[time-nuts] Regulating a pendulum clock (Jim Palfreyman)
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.
Re: [time-nuts] Regulating a pendulum clock
J. Forster wrote: OK. You know better. BTW, op-amp noise is essentially irrelevant in this application, and the C's across the FB resistors limit slew rates so there is no significant dI/dt to cause voltage spikes. Noise is never irrelevant. You havent shown that its insignificant either. In the real world such dv/dt assumptions with inductive loads lead to fried parts. For example if the circuit oscillates at high frequency because the compensation isnt correct/effective or the feedback wire becomes detached or the power supply goes down suddently due to a crowbar event then high dv/dt at the opamp/buffer output is possible. -John Bruce Your naive stabilisation scheme wont work, try simulating it. 741's are somewhat noisier than necessary. Omitting the diodes with an inductive load almost inevitably leads to transistor or opamp destruction. Bruce J. Forster wrote: IMO, far too complicated. I'd use a series pair of u741s each with a complementary emitter follower. 2 u741s, 2x 2N2102, 2x 2N4036, 5 resistors. Maybe 2x .01 caos to stabilize the thing - |\| |---|c DAC --o--| \ | |\ 2N2102 | | / --o-o |--C R |/| | |/ 2N4036 || | |---|c || || |o-to input of mirror image Best, -J = The attached circuit schematic illustrates the Howland current source plus inverting amplifier drive technique. It also illustrates a method of frequency compensation (series RC connected across the coil). Of course one can either use discrete buffers or high current opamps. However for improved accuracy using a difference amplifier with built in pretrimmed resistors for the Howland current source may be preferable, in which case a discrete buffer stage or equivalent may be required. Bruce J. Forster wrote: There are cheap, split supply audio amp ICs that'd work, or you could use a u741 with a complementary-symmetry output buffer of discrete transistors. Crossover distortion would be essentially irrelevant, keeping the parts count very low. -John The 60mA load current would be problematic for most common opamps without an output buffer stage. High voltage opamps are relatively rare. Bruce J. Forster wrote: Since it's inside a closed loop, the design is uncritical. One option is a high voltage Op-Amp with +/- 25 to 30 VDC supplies. You would set the OA gain to about 10, so 2.5 V in would yield 25 V out. and sum in a negative offset voltage so that +2.5 from the DAC yields 0.0 V out. I'd use something like a 100 K FB resistor and a 10K from the DAC, assuming it's a voltage output DAC. A 1 M to the -25 V supply would provide the 2.5 V offset. Another option would be to use two series opamps with the first set up as above, and the second as a unity gain inverter with input connected to the output of the first. The coil would connect between the two OA outputs. As one output swings high, the other mirrors that and goes low (just as in an H bridge). Stability might be an issue, but this has the advantage of only needing a +/- 15 supplies. FWIW, -John = Hi all, I have a Seimens master clock with a Reiffler pendulum. A lovely piece of work that used to provide time services in the 40s. Being a master clock it has contacts that open and close on each pendulum swing and so I can monitor it's accuracy quite easily using gps and my 5370B. I've adjusted it as best I can and the best I can get is about 50 ms over 24 hours. However that was a one off. Temp and air pressure cause variations of up to 300 ms and it changes direction too. Basically it's hard to keep accurate. 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 labelled 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!) It's about 25v in the coil and goes up to 60mA max. Even at levels of 2mA has an effect. Using this control it's quite easy to manually bring the clock back to the
Re: [time-nuts] Regulating a pendulum clock
OK. You know better. BTW, op-amp noise is essentially irrelevant in this application, and the C's across the FB resistors limit slew rates so there is no significant dI/dt to cause voltage spikes. -John > Your naive stabilisation scheme wont work, try simulating it. > 741's are somewhat noisier than necessary. > Omitting the diodes with an inductive load almost inevitably leads to transistor or opamp destruction. > > Bruce > > J. Forster wrote: >> IMO, far too complicated. >> >> I'd use a series pair of u741s each with a complementary emitter follower. >> 2 u741s, 2x 2N2102, 2x 2N4036, 5 resistors. Maybe 2x .01 caos to stabilize >> the thing >> - >> |\| |---|c >> DAC --o--| \ | |\ 2N2102 >>| | / --o-o |--C >>R |/| | |/ 2N4036 >>|| | |---|c >>|| >>|| >>|o-to input of mirror image >> >> Best, >> >> -J >> >> = >> >> >> >> >>> The attached circuit schematic illustrates the Howland current source plus inverting amplifier drive technique. >>> It also illustrates a method of frequency compensation (series RC connected across the coil). >>> Of course one can either use discrete buffers or high current opamps. However for improved accuracy using a difference amplifier with built in >>> pretrimmed resistors for the Howland current source may be preferable, in which case a discrete buffer stage or equivalent may be required. >>> >>> Bruce >>> >>> J. Forster wrote: >>> There are cheap, split supply audio amp ICs that'd work, or you could use a u741 with a complementary-symmetry output buffer of discrete transistors. Crossover distortion would be essentially irrelevant, keeping the parts count very low. -John > The 60mA load current would be problematic for most common opamps without an output buffer stage. > High voltage opamps are relatively rare. > > Bruce > > > J. Forster wrote: > > >> Since it's inside a closed loop, the design is uncritical. >> >> One option is a high voltage Op-Amp with +/- 25 to 30 VDC supplies. You >> would set the OA gain to about 10, so 2.5 V in would yield 25 V out. and >> sum in a negative offset voltage so that +2.5 from the DAC yields 0.0 >> V >> out. I'd use something like a 100 K FB resistor and a 10K from the DAC, >> assuming it's a voltage output DAC. A 1 M to the -25 V supply would provide the 2.5 V offset. >> >> Another option would be to use two series opamps with the first set up >> as >> above, and the second as a unity gain inverter with input connected to >> the >> output of the first. The coil would connect between the two OA outputs. >> As >> one output swings high, the other mirrors that and goes low (just as in >> an >> H bridge). Stability might be an issue, but this has the advantage of >> only >> needing a +/- 15 supplies. >> >> FWIW, >> >> -John >> >> = >> >> >> >> >> >> >> >>> Hi all, >>> >>> I have a Seimens master clock with a Reiffler pendulum. A lovely piece >>> of work that used to provide time services in the 40s. >>> >>> Being a master clock it has contacts that open and close on each pendulum swing and so I can monitor it's accuracy quite easily using >>> gps and my 5370B. >>> >>> I've adjusted it as best I can and the best I can get is about 50 ms >>> over 24 hours. However that was a one off. Temp and air pressure cause >>> variations of up to 300 ms and it changes direction too. Basically it's hard to keep accurate. >>> >>> 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 labelled 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!) >>> >>> It's about 25v in the coil and goes up to 60mA max. Even at levels of >>> 2mA has an effect. >>> >>> Using this control it's quite easy to manually bring the clock back to >>> the right time if it's say half a second fast. >>> >>> What I want to do is control the current in the coil with a micro controller which I have attached to a rubidium oscillator. Getting the >>> pps from the pendulum clock in and comparing to actual time is easy, >>> but I need a way to control the current through the coil so it can dynamically adjust the clock.
Re: [time-nuts] Regulating a pendulum clock
A high voltage opamp (or a low voltage opamp with a discrete output stage with a voltage gain of at least 2) with -3V and + 30V supplies is perhaps the simplest method. The opamp merely senses the current flowing in a current sensing resistor and regulates this voltage drop to equal the output of a DAC. Alternatively it should be feasible to use a pair of opamps (plus output buffers) configured in a bridge arrangement to drive the coil from a single 30V supply. If one end of the coil has to remain near ground then a unity gain difference amplifier (with a discrete buffer with voltage gain) could be employed to implement a current source. A difference amplifier could also be employed together with an opamp (plus unity voltage gain discrete ouput stage) inverter to drive the coil from a single 30V supply. Bruce J. Forster wrote: Since it's inside a closed loop, the design is uncritical. One option is a high voltage Op-Amp with +/- 25 to 30 VDC supplies. You would set the OA gain to about 10, so 2.5 V in would yield 25 V out. and sum in a negative offset voltage so that +2.5 from the DAC yields 0.0 V out. I'd use something like a 100 K FB resistor and a 10K from the DAC, assuming it's a voltage output DAC. A 1 M to the -25 V supply would provide the 2.5 V offset. Another option would be to use two series opamps with the first set up as above, and the second as a unity gain inverter with input connected to the output of the first. The coil would connect between the two OA outputs. As one output swings high, the other mirrors that and goes low (just as in an H bridge). Stability might be an issue, but this has the advantage of only needing a +/- 15 supplies. FWIW, -John = Hi all, I have a Seimens master clock with a Reiffler pendulum. A lovely piece of work that used to provide time services in the 40s. Being a master clock it has contacts that open and close on each pendulum swing and so I can monitor it's accuracy quite easily using gps and my 5370B. I've adjusted it as best I can and the best I can get is about 50 ms over 24 hours. However that was a one off. Temp and air pressure cause variations of up to 300 ms and it changes direction too. Basically it's hard to keep accurate. 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 labelled 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!) It's about 25v in the coil and goes up to 60mA max. Even at levels of 2mA has an effect. Using this control it's quite easy to manually bring the clock back to the right time if it's say half a second fast. What I want to do is control the current in the coil with a micro controller which I have attached to a rubidium oscillator. Getting the pps from the pendulum clock in and comparing to actual time is easy, but I need a way to control the current through the coil so it can dynamically adjust the clock. I need the current to go from say -10 to +10 mA (at 25v) and this needs to be controlled via a micro controller output (which goes from 0 to 5 with 2.5 being the 0mA point). I can either use the D/A in the controller (or PWM an output I suppose). I'd appreciate some thoughts on circuits to do this. Software side is not a problem. 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. <>___ 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
The 60mA load current would be problematic for most common opamps without an output buffer stage. High voltage opamps are relatively rare. Bruce J. Forster wrote: Since it's inside a closed loop, the design is uncritical. One option is a high voltage Op-Amp with +/- 25 to 30 VDC supplies. You would set the OA gain to about 10, so 2.5 V in would yield 25 V out. and sum in a negative offset voltage so that +2.5 from the DAC yields 0.0 V out. I'd use something like a 100 K FB resistor and a 10K from the DAC, assuming it's a voltage output DAC. A 1 M to the -25 V supply would provide the 2.5 V offset. Another option would be to use two series opamps with the first set up as above, and the second as a unity gain inverter with input connected to the output of the first. The coil would connect between the two OA outputs. As one output swings high, the other mirrors that and goes low (just as in an H bridge). Stability might be an issue, but this has the advantage of only needing a +/- 15 supplies. FWIW, -John = Hi all, I have a Seimens master clock with a Reiffler pendulum. A lovely piece of work that used to provide time services in the 40s. Being a master clock it has contacts that open and close on each pendulum swing and so I can monitor it's accuracy quite easily using gps and my 5370B. I've adjusted it as best I can and the best I can get is about 50 ms over 24 hours. However that was a one off. Temp and air pressure cause variations of up to 300 ms and it changes direction too. Basically it's hard to keep accurate. 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 labelled 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!) It's about 25v in the coil and goes up to 60mA max. Even at levels of 2mA has an effect. Using this control it's quite easy to manually bring the clock back to the right time if it's say half a second fast. What I want to do is control the current in the coil with a micro controller which I have attached to a rubidium oscillator. Getting the pps from the pendulum clock in and comparing to actual time is easy, but I need a way to control the current through the coil so it can dynamically adjust the clock. I need the current to go from say -10 to +10 mA (at 25v) and this needs to be controlled via a micro controller output (which goes from 0 to 5 with 2.5 being the 0mA point). I can either use the D/A in the controller (or PWM an output I suppose). I'd appreciate some thoughts on circuits to do this. Software side is not a problem. 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. ___ 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
