Although I have nothing to add to the discussion, I want to say that I too
found it fascinating. I became interested in AC power grid systems through
the exploration of several abandoned power plants and have been doing a lot
of reading recently into their theoretical and operational details.
It
@febo.com
Sent: Sunday, October 08, 2006 6:49 PM
Subject: Re: [time-nuts] Features of a Precision Clock?
I have found this utterly fascinating.I've learned a great deal from
this exchange.
Jay
Bill Hawkins wrote:
O
Since control is not precise, the subject is probably off
topic for this list
In message [EMAIL PROTECTED], Bill Hawkins writes:
Think of the incredible amount of energy stored in many
rotating generators linked by the synchronous network.
This is actually far less than you seem to think.
If the load suddenly increased 10% [...]
Then all generators would trip and
Poul-Henning Kamp wrote:
In message [EMAIL PROTECTED], Bill Hawkins writes:
Think of the incredible amount of energy stored in many
rotating generators linked by the synchronous network.
This is actually far less than you seem to think.
If the load suddenly increased 10%
to be a psychopath with a damaged brain.
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Poul-Henning Kamp
Sent: Sunday, October 08, 2006 1:28 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Features of a Precision
In message [EMAIL PROTECTED], Bill Hawkins writes:
Please do not discredit all of my explanations by saying they
are old. The control engineer that I talked to in 2002 worked
in a 2,400 megawatt coal-fired plant built in the 70's. Many
of the US plants are that old.
The hardware may be old, but
OK, I think the important things to know for people on this
list are the following:
1. A power grid has no natural frequency.
2. The rate of change of frequency for small changes is
determined by the unbalance between generated power and
the amount of load demand. This is because the grid can't
In message [EMAIL PROTECTED], Bill Hawkins writes:
Since control is not precise, the subject is probably off
topic for this list.
It all depends on your integration time.
I was told from Stockholm that they hadn't lost track of a single
cycle in 50 some years, so that's:
20msec / 50 y
From: Poul-Henning Kamp [EMAIL PROTECTED]
Subject: Re: [time-nuts] Features of a Precision Clock?
Date: Sun, 08 Oct 2006 21:12:16 +
Message-ID: [EMAIL PROTECTED]
In message [EMAIL PROTECTED], Bill Hawkins writes:
Since control is not precise, the subject is probably off
topic
Hi guys,
power grids are very large, consider for example the continental US or
Europe, grids can probably extend 1000km's easily.
At the speed of light, that's 3ms transition time! Electric current travels
much slower than that so the time for a wave to propagate from Berlin to
The electric grid is all a myth Below is the truth. (Presented for your
comical enjoyment)
**
**
DARK CONSPIRACY INVOLVING ELECTRICAL POWER COMPANIES SURFACES
I have found this utterly fascinating.I've learned a great deal from
this exchange.
Jay
Bill Hawkins wrote:
O
Since control is not precise, the subject is probably off
topic for this list.
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Over that time period, maybe a calendar :-)
Didier
Poul-Henning Kamp wrote:
In message [EMAIL PROTECTED], Bill Hawkins writes:
Since control is not precise, the subject is probably off
topic for this list.
It all depends on your integration time.
I was told from Stockholm that
Hi there,
Having worked with the folks who operate the power utilities (I designed
protective relaying and recorder electronics for several years), I can
advise that they do take the long-term accuracy of their power
seriously. However, the short-term is not a big concern, and in fact,
they
Dean,
Thank you so much for your detailed and authoritative
note about power utilities.
I am not certain of the rules of operation, or of the way they tweak
things (generator bias?), but could find out from friends and
colleagues, if you wish.
If it wouldn't be too much to ask, yes, I think
Does anybody in this group look at power line frequency drift?
Somebody once told me that they tried to get frequency info from the Palo
Alto utilities. When they finally got through to somebody who knew what
was
going on, the answer was We aren't tariffed for that.
Does anybody have a
Tom Van Baak wrote,
If it wouldn't be too much to ask, yes, I think several
of us would be interested in how, and under what rules,
they tweak the frequency.
It helps to have a mechanical understanding of the problem.
By the time you get to the end of this, you should know
why the frequency
(integrated
frequency) for 24 hours.
Regards,
Bill Hawkins
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Roger Glover
Sent: Saturday, October 07, 2006 2:38 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Features
Does anybody have a URL for the frequency specs? (US or California.)
