Re: [time-nuts] Casio Watches 13 Year Drift in Seattle
and that magic timing machine was the vibrograph, more abot it here: https://www.google.com/search?q=vibrographclient=firefox-ahs=Kyhrls=org.mozilla:en-US:officialchannel=nptbm=ischtbo=usource=univsa=Xei=iK6RVeX4FJTUoASf2KeIBQved=0CB4QsAQbiw=1024bih=507 we had one 73 KJ6UHN On 6/29/2015 12:16 PM, Chuck Harris wrote: Back in the day when mechanical escapement pocket watches, and wrist watches were state of the art, the jeweler would adjust the watch to run at a normal rate, and give them a daily wind. Everything looked nice in the display case. When a customer bought a watch, the jeweler would set the watch to his shop clock, and instruct the customer to wear, and wind the watch normally for two weeks, but do not set it. At the end of the two weeks, bring the watch back to the shop for a check up... When the watch came back, the jeweler would calculate the number of days the watch had been worn, note the difference from his shop clock, and calculate the daily rate of the watch. He would then set his timing machine for the the inverse of that rate, and set the watch to match. Now, when the customer wore his watch, the watch would seem to always be right on because it was adjusted for a rate that compensated for the customer's patterns of wearing the watch...his personal error. This trick had an added advantage because the customer got to see how so-so his brand new watch behaved during those two weeks, and got to be dazzled by his jeweler's rare ability to make the new watch perform so much better than the factory could! If this was normal back at the turn of the 20th century, why wouldn't Casio, and others at least do as well? Especially now that all electronic watches have a microprocessor built in... complete with temperature sensing diodes, battery monitors, and other nifty gadgets. -Chuck Harris Bryan _ wrote: But wouldn't normal watch wear just balance itself over time, one wears their watch for say 12 hours and the rest it sits on a counter at a much colder temperature. So wonder if Casio would actually go to such lengths to compensate. Maybe, interesting though. -=Bryan=- ___ 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] Casio Watches 13 Year Drift in Seattle
Hi Well there are a few possibilities: 1) The person wears their watch 24 hours a day 2) They take it off for random periods of time 3) The person swims marathons weekly in cold water with their watch on 4) The watch sites in a cabinet for 10 years The further down that list the colder the watch runs. Cassio and pretty much everybody else *do* temperature compensate their watches for the nominal temperature characteristic of the crystal they use. It is easy to do digitally and thus costs nothing (either in silicon area or power). They also adjust the watch on frequency digitally rather than mechanically. Compared to the way we used to do it (40 years ago), it’s a lot cheaper to do it the “new way”. It is interesting that the nominal set point is still “fast” though. Bob On Jun 29, 2015, at 2:42 AM, Bryan _ bpl...@outlook.com wrote: But wouldn't normal watch wear just balance itself over time, one wears their watch for say 12 hours and the rest it sits on a counter at a much colder temperature. So wonder if Casio would actually go to such lengths to compensate. Maybe, interesting though. -=Bryan=- From: kb...@n1k.org Date: Sun, 28 Jun 2015 20:41:15 -0400 To: time-nuts@febo.com Subject: Re: [time-nuts] Casio Watches 13 Year Drift in Seattle Hi Just to clarify: In the “art” the watches all ran fast rather than slow. They *would* have run slow if the room temperature / skin temperature delta was an issue. Since they did not, one assumes that Casio digitally compensates this model (and probably all their watches). The typical watch tuning fork will shift more than the observed delta when run in a cold court house if un-compensated. By far the best explanation is the “set to deliberately run fast” one. Bob On Jun 27, 2015, at 8:19 PM, Jim Palfreyman jim77...@gmail.com wrote: My Casio g shock keeps extraordinary time. I did open it up and tune it, but still I'd expect it to drift. After 6 months untouched I still can't separate by eye the second from UTC. Also, with regard to the video's query about all the clocks running slow - they have been tuned to run at the temperature of a person's wrist. On Sunday, 28 June 2015, John Stuart j.w.stu...@comcast.net wrote: I think there may be a new Time-Nut in the Seattle area, , , Art, Engineering and Justice - how accurate is a Casio watch? https://www.youtube.com/watch?v=hwOMUhS8gV0 John, KM6QX ___ time-nuts mailing list -- time-nuts@febo.com javascript:; 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. ___ 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] Casio Watches 13 Year Drift in Seattle
