EDIT (where are we now) :
Mechanic :
- pure mechanical solution (eg : good old clock) is out of topic
- Mechanical part may be introduced if it improve the lifespan and do not require regular servicing (eg : lubrication). But it may greatly increase the manufacturing complexity & cost
Battery :
- no solution found yet
- battery self discharge is a major problem
- super/ultra capacitor are given for < 20 years
Display :
- LED (green one apparently have a better lifespan than red one)
- Electromechanical counter may be a viable option ( [url]https://www.google.com/search?q=electromechanical+counter[/url] )
Oscillator :
- Apparently, aging is not a problem.
- stability may be a problem
- frequency ?
Eprom/flash :
- 100 year doesn't seems to be a problem
- but we need redondancy/error detection
Microcontroller :
- it can be done.
Enclosure :
- need protection from rust/oxidation/moist
- http://en.wikipedia.org/wiki/Poly(methyl_methacrylate)#Acrylate_resin_casting ?
TODO :
- A lot :)
- Grab/post/archive datasheet for future reference
- Power is the main topic.
Interesting...
I'm sure there are countless issues involved in keeping something running for 100 years.
Solvable of course, but so many traps, and how do you test it?
I think a mechanical clock is probably the best way to go here?
and there is 10,000 year clock project:
http://www.10000yearclock.net/learnmore.html (http://www.10000yearclock.net/learnmore.html)
Please report back in 2114 in this thread how it did go :)
And then there are the problems when someone moves to a Mars colony. On mars the solar day is 24 hours and 39 minutes. So you should add some buttons to adjust the length of the day, and to adjust the time if someone just moves to another timezone, because it could display the time as well, and I think it should increase the day count always on midnight.
You would need to develop new components for almost every part of the device, as off the shelf ones have something that will chemically degrade over 100 years.
Why battery? Make it working on mains power, store the start time in non volatile memory, user atomic clock radio signals and you are done. If the clock break, have a way to clone it with the same start time. Piece of cake. ;-)Do you think a compatible atomic clock radio signal will be there in 100 years?
GPS, radiodata, internet over wifi etc
... webpage ...
Why battery? Make it working on mains power, store the start time in non volatile memory, user atomic clock radio signals and you are done. If the clock break, have a way to clone it with the same start time. Piece of cake. ;-)First I thought data retention time of flash memory would be too short. But this (http://www.ti.com/lit/an/slaa334a/slaa334a.pdf) application note says on page 4 that 100 years at 25°C is no problem at all and extremely conservative, it might work as long as 1324 years. I don't know if this is true, there might be other problems for this time, like bit flipping because of cosmic rays etc., but 100 years should be possible for a microcontroller with flash memory. Maybe save the program and data multiple times and add some error correction algorithm, for bit flips or broken bits.
Long life flash is only possible with old Eprom OTP packages, as these use a large cell size, so the stored charge is large. Current memory is getting down to the point where the stored charge can be counted in numbers of electrons in the floating gate. That is statistically going to lose charge at a rate that might do a decade or two. An old 2716 will likely still retain data after a dozen centuries if it is programmed using the slow method of a 50ms pulse per location. Fast programming will reduce the stored charge somewhat as it uses 1ms pulses until it verifies then gives a small extra charge.
If using eprom verify at 4V and again at 6V to ensure the voltage is over the threshold for it to be reliably read.
Sounds more like simple app.
An interesting problem.
I can't think of a display that will last 100 years and is low power, exept maybe this:
(https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcRTT2NrNC5FFmnmUWgA_86CxDmwdAsvML83brgX4mpVXDyfTYnx)
The interesting part is that it is both the display and the memory, but not very attractive.
For setting the DoB and current date, one could use NFC with a mask-programmable (ROM) microcontroller. Since the NFC interface is powered by the master device, the wireless connectivity comes at no cost for the sealed device's battery life.
Will NFC still be around 100 years from now? Probably not.
Achieving 1day/century error could be difficult since crystals could have that much of an error simply from their orientation relative to gravity and temperature. The only way around that would be to use an atomic clock like others suggested but those usually consume too much power for something battery-operated intended to last for years.
Mean Time Between Failures is an indication of the number of hours to pass between failures.
