Re: Network connected/synched Wall Clock

[chris@xxxxxxx]

>
>Now, my Server has a time synchronising applet that I tell to
>update with an atomic clock over the Internet every now and then.
>My other PCs then synchronise their clocks with my Server.
>
>This set me thinking that wouldn't it be great if I had some kind of
>NON-Ticking wall block that behind the scenes synched with a
>network service running on the Server box.
>
>I don't suppose anybody has seen such a toy?
>
>Stuart

A much cheaper alternative might be to use mains-powered wall clocks.
I remember getting a guided tour of a power station once, many years
ago, and the control room had two clocks side-by-side on the wall.
One was synched to atomic time (via MSF ??, I can't remember) the other
was driven from the power stations own output.  Although the output
frequency from the power station would drift during peak load periods,
making the mains clock run slightly slow, the operators would adjust
the power stations output to make it catch up at off-peak periods.
They used the two clocks to get the match as near as possible.  Hence
mains powered clocks might be out by a number of seconds over short
periods, but would be very stable over long periods.

Our very first business computer system (over 20 years ago now) used
to use this principal (it was before RTC chips were available) and I can
vouch for the fact that we never had to correct for clock drift, unlike
modern systems where you have to resynch almost every day!

I'm assuming that current power stations still adjust frequency in
this way.

Chris.

--
Chris Davenport
chris@xxxxxxx