[time-nuts] 1903 Railroad self-Winding / Self-setting Clock

Brooke Clarke brooke at pacific.net
Sat Nov 1 17:14:22 EDT 2014

Hi Hal:

The click-click-click... is the self winding.  A solenoid vibrates back and forth and a pawl and ratchet winds the main 
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Have Fun,

Brooke Clarke
Hal Murray wrote:
> We had something like that in school when I was a kid.  (many years ago)
> I remember occasional click-click-click... as it got reset.
> mpb45 at clanbaker.org said:
>> I am wondering what the easiest approach to this might be?    I suppose I
>> could take the 1-sec pulses from a GPSDO (Trimble Thunderbolt ?) and count
>> 3600 of them to generate a momentary reset 3VDC signal.   In any event, I
>> thought I would pass this by the Time-Nuts gang to see if any feedback is
>> available as to what the least complicated (simplest) way might be to
>> accomplish this.
> Counting to 3600 won't work with leap seconds.  :)
> I don't know the details of how a pulse sets the clock hands.  I assume it
> can't set the time to a fraction of a pendulum swing so I don't see much use
> for something fancy like a GPSDO.  But this is time-nuts, so anything is
> possible.
> I'd probably split the project into two parts.  One is to keep good time on a
> computer, say something like a Raspberry Pi.  You can use the net, or a low
> cost GPS unit, or something fancy like a GPSDO.
> The second part is how and when to generate the pulse.  You can use GPIO
> pins, or modem control signals.
> You could use an old PC, but the payback due to reduced power will pay for a
> Raspberry Pi in a year or two depending on your power rates and how much
> power your old PC burns.

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