[time-nuts] Non electrical time-nuttery

J. Forster jfor at quik.com
Sun Jan 10 00:58:45 UTC 2010


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 <lists at cq.nu>
>>> Date: Sat, 9 Jan 2010 12:36:11
>>> To: Discussion of precise time and frequency
>>> measurement<time-nuts at febo.com>
>>> 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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>>>
>>>
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>>
>>
>>
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>
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