Hi, the range of the adjustment is probably far wider than you would ever need as you will be applying it continuously instead of over a few hours to correct the clock to the latest observations. So all you need is an amplifier run off + and - 15 Volts with enough gain for the DAC output. That should give you + or - 10Volts. You may also need a reference diode, say 2.5 volts, to provide an offset voltage to the input of the amplifier if you want to set the zero of the control range and possibly offset a single ended DAC output to span either side of zero. cheers, Neville Michie On 08/08/2010, at 12:10 PM, J. Forster wrote: Since it's inside a closed loop, the design is uncritical. One option is a high voltage Op-Amp with +/- 25 to 30 VDC supplies. You would set the OA gain to about 10, so 2.5 V in would yield 25 V out. and sum in a negative offset voltage so that +2.5 from the DAC yields 0.0 V out. I'd use something like a 100 K FB resistor and a 10K from the DAC, assuming it's a voltage output DAC. A 1 M to the -25 V supply would provide the 2.5 V offset. Another option would be to use two series opamps with the first set up as above, and the second as a unity gain inverter with input connected to the output of the first. The coil would connect between the two OA outputs. As one output swings high, the other mirrors that and goes low (just as in an H bridge). Stability might be an issue, but this has the advantage of only needing a +/- 15 supplies. FWIW, -John = Hi all, I have a Seimens master clock with a Reiffler pendulum. A lovely piece of work that used to provide time services in the 40s. Being a master clock it has contacts that open and close on each pendulum swing and so I can monitor it's accuracy quite easily using gps and my 5370B. I've adjusted it as best I can and the best I can get is about 50 ms over 24 hours. However that was a one off. Temp and air pressure cause variations of up to 300 ms and it changes direction too. Basically it's hard to keep accurate. 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 labelled 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!) It's about 25v in the coil and goes up to 60mA max. Even at levels of 2mA has an effect. Using this control it's quite easy to manually bring the clock back to the right time if it's say half a second fast. What I want to do is control the current in the coil with a micro controller which I have attached to a rubidium oscillator. Getting the pps from the pendulum clock in and comparing to actual time is easy, but I need a way to control the current through the coil so it can dynamically adjust the clock. I need the current to go from say -10 to +10 mA (at 25v) and this needs to be controlled via a micro controller output (which goes from 0 to 5 with 2.5 being the 0mA point). I can either use the D/A in the controller (or PWM an output I suppose). I'd appreciate some thoughts on circuits to do this. Software side is not a problem. 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. ___ 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
Since it's inside a closed loop, the design is uncritical. One option is a high voltage Op-Amp with +/- 25 to 30 VDC supplies. You would set the OA gain to about 10, so 2.5 V in would yield 25 V out. and sum in a negative offset voltage so that +2.5 from the DAC yields 0.0 V out. I'd use something like a 100 K FB resistor and a 10K from the DAC, assuming it's a voltage output DAC. A 1 M to the -25 V supply would provide the 2.5 V offset. Another option would be to use two series opamps with the first set up as above, and the second as a unity gain inverter with input connected to the output of the first. The coil would connect between the two OA outputs. As one output swings high, the other mirrors that and goes low (just as in an H bridge). Stability might be an issue, but this has the advantage of only needing a +/- 15 supplies. FWIW, -John = > Hi all, > > I have a Seimens master clock with a Reiffler pendulum. A lovely piece > of work that used to provide time services in the 40s. > > Being a master clock it has contacts that open and close on each > pendulum swing and so I can monitor it's accuracy quite easily using > gps and my 5370B. > > I've adjusted it as best I can and the best I can get is about 50 ms > over 24 hours. However that was a one off. Temp and air pressure cause > variations of up to 300 ms and it changes direction too. Basically > it's hard to keep accurate. > > 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 labelled 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!) > > It's about 25v in the coil and goes up to 60mA max. Even at levels of > 2mA has an effect. > > Using this control it's quite easy to manually bring the clock back to > the right time if it's say half a second fast. > > What I want to do is control the current in the coil with a micro > controller which I have attached to a rubidium oscillator. Getting the > pps from the pendulum clock in and comparing to actual time is easy, > but I need a way to control the current through the coil so it can > dynamically adjust the clock. > > I need the current to go from say -10 to +10 mA (at 25v) and this > needs to be controlled via a micro controller output (which goes from > 0 to 5 with 2.5 being the 0mA point). > > I can either use the D/A in the controller (or PWM an output I suppose). > > I'd appreciate some thoughts on circuits to do this. Software side is > not a problem. > > 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.
