[time-nuts] synch for pendulum clock....
namichie at gmail.com
Sun Dec 11 17:04:20 EST 2011
There have been several (dont ask me for references) schemes for
observatory clocks. The problem was often complicated by the
pendulums running in a vacuum or reduced pressure and thus being hard
The type I remember best was a weak electromagnet under the bob that
added or subtracted from the force of gravity
on the bob. The field was applied for several cycles until the
observed error was corrected.
A PLL could use this to correct a pendulum.
cheers, Neville Michie
On 12/12/2011, at 8:32 AM, Brian, WA1ZMS wrote:
> This was talked about several years ago, but did anyone get a fully
> functional design running using electromagnets to synch at one or
> both ends of the travel?
> In the meantime I am using a sensor to measure the time period of
> the pendulum for this particular new grandmother wall clock and
> from that, I can synthesize a pulse train from one of the 10MHz lab
> clocks to drive the electromagnets to cause a subtle synch at the
> end(s) of the pendulum travel. The pulse train freq is custom for a
> given clock.
> Anyway...... that's my scheme for now.
> Feedback welcome.
> -Brian, WA1ZMS
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