[time-nuts] Sensing pendulum position, speed, or height

[Neon John]

On Thu, 29 Mar 2007 15:45:25 -0700, Hal Murray
<hmurray at megapathdsl.net> wrote:

>
>How do modern pendulum clock geeks measure what their pendulum is doing?  I'm 
>picturing a magnet on the bottom of the pendulum and a coil or hall effect 
>sensor.

Prowl around here

http://www.hsn161.com/links.html

Particularly 

http://www.precisionclocks.com/

This guy's work is jaw-dropping.  Fused quartz pendulum and arm, hall
effect position sensing, running the whole affair in a vacuum, having
a custom glass vacuum chamber fabricated by a scientific glass shop.  

Not pendulum related but look at this guy's work.

http://www.angelfire.com/sd/rronnie/

My jaw dropped again.

John
---
John De Armond
See my website for my current email address
http://www.neon-john.com
Cleveland, Occupied TN
All great things are simple and many can be expressed in single words:
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