me to look into more
> reliable and precise
> ways
> > to measure the frequency of one's local grid. I
> had not actually
> considered
> > monitoring electric fields "off the air" before,
> but it seems like this
> > might be fairly practical.
> 
> One very simple method that I have used is plug in a
> AC wall wart transformer with the 6 VAC secondary
> going directly into a HP53131A frequency counter.
> The serial data you get then looks like this:
> 
> 53747.845696 59.996,154,495,1  Hz
> 53747.846854 59.999,588,387,2  Hz
> 53747.848012 60.001,434,856,1  Hz
> 53747.849172 60.001,288,258,8  Hz
> 53747.850330 60.002,697,145,5  Hz
> 53747.850330 N      : 36
> 53747.850330 STD DEV: 0.004,660,852,51 Hz
> 53747.850330 MEAN   : 60.004,606,291,05 Hz
> 53747.850330 MAX    : 60.020,723,348,6  Hz
> 53747.850330 MIN    : 59.996,154,495,1  Hz
> 53747.851489 60.006,143,055,9  Hz
> 53747.852646 60.001,106,173,4  Hz
> 53747.853805 60.003,317,733,6  Hz
> 53747.854963 60.000,519,248,1  Hz
> 53747.856122 59.997,117,006,6  Hz
> 
> which you can run as long as you like and process
> the data as you see fit. In this particular example
> the
> gate time was 100 s and so the statistics were
> hourly.
> 
> Another way is to use a surplus TrueTime TFDM:
> http://www.leapsecond.com/pages/mains/
> 
> /tvb
> 
> 
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>

I've always been interested in the AC mains frequency
precison... I've even imagined a mechanical phase
accumulator, but never made it...

However, my interested was in the actual AC mains
PHASE instead of frequency, since electrical clock
lead/lag is more dependant of the actual phase
(compared to a 60 Hz Cs/Rb/GPS standard) of the hydro
line (a lead/lag of 21600 degrees would correspond to
a one second L/L) than the actual frequency.

Also because phase is the integral of frequency, it is
far easier to monitor errors in phase rather than in
frequency on a long term basis.

Have a good day!

Normand Martel VE2UM
Montreal, Qc. Canada






 
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