Already people have said there are no guarantees, but my experience:
instantaneous frequency might go up and down one or two tenths
of a percent for periods of time of minutes to tens of minutes and
sometimes (but not often)
Dean Weiten wrote:
Hi there,
Having worked with the folks who operate the power utilities (I designed
protective relaying and recorder electronics for several years), I can
advise that they do take the long-term accuracy of their power
seriously. However, the short-term is not a big
Dr Bruce Griffiths said,
Some generators are kept continuously spinning and
synchronised to the mains but generating little power.
These spinning reserve generators are necessary to
stabilise the grid against load fluctuations, they can
very quickly supply power when required.
I hope you don't
Bill Hawkins wrote:
Dr Bruce Griffiths said,
Some generators are kept continuously spinning and
synchronised to the mains but generating little power.
These spinning reserve generators are necessary to
stabilise the grid against load fluctuations, they can
very quickly supply power when
Bill Hawkins said (among other interesting stuff)
Why not use automatic frequency control? Because the controllers
in the different stations would fight each other, because they
are tied together by the synchronous network. In other words,
it is not possible to regulate a stable
Good to hear that this project is coming along nicely!
(1) Synchronize the 1 PPS output rising edge to be near a 1 PPS input
pulse on a one time basis (the 1 PPS edge will have an error of a few
instruction cycles which are each 4/Fin long). If this was done the
manual setting would be
Yes! Yes! Yes! An alarm would be great. Snooze would make it even
better! Although, something I could hook a relay up to would be MUCH
better than a buzzer. This would then replace my bedside alarm clock.
As long as we are wishing
If you have a battery backup on the clock and your 10
On 10/6/06, Hal Murray [EMAIL PROTECTED] wrote:
You
could even power a clock in your bedroom over the coax carrying the 10 MHz
signal.
I'd second that. Adding a bias-T to the clock probably wouldn't cost too
much. While we are all dreaming, it would be cool to send the power, 10 MHz
and 1
I'd second that. Adding a bias-T to the clock probably wouldn't cost
too much. While we are all dreaming, it would be cool to send the
power, 10 MHz and 1 PPS all down the same coax. Maxim/Dallas does
something like this with their 1-wire line. Has anyone tried
something like this with
How about a version that works from the 50/60 Hz power frequency
with a 1 PPS output and internal micro clock oscillator?
Great for watching the power grid lose time and regain it as the
power generated vs. consumed balance varies. If the power line
PPS lags behind at an increasing rate, it's
Does anybody in this group look at power line frequency drift?
http://www.leapsecond.com/pages/mains/
/tvb
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On Fri, Oct 06, 2006 at 03:17:14PM -0500, Bill Hawkins wrote:
Does anybody in this group look at power line frequency drift?
Not currently, but I did so last year during a few months:
http://wwwhome.cs.utwente.nl/~ptdeboer/misc/mains.html
Pieter-Tjerk (PA3FWM)
Hi Bill:
On the to do list is a version based on Richard McCorkle's RS232 Time
Interval counter.
For a minimum cost version a different PIC is needed than the 16F88 used
in the Current Version (PC4).
Once the TI counter is part of the clock then all kinds of neat things
can be done. I'll keep
Does anybody in this group look at power line frequency drift?
Somebody once told me that they tried to get frequency info from the Palo
Alto utilities. When they finally got through to somebody who knew what was
going on, the answer was We aren't tariffed for that.
Does anybody have a URL
, 2006 4:10 PM
Subject: Re: [time-nuts] Features of a Precision Clock?
Does anybody in this group look at power line frequency drift?
Somebody once told me that they tried to get frequency info from the Palo
Alto utilities. When they finally got through to somebody who knew what
was
going
Hi:
I've got the Precision Clock to work and have some questions about the
priority of the features. As it is now the clock allows user selection
of the input frequency at power up that determines the instruction clock
for the PIC micro controller. The choices are 2.5, 5, 10 or 20 Mhz.
The
Hi James:
Can you point me to an example Bulletin C?
Have Fun,
Brooke Clarke
w/Java http://www.PRC68.com
w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml
http://www.precisionclock.com
James Maynard wrote:
On receipt of Bulletin C, can you arm this clock to display the upcoming
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