Please find below the predicted MTBF (Mean Time Between Failure) numbers of
our micro's at different temperatures. The statistical calculations are based
on current reliability qualification data in the "microcontroller
reliability data package".
Atmel has been shipping NVM parts for 20 years and Flash Micro's for 13
years. We have never experienced a long term reliability problem.
Here are the MTBF numbers calculated from life test and data retention
results:
65ºC 1.69x10e7 hours. => 1929 years
85ºC 4.46x10e6 hours. => 509 years
105ºC 1.34x10e6 hours. => 153 years
The battery with the longest lifespan I could find were NiFe batteries. http://en.wikipedia.org/wiki/Nickel%E2%80%93iron_battery (http://en.wikipedia.org/wiki/Nickel%E2%80%93iron_battery)
What would the lifespan of a CR2032 battery be? Vendors don't seem to specify this. I've never seen one leak, as opposed to Alkalines.
SELF-DISCHARGE
CELL TYPE NI-MH NI-CD LI-ION
@ 20°C (%/MONTH) 20-30 15-20 5-10
What about a combined electrical and mechanical solution?
You would have to do some calculations to figure out the power involved... but I wonder how much energy a wound-up spring contains and how that compares to a battery?
You could have a clock-like mechanism but beefier that is wound up when the unit is made... then some sort of latching (or breakable) device that keeps the unit in an inactive state.
When the unit is activated (perhaps by hitting it on a surface, breaking a tiny glass latch that then allows the mechanism to start running), the device starts counting from a set point - like 10 days or 30 days. This gives the proud parents an opportunity to buy it and have it engraved. If you can store enough energy in the mechanical mechanism, you will never need a battery and will never have to replace anything. You could put the whole thing in some sort of glass or plastic container which has a vacuum (or nitrogen) inside so it never corrodes or wears out.
100 years contains very low frequencies, so you have very big pink noise.
This can include lightnings, nuclear wars, collisions with other space objects... So I would put as much protection devices on board as possible.
I would use an antifuse FPGA for this. The crystal has to be in a super package.
Einstein said, that human stupidity is infinite, so I would power it from that.
Let's make a list of things that absolutely cannot possibly be used:Both Atmel (for AVR) and TI (for MSP430) claims at least 100 years data retention for their flash, so I don't see a problem. Of course, single bit failures could still happen, like from cosmic rays or if one bit is not as reliable. Best would be to use many microcontrollers and an external majority circuit, like used in safety critical systems like nuclear reactors and spacecrafts, and self testing and error correcting firmware.
[...]
Active Components
- Flash memory, EEPROM (and the vast array of programmable devices which integrate these): charge decays over time, and programming causes incremental damage.
I'll write a memo "warranty void if nuclear winter seal is broken" :P
Just for fun, I went searching for a low-power atomic clocks and found this:
http://www.microsemi.com/products/timing-synchronization-systems/embedded-timing-solutions/components/sa-45s-chip-scale-atomic-clock (http://www.microsemi.com/products/timing-synchronization-systems/embedded-timing-solutions/components/sa-45s-chip-scale-atomic-clock)
Sub-120mW chip-scale atomic clock, sounds interesting. Only rated for 100k hours MTBF though. Sounds like a great fit/upgrade for those Agilent frequency counters with lousy stock oscillator.
Underwater sensors for seismic research or gas and oil exploration
Just for fun, I went searching for a low-power atomic clocks and found this:Does anyone know how a device like this can be atomic, and yet have such a poor aging characteristic? Atomic clocks are supposed to use very fundamental qualities of matter. How can that age?
http://www.microsemi.com/products/timing-synchronization-systems/embedded-timing-solutions/components/sa-45s-chip-scale-atomic-clock (http://www.microsemi.com/products/timing-synchronization-systems/embedded-timing-solutions/components/sa-45s-chip-scale-atomic-clock)
Sub-120mW chip-scale atomic clock, sounds interesting. Only rated for 100k hours MTBF though. Sounds like a great fit/upgrade for those Agilent frequency counters with lousy stock oscillator.
