[Erik[_5_]]

I smell issues arising with this...

http://www.google.com/hostednews/ap/...lOzOkUg9wNC2jV
Kugkw?docId=371623ab59694aef9f0a02fe83faca8a

Erik

[[email protected][_2_]]

On Jun 25, 12:23*am, Erik wrote:
I smell issues arising with this...

http://www.google.com/hostednews/ap/...C9wYlOzOkUg9wN...
Kugkw?docId=371623ab59694aef9f0a02fe83faca8a

Erik

I have one issue already. The linked article comes up as unavailable.

[Dean Hoffman[_7_]]

On 6/25/11 7:11 AM, wrote:
On Jun 25, 12:23 am, wrote:
I smell issues arising with this...

http://www.google.com/hostednews/ap/...C9wYlOzOkUg9wN...
Kugkw?docId=371623ab59694aef9f0a02fe83faca8a

Erik

I have one issue already. The linked article comes up as unavailable.


A short article he http://tinyurl.com/5vk4lc4

Does it really take that much effort to synchronize the grid's
frequency?

[Rebel1]

wrote:
On Jun 25, 12:23 am, Erik wrote:
I smell issues arising with this...

http://www.google.com/hostednews/ap/...C9wYlOzOkUg9wN...
Kugkw?docId=371623ab59694aef9f0a02fe83faca8a

Erik

I have one issue already. The linked article comes up as unavailable.

Try he
http://news.yahoo.com/s/ap/20110624/...i_power_clocks

[Ed Pawlowski[_2_]]

"Dean Hoffman" wrote in message
...
On 6/25/11 7:11 AM, wrote:
On Jun 25, 12:23 am, wrote:
I smell issues arising with this...

http://www.google.com/hostednews/ap/...C9wYlOzOkUg9wN...
Kugkw?docId=371623ab59694aef9f0a02fe83faca8a

Erik

I have one issue already. The linked article comes up as unavailable.


A short article he http://tinyurl.com/5vk4lc4

Does it really take that much effort to synchronize the grid's
frequency?


I have no idea, but according to the articles, yes.

I know that a clock motor will be affected as you change from 60 cycles,
but digital? I thought they had something to do with a crystal frequency
oscillation. Or is that just watches?

"But wall clocks and those on ovens and coffeemakers - anything that flashes
"12:00" when it loses power - may be just a bit off every second, and that
error can grow with time."

[The Daring Dufas[_7_]]

On 6/25/2011 7:11 AM, wrote:
On Jun 25, 12:23 am, wrote:
I smell issues arising with this...

http://www.google.com/hostednews/ap/...C9wYlOzOkUg9wN...
Kugkw?docId=371623ab59694aef9f0a02fe83faca8a

Erik

I have one issue already. The linked article comes up as unavailable.

You have to copy and paste the whole link to your web browser because
the bottom line wasn't automatically highlighted as a link. It happens
all the time with some news readers. That's why I use the address
shortening site "http://tinyurl.com/" whenever I want to post a very
long address. :-)

TDD

[George]

On 6/25/2011 12:23 AM, Erik wrote:
I smell issues arising with this...

http://www.google.com/hostednews/ap/...lOzOkUg9wNC2jV
Kugkw?docId=371623ab59694aef9f0a02fe83faca8a

Erik

Consider the government dufas who is in charge:

"Tweaking the power grid’s frequency is expensive and takes a lot of
effort, said Joe McClelland, head of electric reliability for the
Federal Energy Regulatory Commission.

"Is anyone using the grid to keep track of time?" McClelland asked.
"Let’s see if anyone complains if we eliminate it." "

I guess he doesn't know about how clocks with synchronous motors operate.

I guess he is trying to top Obamas technically incompetent FCC chairman
who gave permission (after his boss got a big donation) to proceed with
a system that interferes with GPS?


http://nlpc.org/stories/2011/03/01/w...s-interference

http://preview.tinyurl.com/3fk5nu6


http://www.flightglobal.com/articles...-concerns.html


http://preview.tinyurl.com/678b4sy

[Smarty]

On 6/25/2011 9:35 AM, George wrote:
On 6/25/2011 12:23 AM, Erik wrote:
I smell issues arising with this...

http://www.google.com/hostednews/ap/...lOzOkUg9wNC2jV

Kugkw?docId=371623ab59694aef9f0a02fe83faca8a

Erik

Consider the government dufas who is in charge:

"Tweaking the power grid’s frequency is expensive and takes a lot of
effort, said Joe McClelland, head of electric reliability for the
Federal Energy Regulatory Commission.

"Is anyone using the grid to keep track of time?" McClelland asked.
"Let’s see if anyone complains if we eliminate it." "

I guess he doesn't know about how clocks with synchronous motors operate.

