[time-nuts] synch for pendulum clock....

Tom Van Baak tvb at LeapSecond.com
Sun Dec 11 19:04:37 EST 2011

> I'm seriously toying with the idea of putting a small heater in the
> cabinet, so I can have an OCPO - oven controlled pendulum oscillator.

Hi Jim,

Yes, do it! No joke. It should work really well and be easy to
do. Temperature is a useful lever in almost all clocks.

Also consider a 1 Hz speed modulated fan (note that 1PPS
can also mean one Puff Per Second) to both energize and
to synchronize your clock.

Your timing is good; I'm writing a HSN article right now that
touches on all the levers:

LCPC -- length controlled pendulum clock (variable rod)
MCFC -- mass controlled pendulum clock (variable CoG)
GCPC -- gravity controlled pendulum clock (elevation)
ACPC -- amplitude controlled pendulum clock (PE)
VCPC -- velocity controlled pendulum clock (KE)
FCFC -- friction controlled pendulum clock (Q)
TCPC -- temperature controlled pendulum clock
QCPC -- quartz controlled pendulum clock
QEPC -- quartz enhanced pendulum clock
APC -- atomic pendulum clock
GPSDPC -- GPS disciplined pendulum clock

The paper examines the debate between "controlling" as in
keeping one or many external parameters constant, which
is fair and reputable, letting the free pendulum stay free vs.
"controlling" as in the active, hands-on, precise electronic
measurement and unabashed manipulation of the pendulum
swing itself.

Although not "pure" by some measure, there's nothing wrong
with the latter approach. In fact there are so many ways to
manipulate pendulum clock performance that it becomes an
art form in itself. I really encourage you to try the heater or
the fan approach and let us know (or HSN article) how it goes.

Within a certain capture range, you know the same model
works for quartz and some atomic clocks as well. It's a good
day in the lab when tempco can be your clever tool instead
of your constant torment.


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