On Dec 14, 6:01*pm, George wrote:
On 12/14/2010 4:44 PM, Metspitzer wrote:



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
charge.

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
it?

Its a pretty common feature in devices anymore. Even my 5 year old low
end weather station has a receiver that listens to WWVB and gets very
accurate time and additional stuff like automatic DST changes since they
set a flag when we transition to DST.

http://www.nist.gov/pml/div688/grp40/wwvb.cfm

http://www.nist.gov/pml/div688/grp40/radioclocks.cfm

http://www.amazon.com/Crosse-Technol...h-Atomic/dp/B0...

http://www.amazon.com/Elegant-Radio-...tors/dp/B0...- Hide quoted text -

- Show quoted text -

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 $$$.