I guess he is trying to top Obamas technically incompetent FCC
chairman who gave permission (after his boss got a big donation) to
proceed with a system that interferes with GPS?


http://nlpc.org/stories/2011/03/01/w...s-interference


http://preview.tinyurl.com/3fk5nu6


http://www.flightglobal.com/articles...-concerns.html


http://preview.tinyurl.com/678b4sy

Apparently Joe Mc Clelland is an electrical engineer. Thankfully not
another lawyer who is clueless about technology:

http://www.ferc.gov/about/offices/oe...mcclelland.asp

[Bill[_9_]]

A short article he http://tinyurl.com/5vk4lc4


Electricity does not just go to homes! There are all sorts of
industrial plants / manufacturing plants / chemical plants and so
forth which have numerous control gizmos which depend on an accurate
power line frequency.

Think of all the things unearthed with the Y2K problem. Same with
this. All sorts of stuff out there!

And the 60 Hz power supply has always been a "rock". Something
guaranteed to be exact. So electrical engineers have made use of that
in many different products which have been manufactured in the past.

Now that "rock" is going to turn to mush?

If they are going to do this, then they should give many years notice
prior to doing so. Same as with Y2K. It took a lot of investigation,
time, and work to root out all the potential problems...

[The Daring Dufas[_7_]]

On 6/25/2011 8:35 AM, George wrote:
On 6/25/2011 12:23 AM, Erik wrote:
I smell issues arising with this...

http://www.google.com/hostednews/ap/...lOzOkUg9wNC2jV
Kugkw?docId=371623ab59694aef9f0a02fe83faca8a

Erik

Consider the government dufas who is in charge:

"Tweaking the power grid’s frequency is expensive and takes a lot of
effort, said Joe McClelland, head of electric reliability for the
Federal Energy Regulatory Commission.

"Is anyone using the grid to keep track of time?" McClelland asked.
"Let’s see if anyone complains if we eliminate it." "

I guess he doesn't know about how clocks with synchronous motors operate.

I guess he is trying to top Obamas technically incompetent FCC chairman
who gave permission (after his boss got a big donation) to proceed with
a system that interferes with GPS?


http://nlpc.org/stories/2011/03/01/w...s-interference


http://preview.tinyurl.com/3fk5nu6


http://www.flightglobal.com/articles...-concerns.html


http://preview.tinyurl.com/678b4sy


Uhem! "Dufas" is a proper family name, I hope you mean "doofus" which
describes a complete dolt. As far as I know none of the Dufas family is
in charge of the national power grid. ^_^

TDD

[HeyBub[_3_]]

The Daring Dufas wrote:
On 6/25/2011 7:11 AM, wrote:
On Jun 25, 12:23 am, wrote:
I smell issues arising with this...

http://www.google.com/hostednews/ap/...C9wYlOzOkUg9wN...
Kugkw?docId=371623ab59694aef9f0a02fe83faca8a

Erik

I have one issue already. The linked article comes up as
unavailable.

You have to copy and paste the whole link to your web browser because
the bottom line wasn't automatically highlighted as a link. It happens
all the time with some news readers. That's why I use the address
shortening site "http://tinyurl.com/" whenever I want to post a very
long address. :-)


It won't happen if you surround the link with angle brackets ((link)).
http://www.google.com/hostednews/ap/...0a02fe83faca8a

[Salmon Egg]

In article ,
"Bill" wrote:


A short article he http://tinyurl.com/5vk4lc4


Electricity does not just go to homes! There are all sorts of
industrial plants / manufacturing plants / chemical plants and so
forth which have numerous control gizmos which depend on an accurate
power line frequency.

Think of all the things unearthed with the Y2K problem. Same with
this. All sorts of stuff out there!

And the 60 Hz power supply has always been a "rock". Something
guaranteed to be exact. So electrical engineers have made use of that
in many different products which have been manufactured in the past.

Now that "rock" is going to turn to mush?

If they are going to do this, then they should give many years notice
prior to doing so. Same as with Y2K. It took a lot of investigation,
time, and work to root out all the potential problems...

So what. Cumulative phase error on rhe grid was allowed to grow pretty
large. I think I remember a minute error or more. The total cycle count,
however was always corrected, often late at night.

Applications that required accurate frequency provided their own
standards. It was a big business for HP and others. Television used a
field rate of 60/sex. My entire remembrance of commercial TV has been
standards that provided their own synchroinzation that did not require
accurate timing from the grid.

--

Sam

Conservatives are against Darwinism but for natural selection.
Liberals are for Darwinism but totally against any selection.

[The Ghost in The Machine]

On Jun 25, 10:07*am, "Bill" wrote:
* * A short article he *http://tinyurl.com/5vk4lc4

Electricity does not just go to homes! There are all sorts of
industrial plants / manufacturing plants / chemical plants and so
forth which have numerous control gizmos which depend on an accurate
power line frequency.

Think of all the things unearthed with the Y2K problem. Same with
this. All sorts of stuff out there!

And the 60 Hz power supply has always been a "rock". Something
guaranteed to be exact. So electrical engineers have made use of that
in many different products which have been manufactured in the past.

Now that "rock" is going to turn to mush?

