[time-nuts] World's most precise.... wall clock

[Chris Caudle]

> On Tue, 02 Mar 2021 22:42:45 -0800
> Hal Murray <hmurray at megapathdsl.net> wrote:
> 
>> The basic idea is to mount a magnet on a stiff wire so that it sticks 
>> out to
>> the side of the pendulum arm, then mount a coil so the magnet will 
>> swing
>> through it.  Now pulse the coil to get the desired results.

On 2021-03-03 02:54, Attila Kinali wrote:
> This is basically injection locking of a pendulum clock.
> Pendulum clocks are very nice for injection locking, due
> to their relatively low Q and because a magnetic field can
> be easily adjusted in strength.


I don't have the reference at hand right away, but I did see an article 
in the past describing a mechanism which placed the magnet on the end of 
the pendulum, and had one coil to sense the magnet swinging past, and 
another coil to provide the impulse to the pendulum.  The timing of the 
impulse was controlled by a microcontroller, so it could provide some 
rough phase locking function by varying the time between the detection 
pulse and the driven impulse, and maybe the amplitude or length of the 
impulse.
If there is interest I can see if I can find that article again, but 
that may be straying from the original request, which seemed to be 
looking for something with a digital display.

-- 
Chris Caudle