[time-nuts] Features of a Precision Clock?

Brooke Clarke brooke at pacific.net
Fri Oct 6 17:08:40 EDT 2006

Hi Bill:

On the "to do" list is a version based on Richard McCorkle's RS232 Time 
Interval counter.
For a minimum cost version a different PIC is needed than the 16F88 used 
in the Current Version (PC4).
Once the TI counter is part of the clock then all kinds of neat things 
can be done.  I'll keep in the looking at the mains.

In the PC4 there's a software TI counter good to 1 ms that can be used 
to trim the Real Time Clock chip.

Have Fun,

Brooke Clarke

w/Java http://www.PRC68.com
w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml

Bill Hawkins wrote:

>How about a version that works from the 50/60 Hz power frequency
>with a 1 PPS output and internal micro clock oscillator?
>Great for watching the power grid lose time and regain it as the
>power generated vs. consumed balance varies. If the power line
>PPS lags behind at an increasing rate, it's time to turn off the
>air conditioner and run all those clock ovens on battery before
>the under-frequency relays start cascading.
>Of course, you need the precision version for comparison.
>Does anybody in this group look at power line frequency drift?
>Bill Hawkins
>time-nuts mailing list
>time-nuts at febo.com

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