Just for fun, I went searching for a low-power atomic clocks and found this:Does anyone know how a device like this can be atomic, and yet have such a poor aging characteristic? Atomic clocks are supposed to use very fundamental qualities of matter. How can that age?
http://www.microsemi.com/products/timing-synchronization-systems/embedded-timing-solutions/components/sa-45s-chip-scale-atomic-clock (http://www.microsemi.com/products/timing-synchronization-systems/embedded-timing-solutions/components/sa-45s-chip-scale-atomic-clock)
Sub-120mW chip-scale atomic clock, sounds interesting. Only rated for 100k hours MTBF though. Sounds like a great fit/upgrade for those Agilent frequency counters with lousy stock oscillator.
Power is clearly going to be the biggest issue, so if you can decouple the time count from any processing & display, that would probably simplify things a lot.
So for example find the lowest power RTC chip you can find to keep time, and an MCU/display that's only powered when there is enough power available - I think Solar is probably the only option if you don't want a radioactive battery.
Maybe multiple RTCs with multiple power sources for backup.
Any storage capacitance probably doesn't want to have anything liquid in it, so maybe (a lot of) tantalum, polymer or ceramic.
A mechanical system (spring) that hits a piezo every once in a while to recharge your energy harvesting solution.
They've made switches that send wireless signals when switched. All powered from a piezo energy of the click itself.
Also... why a RTC ? It seems to be much more complex than it need to be.Because an RTC is specifically engineered for the job - the counter isn't a huge issue but the oscillator is, and is probably the largest power consumer. Date range is not an issue - just keep any higher-order count seperately - many RTCs have some extra registers for user data, so have a bit for year rollover
Why not a simple counter ? It's all about counting days. (also, i didn't find RTC that will still work after 2099, which is a problem)
QuoteAlso... why a RTC ? It seems to be much more complex than it need to be.Because an RTC is specifically engineered for the job - the counter isn't a huge issue but the oscillator is, and is probably the largest power consumer. Date range is not an issue - just keep any higher-order count seperately - many RTCs have some extra registers for user data, so have a bit for year rollover
Why not a simple counter ? It's all about counting days. (also, i didn't find RTC that will still work after 2099, which is a problem)
This stuff can all be dealt with easily in software whenever the main controller is running - you don't have to use the RTCs logic - all you need is an elaped time countQuoteAlso... why a RTC ? It seems to be much more complex than it need to be.Because an RTC is specifically engineered for the job - the counter isn't a huge issue but the oscillator is, and is probably the largest power consumer. Date range is not an issue - just keep any higher-order count seperately - many RTCs have some extra registers for user data, so have a bit for year rollover
Why not a simple counter ? It's all about counting days. (also, i didn't find RTC that will still work after 2099, which is a problem)
The problem is leap year managment :
If the year can be evenly divided by 100, it is NOT a leap year,
unless; The year is also evenly divisible by 400. Then it is a leap year.
This means that 2000 and 2400 are leap years, while 1800, 1900, 2100, 2200, 2300 and 2500 are NOT leap years.
Its not bad if you are used to crystals, but its horrible for an atomic source. My point is, where does it come from? If the source of the timing is an atomic physics measurement, how does that age so much?Just for fun, I went searching for a low-power atomic clocks and found this:Does anyone know how a device like this can be atomic, and yet have such a poor aging characteristic? Atomic clocks are supposed to use very fundamental qualities of matter. How can that age?
http://www.microsemi.com/products/timing-synchronization-systems/embedded-timing-solutions/components/sa-45s-chip-scale-atomic-clock (http://www.microsemi.com/products/timing-synchronization-systems/embedded-timing-solutions/components/sa-45s-chip-scale-atomic-clock)
Sub-120mW chip-scale atomic clock, sounds interesting. Only rated for 100k hours MTBF though. Sounds like a great fit/upgrade for those Agilent frequency counters with lousy stock oscillator.
It's aging is specified at 3.0E-10/month, doesn't seem too bad to me!
The problem is leap year managment :
If the year can be evenly divided by 100, it is NOT a leap year,
unless; The year is also evenly divisible by 400. Then it is a leap year.
This means that 2000 and 2400 are leap years, while 1800, 1900, 2100, 2200, 2300 and 2500 are NOT leap years.
