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Auto synchronising real clocks (e.g not PC clocks)

Posted: Sun, 05 Apr 2009 7:35 am
by Yutenji
Hi, I'm trying to find clocks that automatically reset themselves to the correct time periodically. Before you answer, let me clarify:
- I am refering to real, physical clocks, not the clocks inside PCs, DVD players etc.
- In many countries (especially Europe) the government broadcast a radio signal that allows clocks (that have the proper equipment built-in) to automatically reset themselves. This is of particular value when the time changes to/from Standard to Daylight Saving. See http://mindprod.com/bgloss/radiosynchedclock.html for some examples of these clocks.

However, (a) many other countries do not broadcast this signal, and (b) it's probably not necessary to do so nowadays, since a properly enabled clock could just synch via wireless home LAN to get to a time server.

I've found this one ( http://www.primexwireless.com/data/spec ... ns/AMP.pdf ) but it's over-the-top for my needs. Anyone know of something a bit simpler?

One other, slightly more extreme, idea would be to find a way to simulate the Radio signal. E.g. Build a transmitter that picks up the accurate time from a PC and then transmit that in a small range.

Thanks

Posted: Mon, 06 Apr 2009 10:17 pm
by durain

Posted: Tue, 07 Apr 2009 8:39 am
by Yutenji
durain wrote:how about a casio wave ceptor?
Thanks, but that's just another example of the technology (albeit a good example) that I'm trying to reproduce. To elaborate, there are two technologies in play, and I guess I'm trying to blend them:

Method #1:
Special radio signal -> broadcast to -> Specially enabled clocks (or watches!)

Method #2:
Computer based Time servers (NIST etc.) -> broadcast thru networks to -> pretty much any client computer

Pros and Cons:
Method #1 is solid, reliable, a bit old fashioned, works only with special clocks and only works in Europe, USA and one or two other places.
Method #2 is solid, reliable, up to date, works only with computers, works worldwide.

What I want is to get Clocks synching with computer-based time servers, such as NIST. This means either (a) Get a clock than connects to a computer network and is enabled to make "what time is it" requests to the time server, or (b) Get an interface from a computer network that can re-broadacst the special radio signal that the Clocks can understand.

I suspect this topic is a little beyond the normal SingaporeExpats discussions, but hey, there's lots of smart, well-connected people reading this, so maybe someone will know something.

Cheers

Posted: Tue, 07 Apr 2009 6:38 pm
by Asian_Geekette
You may want to look at the link below about radio referenced NTP server.


URL CENSORED DUE TO COPYRIGHT ISSUES

But I believe you want something which is a bit different than the one above. Like get the timing from the NTP server and create a radio signal?[/url]

Posted: Tue, 07 Apr 2009 6:39 pm
by Asian_Geekette
Opps... The URL link didn't work. You can just try googling the Radio Referenced NTP Server.

NTP / Radio referenced clocks

Posted: Tue, 07 Apr 2009 8:52 pm
by Yutenji
Asian_geekette thanks, that's certainly interesting. But, what I'm after is the other way round, e.g. generating the radio signal given a reliable time source (NTP).

I'll try emailing to some of the people in the sites you've pointed me to.

Thanks again.