If they are going to do this, then they should give many years notice
prior to doing so. Same as with Y2K. It took a lot of investigation,
time, and work to root out all the potential problems...

NO **** SHERLOCK.
TGITM

[Pete C.]

Ed Pawlowski wrote:

"Dean Hoffman" wrote in message
...
On 6/25/11 7:11 AM, wrote:
On Jun 25, 12:23 am, wrote:
I smell issues arising with this...

http://www.google.com/hostednews/ap/...C9wYlOzOkUg9wN...
Kugkw?docId=371623ab59694aef9f0a02fe83faca8a

Erik

I have one issue already. The linked article comes up as unavailable.


A short article he http://tinyurl.com/5vk4lc4

Does it really take that much effort to synchronize the grid's
frequency?


I have no idea, but according to the articles, yes.

I know that a clock motor will be affected as you change from 60 cycles,
but digital? I thought they had something to do with a crystal frequency
oscillation. Or is that just watches?

"But wall clocks and those on ovens and coffeemakers - anything that flashes
"12:00" when it loses power - may be just a bit off every second, and that
error can grow with time."

Most anything that "flashes 12:00" is going to be using a crystal
timebase and not care about power line frequency. They flash 12:00 since
when they loose power they need to have the time set again, not anything
to do with line frequency.

There are still a great many timing devices that rely on synchronus
motors and thus line frequency, and these mostly have just dials, such
as timers for sign and landscape lighting, water softener regeneration,
water heater timers and the like.

[harry]

On Jun 25, 5:23*am, Erik wrote:
I smell issues arising with this...

http://www.google.com/hostednews/ap/...C9wYlOzOkUg9wN...
Kugkw?docId=371623ab59694aef9f0a02fe83faca8a

Erik

The issue is pretty straightforward and has already arisen in Europe.
With the rise of microgeneration, (windmills,PV electricity and other
forms of micro-generation), it becomes increasingly difficult to
maintain tight conrol of frequency. Winmills are a special problem in
this respect.
So, they intend not to guarantee frequecy and "catchup" if it does
fall behind.

In days of yore many electric clocks depended on mains frequency to be
correct, this is no longer true many are crystal controlled/battery/
remote sensor so accurate frequency is not the same issue as it was
back then.

[Charlie[_7_]]

"Erik" wrote in message
...
I smell issues arising with this...

http://www.google.com/hostednews/ap/...lOzOkUg9wNC2jV
Kugkw?docId=371623ab59694aef9f0a02fe83faca8a

Erik

A long time ago I was working at company that was running a lot of
equipment that was using the frequency of 60 Hz power line to control some
critical processes.

I got the task of getting the specs of the frequency tolerance. It took a
few phone calls to get to the engineering offices of Boston Edison. The
engineer I reached told me the allowable frequency deviation and reminded me
of something I had learned years before. If alternators running in parallel
are not in phase,one tries to act as if it were a motor and the system could
lock up, We had done this experiment in an AC power lab coupling a pair of
alternators that were being driven by DC motors so that their speeds could
be adjusted and they could be brought into phase with each other. Students
who tried to put them in parallel when they were not close enough got to
produce a pretty loud squeal from the complaining equipment.

As the electric company engineer and I talked he pointed out that the Great
Northeast Blackout in 1964 was not simply that some parts of the grid had
been overloaded but that a surge/spike/anomaly had created a phase mismatch
which snowballed along as some units fell out of the allowable frequency and
knocked alternators of the grid. The short term fix was to get off the grid
and come back on when the frequency mismatches had been resolved.

At any rate, I can hardly wait to see what happens,

Charlie
BSEE 1956

[harry]

On Jun 25, 5:54*pm, "Pete C." wrote:
Ed Pawlowski wrote:

"Dean Hoffman" wrote in message
...
On 6/25/11 7:11 AM, wrote:
On Jun 25, 12:23 am, *wrote:
I smell issues arising with this...

http://www.google.com/hostednews/ap/...C9wYlOzOkUg9wN...
Kugkw?docId=371623ab59694aef9f0a02fe83faca8a

Erik

I have one issue already. *The linked article comes up as unavailable.

* * A short article he *http://tinyurl.com/5vk4lc4

* *Does it really take that much effort to synchronize the grid's
frequency?

I have no idea, but according to the articles, yes.

I know that a clock motor will be affected as you change from 60 *cycles,
but digital? *I thought they had something to do with a crystal frequency
oscillation. *Or is that just watches?

"But wall clocks and those on ovens and coffeemakers - anything that flashes
"12:00" when it loses power - may be just a bit off every second, and that
error can grow with time."

Most anything that "flashes 12:00" is going to be using a crystal
timebase and not care about power line frequency. They flash 12:00 since
when they loose power they need to have the time set again, not anything
to do with line frequency.

There are still a great many timing devices that rely on synchronus
motors and thus line frequency, and these mostly have just dials, such
as timers for sign and landscape lighting, water softener regeneration,
water heater timers and the like.- Hide quoted text -

- Show quoted text -

I think you will find that most timers are crystal controlled/
electronic these days with battery backup. Electro mechanical devices
are disappearing.
In the event of mains failure, the correct time is maintained.

