Falling water has been used by the Earl of Meath
to make a sustained pendulum.
It was large and damp and it probably inspired Heath Robinson.
The water fell in a stream that impinged on an angled plate to give a
force to propel the pendulum.
The stream was then interrupted by a plate on the pendulum rod.
Because the water took a finite time to fall there was a phase shift so
that the returning pendulum missed the water impulse.
The pendulum then drove a count wheel that drove the dial.
Conical pendulums are a good idea except that no-one has found a good
way to excite them.
They were used on the clock motion of telescopes to track stars for
time photography,
as you could not afford to have a ticking clock drive.
cheers, Neville Michie
On 10/01/2010, at 1:24 PM, Lux, Jim (337C) wrote:
Sunlight? You have a clock driven heliostat generate a fixed beam
of light.
Sure, your sync mechanism only works half the day (half the "clear"
days)...
There's a whole literature on regulating light intensity of flames,
dating
back to Faraday, if not earlier.
On 1/9/10 6:13 PM, "Bob Camp" <[email protected]> wrote:
Hi
It's probably independent of the light as long as you have a
linear spring. My
concern is that you likely do not have a completely linear spring.
Since by definition you can't use an electric light, some kind of
gas light
would be an option. I suspect that if you regulate pressure you
could keep the
light pretty constant. Dry gas for both the fuel and oxidizer
would take out
the humidity issue.
Bob
On Jan 9, 2010, at 8:39 PM, J. Forster wrote:
No, I don't think so.
The period of a pendulum is independent of the amplitude of the
swing to
first order, at least. I think the same applies to a torsional
pendulum.
Maybe moreso if the fiber is a linear torsional spring.
-John
=================
Hi
All you would still need is a way to regulate the light intensity.
Bob
On Jan 9, 2010, at 7:58 PM, J. Forster wrote:
Consider this:
A torsion pendulum with blackened vanes on the perimeter
suspended from
a
fiber. Part way up the fiber is an optical shutter and a small
fixed
magnet so the shutter is stable in two positions with some
hysteresis.
One
position lets light fall on the vanes, one does not.
This would make an optically pumped pendulum w/ no electronics.
-John
==============
Hi
If you abandoned the non-elecronic side of the requirement,
you could
hit
it with a pulsed LED and probably get phase data off of a
couple of
photo
detectors.
Crazy stuff ...
Bob
On Jan 9, 2010, at 6:21 PM, J. Forster wrote:
Maybe you could "pump" the pendulum optically, using a beam
of light,
like
those glass bulb "radiometers" they sell that spin on a sunny
window
ledge.
-John
=============
Like a magnetically coupled escapement
Sent via BlackBerry by AT&T
-----Original Message-----
From: Bob Camp <[email protected]>
Date: Sat, 9 Jan 2010 12:36:11
To: Discussion of precise time and frequency
measurement<[email protected]>
Subject: Re: [time-nuts] Non electrical time-nuttery
Hi
How about a rotary pendulum on a quartz fiber spring with
some kind
of
trick magnets to drive it / read it out? Put the pendulum
and spring
inside an evacuated glass envelope to get around the vacuum
pump
issue.
The enclosure could be pretty small.
Drive the magnets with a second external clock, and feedback
compensate
it. Let the external clock do all the readout via a very
normal gear
and
pointers system. The trick would be getting the feedback
loop to work
purely mechanically with enough gain to "unload" the master
pendulum.
Bob
On Jan 9, 2010, at 2:07 PM, Lux, Jim (337C) wrote:
OK.. So we're moving back in electrical technology....
But what about mechanical? Could modern technology get a
substantial
(>order of magnitude) improvement over 19th century
chronometers
(either
pendulum or balance wheel or whatever). I know there's
some really
good
quartz fiber torsional spring schemes, but I think they
still need
electrical means to keep them moving and to read it out.
So how good can one do with a mechanical, hydraulic, (or
chemical, I
suppose) system? Let's assume it has to have a "direct"
readout
that
is
human readable by a causal bystander. (this starts to
sound like
the
10,000 year clock or whatever it is..)
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