A friend of mine is the test engineer/clock guru for one of the major manufacturers of clock chips. Rest assured that all watch makers know the usage profiles for their customers quite well and they do indeed tweak the chip to compensate for the typical profile. If your usage pattern does not match that of the masses, your accuracy can suffer. Also, you cant assume that all clock circuits will run faster or slower with rising/falling temperature changes. Some circuits run faster with rising temperatures, others will run slower. A very big concern in the clock chip world these days is getting the clock/crystal to start/run reliably with the ever decreasing power requirements of the customers. A clock chip oscillator these days draws in the low nanoamp area, and they can be very sensitive to things like electrical noise (beware of the dreaded stepper noise), board layout, IC process variations, etc. ___ 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] Casio Watches 13 Year Drift in Seattle
If this was normal back at the turn of the 20th century, why wouldn't Casio, and others at least do as well? Especially now that all electronic watches have a microprocessor built in... complete with temperature sensing diodes, battery monitors, and other nifty gadgets. I am guessing the vast majority of Casio owners don't especially care if their watch gains or loses a minute every month. So why bother to add sensors and circuitry to compensate for its environment? Furthermore, it requires setting the initial frequency on each watch built, to compensate for the crystal's initial error. And that jacks up the cost, perhaps more than adding those sensors would. Better to just churn them out with as little per-unit testing as possible. That's just my guess ... but who am I to say? Regards, Andy ___ 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] Casio Watches 13 Year Drift in Seattle
Hi Andy, I think you would be guessing wrongly. The vast majority of watch owners don't want to ever have to set, wind, adjust the calendar, or in anyway think, or fiddle with their watch's time. They want it to just be right. In other words, their disinterest makes them the anti-time-nut. The engineering team that designed the watch is where the concerns about the watch always being right get turned into hardware. It costs them only a few days of an engineer's time to put, a temperature sensor, battery voltage sensor, and a table describing the nominal performance of the crystal at a normal range of temperatures and voltages, into the watch. It costs nothing on a per watch basis, as it is a trivial amount of additional silicon... silicon that resides within the necessary spaces between the pads used to connect the silicon die to the circuit board. As to per unit testing, the only testing required (after the initial design phase) is to program an offset into the watch that makes up for minor frequency variations in the crystal at nominal room temperature. Crystal manufacture is an imperfect process, so they have to do that anyway. -Chuck Harris Andy wrote: If this was normal back at the turn of the 20th century, why wouldn't Casio, and others at least do as well? Especially now that all electronic watches have a microprocessor built in... complete with temperature sensing diodes, battery monitors, and other nifty gadgets. I am guessing the vast majority of Casio owners don't especially care if their watch gains or loses a minute every month. So why bother to add sensors and circuitry to compensate for its environment? Furthermore, it requires setting the initial frequency on each watch built, to compensate for the crystal's initial error. And that jacks up the cost, perhaps more than adding those sensors would. Better to just churn them out with as little per-unit testing as possible. That's just my guess ... but who am I to say? Regards, Andy ___ 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] Casio Watches 13 Year Drift in Seattle