If you want an accurate clock in Europe, you get one that responds to
a daily correction signal broadcast from various sources.

[harry]

On Jun 25, 7:43*pm, "Charlie" wrote:
"Erik" wrote in message

...

I smell issues arising with this...

http://www.google.com/hostednews/ap/...C9wYlOzOkUg9wN...
Kugkw?docId=371623ab59694aef9f0a02fe83faca8a

Erik

A long time ago I was working at *company that was running a lot of
equipment that was using the frequency of 60 Hz power line to control some
critical processes.

I got the task of getting the specs of the frequency tolerance. *It took a
few phone calls to get to the engineering offices of Boston Edison. The
engineer I reached told me the allowable frequency deviation and reminded me
of something I had learned years before. *If alternators running in parallel
are not in phase,one tries to act as if it were a motor and the system could
lock up, *We had done this experiment in an AC power lab coupling a pair of
alternators that were being driven by DC motors so that their speeds could
be adjusted and they could be brought into phase with each other. Students
who tried to put them in parallel when they were not close enough got to
produce a pretty loud squeal from the complaining *equipment.

As the electric company engineer and I talked he pointed out that the Great
Northeast Blackout *in 1964 was not simply that some parts of the grid had
been overloaded but that a surge/spike/anomaly had created a phase mismatch
which snowballed along as some units fell out of the allowable frequency and
knocked alternators of the grid. *The short term fix was to get off the grid
and come back on when the frequency mismatches had been resolved.

At any rate, I can hardly wait to see what happens,

Charlie
BSEE 1956

Alternators have to be synchronised before they can be connected into
the grid.
Either they are synchronised or they are not.

The term you seek is not "phase angle" but "load angle".

http://www.control.com/thread/1250544684

[HeyBub[_3_]]

harry wrote:

I think you will find that most timers are crystal controlled/
electronic these days with battery backup. Electro mechanical devices
are disappearing.
In the event of mains failure, the correct time is maintained.

If you want an accurate clock in Europe, you get one that responds to
a daily correction signal broadcast from various sources.

There are a LOT of things that depend on 60Hz. Since forever 60Hz has been a
standard piped into every establishment in the country. The article
mentioned traffic lights, security systems, and computers, but thousands of
other devices depend on a stable line frequency.

To let the frequency meander all over the place would be similar to letting
the National Bureau of Standards allowing the official meter to vary by one
or two millimeters per day.

On the other hand, this change will open a new business opportunity to
provide standard frequency power.

[[email protected]]

Most anything that "flashes 12:00" is going to be using a crystal
timebase and not care about power line frequency. They flash 12:00 since
when they loose power they need to have the time set again, not anything
to do with line frequency.

Ah, no...

Anyone who has a device with a crystal oscillator timebase knows that
the device has to be reset to the correct time occasionally. On the
other hand, plug-in devices that use the 60 Hz signal for the timebase
have been (up until now) essentially perfect since the signal has been
manually twiddled to make it so. (There is actually a 10 second
tolerance in the East, less in the West.) And implementation is dirt
cheap: you capacitively couple to the power line, use a Schmitt
trigger, and some divide-by-60 counters. With better performance at
less cost, using the power-line frequency as a reference is the
preferred method.

Thing become ambiguous in plug-in devices with "battery backup."
These devices do have crystal oscillators to ride out the power
outage. When the power is on they can either use the crystal
oscillator as reference, or the power line as reference, however the
device was designed.

- Jonathan

[hr(bob) [email protected]]

On Jun 25, 3:49*pm, " wrote:
Most anything that "flashes 12:00" is going to be using a crystal
timebase and not care about power line frequency. They flash 12:00 since
when they loose power they need to have the time set again, not anything
to do with line frequency.

Ah, no...

Anyone who has a device with a crystal oscillator timebase knows that
the device has to be reset to the correct time occasionally. *On the
other hand, plug-in devices that use the 60 Hz signal for the timebase
have been (up until now) essentially perfect since the signal has been
manually twiddled to make it so. *(There is actually a 10 second
tolerance in the East, less in the West.) *And implementation is dirt
cheap: *you capacitively couple to the power line, use a Schmitt
trigger, and some divide-by-60 counters. *With better performance at
less cost, using the power-line frequency as a reference is the
preferred method.

Thing become ambiguous in plug-in devices with "battery backup."
These devices do have crystal oscillators to ride out the power
outage. *When the power is on they can either use the crystal
oscillator as reference, or the power line as reference, however the
device was designed.

* * *- Jonathan

You are the first poster to actually get it correct. Thanks!!!

[aemeijers]

On 6/25/2011 4:29 PM, HeyBub wrote:
harry wrote:

I think you will find that most timers are crystal controlled/
electronic these days with battery backup. Electro mechanical devices
are disappearing.
In the event of mains failure, the correct time is maintained.