Re: [time-nuts] Regulating a pendulum clock
A high voltage opamp (or a low voltage opamp with a discrete output stage with a voltage gain of at least 2) with -3V and + 30V supplies is perhaps the simplest method. The opamp merely senses the current flowing in a current sensing resistor and regulates this voltage drop to equal the output of a DAC. Alternatively it should be feasible to use a pair of opamps (plus output buffers) configured in a bridge arrangement to drive the coil from a single 30V supply. If one end of the coil has to remain near ground then a unity gain difference amplifier (with a discrete buffer with voltage gain) could be employed to implement a current source. A difference amplifier could also be employed together with an opamp (plus unity voltage gain discrete ouput stage) inverter to drive the coil from a single 30V supply. Bruce Jim Palfreyman wrote: Hi all, I have a Seimens master clock with a Reiffler pendulum. A lovely piece of work that used to provide time services in the 40s. Being a master clock it has contacts that open and close on each pendulum swing and so I can monitor it's accuracy quite easily using gps and my 5370B. I've adjusted it as best I can and the best I can get is about 50 ms over 24 hours. However that was a one off. Temp and air pressure cause variations of up to 300 ms and it changes direction too. Basically it's hard to keep accurate. 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 labelled 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!) It's about 25v in the coil and goes up to 60mA max. Even at levels of 2mA has an effect. Using this control it's quite easy to manually bring the clock back to the right time if it's say half a second fast. What I want to do is control the current in the coil with a micro controller which I have attached to a rubidium oscillator. Getting the pps from the pendulum clock in and comparing to actual time is easy, but I need a way to control the current through the coil so it can dynamically adjust the clock. I need the current to go from say -10 to +10 mA (at 25v) and this needs to be controlled via a micro controller output (which goes from 0 to 5 with 2.5 being the 0mA point). I can either use the D/A in the controller (or PWM an output I suppose). I'd appreciate some thoughts on circuits to do this. Software side is not a problem. 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.
[time-nuts] Regulating a pendulum clock
Hi all, I have a Seimens master clock with a Reiffler pendulum. A lovely piece of work that used to provide time services in the 40s. Being a master clock it has contacts that open and close on each pendulum swing and so I can monitor it's accuracy quite easily using gps and my 5370B. I've adjusted it as best I can and the best I can get is about 50 ms over 24 hours. However that was a one off. Temp and air pressure cause variations of up to 300 ms and it changes direction too. Basically it's hard to keep accurate. 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 labelled 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!) It's about 25v in the coil and goes up to 60mA max. Even at levels of 2mA has an effect. Using this control it's quite easy to manually bring the clock back to the right time if it's say half a second fast. What I want to do is control the current in the coil with a micro controller which I have attached to a rubidium oscillator. Getting the pps from the pendulum clock in and comparing to actual time is easy, but I need a way to control the current through the coil so it can dynamically adjust the clock. I need the current to go from say -10 to +10 mA (at 25v) and this needs to be controlled via a micro controller output (which goes from 0 to 5 with 2.5 being the 0mA point). I can either use the D/A in the controller (or PWM an output I suppose). I'd appreciate some thoughts on circuits to do this. Software side is not a problem. 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] On Finding Things
On Sun, 8 Aug 2010 02:38:53 +1200, Steve Rooke wrote: >Well, that does make a lot of sense, it's just a pity that searching >for the item you want frequently ends up fruitless but I agree that if >you search for anything, your sure to find it. Senior moments are lifesavers; after a few moments I've forgotten what is was I was looking for and there it is. Of course, I've also forgotten why I was looking for whatever it was and my interests take a possibly new turn. Keeps life fresh. -- kc0ukk at msosborn dot 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] LCD monitor for TBolt
You do not need a switch, the T-Bolt Monitor only reads what's coming from the T-Bolt, you just need to wire two connectors in parallel, and as long as Lady Heather uses the same T-SIP protocol, which I believe is the case, you should be OK. Didier KO4BB --Original Message-- From: Dr. Frank Stellmach Sender: time-nuts-boun...@febo.com To: Time-Nuts ReplyTo: Time-Nuts Subject: [time-nuts] LCD monitor for TBolt Sent: Aug 7, 2010 2:34 AM Dick, I also ordered an LCD monitor from fluke.l (beneath an LPRO Rubidium). For Lady Heather, do I have to add a switch between the monitor and the PC, or does the monitor have an additional RS232 port to feed through the PC communication automatically? Frank ___ 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. Sent from my BlackBerry Wireless thingy while I do other things... ___ 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] Shipping IC chips
