Re: [time-nuts] Regulating a pendulum clock (Jim Palfreyman)
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 donm...@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. ___ 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. -- Steve Rooke - ZL3TUV G8KVD The only reason for time is so that everything doesn't happen at once. - Einstein ___ 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] Regulating a pendulum clock (Jim Palfreyman)
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 donm...@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. ___ 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. -- Steve Rooke - ZL3TUV G8KVD The only reason for time is so that everything doesn't happen at once. - Einstein ___ 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] Regulating a pendulum clock (Jim Palfreyman)
Sorry for double post, modem dropped during sending and a refresh on the browser when it was up resent the message. Steve On 08/08/2010, Steve Rooke sar10...@gmail.com 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 donm...@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. ___ 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. -- Steve Rooke - ZL3TUV G8KVD The only reason for time is so that everything doesn't happen at once. - Einstein -- Steve Rooke - ZL3TUV G8KVD The only reason for time is so that everything doesn't happen at once. - Einstein ___ 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] Regulating a pendulum clock (Jim Palfreyman)
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 donm...@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. ___ 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. -- Steve Rooke - ZL3TUV G8KVD The only reason for time is so that everything doesn't happen at once. - Einstein ___ 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] Regulating a pendulum clock (Jim Palfreyman)
I was rather more thinking of the setup that Don was suggesting as not many domestic clocks have a seconds pendulum and it would otherwise take dividing down a referenced oscillator to the correct frequency. Cheers, Steve On 08/08/2010, Neville Michie namic...@gmail.com wrote: 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 donm...@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. ___ 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. -- Steve Rooke - ZL3TUV G8KVD The only reason for time is so that everything doesn't happen at once. - Einstein ___ 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. -- Steve Rooke - ZL3TUV G8KVD The only reason for time is so that everything doesn't happen at once. - Einstein ___ 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] Regulating a pendulum clock (Jim Palfreyman)
Check out Bryan Mumfords page. http://www.bmumford.com/clocks/em2/index.html Le 08/08/2010 11:14, Steve Rooke a écrit : I was rather more thinking of the setup that Don was suggesting as not many domestic clocks have a seconds pendulum and it would otherwise take dividing down a referenced oscillator to the correct frequency. Cheers, Steve On 08/08/2010, Neville Michienamic...@gmail.com wrote: 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 Mimlitchdonm...@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. ___ 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. -- Steve Rooke - ZL3TUV G8KVD The only reason for time is so that everything doesn't happen at once. - Einstein ___ 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 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] Regulating a pendulum clock (Jim Palfreyman)
On 08/08/2010, mike cook mike.c...@orange.fr wrote: Check out Bryan Mumfords page. http://www.bmumford.com/clocks/em2/index.html I did not want to kick the pendulum with a pulse each swing as the drive would be part and parcel of the existing clock mechanism. What I was interested in was Don Mimlitch's description of how the Riefler Pendulum and Warren Telechron Master Clocks work. The control of constant current to the electromagnet under the pendulum seems quite similar to an EFC and could perhaps be used in a PLL to sync with a reference source, as Jim was originally proposing. Of course, retrofitting a conventional clock like this would require the attachment of a magnet to the pendulum, necessitating reducing the weight of the pendulum to account for it, installing an electromagnet under the pendulum and arranging for each swing of the pendulum to produce some form of pulse signal. Of course, the timing in pulses per second of the original clock would have to be determined and the frequency standard divided down to match this rate before both signals are fed to a comparator and LPF to provide the 'EFC' voltage to control the electromagnetic current. Steve Le 08/08/2010 11:14, Steve Rooke a écrit : I was rather more thinking of the setup that Don was suggesting as not many domestic clocks have a seconds pendulum and it would otherwise take dividing down a referenced oscillator to the correct frequency. Cheers, Steve On 08/08/2010, Neville Michienamic...@gmail.com wrote: 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 Mimlitchdonm...@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. ___ 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. -- Steve Rooke - ZL3TUV G8KVD The only reason for time is so that everything doesn't happen at once. - Einstein ___ 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
