[time-nuts] 60 Hz measurement party

Magnus Danielson magnus at rubidium.dyndns.org
Sat Jun 25 23:30:52 UTC 2011


Hi Tom,

On 06/26/2011 01:07 AM, Tom Van Baak wrote:
> Magnus,
>
> Yes, after the current 60 Hz excitement here in the US winds down
> my longer-term idea is for many of us to continuously monitor our
> local power frequency with some sort of web-uploading TAPR kit
> and then have an informal international TDEV competition. There
> are now time-nuts in dozens of countries so this is both possible
> and interesting.
>
> You're welcome to collect data on your 50 Hz; it could serve as a
> benchmark for us time drifters here in the west.
>
> Extrapolating further, I wonder if anyone has done common view
> time transfer based on synchronized power grids? Although not
> as precise as LF or TV or GPS methods it would make a nice
> demo of the concept.

Infact, Poul-Henning and I had the idea to test this on our grid to see 
what kind of performance we would get out of it. He sent me a 
transformer prepped for the work, but it seems both of us got caught up 
doing other stuff to follow through, but this is a good trigger.

We should recall that IEEE 1588 was originally created to meet the power 
industries need for synchronisation. There are players in the PTP world 
that became big thanks to the power industry.

Anyway, a suitable measurement set-up would include a GPS, a transformer 
for measurement signal, and a simple TIC of choice, such as a PICTIC. 
Hook the start pulse to the PPS and the stop pulse to the power grid. 
Cycle slips will be easy to see in data (20 ms or 16.67 ms steps) so 
compensation and counting is quite easy to do in post-processing.

It could be interesting just to monitor the phase of the L1, L2 and L3 
phases of the house. :)

Cheers,
Magnus



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