Mea culpa. However, I did propose the option of choosing flat rate boxes in lieu of the envelopes, and no one replied with such a request. This was actually Bob Camp's idea, and he was the only one who specifically asked for this packing method. It costs substantially more, but apparently is worth it. Joseph Gray wrote: Without naming names, I want to suggest that if anyone on this list is going to ship IC chips in the future (DIP in particular), that they either use the hard plastic tube the chips come in, or put the chips inside a box. Antistatic foam inside a padded envelope results in very flat pancakes. Just a friendly suggestion. Hopefully I can straighten the IC legs without breaking them. Joe Gray W5JG ___ 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] PICTIC Thank you
I would like to thank everybody involved on this list who have made it possible to get the necessary parts distributed. For me these are Stanley (for the boards), Nigel (for the 74ac175) and Poul Henning (for shipping the boards inside Europe) And of course Richard who was willing to share his design with all of us. And now of to get it all assembled and start playing. Regards, Stijn ___ 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] Shipping IC chips
Just an FYI guys, the PIC chips are shipping in the hard anti-static tubes. I bought 10 of each from here: http://www.elexp.com/ics_icst.htm They were easy to cut up with a utility knife without shattering and I bought 150 of their rubber stoppers for the ends. They had very inexpensive shipping and my order came quickly. Now if I can only get over to a post office while they're open I will be able to get these chips out the door. -Bob On Sat, Aug 7, 2010 at 2:02 PM, Joseph Gray wrote: > Without naming names, I want to suggest that if anyone on this list is > going to ship IC chips in the future (DIP in particular), that they > either use the hard plastic tube the chips come in, or put the chips > inside a box. Antistatic foam inside a padded envelope results in very > flat pancakes. Just a friendly suggestion. Hopefully I can straighten > the IC legs without breaking them. > > Joe Gray > W5JG > > ___ > 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] Shipping IC chips
Without naming names, I want to suggest that if anyone on this list is going to ship IC chips in the future (DIP in particular), that they either use the hard plastic tube the chips come in, or put the chips inside a box. Antistatic foam inside a padded envelope results in very flat pancakes. Just a friendly suggestion. Hopefully I can straighten the IC legs without breaking them. Joe Gray W5JG ___ 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] Homebrew Rubidium oscillator, jitter and other tales :-)
On 08/07/2010 07:31 PM, Richard (Rick) Karlquist wrote: ulm...@vaxman.de wrote: blinked. This problem was eventually solved by driving the LED with a discrete transistor instead of a free 74AC14 gate and decoupling this driver with an RC-combination. CMOS logic gates have a totem pole output that is famous for "overlap" where both transistors on briefly turned on at the same time, resulting in large current spike from the power supply. It would be interesting to see if this was the problem, or whether it was the "antenna" connected to the output. Also depends on the load. If you have enough capacitive load, current switch-over occurs when both transistors is driving. But with a load such as a LED, I would suspect it would be too big current load to be handled that way. Separate transistor is much better. Cheers, Magnus ___ 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] Homebrew Rubidium oscillator, jitter and other tales :-)
ulm...@vaxman.de wrote: blinked. This problem was eventually solved by driving the LED with a discrete transistor instead of a free 74AC14 gate and decoupling this driver with an RC-combination. CMOS logic gates have a totem pole output that is famous for "overlap" where both transistors on briefly turned on at the same time, resulting in large current spike from the power supply. It would be interesting to see if this was the problem, or whether it was the "antenna" connected to the output. Rick N6RK ___ 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] Homebrew Rubidium oscillator, jitter and other tales :-)
Hello all - first of all, I would like to thank you for the many replies I got regarding my first posting a couple of weeks ago where I described my homebrew Rubidium oscillator based on an LPRO-101. During the last couple of days I found enough spare time to dig deeper into some issues. In addition to that I was lucky enough to find a Tracor 527E (literally from a scrap heap) for 50 EUR which looked horrible and was non- functional with a large red sticker "REJECT". After two evenings of digging through its circuitry it is now in perfect working condition again (actually there were only two faults: a defective transistor in the mixer of the first error multiplier which essentially rendered the machine useless, and a cold solder joint in the single shot which caused erratic operation after fixing the first bug). Since some of you mentioned that my (way too?) simple digital divider chain would produce output signals with non-neglectible phase jitter, I had a deeper look into this issue using the Tracor 527E and an old HCD 1519 precision oscillator which I assume to have better phase stability than my initial dividing circuitry. First of all, you were perfectly right - there was substantial jitter which I got rid of by inserting a 74LS175 between the respective divider stages and the output drivers of my divider circuit. The common clock line of the 74LS175 is driven by the TTL converted output of the LPRO-101. (I am aware of the problem that with enough temperatur shift it might happen that my divider chain might "slip" a whole clock period, but at the moment this simple solution seems to work really nice.) What came quite as a surprise to me was that my stupid idea of having a LED which blinks once per second would cause me so much headaches. Using the Tracor 527E and the HCD 1519 which was running for more than a day, I was able to adjust the quartz oscillator to the Rubidium clock with an error of < 1 in 10**10. After switching the Tracor to a resolution of 10**11 it became apparent that there still was a substantial phase shift every second then the *...