[time-nuts] Quartz assisted pendulum clock.
cfmd at bredband.net
Fri Jan 6 00:05:24 EST 2006
From: Chuck Harris <cfharris at erols.com>
Subject: Re: [time-nuts] Quartz assisted pendulum clock.
Date: Thu, 05 Jan 2006 23:53:38 -0500
Message-ID: <43BDF7D2.6060702 at erols.com>
> John Miles wrote:
> >> 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.
> A pendulum swings at the same rate, regardless of its weight. The controlling
> feature is the length of the pendulum.
By adding weight with pennies, the effective centrum of gravity is moved and
thus the effective length of the pendulum.
> A balance wheel, is a different beast, because the weight of the wheel is
> balanced against the tension of the spring.
The trimming of a balance wheel works similar to that of the pendulum, but here
better wheels also has a number of trimmers to keep the wheel axis properly
BTW. Somewere I have the report from a pair of studens which made a pendulum
driven studio clock. A studio clock has numerical presentation of hours,
minutes and possibly also seconds, but also has the seconds markers around the
clock going increasingly lightend up as the seconds go, just as if the second
handle had lit them up. They used a bought pendulum mechanism, used an optical
sensor for the pendulum movement which triggered the second update mechanism in
a PIC processor which did all the digital stuff such as presentation.
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