If you want an accurate clock in Europe, you get one that responds to
a daily correction signal broadcast from various sources.

There are a LOT of things that depend on 60Hz. Since forever 60Hz has been a
standard piped into every establishment in the country. The article
mentioned traffic lights, security systems, and computers, but thousands of
other devices depend on a stable line frequency.

To let the frequency meander all over the place would be similar to letting
the National Bureau of Standards allowing the official meter to vary by one
or two millimeters per day.

On the other hand, this change will open a new business opportunity to
provide standard frequency power.


On any long-haul telecom circuit, like the ones the Internet runs on,
somewhere in the path for that circuit, is a rack in a basement
somewhere with a cesium clock. All the other racks that particular
circuit runs through, from point A to point Z, anywhere in the world,
have to be told to take that clock's word as gospel. When they screw up,
and have 2 different clocks in the path, sometimes it can get amusing if
they get out of synch.

--
aem sends...

[bob]

Does it really take that much effort to synchronize the grid's
frequency?

To change the frequency they have to brake or accelerate the generator. What
I can't understand is which station is in charge of monitoring the frequency
and issuing commands to other power stations to speed up or slow down?

Frequency variation is not a big deal. When you have a power outage, the
voltage and hence frequency go to zero in a haphazard way. So if line
frequency variation would cause chaos, power outage should cause many times
the chaos.

But we have been living with the ocassional power outage, I think the minute
line frequency variation is not going to do any worse than power outage. In
fact it probably won't affect anyone at all.

[Jim Yanik]

"Charlie" wrote in
:


"Erik" wrote in message
...
I smell issues arising with this...

http://www.google.com/hostednews/ap/...9wYlOzOkUg9wNC
2jV Kugkw?docId=371623ab59694aef9f0a02fe83faca8a

Erik

A long time ago I was working at company that was running a lot of
equipment that was using the frequency of 60 Hz power line to control
some critical processes.

I got the task of getting the specs of the frequency tolerance. It
took a few phone calls to get to the engineering offices of Boston
Edison. The engineer I reached told me the allowable frequency
deviation and reminded me of something I had learned years before. If
alternators running in parallel are not in phase,one tries to act as
if it were a motor and the system could lock up, We had done this
experiment in an AC power lab coupling a pair of alternators that were
being driven by DC motors so that their speeds could be adjusted and
they could be brought into phase with each other. Students who tried
to put them in parallel when they were not close enough got to produce
a pretty loud squeal from the complaining equipment.

As the electric company engineer and I talked he pointed out that the
Great Northeast Blackout in 1964 was not simply that some parts of
the grid had been overloaded but that a surge/spike/anomaly had
created a phase mismatch which snowballed along as some units fell out
of the allowable frequency and knocked alternators of the grid. The
short term fix was to get off the grid and come back on when the
frequency mismatches had been resolved.

At any rate, I can hardly wait to see what happens,

Charlie
BSEE 1956





When you have a phase mismatch,you get partial wave cancellations and
additions (and standing waves)between the different out-of-phase
sources,resulting in power losses,and for the gigawatts electrical
grid,that is meaningful.

--
Jim Yanik
jyanik
at
localnet
dot com

[George]

On 6/25/2011 9:40 AM, Smarty wrote:
On 6/25/2011 9:35 AM, George wrote:
On 6/25/2011 12:23 AM, Erik wrote:
I smell issues arising with this...

http://www.google.com/hostednews/ap/...lOzOkUg9wNC2jV

Kugkw?docId=371623ab59694aef9f0a02fe83faca8a

Erik

Consider the government dufas who is in charge:

"Tweaking the power grid’s frequency is expensive and takes a lot of
effort, said Joe McClelland, head of electric reliability for the
Federal Energy Regulatory Commission.

"Is anyone using the grid to keep track of time?" McClelland asked.
"Let’s see if anyone complains if we eliminate it." "

I guess he doesn't know about how clocks with synchronous motors operate.

I guess he is trying to top Obamas technically incompetent FCC
chairman who gave permission (after his boss got a big donation) to
proceed with a system that interferes with GPS?


http://nlpc.org/stories/2011/03/01/w...s-interference


http://preview.tinyurl.com/3fk5nu6


http://www.flightglobal.com/articles...-concerns.html


http://preview.tinyurl.com/678b4sy

Apparently Joe Mc Clelland is an electrical engineer. Thankfully not
another lawyer who is clueless about technology:

http://www.ferc.gov/about/offices/oe...mcclelland.asp

Sounds like a he must have turned off his brain when he started working
for Obama considering the statement he made.

[Don Kelly[_2_]]

"Gz" wrote in message
...

