Re: [time-nuts] synch for pendulum clock....
Tom Curlee wrote: Check the Scientific American Amateur Scientist index for clocks here: http://amasci.com/amateur/sciamdx.html#52-CC It looks like the September 1974 issue has the article on using discrete cmos logic to synchronize a pendulum clock to a quartz crystal. The article is here: http://c-c-i.com/node/157 <>___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] synch for pendulum clock....
Jim- As soon as I hit the send icon, I knew I should have been more specific! :-) How about this...when I'm in the ham shack and I hear the clock down the hall (approx. 10mtrs away) chime, I'd like to be able to glance up at the large LED display at the top of one of the test equipment racks I have and see that at least the minute's digits read either: 00, 15, 30, or 45. And FWIWthe LED display is driven by the NMEA data coming out of the GPS RX inside a Z3810A. How's that? -Brian, WA1ZMS -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Jim Lux Sent: Sunday, December 11, 2011 9:39 PM To: time-nuts@febo.com Subject: Re: [time-nuts] synch for pendulum clock On 12/11/11 5:53 PM, Brian, WA1ZMS wrote: > Thanks guys. Got the info I had been looking for. This group is a great > resource! > Only purpose for this project is so that the Westminster clock chimes > at the same exact moment at the GPS driven UTC LED display in the lab > shows the quarter hour. > Why > > Why not! :- ) > I'm more concerned about your glib statement of "same exact moment"... we'll have none of this same exact stuff without careful specification of the reference points, accounting for light time delay, etc. Now, let's get right to it... on that chime... is it the time when the hammer hits the bell, or when the peak of the first cycle occurs, or what? Sounds like a cool idea... Jim ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] synch for pendulum clock....
On 12/11/11 5:53 PM, Brian, WA1ZMS wrote: Thanks guys. Got the info I had been looking for. This group is a great resource! Only purpose for this project is so that the Westminster clock chimes at the same exact moment at the GPS driven UTC LED display in the lab shows the quarter hour. Why Why not! :- ) I'm more concerned about your glib statement of "same exact moment"... we'll have none of this same exact stuff without careful specification of the reference points, accounting for light time delay, etc. Now, let's get right to it... on that chime... is it the time when the hammer hits the bell, or when the peak of the first cycle occurs, or what? Sounds like a cool idea... Jim ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] synch for pendulum clock....
Thanks guys. Got the info I had been looking for. This group is a great resource! Only purpose for this project is so that the Westminster clock chimes at the same exact moment at the GPS driven UTC LED display in the lab shows the quarter hour. Why Why not! :- ) -Brian, WA1ZMS -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Don Latham Sent: Sunday, December 11, 2011 5:14 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] synch for pendulum clock Try: http://www.bmumford.com/clocks/hj/hj0199.html and similar stuff found by googling "driving pendulum clock" Lots of food for thought. Mumford has put some thought into it. A lot depends on why you want to drive the thing; e.g. measuring perturbations in the gravitational field, a sensitive barometer, temperature sensor, etc. etc. Don ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] synch for pendulum clock....
You could put two metal tabs on the pendulum arm to be influenced by two proportionally biased electromagnets. A ferrous one to speed up the arm and a non-ferrous one to slow down the arm using eddy current. -- Joe Leikhim Leikhim and Associates Communications Consultants Oviedo, Florida www.Leikhim.com jleik...@leikhim.com 407-982-0446 Note to GMail Account users. Due to an abnormally high volume of spam originating from bogus GMail accounts, I have found it necessary to block certain GMail traffic. Please phone me if you believe your message was not received. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] synch for pendulum clock....
>Your timing is good; I'm writing a HSN article right now that >touches on all the levers: Hi Tom - what is HSN? John K1AE ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] synch for pendulum clock....
Once upon a time, I synced a 200+ year old grandfather clock to a GPS 1PPS output. It used a PIC to convert the 1PPS signal to a 24 pulse per minute (if I remember correctly) signal to a model airplane servo. The servo just nudged the (optically sensed) pendulum. It pretty much worked the first time. The mods to the clock were done in such a way that no changes were made to the clock or case. I considered adding an auto-winder to it... ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] synch for pendulum clock....