* LED blinked. This problem was eventually solved by driving the LED with a discrete transistor instead of a free 74AC14 gate and decoupling this driver with an RC-combination. All in all, I think my Rubidium oscillator is now way better than its first incarnation, so thank you all very much for your help and hints. Best regards - Bernd. :-) ___ 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] On Finding Things
Perhaps its the fairies at the bottom of my garden :) Steve On 08/08/2010, J. L. Trantham wrote: > Are you sure it was there all the time? The same thing happens to me. > > I wonder about these things. :^) > > Joe > > -Original Message- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of Steve Rooke > Sent: Saturday, August 07, 2010 9:56 AM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] On Finding Things > > > What your saying is that it is a form of selective blindness where the brain > filters out an item it does not want to see but if your looking for > something specifically, I wonder why this happens. I have experienced this > many times, I try to find something that I had just a moment ago and cannot > find it until it suddenly appears, as if by magic, right in front of me and > was there all the time. > > Steve > > On 08/08/2010, Arthur Dent wrote: >> Brooke Clarke posted this quote, which I really like: >> "Now, a few words on looking for things. When you go looking for >> something specific, your chances of finding it are very bad. Because >> of all the things in the world, you're only looking for one of them. >> When you go looking for anything at all, your chances of finding it >> are very good. Because of all the things in the world, you're sure to >> find some of them." >> >> Although not the same, I think that this theory of trying to find >> things may be related to the SEP, or Somebody Else's Problem, that >> Douglas Adams describes in "Life, the Universe and Everything" >> +++ >> "An SEP is something we can't see, or don't see, or our brain doesn't >> let us see, because we think that it's somebody else's problem The >> brain just edits it out, >> it's like a blind spot. If you look at it directly you won't see it unless >> you know precisely >> what it is. Your only hope is to catch it by surprise out of the corner of >> your eye." >> >> -Arthur Dent >> >> >> >> >> ___ >> 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] On Finding Things
Are you sure it was there all the time? The same thing happens to me. I wonder about these things. :^) Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Steve Rooke Sent: Saturday, August 07, 2010 9:56 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] On Finding Things What your saying is that it is a form of selective blindness where the brain filters out an item it does not want to see but if your looking for something specifically, I wonder why this happens. I have experienced this many times, I try to find something that I had just a moment ago and cannot find it until it suddenly appears, as if by magic, right in front of me and was there all the time. Steve On 08/08/2010, Arthur Dent wrote: > Brooke Clarke posted this quote, which I really like: > "Now, a few words on looking for things. When you go looking for > something specific, your chances of finding it are very bad. Because > of all the things in the world, you're only looking for one of them. > When you go looking for anything at all, your chances of finding it > are very good. Because of all the things in the world, you're sure to > find some of them." > > Although not the same, I think that this theory of trying to find > things may be related to the SEP, or Somebody Else's Problem, that > Douglas Adams describes in "Life, the Universe and Everything" > +++ > "An SEP is something we can't see, or don't see, or our brain doesn't > let us see, because we think that it's somebody else's problem The > brain just edits it out, > it's like a blind spot. If you look at it directly you won't see it unless > you know precisely > what it is. Your only hope is to catch it by surprise out of the corner of > your eye." > > -Arthur Dent > > > > > ___ > 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] On Finding Things
What your saying is that it is a form of selective blindness where the brain filters out an item it does not want to see but if your looking for something specifically, I wonder why this happens. I have experienced this many times, I try to find something that I had just a moment ago and cannot find it until it suddenly appears, as if by magic, right in front of me and was there all the time. Steve On 08/08/2010, Arthur Dent wrote: > Brooke Clarke posted this quote, which I really like: > "Now, a few words on looking for things. When you go looking for > something specific, your chances of finding it are very bad. Because of > all the things in the world, you're only looking for one of them. When > you go looking for anything at all, your chances of finding it are very > good. Because of all the things in the world, you're sure to find some > of them." > > Although not the same, I think that this theory of trying to find things may > be related to the SEP, or Somebody Else's Problem, that Douglas Adams > describes in "Life, the Universe and Everything" > +++ > "An SEP is something we can't see, or don't see, or our brain doesn't let us > see, > because we think that it's somebody else's problem The brain just edits > it out, > it's like a blind spot. If you look at it directly you won't see it unless > you know precisely > what it is. Your only hope is to catch it by surprise out of the corner of > your eye." > > -Arthur Dent > > > > > ___ > 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] On Finding Things
