Digital clock 101 question

[dakota7]

I am a fiend about clock accuracy - my computers synch up with a time
server on startup, and all the clocks in our house are synchronized to
the second. And I notice almost immediately when any of this changes.

Last night, I was awake in bed and noticed that the clock by my bed said
4:28 when a downstairs windup clock was bonging 4:30. The windup clock
isn't perfectly accurate, but when it slips by a minute, typically once
a month, I just reset it and it's acceptable for another 30 days.

When I woke up this morning, I noticed an interesting phenomenon: EVERY
electric digital clock in the house (five in all, not counting VCR) was
two minutes slow.

So my question: Could this somehow be related to the northeastern US
power failure? Our house didn't lose power. But if the local utility
was somehow "cycling down" its output as a conservation technique - I
have no idea if such a thing is possible of course - could THAT have
caused my clocks to all lose two minutes?

No other scenario is possible:

- Virtually every night, I notice if the bedside clock matches the
windup clock. It did Wednesday night; it didn't Thursday.
- No one else in the house reset the clocks.
- The oldest digital clock has no battery or memory - cut power to it
for a nanosecond, and it resets to 12:00 and starts flashing.
- My watch, the computer clocks, the windup clock, and the two
battery-powered clocks in the house, along with the clocks in our cars,
all had the same (correct) time, two minutes ahead of the one shown on
the digital clocks.

 

[Richard Crowley]

"dakota7" wrote ....

When I woke up this morning, I noticed an interesting phenomenon: EVERY
electric digital clock in the house (five in all, not counting VCR) was
two minutes slow.

Time to call Mulder and Sculley. <whistle X-Files music here>

My understanding was that they shed loads before letting the
frequency slip. If you are not at the exact frequency (and PHASE),
you can't interconnect to your regional grid. Hard to believe that any
area could slip frequency to that extent. Mr. Dakota7 doesn't
reveal where he is, either.

 

[JeffM]

...this morning...EVERY electric digital clock...was...two minutes slow.
..related to the northeastern US power failure?
...Our house didn't lose power.
..."cycling down"
dakota7

Imagine putting your finger into a running fan.
If you don't insert and remove it at exactly the right moment,
bad things happen.

Similarly, power generators on the electric grid of the US & Canada
have to be synced EXACTLY or bad things happen.

My sense of it is, you DID lose power.

When clocks switch over
from the precise 60Hz power line as a timebase
to internal (usually cheap) oscillators,
they generally gain or lose time.

 

[CWatters]

Most likely the chimes on the wind up just went off early? Did you check
against an outside source?

Who was it who said "A man with a watch knows the exact time, but a man with
two watches is never quite sure"



"dakota7" <faked@fake.moc> wrote in message
news:faked-CBA3C1.08405415082003@syrcnyrdrs-03-ge0.nyroc.rr.com...

I am a fiend about clock accuracy - my computers synch up with a time
server on startup, and all the clocks in our house are synchronized to
the second. And I notice almost immediately when any of this changes.

Last night, I was awake in bed and noticed that the clock by my bed said
4:28 when a downstairs windup clock was bonging 4:30. The windup clock
isn't perfectly accurate, but when it slips by a minute, typically once
a month, I just reset it and it's acceptable for another 30 days.

When I woke up this morning, I noticed an interesting phenomenon: EVERY
electric digital clock in the house (five in all, not counting VCR) was
two minutes slow.

So my question: Could this somehow be related to the northeastern US
power failure? Our house didn't lose power. But if the local utility
was somehow "cycling down" its output as a conservation technique - I
have no idea if such a thing is possible of course - could THAT have
caused my clocks to all lose two minutes?

No other scenario is possible:

- Virtually every night, I notice if the bedside clock matches the
windup clock. It did Wednesday night; it didn't Thursday.
- No one else in the house reset the clocks.
- The oldest digital clock has no battery or memory - cut power to it
for a nanosecond, and it resets to 12:00 and starts flashing.
- My watch, the computer clocks, the windup clock, and the two
battery-powered clocks in the house, along with the clocks in our cars,
all had the same (correct) time, two minutes ahead of the one shown on
the digital clocks.