I'm seriously toying with the idea of putting a small heater in the cabinet, so I can have an OCPO - oven controlled pendulum oscillator. Hi Jim, Yes, do it! No joke. It should work really well and be easy to do. Temperature is a useful lever in almost all clocks. Also consider a 1 Hz speed modulated fan (note that 1PPS can also mean one Puff Per Second) to both energize and to synchronize your clock. Your timing is good; I'm writing a HSN article right now that touches on all the levers: LCPC -- length controlled pendulum clock (variable rod) MCFC -- mass controlled pendulum clock (variable CoG) GCPC -- gravity controlled pendulum clock (elevation) ACPC -- amplitude controlled pendulum clock (PE) VCPC -- velocity controlled pendulum clock (KE) FCFC -- friction controlled pendulum clock (Q) TCPC -- temperature controlled pendulum clock QCPC -- quartz controlled pendulum clock QEPC -- quartz enhanced pendulum clock APC -- atomic pendulum clock GPSDPC -- GPS disciplined pendulum clock The paper examines the debate between "controlling" as in keeping one or many external parameters constant, which is fair and reputable, letting the free pendulum stay free vs. "controlling" as in the active, hands-on, precise electronic measurement and unabashed manipulation of the pendulum swing itself. Although not "pure" by some measure, there's nothing wrong with the latter approach. In fact there are so many ways to manipulate pendulum clock performance that it becomes an art form in itself. I really encourage you to try the heater or the fan approach and let us know (or HSN article) how it goes. Within a certain capture range, you know the same model works for quartz and some atomic clocks as well. It's a good day in the lab when tempco can be your clever tool instead of your constant torment. /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] synch for pendulum clock....
I acquired an old pendulum regulator from about the 30's-40's and it had an electromagnetic coil and a small magnet attached to the pendulum. Some old electronics passed a constant (but adjustable) current through the coil either pushing or pulling the pendulum slightly to make its amplitude bigger or smaller. This enabled you to make slight adjustments in its period, so you could speed it up or slow it down gently. I disconnected those electronics and instead passed a small current through from a digital clock built from a microcontroller and a cheap ebay rubidium. This current was periodic so it gave the pendulum a very slight nudge every swing (like pushing a child on a swing). This worked extremely well and the clock's second hand was spot on (to the eye) for months. Then I moved house and the clock was no longer inside but relegated to the garage where the temperature varies quite a bit (10-30 depending on time of year). The temperature variations overpowered the slight nudges and it no longer keeps good time. I'm seriously toying with the idea of putting a small heater in the cabinet, so I can have an OCPO - oven controlled pendulum oscillator. :-) On 12 December 2011 09:13, Don Latham wrote: > Try: > http://www.bmumford.com/clocks/hj/hj0199.html > and similar stuff found by googling "driving pendulum clock" > Lots of food for thought. Mumford has put some thought into it. > A lot depends on why you want to drive the thing; e.g. measuring > perturbations in the gravitational field, a sensitive barometer, > temperature sensor, etc. etc. > Don > > Brian, WA1ZMS > > 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 > > ___ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > > > -- > "Neither the voice of authority nor the weight of reason and argument > are as significant as experiment, for thence comes quiet to the mind." > R. Bacon > "If you don't know what it is, don't poke it." > Ghost in the Shell > > > Dr. Don Latham AJ7LL > Six Mile Systems LLP > 17850 Six Mile Road > POB 134 > Huson, MT, 59846 > VOX 406-626-4304 > www.lightningforensics.com > www.sixmilesystems.com > > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] synch for pendulum clock....
Try: http://www.bmumford.com/clocks/hj/hj0199.html and similar stuff found by googling "driving pendulum clock" Lots of food for thought. Mumford has put some thought into it. A lot depends on why you want to drive the thing; e.g. measuring perturbations in the gravitational field, a sensitive barometer, temperature sensor, etc. etc. Don Brian, WA1ZMS > 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 > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- "Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind." R. Bacon "If you don't know what it is, don't poke it." Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] synch for pendulum clock....
Check the Scientific American Amateur Scientist index for clocks here: http://amasci.com/amateur/sciamdx.html#52-CC It looks like the September 1974 issue has the article on using discrete cmos logic to synchronize a pendulum clock to a quartz crystal. Tom WB6UZZ --- On Sun, 12/11/11, Brian, WA1ZMS wrote: From: Brian, WA1ZMS Subject: [time-nuts] synch for pendulum clock To: "Time Nuts" Date: Sunday, December 11, 2011, 1:32 PM 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 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] synch for pendulum clock....
There have been several (dont ask me for references) schemes for synchronising observatory clocks. The problem was often complicated by the pendulums running in a vacuum or reduced pressure and thus being hard to adjust. 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 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] synch for pendulum clock....
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 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