On 08/08/2010, Brooke Clarke wrote: > Hi Steve: > > In the movie "Zero Effect" Daryl Zero says: > "Now, a few words on looking for things. When you go looking for > something specific, your chances of finding it are very bad. Because of > all the things in the world, you're only looking for one of them. When > you go looking for anything at all, your chances of finding it are very > good. Because of all the things in the world, you're sure to find some > of them." Well, that does make a lot of sense, it's just a pity that searching for the item you want frequently ends up fruitless but I agree that if you search for anything, your sure to find it. Maybe there is some higher order philosophical relevance in this. Perhaps we would advance more if our research was basically open, random, instead of closed on a specific idea. Instead of trying to work out which road to take to get to Rome, just take any road as all roads lead toe Rome. Hmmm, interesting. Cheers, Steve > Have Fun, > > Brooke Clarke > http://www.PRC68.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] On Finding Things
Brooke Clarke posted this quote, which I really like: "Now, a few words on looking for things. When you go looking for something specific, your chances of finding it are very bad. Because of all the things in the world, you're only looking for one of them. When you go looking for anything at all, your chances of finding it are very good. Because of all the things in the world, you're sure to find some of them." Although not the same, I think that this theory of trying to find things may be related to the SEP, or Somebody Else's Problem, that Douglas Adams describes in "Life, the Universe and Everything" +++ "An SEP is something we can't see, or don't see, or our brain doesn't let us see, because we think that it's somebody else's problem The brain just edits it out, it's like a blind spot. If you look at it directly you won't see it unless you know precisely what it is. Your only hope is to catch it by surprise out of the corner of your eye." -Arthur Dent ___ 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] On Finding Things
Hi Steve: In the movie "Zero Effect" Daryl Zero says: "Now, a few words on looking for things. When you go looking for something specific, your chances of finding it are very bad. Because of all the things in the world, you're only looking for one of them. When you go looking for anything at all, your chances of finding it are very good. Because of all the things in the world, you're sure to find some of them." Have Fun, Brooke Clarke http://www.PRC68.com Steve Rooke wrote: Hi Bob, Oh, I'll be doing that, for sure, as I expect most if not all the passives are in the junk-box. It's just finding them, my "filing system" seems to be having a bit of a meltdown of late and I'm frequently in the state of know I have something, somewhere, but I can't for the life of me find it. Guess it's time for me to be put out to grass :( The good thing about trying to find things is that it's quite amazing the items that turn up that you didn't really know you had lost. The only problem is that I can never find the actual item I'm looking for. My place is far too small for all the stuff I have and that makes it difficult to organise things. Cheers, Steve On 08/08/2010, Bob Camp wrote: Hi I strongly recommend checking your local inventory (dare I say junk box.) off a lot of the parts. Stuff like bypass caps likely something you have. Bob On Aug 7, 2010, at 5:10 AM, Steve Rooke wrote: Hi Bob, I have the correct DIL 74175 so I can untick that item. Steve On 07/08/2010, Bob Camp wrote: Hi As far as I know all the parts are correct except the 74175. It is the soic version. Bob On Aug 6, 2010, at 7:16 PM, Steve Rooke wrote: Bob, Thanks for that, this Mouser project has all available parts. Do you know if the pots, trimmers, etc. are ones as suggested for the correct orientation, pin spacing, etc. as i believe there was some discussion regarding this in among the many postings on this topic? Steve On 07/08/2010, Bob Camp wrote: Hi I believe the project at: http://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=8736DCEE10 is up to date in (no un-orderable parts). Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Didier Juges Sent: Friday, August 06, 2010 8:36 AM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] What's the latest correct PICTIC II Mouser project? I have not seen an answer to that question (for people in the US) ? I am waiting for the PWB, which I believe I paid for, and I am planning to buy or make (have not looked into that yet) a PIC programmer, since it looks like I may get some mileage out of that anyhow. No rush, but there is no good reason to delay either at that point. Thanks Didier ___ 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. ___ 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] What's the latest correct PICTIC II Mouser project?