On Jun 25, 4:49 pm, " wrote:
--------snip--------
Seems like the variation allowed, the more variation syncing is
problematic. The whole grid is always loosing power to all the
stations producing slight variation pulling on each other.
-------
Not really:

a)synchronizing is matching an incoming generator to the grid frequency,
voltage and phase. Normal variations in these are not a problem- if they
are, then there are more serious problems occuring.

b)There is power transfer between machines- the resultant forces act to
pull all machines to the same frequency. You can't run one machine at 60Hz
and another at 60.1 Hz. However, the system transmission losses, for short
periods of time, may increase or decrease slightly. It averages out.

c) Not correcting time as often will not adversely affect operation of the
system - all it means is that there may be (not will be) some more time
error before correction. This is really not a big issue.

Don Kelly
cross out to reply

[Salmon Egg]

In article
,
" wrote:

Anyone who has a device with a crystal oscillator timebase knows that
the device has to be reset to the correct time occasionally. On the
other hand, plug-in devices that use the 60 Hz signal for the timebase
have been (up until now) essentially perfect since the signal has been
manually twiddled to make it so. (There is actually a 10 second
tolerance in the East, less in the West.) And implementation is dirt
cheap: you capacitively couple to the power line, use a Schmitt
trigger, and some divide-by-60 counters. With better performance at
less cost, using the power-line frequency as a reference is the
preferred method.

Thing become ambiguous in plug-in devices with "battery backup."
These devices do have crystal oscillators to ride out the power
outage. When the power is on they can either use the crystal
oscillator as reference, or the power line as reference, however the
device was designed.

I must have lucked out. For about $30 I bought a Pulsar wrist watch at
least 15 years ago. I estimate its stability as about one or two parts
in 10^7 as long as the temperature does not have extreme deviations. I
only reset it when I need to change for daylight savings time or for a
new cell. It is about four seconds fast this now. That may be because of
the cell having been in the watch for over two years now and it is
probably going to fail soon.

--

Sam

Conservatives are against Darwinism but for natural selection.
Liberals are for Darwinism but totally against any selection.

[harry]

On Jun 25, 9:29*pm, "HeyBub" wrote:
harry wrote:

I think you will find that most timers are crystal controlled/
electronic these days with battery backup. *Electro mechanical devices
are disappearing.
In the event of mains failure, the correct time is maintained.

If you want an accurate clock in Europe, you get one that responds *to
a daily correction signal broadcast from various sources.

There are a LOT of things that depend on 60Hz. Since forever 60Hz has been a
standard piped into every establishment in the country. The article
mentioned traffic lights, security systems, and computers, but thousands of
other devices depend on a stable line frequency.

To let the frequency meander all over the place would be similar to letting
the National Bureau of Standards allowing the official meter to vary by one
or two millimeters per day.

On the other hand, this change will open a new business opportunity to
provide standard frequency power.

None of the above mentioned devices rely on accurate frequency
control.

[dpb[_2_]]

harry wrote:

....


None of the above mentioned devices rely on accurate frequency
control.


Well, my turntable does...

--

[JIMMIE]

On Jun 25, 10:07*am, "Bill" wrote:
* * A short article he *http://tinyurl.com/5vk4lc4

Electricity does not just go to homes! There are all sorts of
industrial plants / manufacturing plants / chemical plants and so
forth which have numerous control gizmos which depend on an accurate
power line frequency.

Think of all the things unearthed with the Y2K problem. Same with
this. All sorts of stuff out there!

And the 60 Hz power supply has always been a "rock". Something
guaranteed to be exact. So electrical engineers have made use of that
in many different products which have been manufactured in the past.

Now that "rock" is going to turn to mush?

If they are going to do this, then they should give many years notice
prior to doing so. Same as with Y2K. It took a lot of investigation,
time, and work to root out all the potential problems...

The 60 Hz has never been the "rock" you think it is. While its long
term accuracy is pretty good its short term accuracy isnt that great
and very rarely exactly 60hz. As a matter of fact my freq counter says
it is 60.07xxx Hz, the xxx means that these digits are constantly
chnging. Georgia Power used to give a tour of their Plant Hatch
facility and one of the topics mentioned was frequency accuracy. I
would like a couple of examples of any products that use the power
line frequency as a CRITICAL reference as I know of none.

Jimmie

[Dean Hoffman[_7_]]

On 6/26/11 7:25 AM, dpb wrote:
harry wrote:

...


None of the above mentioned devices rely on accurate frequency
control.


Well, my turntable does...

--

I wonder how many people under 30 know what a turntable is.
Spinning records? Etc.
I was wandering around a museum a few years ago. Some teenagers were
there on a school tour. One asked me what time it was. I said "It's
about a quarter past eleven." That didn't register with her. She
apparently had no idea what that meant. 11:15 made sense to her though.

[Bill[_9_]]

I would like a couple of examples of any products that use the power
line frequency as a CRITICAL reference as I know of none.


