[time-nuts] Clock Powers of Ten

Sylvain RICHARD sr75pro at free.fr
Thu Jan 31 19:25:54 EST 2008


   michael taylor a écrit :

On Jan 31, 2008 5:27 PM, Sylvain RICHARD [1]<sr75pro at free.fr> wrote:

Re the mains frequency, I believe it changes with the load on the grid.
Do you have a record of this?

I forget the reasoning for frequency variation, but it is load or
source related I believe. Part of the reason it

   It is a balance between production and grid load. In the European case,
   the grids are phase synchronous over several countries. The (oldish)
   data I have is
   - Nordel : Finland, Norway, Sweden, Denmark
   - Uktsoa :  UK.
   - Atsoi : Irland
   - Ucte : everybody else in Western Europe : Portugal, Spain, France,
   Netherlands, Belgium, Luxembourg, Germany, Switzerland, Austria, Italy,
   Czech Republic, Slovakia, Poland, Hungary, Romania, ex-Yougoslavia
   During the 2006 blackout, the frequency went down by several hertz
   before some customers were disconnected ("load shedding"). The so
   familiar 50Hz line on VLF spectrograms took a dip.

A project for a easy to build AC frequency measuring device:
 [2]<http://www.sparetimegizmos.com/Hardware/AC_Monitor.htm>

I could log the frequency deviations from my local AC mains if you
want some sample data.

   This gadget looks nice, but I think I'll pass.
   Good night
   Sylvain

References

   1. mailto:sr75pro at free.fr
   2. http://www.sparetimegizmos.com/Hardware/AC_Monitor.htm


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