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Master and Commander
Posts: 2191
Location: Port Ludlow, WA (the Olympic Penninsula) | Subject: Current Technology Question - NSR
Technology Question: I bought a bedside alarm clock at the exchange the other day (forgot the brand) - but - on the box it advertised "just plug in and it automatically sets the right time by itself" (or words to that effect). I plugged the thing in and sure enough the damn thing set the correct time. I unplugged it, moved it upstairs to the bedroom, plugged it back in and once again the right time! How the **+=&&*^^ does this thing do it? (I'm only a three wire Chief Electrician and not privy to these scientific advances)... |
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Master and Commander
Posts: 1405
Location: Houston, TX (Best state in the US) | Subject: RE: Current Technology Question - NSR
Just a guess on my part, since I am also a three wire electrician (and not a chief), but I'd suspect it is getting the time signal from a cellular phone tower in the area or maybe a tv broadcast signal.
Edited by Stoops 2008-04-09 8:06 AM
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Master and Commander
Posts: 1262
Location: Va.Beach,Va. | Subject: RE: Current Technology Question - NSR
crystal - 2008-04-09 7:56 AM
Technology Question: I bought a bedside alarm clock at the exchange the other day (forgot the brand) - but - on the box it advertised "just plug in and it automatically sets the right time by itself" (or words to that effect). I plugged the thing in and sure enough the damn thing set the correct time. I unplugged it, moved it upstairs to the bedroom, plugged it back in and once again the right time! How the **+=&&*^^ does this thing do it? (I'm only a three wire Chief Electrician and not privy to these scientific advances)...
Crystal,I think it's something akin to what we used to call PFM.
(Pure F...... Magic) |
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Master and Commander
Posts: 1431
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My wrist watch does the same thing. Even compensates for daylight saving time. It recieves a single from the atomic clock in the Rocky Mountains that keeps it up to the right time. It will lose 1 second every 23 million years or something like that. |
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Mess cooking
Posts: 7
Location: San Francisco Bay Area | Subject: RE: Current Technology Question - NSR
I have an Indoor-Outdoor Thermometer that does the same thing. It gets it's time by radio freq. from one of many clocks slaved to very accurate Atomic clocks. Check out the following article...
http://en.wikipedia.org/wiki/Radio_clock
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Great Sage of the Sea
Posts: 602
Location: Visalia, Ca. | Subject: RE: Current Technology Question - NSR
RCK - 2008-04-09 6:36 AM
My wrist watch does the same thing. Even compensates for daylight saving time. It recieves a single from the atomic clock in the Rocky Mountains that keeps it up to the right time. It will lose 1 second every 23 million years or something like that.
If memory serves, the atomic clock is at the US Naval Observatory, and it drives two or three radio signals across the country. We have 8 of those self-setting clocks at the USDA Cotton Program facility where I work. The ones in the office and on the patio work great, the ones in the grading lab don't get a good signal - probably all the metal walls and environmental control piping.
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Old Salt
Posts: 489
Location: San Freakcisco CA area | Subject: RE: Current Technology Question - NSR
Don't get tangled up with cell towers and NBS/WWV, guys - stop and think a second - the GPS system transmits accurate time - since about 1999, these automatic timesetting features generally have the time side of a GPS chip in them.
They add maybe $2.50 or so to the total cost at the consumer product retail level. A lot of master clocks in public safety command systems and schools are now using GPS instead of WWV for auto-timesetting. And the neat thing is that they need see only one satellite in order to pick off time - and are a lot cheaper than WWV-based auto-timeset systems.
Edited by SOB490 2008-04-10 6:41 AM
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Current Technology Question - NSR