Designer talk...
http://www.electronicspoint.com/long...on-t70834.html

Then I've read tons of stuff like this...
"One way to provide an RTC solution with a fairly high degree
of accuracy over-temperature is to use an external, very
accurate clock source. The AC power in the U.S. and
Europe is such a source, with either 60Hz or 50Hz frequency
that is extremely stable over long time periods as well as
over- temperature."...
http://www.intersil.com/data/an/an1342.pdf

Another...
"The HSI frequency is not measured directly, but it is estimated from
the number of HSI clock
pulses counted using a timer, and compared to an ideal value: 8 000
000 Hz. To do so, a
very accurate reference frequency must be available such as the RTC/64
signal provided by
the external 32 kHz crystal or the 50 Hz/60 Hz of the mains"
See page 6 and 7...
http://www.st.com/internet/com/TECHN...CD00221839.pdf

[cjt]

On 06/25/2011 03:29 PM, HeyBub wrote:
harry wrote:

I think you will find that most timers are crystal controlled/
electronic these days with battery backup. Electro mechanical devices
are disappearing.
In the event of mains failure, the correct time is maintained.

If you want an accurate clock in Europe, you get one that responds to
a daily correction signal broadcast from various sources.

There are a LOT of things that depend on 60Hz. Since forever 60Hz has been a
standard piped into every establishment in the country. The article
mentioned traffic lights, security systems, and computers, but thousands of
other devices depend on a stable line frequency.

To let the frequency meander all over the place would be similar to letting
the National Bureau of Standards allowing the official meter to vary by one
or two millimeters per day.

On the other hand, this change will open a new business opportunity to
provide standard frequency power.


20 minutes in a year isn't exactly "meander[ing] all over the place."
And frequency stability is different from long-term time accuracy.

[daestrom[_2_]]

On 6/25/2011 22:28 PM, Salmon Egg wrote:
In article
,
wrote:

Anyone who has a device with a crystal oscillator timebase knows that
the device has to be reset to the correct time occasionally. On the
other hand, plug-in devices that use the 60 Hz signal for the timebase
have been (up until now) essentially perfect since the signal has been
manually twiddled to make it so. (There is actually a 10 second
tolerance in the East, less in the West.) And implementation is dirt
cheap: you capacitively couple to the power line, use a Schmitt
trigger, and some divide-by-60 counters. With better performance at
less cost, using the power-line frequency as a reference is the
preferred method.

Thing become ambiguous in plug-in devices with "battery backup."
These devices do have crystal oscillators to ride out the power
outage. When the power is on they can either use the crystal
oscillator as reference, or the power line as reference, however the
device was designed.

I must have lucked out. For about $30 I bought a Pulsar wrist watch at
least 15 years ago. I estimate its stability as about one or two parts
in 10^7 as long as the temperature does not have extreme deviations. I
only reset it when I need to change for daylight savings time or for a
new cell. It is about four seconds fast this now. That may be because of
the cell having been in the watch for over two years now and it is
probably going to fail soon.


An interesting story, some of the early crystal watches had their
accuracy tied to maintaining the crystal temperature. By accounting for
the watch being on a human's wrist, the designers were able to design
for a specific temperature at the back of the watch.

In some old power plants, we had ovens to maintain the crystal
temperature of our frequency base. But curiously, the frequency base
was not used for controlling the generator (base-load plant), only the
oscillograph for transient plots.

daestrom

[Mark Lloyd]

On Sat, 25 Jun 2011 09:04:48 -0400, "Ed Pawlowski"
wrote:

[snip]

I know that a clock motor will be affected as you change from 60 cycles,
but digital? I thought they had something to do with a crystal frequency
oscillation. Or is that just watches?


A digital clock is a counter. A plug-in clock counts the cycles of the
AC coming in. A battery clock uses a crystal oscillator.

A plug in clock with battery backup probably does NOT have a crystal,
but a cheap RC circuit. That's not very precise. Most seem to be fast
during power failures. If power fails from 6:00 to 7:00, the clock may
show 7:34.

"But wall clocks and those on ovens and coffeemakers - anything that flashes
"12:00" when it loses power - may be just a bit off every second, and that
error can grow with time."

BTW, I once worked on a fancy clock that runs a chart recorder. It
used a PLL to convert the 60Hz to something higher (6.4KHZ IIRC),
which would then be divided down to 64Hz to drive a stepper motor.
This extra complexity had to do with being able to get the exact same
speeds while using 50Hz.
b
--
Mark Lloyd
http://notstupid.us

"Religion is fundamentally opposed to everything I hold in veneration -
courage, clear thinking, honesty, fairness, and, above all, love of the
truth." -- Henry Louis Mencken

[Pete C.]

HeyBub wrote:

harry wrote:

I think you will find that most timers are crystal controlled/
electronic these days with battery backup. Electro mechanical devices
are disappearing.
In the event of mains failure, the correct time is maintained.

If you want an accurate clock in Europe, you get one that responds to
a daily correction signal broadcast from various sources.

There are a LOT of things that depend on 60Hz. Since forever 60Hz has been a
standard piped into every establishment in the country. The article
mentioned traffic lights, security systems, and computers, but thousands of
other devices depend on a stable line frequency.

I take it you haven't looked at a computer since the '70s. There hasn't
been a computer power supply that cared about line frequency in decades,
most these days don't care about line voltage either.