Well, this comes from an article about pink noise I've read a long time ago. Since our electronics products have a lifetime which measures in years, the 0.00...01 Hz noise is going to be very large. The circuit is switched on, switched off, environment changes, parts are ageing... All of this can be inspected in the frequency region. 0.00001Hz region is something happening every day, and so on. The wider the frequency range on the lower end, the harder to make something work. So making your stuff work is not only a problem in the MHZ region, but also in the microhertz region. And your DC voltage in the specification becomes "1mHz is good enough".100 years contains very low frequencies, so you have very big pink noise.
I don't understand this partQuoteThis can include lightnings, nuclear wars, collisions with other space objects... So I would put as much protection devices on board as possible.
I would use an antifuse FPGA for this. The crystal has to be in a super package.
Einstein said, that human stupidity is infinite, so I would power it from that.
I'll write a memo "warranty void if nuclear winter seal is broken" :P
The problem with stupidity : even if it potentially hold an infinite amount of energy, its power efficiency sux ^-^
The problem is leap year managment :
If the year can be evenly divided by 100, it is NOT a leap year,
unless; The year is also evenly divisible by 400. Then it is a leap year.
This means that 2000 and 2400 are leap years, while 1800, 1900, 2100, 2200, 2300 and 2500 are NOT leap years.
Why would you worry about leap years if all you do is count days?
As long as you know how the RTC behaves, you can deal with it. This is an insignificant issue compared to everything else.The problem is leap year managment :
If the year can be evenly divided by 100, it is NOT a leap year,
unless; The year is also evenly divisible by 400. Then it is a leap year.
This means that 2000 and 2400 are leap years, while 1800, 1900, 2100, 2200, 2300 and 2500 are NOT leap years.
Why would you worry about leap years if all you do is count days?
If you use a counter : don't care
If you use a RTC with "days since birth = today date - birth date" then you have a problem with leap year. All rtc seems to handle the 4 years leap, but not the 100 & 400 year leap :-//
Yes, power is the bigest issue. no solution found yet.
I wrote to energizer with a simple description of the project and a simple a question : "is there any battery form factor guaranteed to still exist in 100 years ?"
Perhaps some kind of industrial form factor have a guaranteed minimum EOL.
I'm not expecting a reply but... who knows ? ;D
It's Tadiran you want to write to for this: http://www.tadiranbat.com (http://www.tadiranbat.com). They "only" aim for 40 years lifetime, but given the tiny energy requirements you have for the RTC I suspect they'd manage. They might enjoy the challenge ;)
Its not bad if you are used to crystals, but its horrible for an atomic source. My point is, where does it come from? If the source of the timing is an atomic physics measurement, how does that age so much?It's aging is specified at 3.0E-10/month, doesn't seem too bad to me!Just for fun, I went searching for a low-power atomic clocks and found this:Does anyone know how a device like this can be atomic, and yet have such a poor aging characteristic? Atomic clocks are supposed to use very fundamental qualities of matter. How can that age?
http://www.microsemi.com/products/timing-synchronization-systems/embedded-timing-solutions/components/sa-45s-chip-scale-atomic-clock (http://www.microsemi.com/products/timing-synchronization-systems/embedded-timing-solutions/components/sa-45s-chip-scale-atomic-clock)
Sub-120mW chip-scale atomic clock, sounds interesting. Only rated for 100k hours MTBF though. Sounds like a great fit/upgrade for those Agilent frequency counters with lousy stock oscillator.
The same way rubidium and cesium clocks age: the material used in the oscillator evaporates, embeds itself in the resonating cavity's walls, is no longer part of the resonant cavity and the loss of vapor pressure is enough to cause minor drift. You also have the atoms' decay rate, possible impurities, the VCSEL and sensor's aging, etc. National standard atomic clocks require periodic maintenance to maintain their stability so expecting perfect long-term stability out of a sealed, maintenance-free autonomous module is not very realistic.Just for fun, I went searching for a low-power atomic clocks and found this:Does anyone know how a device like this can be atomic, and yet have such a poor aging characteristic? Atomic clocks are supposed to use very fundamental qualities of matter. How can that age?
http://www.microsemi.com/products/timing-synchronization-systems/embedded-timing-solutions/components/sa-45s-chip-scale-atomic-clock (http://www.microsemi.com/products/timing-synchronization-systems/embedded-timing-solutions/components/sa-45s-chip-scale-atomic-clock)
Sub-120mW chip-scale atomic clock, sounds interesting. Only rated for 100k hours MTBF though. Sounds like a great fit/upgrade for those Agilent frequency counters with lousy stock oscillator.