Hi On Jun 29, 2015, at 6:03 PM, Andy ai.egrps...@gmail.com wrote: If this was normal back at the turn of the 20th century, why wouldn't Casio, and others at least do as well? Especially now that all electronic watches have a microprocessor built in... complete with temperature sensing diodes, battery monitors, and other nifty gadgets. I am guessing the vast majority of Casio owners don't especially care if their watch gains or loses a minute every month. Most don’t, but some do. The ones that do care talk a lot. When they go online with a “this watch is junk” post (with lots of data) it impacts the market. So why bother to add sensors and circuitry to compensate for its environment? Furthermore, it requires setting the initial frequency on each watch built, to compensate for the crystal's initial error. That’s been done since the original quartz watch designs. It’s done with a robot these days and is part of the checkout process on the module. It actually saves money. The precision of the crystal (and other parts) used can be lower if you do the calibration. Lower precision = better yield = lower cost. The chip in the watch likely goes into just about every watch they make. The size of the die is dictated by their ability to dice the wafer (roughly 1 mm square). Anything smaller than that makes no sense. However many devices you can pack into that much area, you get for free. With a modern process, that’s a *lot* of devices. One might think that running a much older process would be cheaper. That would only work if you made more watch chips (by wafer lots) than you make of everything else. That’s just not true. The answer is (as with everything else) that you keep up fairly close to a modern process. The process parameters for an ultra low power watch chip will be a bit different, but the geometry is dictated by the basic gear on the line. They all rumble down the same basic line at one of many (massively large) foundaries And that jacks up the cost, perhaps more than adding those sensors would. Better to just churn them out with as little per-unit testing as possible. An accurate watch “with all the testing” sells for $10. The market for an much less accurate watch would (presumably) be at an even lower sell point…. Bob That's just my guess ... but who am I to say? Regards, Andy ___ 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] Casio Watches 13 Year Drift in Seattle
Hi Even back in the 1970’s we used computing counters to read the 32 KHz. You get 7 digits in about 10 ms these days. It will take you longer to power up the module and stabilize it than the frequency reading takes. The semiconductor process for the watch chips has always been a bit odd. They never need anything faster than 32 KHz for a clock. They are after *very* low leakage. Back in the old days having it run at 1 V was considered strange. It’s pretty common today. They use the same tricks to dump an analog function into a digital process as the MCU people. It’s not a *great* analog sub system, but it’s good enough for the purpose. They may even calibrate the temperature and voltage when the set the frequency. That would let them get away with a *lot* of slop on those sub systems. If they digitize the temperature range from 0 to 50 C, that’s plenty for any normal environment the watch will see. A 5 bit ADC would be good enough for that task (with the proper full scale input). The same thing likely applies to the voltage. The circuit is unlikely to function below half voltage on the battery. Again a few bits of ADC will tell you everything you need to know to drive the table. I’d bet that they run a sigma delta and are quite happy with information at a “once a minute” sort of rate. There’s not a lot of “analog” stuff in that case. It would be pretty easy to dump onto the die. Bob On Jun 30, 2015, at 4:42 PM, Andy ai.egrps...@gmail.com wrote: Measuring a 32kHz frequency to ~100 PPB accuracy takes some time, even for ATE. Time is money. I didn't think the hardware to do the computations and the digital offset was any problem. I thought the temperature and voltage sensors might be, since they are analog. But you can integrate them into a good mixed technology IC process. I just didn't think that was what they are using. Andy ___ 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] Casio Watches 13 Year Drift in Seattle
Measuring a 32kHz frequency to ~100 PPB accuracy takes some time, even for ATE. Time is money. I didn't think the hardware to do the computations and the digital offset was any problem. I thought the temperature and voltage sensors might be, since they are analog. But you can integrate them into a good mixed technology IC process. I just didn't think that was what they are using. Andy ___ 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] Casio Watches 13 Year Drift in Seattle