Re: [time-nuts] Regulating a pendulum clock (Jim Palfreyman)
Hi all, I think at this point I need to explain the electromagnet positioning. The permanent magnet is on the rod about 25cm down (out of 100cm). The electromagnet is on the left side and so gets close to the permanent magnet every two seconds. Injection locking would be a simple solution and worth a try. I could use a solid state relay triggered by the micro controller that passes a fixed current every second to the coil (it would of course only interact every other second). The location of the coil and magnet I think are perfect for that. My original proposal is more true because it acts like a gpsdo and let's the original pendulum do most of the work. But the injection locking is quick and dirty and exactly how the slave to this clock would have worked anyway. So I think I will do that. In the meantime tvb has convinced me to run it free in the meantime to see if it can detect tidal forces. Jim Palfreyman On Sunday, August 8, 2010, Steve Rooke sar10...@gmail.com wrote: On 08/08/2010, mike cook mike.c...@orange.fr wrote: Check out Bryan Mumfords page. http://www.bmumford.com/clocks/em2/index.html I did not want to kick the pendulum with a pulse each swing as the drive would be part and parcel of the existing clock mechanism. What I was interested in was Don Mimlitch's description of how the Riefler Pendulum and Warren Telechron Master Clocks work. The control of constant current to the electromagnet under the pendulum seems quite similar to an EFC and could perhaps be used in a PLL to sync with a reference source, as Jim was originally proposing. Of course, retrofitting a conventional clock like this would require the attachment of a magnet to the pendulum, necessitating reducing the weight of the pendulum to account for it, installing an electromagnet under the pendulum and arranging for each swing of the pendulum to produce some form of pulse signal. Of course, the timing in pulses per second of the original clock would have to be determined and the frequency standard divided down to match this rate before both signals are fed to a comparator and LPF to provide the 'EFC' voltage to control the electromagnetic current. Steve Le 08/08/2010 11:14, Steve Rooke a écrit : I was rather more thinking of the setup that Don was suggesting as not many domestic clocks have a seconds pendulum and it would otherwise take dividing down a referenced oscillator to the correct frequency. Cheers, Steve On 08/08/2010, Neville Michienamic...@gmail.com wrote: 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 Mimlitchdonm...@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
Re: [time-nuts] Regulating a pendulum clock (Jim Palfreyman)
I real purist would adjust the pendulum moment-of-inertia, rather than drive it. If I ever get around to it, I will attach a long tube of mercury (or cesium) to my pendulum and use heat to adjust the column height. A slightly less elegant solution would use a stepping motor to adjust the location of a weight along the pendulum. -RL --- -- From: Steve Rooke sar10...@gmail.com Sent: Sunday, August 08, 2010 7:30 AM To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Regulating a pendulum clock (Jim Palfreyman) On 08/08/2010, mike cook mike.c...@orange.fr wrote: Check out Bryan Mumfords page. http://www.bmumford.com/clocks/em2/index.html I did not want to kick the pendulum with a pulse each swing as the drive would be part and parcel of the existing clock mechanism. What I was interested in was Don Mimlitch's description of how the Riefler Pendulum and Warren Telechron Master Clocks work. The control of constant current to the electromagnet under the pendulum seems quite similar to an EFC and could perhaps be used in a PLL to sync with a reference source, as Jim was originally proposing. Of course, retrofitting a conventional clock like this would require the attachment of a magnet to the pendulum, necessitating reducing the weight of the pendulum to account for it, installing an electromagnet under the pendulum and arranging for each swing of the pendulum to produce some form of pulse signal. Of course, the timing in pulses per second of the original clock would have to be determined and the frequency standard divided down to match this rate before both signals are fed to a comparator and LPF to provide the 'EFC' voltage to control the electromagnetic current. Steve Le 08/08/2010 11:14, Steve Rooke a écrit : I was rather more thinking of the setup that Don was suggesting as not many domestic clocks have a seconds pendulum and it would otherwise take dividing down a referenced oscillator to the correct frequency. Cheers, Steve On 08/08/2010, Neville Michienamic...@gmail.com wrote: 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 Mimlitchdonm...@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. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow
Re: [time-nuts] Regulating a pendulum clock (Jim Palfreyman)
That's why I suggested killing the BW of the opamps in the partial H bridge configuration previously suggested. Transient response is almost unneeded. -John == On 08/08/2010, mike cook mike.c...@orange.fr wrote: Check out Bryan Mumfords page. http://www.bmumford.com/clocks/em2/index.html I did not want to kick the pendulum with a pulse each swing as the drive would be part and parcel of the existing clock mechanism. What I was interested in was Don Mimlitch's description of how the Riefler Pendulum and Warren Telechron Master Clocks work. The control of constant current to the electromagnet under the pendulum seems quite similar to an EFC and could perhaps be used in a PLL to sync with a reference source, as Jim was originally proposing. Of course, retrofitting a conventional clock like this would require the attachment of a magnet to the pendulum, necessitating reducing the weight of the pendulum to account for it, installing an electromagnet under the pendulum and arranging for each swing of the pendulum to produce some form of pulse signal. Of course, the timing in pulses per second of the original clock would have to be determined and the frequency standard divided down to match this rate before both signals are fed to a comparator and LPF to provide the 'EFC' voltage to control the electromagnetic current. Steve Le 08/08/2010 11:14, Steve Rooke a écrit : I was rather more thinking of the setup that Don was suggesting as not many domestic clocks have a seconds pendulum and it would otherwise take dividing down a referenced oscillator to the correct frequency. Cheers, Steve On 08/08/2010, Neville Michienamic...@gmail.com wrote: 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 Mimlitchdonm...@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. ___ 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. -- Steve Rooke - ZL3TUV G8KVD The only reason for time is so that everything doesn't happen at once. - Einstein ___ 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] Regulating a pendulum clock (Jim Palfreyman)
Well last night I did a quick and dirty. I got my (GPS locked) 3325B to generate square waves (0-5V) at 1 Hz. 500ms on. 500ms off. I ran this through a relay that delivered 10mA at 25V to the coil. By adjusting the phase of the 3325B I got the ON to occur as the magnets approached. But I had no idea whether the magnets were attracting or repelling at that point. Watching the timing of the pendulum it started to radically deviate. I concluded it was repelling and so reverse the polarity. It started heading back the other way. Cool. As it was late - I went to bed. Next morning the pendulum had locked in nicely. It was only deviating a few ms either side of a fixed point. I will let this run for today and make sure it has settled in and doesn't vary. The pendulum clock is fast by 200ms and so I'll adjust the phase to correct it tonight. Next step will be to drive it properly from my rubidium driven microcontroller. While I organise that I'll turn off the electromagnet and see if I can pick up the tides. Regards, Jim Palfreyman ___ 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] Regulating a pendulum clock (Jim Palfreyman)
Nice! Don - Original Message - From: Jim Palfreyman jim77...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sunday, August 08, 2010 6:12 PM Subject: Re: [time-nuts] Regulating a pendulum clock (Jim Palfreyman) Well last night I did a quick and dirty. I got my (GPS locked) 3325B to generate square waves (0-5V) at 1 Hz. 500ms on. 500ms off. I ran this through a relay that delivered 10mA at 25V to the coil. By adjusting the phase of the 3325B I got the ON to occur as the magnets approached. But I had no idea whether the magnets were attracting or repelling at that point. Watching the timing of the pendulum it started to radically deviate. I concluded it was repelling and so reverse the polarity. It started heading back the other way. Cool. As it was late - I went to bed. Next morning the pendulum had locked in nicely. It was only deviating a few ms either side of a fixed point. I will let this run for today and make sure it has settled in and doesn't vary. The pendulum clock is fast by 200ms and so I'll adjust the phase to correct it tonight. Next step will be to drive it properly from my rubidium driven microcontroller. While I organise that I'll turn off the electromagnet and see if I can pick up the tides. Regards, Jim Palfreyman ___ 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.
