[time-nuts] Sidereal seconds

Neville Michie namichie at gmail.com
Fri Mar 2 04:13:37 UTC 2012


I have a problem with two pendulum clocks that interfere with each  
other, even though they are bolted to a brick wall on bedrock  
foundations.
A solution to this problem is to run one on mean time the other on  
sidereal time. Then I can analyse the operation of each of them.
Now there is a problem with sidereal time that neither the GPS system  
or WWV transmit reference signals for sidereal time and the
method of converting mean time to sidereal by calculation is  
difficult for clock synchronisation.
A possible solution is to take mean time (from a TBolt 10MHz) and  
divide it by 9,972,695.7 to give a PPS(sid) signal that can run a  
digital clock dial
and give one second(sid) ticks to phase the pendulum. It may be  
simpler to divide by 9,972,696 to stay with integer division and have  
an error in the
order of a second per annum. (which we have from leap seconds anyway).
TVB made some picDIV chips with a synch pin that do a similar task,  
but have I got the number correct? and are there other nuts that would
like to add a sidereal clock to their clock vaults to make it worth  
while to make such a chip?
If I set up the sidereal clock then I can use my theodolite to check  
time against the stars.
cheers,
Neville Michie
Sydney
Australia



More information about the time-nuts mailing list