TS3005: A 1.55V TO 5.25V, 1.35µA, 1.7ms TO 33hrs, PIN-PROGRAMMABLE TIMER IC
http://touchstonesemi.com/products/ts3005 (http://touchstonesemi.com/products/ts3005)
TS3005: A 1.55V TO 5.25V, 1.35µA, 1.7ms TO 33hrs, PIN-PROGRAMMABLE TIMER IC
http://touchstonesemi.com/products/ts3005 (http://touchstonesemi.com/products/ts3005)
jellybean DS1307 consumes only 400nA
so 1.35uA is very high.
Also check this one:
http://www.abracon.com/Precisiontiming/AB18XX.pdf (http://www.abracon.com/Precisiontiming/AB18XX.pdf)
If the total amount of power needed was known, the mass and height of a weight could be calculated needed to power the device. Plus, it would be pretty cool that, year-after-year, the weight drops fractionally... like a few millimeters or less. Almost like... "when the weight reaches the bottom... you're dead"
(3V * 1 uA * 1 year) / (1 m * 9.81 m/s^2)Someone who is less lazy than me still should work out the math... what would the TOTAL power consumption of the device be over 100 years?
Because I don't think you can get around the power issue unless you use nuclear materials (might be hard to source now that Ghaddafi is gone) or go with the mechanically stored power.
Anything else - heat, light, batteries or whatever else will always require human interaction, and I think the fact that it will run for 100 years untouched is the appeal of the device.
If the total amount of power needed was known, the mass and height of a weight could be calculated needed to power the device. Plus, it would be pretty cool that, year-after-year, the weight drops fractionally... like a few millimeters or less. Almost like... "when the weight reaches the bottom... you're dead"
Someone who is less lazy than me still should work out the math... what would the TOTAL power consumption of the device be over 100 years?1uA over 100 years is 876mAh so in principle an AA cell or 2477 lithium, but shelf-life is going to be the dominant factor by far with any chemical battery.
Not to mention he wants display.Someone who is less lazy than me still should work out the math... what would the TOTAL power consumption of the device be over 100 years?1uA over 100 years is 876mAh so in principle an AA cell or 2477 lithium, but shelf-life is going to be the dominant factor by far with any chemical battery.
I'd say for a solution based on readily available tech, solar plus large value low-leakage capacitor probably has the best chance, as long as it's kept somewhere that receives some light each day.
Not to mention he wants display.
There always a nuclear option. It looks like a NanoTritium (http://www.citylabs.net/index.php?option=com_wrapper&view=wrapper&Itemid=20) will last about twenty years. Maybe a few of these?
You can even get one on TaoBao (http://item.taobao.com/item.htm?spm=a1z10.1.4004-56656384.29.dysKyM&id=15659486189)
Perhaps :-//
But if they all die of old age after 20y, it won't help to have 1 or many of them :-\
The page states
The NanoTritium™ betavoltaic power source provides a source of continuous nanoWatt power for twenty years or more in microelectronic platforms. Sounds like it's only a matter of half-life. :)
Perhaps :-//
But if they all die of old age after 20y, it won't help to have 1 or many of them :-\
The page states
The NanoTritium™ betavoltaic power source provides a source of continuous nanoWatt power for twenty years or more in microelectronic platforms. Sounds like it's only a matter of half-life. :)
Not to mention he wants display.
Some kind of display indeed.
It need a way to show the days. but temporarly , not a permanent display.
It's certainly possible with today's technology.
There's the Oxford electric bell which is powered from batteries and has been ringing since 1840.
http://en.wikipedia.org/wiki/Oxford_Electric_Bell (http://en.wikipedia.org/wiki/Oxford_Electric_Bell)
Firstly, I haven't the time to read all the comments, I won't pretend to have done so:
Power - Solar could work just fine, given the right amount of cells, it would last an overnight discharge process. However, you'll run into problems during winter, and rainfall. It is entirely possible to keep a container sealed from the elements, with it being glass, even if you have a cable running into it; You simply need to ensure all holes are sealed. Epoxy resins can do this rather well.