But wouldn't normal watch wear just balance itself over time, one wears their watch for say 12 hours and the rest it sits on a counter at a much colder temperature. So wonder if Casio would actually go to such lengths to compensate. Maybe, interesting though. -=Bryan=- From: kb...@n1k.org Date: Sun, 28 Jun 2015 20:41:15 -0400 To: time-nuts@febo.com Subject: Re: [time-nuts] Casio Watches 13 Year Drift in Seattle Hi Just to clarify: In the “art” the watches all ran fast rather than slow. They *would* have run slow if the room temperature / skin temperature delta was an issue. Since they did not, one assumes that Casio digitally compensates this model (and probably all their watches). The typical watch tuning fork will shift more than the observed delta when run in a cold court house if un-compensated. By far the best explanation is the “set to deliberately run fast” one. Bob On Jun 27, 2015, at 8:19 PM, Jim Palfreyman jim77...@gmail.com wrote: My Casio g shock keeps extraordinary time. I did open it up and tune it, but still I'd expect it to drift. After 6 months untouched I still can't separate by eye the second from UTC. Also, with regard to the video's query about all the clocks running slow - they have been tuned to run at the temperature of a person's wrist. On Sunday, 28 June 2015, John Stuart j.w.stu...@comcast.net wrote: I think there may be a new Time-Nut in the Seattle area, , , Art, Engineering and Justice - how accurate is a Casio watch? https://www.youtube.com/watch?v=hwOMUhS8gV0 John, KM6QX ___ time-nuts mailing list -- time-nuts@febo.com javascript:; 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. ___ 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] Casio Watches 13 Year Drift in Seattle
Back in the day when mechanical escapement pocket watches, and wrist watches were state of the art, the jeweler would adjust the watch to run at a normal rate, and give them a daily wind. Everything looked nice in the display case. When a customer bought a watch, the jeweler would set the watch to his shop clock, and instruct the customer to wear, and wind the watch normally for two weeks, but do not set it. At the end of the two weeks, bring the watch back to the shop for a check up... When the watch came back, the jeweler would calculate the number of days the watch had been worn, note the difference from his shop clock, and calculate the daily rate of the watch. He would then set his timing machine for the the inverse of that rate, and set the watch to match. Now, when the customer wore his watch, the watch would seem to always be right on because it was adjusted for a rate that compensated for the customer's patterns of wearing the watch...his personal error. This trick had an added advantage because the customer got to see how so-so his brand new watch behaved during those two weeks, and got to be dazzled by his jeweler's rare ability to make the new watch perform so much better than the factory could! If this was normal back at the turn of the 20th century, why wouldn't Casio, and others at least do as well? Especially now that all electronic watches have a microprocessor built in... complete with temperature sensing diodes, battery monitors, and other nifty gadgets. -Chuck Harris Bryan _ wrote: But wouldn't normal watch wear just balance itself over time, one wears their watch for say 12 hours and the rest it sits on a counter at a much colder temperature. So wonder if Casio would actually go to such lengths to compensate. Maybe, interesting though. -=Bryan=- ___ 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] Casio Watches 13 Year Drift in Seattle
Hi Just to clarify: In the “art” the watches all ran fast rather than slow. They *would* have run slow if the room temperature / skin temperature delta was an issue. Since they did not, one assumes that Casio digitally compensates this model (and probably all their watches). The typical watch tuning fork will shift more than the observed delta when run in a cold court house if un-compensated. By far the best explanation is the “set to deliberately run fast” one. Bob On Jun 27, 2015, at 8:19 PM, Jim Palfreyman jim77...@gmail.com wrote: My Casio g shock keeps extraordinary time. I did open it up and tune it, but still I'd expect it to drift. After 6 months untouched I still can't separate by eye the second from UTC. Also, with regard to the video's query about all the clocks running slow - they have been tuned to run at the temperature of a person's wrist. On Sunday, 28 June 2015, John Stuart j.w.stu...@comcast.net wrote: I think there may be a new Time-Nut in the Seattle area, , , Art, Engineering and Justice - how accurate is a Casio watch? https://www.youtube.com/watch?v=hwOMUhS8gV0 John, KM6QX ___ time-nuts mailing list -- time-nuts@febo.com javascript:; 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.
[time-nuts] Casio Watches 13 Year Drift in Seattle
I think there may be a new Time-Nut in the Seattle area, , , https://www.youtube.com/watch?v=hwOMUhS8gV0 John, KM6QX ___ 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.
