[time-nuts] Quartz assisted pendulum clock.

[Tom Van Baak]

> The man made a quarts crystal oscillator that sent a pulse to an
electromagnet
> that was placed near a permanent magnet mounted on the pendulum of a wall
(not
> a grandfather) clock. The pendulum was set a bit slow for its 72 per
minuet
> beat and the electronics gave it a push each cycle to make it swing at the
> correct rate.

For a modern treatment of this see Bryan Mumford's
excellent web site:

http://www.bmumford.com/clocks/index.html

Those of you time-nuts who also keep "real" clocks
in addition to atomic clocks you'll find his Microset
timer an excellent way to track the performance of
your chronometers and pendulum clocks:

http://www.bmumford.com/microset.html

One last thing I should point out is that for every
person on this "electronic timekeeping" time-nuts
list there are a hundred old guys out there who
collect old mechanical clocks and watches. They
are members of the NAWCC (National Association
of Watch and Clock Collectors).

A small subset are NAWCC Horological Science
Chapter #161. This is a group of modern pendulum
clock makers and are driven more by the amazingly
deep science and technology of vintage and modern
precision pendulum clocks than the art and fashion
of wristwatches. See also:

Horological Science Newsletter
http://www.ubr.com/clocks/nawcc/hsc/hsn.html
Horological Science Issue Index
http://www.iinet.com/~holmstro/hsnissueindex.php
Subject Index to Horological Science Newsletter
http://www.horology.com/hip-hsin.html

/tvb
http://www.leapsecond.com/time-nuts.htm