Hi Bob, Oh, I'll be doing that, for sure, as I expect most if not all the passives are in the junk-box. It's just finding them, my "filing system" seems to be having a bit of a meltdown of late and I'm frequently in the state of know I have something, somewhere, but I can't for the life of me find it. Guess it's time for me to be put out to grass :( The good thing about trying to find things is that it's quite amazing the items that turn up that you didn't really know you had lost. The only problem is that I can never find the actual item I'm looking for. My place is far too small for all the stuff I have and that makes it difficult to organise things. Cheers, Steve On 08/08/2010, Bob Camp wrote: > Hi > > I strongly recommend checking your local inventory (dare I say junk box.) > off a lot of the parts. Stuff like bypass caps likely something you have. > > Bob > > > > On Aug 7, 2010, at 5:10 AM, Steve Rooke wrote: > >> Hi Bob, >> >> I have the correct DIL 74175 so I can untick that item. >> >> Steve >> >> On 07/08/2010, Bob Camp wrote: >>> Hi >>> >>> As far as I know all the parts are correct except the 74175. It is the >>> soic >>> version. >>> >>> Bob >>> >>> >>> >>> On Aug 6, 2010, at 7:16 PM, Steve Rooke wrote: >>> Bob, Thanks for that, this Mouser project has all available parts. Do you know if the pots, trimmers, etc. are ones as suggested for the correct orientation, pin spacing, etc. as i believe there was some discussion regarding this in among the many postings on this topic? Steve On 07/08/2010, Bob Camp wrote: > Hi > > I believe the project at: > > http://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=8736DCEE10 > > is up to date in (no un-orderable parts). > > Bob > > -Original Message- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of Didier Juges > Sent: Friday, August 06, 2010 8:36 AM > To: 'Discussion of precise time and frequency measurement' > Subject: Re: [time-nuts] What's the latest correct PICTIC II Mouser > project? > > > I have not seen an answer to that question (for people in the US) ? > > I am waiting for the PWB, which I believe I paid for, and I am planning > to > buy or make (have not looked into that yet) a PIC programmer, since it > looks > like I may get some mileage out of that anyhow. > > No rush, but there is no good reason to delay either at that point. > > Thanks > > Didier > > > ___ > 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. >>> >>> ___ >>> 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] What's the latest correct PICTIC II Mouser project?
Hi I strongly recommend checking your local inventory (dare I say junk box.) off a lot of the parts. Stuff like bypass caps likely something you have. Bob On Aug 7, 2010, at 5:10 AM, Steve Rooke wrote: > Hi Bob, > > I have the correct DIL 74175 so I can untick that item. > > Steve > > On 07/08/2010, Bob Camp wrote: >> Hi >> >> As far as I know all the parts are correct except the 74175. It is the soic >> version. >> >> Bob >> >> >> >> On Aug 6, 2010, at 7:16 PM, Steve Rooke wrote: >> >>> Bob, >>> >>> Thanks for that, this Mouser project has all available parts. Do you >>> know if the pots, trimmers, etc. are ones as suggested for the correct >>> orientation, pin spacing, etc. as i believe there was some discussion >>> regarding this in among the many postings on this topic? >>> >>> Steve >>> >>> On 07/08/2010, Bob Camp wrote: Hi I believe the project at: http://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=8736DCEE10 is up to date in (no un-orderable parts). Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Didier Juges Sent: Friday, August 06, 2010 8:36 AM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] What's the latest correct PICTIC II Mouser project? I have not seen an answer to that question (for people in the US) ? I am waiting for the PWB, which I believe I paid for, and I am planning to buy or make (have not looked into that yet) a PIC programmer, since it looks like I may get some mileage out of that anyhow. No rush, but there is no good reason to delay either at that point. Thanks Didier ___ 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. >>> >> >> ___ >> 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] LCD monitor for TBolt
"For Lady Heather, do I have to add a switch between the monitor and the PC, or does the monitor have an additional RS232 port to feed through the PC communication automatically?" ++ I just soldered the monitor lead to the transmit pin on the T-bolt's RS232 connector and can use the monitor and the PC at the same time with no problems. -Arthur ___ 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] What's the latest correct PICTIC II Mouser project?
Hi Bob, I have the correct DIL 74175 so I can untick that item. Steve On 07/08/2010, Bob Camp wrote: > Hi > > As far as I know all the parts are correct except the 74175. It is the soic > version. > > Bob > > > > On Aug 6, 2010, at 7:16 PM, Steve Rooke wrote: > >> Bob, >> >> Thanks for that, this Mouser project has all available parts. Do you >> know if the pots, trimmers, etc. are ones as suggested for the correct >> orientation, pin spacing, etc. as i believe there was some discussion >> regarding this in among the many postings on this topic? >> >> Steve >> >> On 07/08/2010, Bob Camp wrote: >>> Hi >>> >>> I believe the project at: >>> >>> http://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=8736DCEE10 >>> >>> is up to date in (no un-orderable parts). >>> >>> Bob >>> >>> -Original Message- >>> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On >>> Behalf Of Didier Juges >>> Sent: Friday, August 06, 2010 8:36 AM >>> To: 'Discussion of precise time and frequency measurement' >>> Subject: Re: [time-nuts] What's the latest correct PICTIC II Mouser >>> project? >>> >>> >>> I have not seen an answer to that question (for people in the US) ? >>> >>> I am waiting for the PWB, which I believe I paid for, and I am planning >>> to >>> buy or make (have not looked into that yet) a PIC programmer, since it >>> looks >>> like I may get some mileage out of that anyhow. >>> >>> No rush, but there is no good reason to delay either at that point. >>> >>> Thanks >>> >>> Didier >>> >>> >>> ___ >>> 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. >> > > ___ > 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] LCD monitor for TBolt
Dick, I also ordered an LCD monitor from fluke.l (beneath an LPRO Rubidium). For Lady Heather, do I have to add a switch between the monitor and the PC, or does the monitor have an additional RS232 port to feed through the PC communication automatically? Frank ___ 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.
