[time-nuts] 1903 Railroad self-Winding / Self-setting Clock
kb8tq at n1k.org
Sat Nov 1 08:50:26 EDT 2014
The “easy way” is probably to take a GPS module and get the time out of that. There’s not a big need for a GPSDO in this case. The modules cost < $20 and run on very little power.
Mate the module up with your processor du-jour and let it figure out when the top of the hour is. There are a *bunch* of < $15 boards out there. No need for anything fancy. The advantage of having a bit of code is that it can *know* when you are at 12:00:00 rather than having to count 3600 seconds past the last reset.
I would use a … relay… to drive the clock. That way everything is isolated from everything else. You also get a nice real sounding click when it fires.
Total cost of everything < $50. Total time to get it all done…..
I would take the clock to a “clock guy” to make sure it’s up to running this way. It would be a shame to fire things up and find that there is a problem with the clock. Even worse if you break something in the clock.
Totally off topic … we had a similar system in 8th grade. For some odd reason the reset didn’t work quite right. The clock tended to go nuts when the reset signal came through. Very distracting …. wonder why it did that ….
> On Oct 31, 2014, at 9:29 PM, Mike Baker <mpb45 at clanbaker.org> wrote:
> Hello, Time-Nutters--
> A friend has a vintage oak-cabinet pendulum movement
> clock made by The Self Winding Clock Company some time
> around 1903. The company was formed in 1886. By the
> early 1900's era, this clock was known for its relative
> accuracy. These clocks were pendulum controlled and
> powered by a rather small and frequently reset
> mainspring that was wound hourly by a set of 1.5 VDC
> dry-cell batteries. In 1890 (?) the Naval Observatory agreed
> to telegraph standard railway time. Western Union,
> which also owned the Self-Winding Clock Company, sold
> these clocks to the railroads and sent the hourly time
> coordinating signals around the country by telegraph.
> My friend has one of the railroad clocks that has the
> Western Union Telegraph hourly resetting option.
> My friend thought it would be an interesting juxtaposition
> of technology from two different eras by creating the
> momentary 3-volt resetting pulse every hour from a
> GPS disciplined oscillator / clock pulse.
> 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.
> Mike Baker
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