[time-nuts] Quartz assisted pendulum clock.

John Miles jmiles at pop.net
Thu Jan 5 20:48:10 EST 2006

> I can see that. Although there are no permanent modifications required.
> Just a magnet attached to a pendulum (screw onto thread on pendulum,
> which is threaded) and the rest is electromagnetically coupled.

I didn't read the earlier part of the thread, so maybe this is how the
stabilizer actually works... but once you have a magnet on the pendulum and
a coil next to it, you could design a circuit that spends most of its time
sampling the pendulum's rate and the rest of its time correcting the
pendulum by "holding" or "pushing" as necessary.  That way, you wouldn't
have to monitor and adjust the rate at all.

Given a long-enough integration time (days?), that electromagnet could be a
LONG way from the pendulum.  Maybe as far as several inches or a foot.

> I believe Big-Ben in the UK can be corrected by adding pennies to it, so
> providing an upwards force. That is what I am told, but I must admit it
> seems a bit unlikely. Perhaps possible if there are a lot of pennies
> there. Apparently this is done, as it allows corrections without
> stopping the clock.

Sounds like the same idea as the regulator weight tray on the GE master
clock described on that Telechron site.  You're supposed to add/remove
weights from the tray until the clock is running at the desired rate.

-- john, KE5FX

More information about the time-nuts mailing list