I doubt that there are any synchronous motor based traffic light
controls left in use anywhere in the US either. The only places rural
enough to have such old controllers are also too rural to have traffic
lights.

I don't recall ever seeing a security system that cared about line
frequency either, all they care about is if there is line power present.

[Pete C.]

dpb wrote:

harry wrote:

...

None of the above mentioned devices rely on accurate frequency
control.

Well, my turntable does...

--

Even the newer / better turntables don't rely on line frequency, they
have crystal references and servo loops to maintain accurate speed even
with varying loading.

[Steve Barker[_6_]]

On 6/26/2011 2:01 PM, Pete C. wrote:

dpb wrote:

harry wrote:

...

None of the above mentioned devices rely on accurate frequency
control.

Well, my turntable does...

--

Even the newer / better turntables don't rely on line frequency, they
have crystal references and servo loops to maintain accurate speed even
with varying loading.

he was probably referring to the old direct drive models that had a neon
light and hash marks on the edge that you used to set the proper speed.

--
Steve Barker
remove the "not" from my address to email

[Pete C.]

Jim Yanik wrote:

"Pete C." wrote in
ster.com:


Ed Pawlowski wrote:

"Dean Hoffman" wrote in message
...
On 6/25/11 7:11 AM, wrote:
On Jun 25, 12:23 am, wrote:
I smell issues arising with this...

http://www.google.com/hostednews/ap/...HrMC9wYlOzOkUg
9wN... Kugkw?docId=371623ab59694aef9f0a02fe83faca8a

Erik

I have one issue already. The linked article comes up as
unavailable.


A short article he http://tinyurl.com/5vk4lc4

Does it really take that much effort to synchronize the grid's
frequency?


I have no idea, but according to the articles, yes.

I know that a clock motor will be affected as you change from 60
cycles, but digital? I thought they had something to do with a
crystal frequency oscillation. Or is that just watches?

"But wall clocks and those on ovens and coffeemakers - anything that
flashes "12:00" when it loses power - may be just a bit off every
second, and that error can grow with time."

Most anything that "flashes 12:00" is going to be using a crystal
timebase and not care about power line frequency. They flash 12:00
since when they loose power they need to have the time set again, not
anything to do with line frequency.

There are still a great many timing devices that rely on synchronus
motors and thus line frequency, and these mostly have just dials, such
as timers for sign and landscape lighting, water softener
regeneration, water heater timers and the like.


many of those "flashing 12:00" clocks DO need line frequency to count time.
Not all of them have xtal or ceramic resonators providing the 1 sec pulses
needed for the time count.

Nope, that was the very very early days of digital clocks with discrete
logic. Any device built in the last few decades that "flashes 12:00" is
microprocessor based and will not be using line frequency for reference.

Otherwise,a simple lithium coin cell or Supercap backup would retain the
timekeeping for a long time,and short power interruptions would not send
the clock back to flashing 12:00.

Adding such a backup adds cost to the device, which is why many do not
have such backup. Most actual clocks have a backup battery compartment
for use with regular batteries.


Actually,using line freq is usually more accurate than the xtal or ceramic
resonator timebases,over a long time frame. Unless an xtal timebase is
precisely tuned and temp compensated,they are not accurate over long times.

Sure, but the crystal is accurate enough for consumer use. Many of the
consumer devices don't even have AC power available to them to monitor
the line frequency of since they use wall wart or line lump DC power
supplies.


I used to do such calibrations.

I've soldered PTC thermister heaters onto crystals to provide
temperature stabilization. Most applications, including consumer timing
don't need that level of accuracy, particularly given that most such
devices have their time reset at least twice a year.

[Pete C.]

George wrote:

On 6/25/2011 12:54 PM, Pete C. wrote:

Ed Pawlowski wrote:

"Dean wrote in message
...
On 6/25/11 7:11 AM, wrote:
On Jun 25, 12:23 am, wrote:
I smell issues arising with this...

http://www.google.com/hostednews/ap/...C9wYlOzOkUg9wN...
Kugkw?docId=371623ab59694aef9f0a02fe83faca8a

Erik

I have one issue already. The linked article comes up as unavailable.


A short article he http://tinyurl.com/5vk4lc4

Does it really take that much effort to synchronize the grid's
frequency?


I have no idea, but according to the articles, yes.

I know that a clock motor will be affected as you change from 60 cycles,
but digital? I thought they had something to do with a crystal frequency
oscillation. Or is that just watches?

"But wall clocks and those on ovens and coffeemakers - anything that flashes
"12:00" when it loses power - may be just a bit off every second, and that
error can grow with time."

Most anything that "flashes 12:00" is going to be using a crystal
timebase and not care about power line frequency. They flash 12:00 since
when they loose power they need to have the time set again, not anything
to do with line frequency.

Often they are simply counting zero crossings as a timebase so if the
line frequency drifts the device does too.

Only if the device in question is about 30+ years old and using discrete
logic. Anything "flashing 12:00" built in the last few decades is
microprocessor controlled and using a crystal timebase.