I really have no need to know the exact second of time. I do,
however, often wish electronic clocks could automatically set
themselves to an accuracy of a minute or so. I am sure I am not the
first to be unconvinced by having to reset the clock on my answering
machine or coffee maker after a power outage. I would also be nice if
my new camera could get the correct time/date from it's initial
Because it is not already being done, there must be more to it than
meets the eye. It seems like it would be trivial to just transmit the
time/date code over the power lines. Anything plugged in should
become automatically set. Can someone enlighten me on why this
doesn't already happen?
Ok.........I know the answer. Cost. It is always about money, isn't
Dollars and cents explain why this does not happen automatically
and without charge. Standard time laboratories all over the world
broadcast the time free via Internet, so your PC's internal clock can
reset itself accurately to a few seconds. The same laboratories
broadcast fee-paid time service capable of recalibrating laboratory
instruments etc. accurately to microseconds. No economic
market has yet emerged that will reset your mains-fed microwave or
your battery-operated camera at a price you are willing to pay.
Are you sure those are time-radio based? The ones I bought just have a huge
coin cell battery to "remember" the time and a super-accurate clock
mechanism. That's what they call "SmartSet" - The giveaway is that when the
power returns, they spend a few seconds running through the numbers on he
display. CKS1862 is the model I have and IIRC, the box was quite deceptive
about whether it was a "radio set" clock. I was going to take it back (to
Wal-mart) but after setting it up, I decided "what the heck" and kept it.
Glad I did. It's a very good clock.
I actually prefer a non-radio clock because updating inside the house is a
spotty procedure at best because of plaster lath making some rooms a Faraday
cage. I believe the Emersons come set to the proper "zulu" time when you
buy the clock (battery is good for 5 years - it's the biggest coin cell
battery I've ever seen) and you just set the time zone you're in. I believe
if that battery goes dead or you remove it, you'll have to reset the time
manually. That test is up to you because mine's been holding time as well
as my PC that gets the time from the Naval Observatory so I can't complain.
The clock also allows you to reset the onset/end of DST if Congress decides
to muck with it *again.*
So radio set or not, I'd still recommend them. Mine's been going over two
years without dropping a minute and has big blue numbers I can read without
my glasses - mostly.
On Thu 16 Dec 2010 01:46:35p, Robert Green told us...
No, I'm not positive that they are time-radio based. However, the
two we bought came with the coin cell batteries uninstalled. The
instructions said to first install the batter, then plug into the
AC. At that point the display had blinking dashes for about a
minute, then displayed the time in the Eastern Standard Zone. The
last instruction was to set the actual Time Zone you lived in, which
then changed to the correct time. If the AC is off or the clock is
ujplugged, when the power is back on the display immediately appears
with no running through the numbers to reach the time.
The only downside for us is that it doesn't have a setting for
"Arizona Time" or a switch to disable adjusting for daylight savings
time. I compensate by shifting the time zone that gives us the
correct time one way or the other.
Ours seems to be automatic. We've not yet had occasion to
remove/replace the battery either, but I assume it will do the same
thing it did when originally installed by us.
We're happy with the clocks and I would also reocmmend them. Our
display is also blue and large enough to read without glasses. BTW,
our model looks virtually identical to yours based on the drawing in
~~ If there's a nit to pick, some nitwit will pick it. ~~
You're just buying the wrong stuff. I have clocks that are set by
the atomic clock via satellite [though because of where we live the
clocks have to sit in a west facing window to be set]-- my DVR sets
itself through the cable- I suspect that's where my VCR figured out
what time it was- my InfoGlobe sets itself through the telephone
My $20 clock radio [one of the
has a battery so I only need to set it once every few years. I hope
I didn't pay much for the unhandy feature of being able to set itself.
Actually it's set by direct transmission from a ground station. Same
idea though. These clocks are often, amusingly, labeled "atomic
clock". Just a minor elision there ...
It's already so cheap to pick up this signal that investing in another
one would be mostly redundant -- not always but usually.
GPS receivers get the time from the GPS birds, and that's an extremely
precise time. But a GPS receiver chip, even a very low end one, would
be considerably more expensive and would usually fail indoors.
Same here. I have one of the Crosse Technologies wireless outdoor/
indoor temp displays and it sets the
clock via WWVB. Works great. I agree they should put this in more
appliances or at least a battery so
that it will keep time for a few hours if the power goes out. Around
here, the power loss isn't frequent and when
it does, 90% of the time it's for less than a minute. I suspect the
reason they don't put the radio link in appliances is that unlike the
wireless thermostat, a lot of time you don't have much control over
where to put it. And it might
not get pickup, then people would be complaining.
As for why not transmit it over the powerline, I think it comes down
to who would pay for it? You can't just have one
transmitter at the power plant. There would have to be eqpt installed
closer to the distribution endpoints and there
is no incentive for the power company to shell out the $$$.
See, you know the answer. The old motor driven analog clocks were very
accurate with the 60 cycle electricity. Digital are timed differently and
drift. They use a crystal oscillator that is not a perfect cycle of 60.
I'm sure someone can explain it better.
I haven't seen new clocks which use the mains frequency for a long time.
Quartz cock movements had be had for a couple of pounds now.
Here in the UK we used to have a radio time signal transmitted from Rugby.
A few years ago BT lost the contract for it, and it's now transmitted by a
different company from a transmitter in Cumbria. The frequency is very low,
so the old Rugby transmitter needed a large tuning coil, this large:-
On 18/12/10 03:34, in article fZVOo.182$ firstname.lastname@example.org,
This technology has been on the gonna happen shelf for a long time. It
may be getting a lot closer. Power companies are begining to charge by
"net metering" Cost per KWH will depend on the time of day you use it.
Your power meter will be in relatively constant communication with the
PoCo so the data will be on the the powerlines. When this happens
added circuitry in a device to set clocks should only cost a few
cents. The chip in your clock that does the main work probably isnt a
dedicated clock chip. More than likely it is in fact a microprocessor
so most of the hardware to do this job is already there.
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