[time-nuts] Regulating a pendulum clock (Jim Palfreyman)

[Neville Michie]

Not many clocks are set up with the gear to modulate the rate,
but they are all still sensitive to injection locking.
A tiny rare earth magnet on the pendulum (say 1/2 way down the  
pendulum rod)
and a coil fed with a stretched (say 250ms long) PPS or for a seconds  
pendulum
PP2S pulse will pull the pendulum into phaselock with a surprisingly  
small amount of power.
In fact if you turn off the drive it would keep the pendulum swinging.
Cheers, Neville Michie

On 08/08/2010, at 6:00 PM, Steve Rooke wrote:

> This is very interesting and I wonder if the capabilities of this
> system being applied to any clock pendulum. If this sort of control
> any pendulum, then I wonder if it's possible to sync it to some
> standard.
>
> Steve
>
> On 08/08/2010, Don Mimlitch <donmeis at yahoo.com> wrote:
>> Jim Said:
>>> It also has a coil mounted near the pendulum and a fixed magnet  
>>> on the
>>> pendulum bar and this coil connects to a box down below with a meter
>>> and a knob. They are labeled in sec/day. The electronics in the box
>>> are not clear (being quite old) but by measuring the current in the
>>> coil it quite simply increases the current one way to slow the clock
>>> and the other way to speed it up. (I'll admit the physics of this
>>> doesn't make sense to me - but it works!)
>>
>> I have a Warren Telechron Master Clock used in Power Stations in  
>> the 20's to
>> regulate the 60 Cycle so that household clocks using synchronous  
>> motors
>> would be accurate to seconds a day.
>>
>> This clock has a similar permanent magnet at the end of the  
>> Pendulum and
>> a battery connected to a potentiometer to adjust the current flow  
>> positive
>> or negative in an electro-magnet below the pendulum..
>> If the bottom of the magnet in the pendulum is "north" and the  
>> current in
>> the electromagnet is flowing such that its top face is North, then  
>> this will
>> repel the pendulum causing its swing to be wider and contrary to  
>> common
>> knowledge the swing of a fixed length pendulum is not constant  
>> regardless of
>> the swing. (Huygens discovered this in 1670 an found by forcing  
>> the arc of
>> the swing to be cycloid instead of circular he could produce uniform
>> oscillation) Thus if the arc is longer the swing takes more time  
>> and the
>> clock runs slower.
>> If the current flows in the opposite direction and the two magnets  
>> attract
>> then the arc is shortened and the clock runs faster. Of course my  
>> master
>> clock isn't as accurate as a Riefler pendulum clock. Also the  
>> magnet in my
>> clock has lost it's magnetism over time and I can't use this  
>> regulation.
>>
>> So the goal of your adaptation is to have precision control of the  
>> current
>> flow in the positive or negative direction. Others on the list are  
>> better
>> then me at describing how you might achieve this.
>>
>>
>>
>>
>>
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>
>
> -- 
> Steve Rooke - ZL3TUV & G8KVD
> The only reason for time is so that everything doesn't happen at once.
> - Einstein
>
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