Moisture, et cætera - You would be surprised how much heat electronics can survive, for intermittent periods, as it would take to seal a glass container. Regardless, I would try treating the whole thing like a vacuum tube, and flash some kind of "getter" into the sealed container, to remove an gasses which might develop over time; As gases are emitted from glass and other elements over time ... Especially in a vacuum.
Interface: It could be powered on/off with a magnetic switch. No need for any fancy switching/remotes (which die, or get lost, and replacing them can be difficult, in say, 50 years). Magnets will be around for a looooooong time; some might even say "forever."
PCB: That, I would say, is personal preference. I like seeing things which are like a sculpture, not flat. Those things rarely get done, anymore.
Anyway, good luck. I assume you'll post something herein.
Come on, you know what I meant. If it couldbe done back then, it can be done today but better.It's certainly possible with today's technology.
There's the Oxford electric bell which is powered from batteries and has been ringing since 1840.
http://en.wikipedia.org/wiki/Oxford_Electric_Bell (http://en.wikipedia.org/wiki/Oxford_Electric_Bell)
Yeah, try to run a clock oscillator and a display from that...
The problem with solar+cell is that the cell will die after ~20yearsDo you have a reference for this? In this posting (https://www.eevblog.com/forum/beginners/a-100y-lifetime-project-incredibly-difficult/msg503358/#msg503358) I wrote about solar cells. And for even higher lifetime, you don't need to exposure it to full sun light, like the solar cell calculators, which work in the shadow or dim artificial lighting, too.
The problem with solar+cell is that the cell will die after ~20yearsDo you have a reference for this? In this posting (https://www.eevblog.com/forum/beginners/a-100y-lifetime-project-incredibly-difficult/msg503358/#msg503358) I wrote about solar cells. And for even higher lifetime, you don't need to exposure it to full sun light, like the solar cell calculators, which work in the shadow or dim artificial lighting, too.
I see, you meant solar cell + battery cell. Just "solar" means "relating to the Sun", only, for me, if you don't say "solar cell" or "solar panel", but this might be because English is not my native language :)
A vacuum fluorescent display needs a heated filament. Wikipedia says (http://en.wikipedia.org/wiki/Vacuum_fluorescent_display) at least 0.2 W (but it doesn't say if this is per digit or per display). Might work, if you have a big solar panel and a lot of ceramic backup capacitors.
There is only one power source capable of supplying a project like this, standalone, for a long time.
A radioisotope thermoelectric generator, the Russians powered lighthouses from that. I even think electric cars can be equipped with these if they weren't dangerous when opened.
a very small flip dot display for the day fields onwards, and an lcd for the hours minutes seconds, that stays on for a few minutes after pushing a button? in my own experience an LCD lasts longer when not constantly on and not in even medium brightness sunlight for extended periods,
I Commonly deal with automotive displays from the early 90's which have suffered mechanical faults but have not faded by any great measure, By mechanical faults it is generally from a poorly designed plastic housing warping over time and stressing the die on glass controllers connections, or the flat flex traces debonding from the material, in the direct sunlight cases,
That on its own would likely be a decent place to look, as there are a large number of automotive LCD clock displays out there, and i have no doubts if you kept a few spares tucked under some cover it would not be cheating as long as it did not loose time while replacing,
I don't know about LCD material degrading over time. I thought LCD displays only degraded with use, because of asymmetry in the waveforms. If you only run the LCD when it is needed I think the lifetime can be extremely long. I believe cholesteric displays have an enormous expected lifetime, because you don't need to keep refreshing them.
- the liquid crystal in all types of LCDs are known to degrade over time
- E-ink isn't proven and manufacturer claims of 5 years: http://www.eink.com/sell_sheets/pearl_spec_sheet.pdf (http://www.eink.com/sell_sheets/pearl_spec_sheet.pdf)
- LEDs have a theoretical life expectancy of 20000 - 50000 years (but real-life figures are variable)
- Mechanical devices have obvious wear issues
There are a couple of ways you could do it. But I would recommend:
oscillator + microcontroller + solar + mechanical counter.
Day = oscillator hz * 86400
Program the microcontroller with a simple digital counter (store in one of the controllers registers), everytime the digital counter gets up to the value Day. Move the mechanical counter up by one, and set the digital counter back to zero.
Its that simple.
Thanks
Brendan
Instead of a mech counter, how about taking a battery operated wall clock, replacing the scale so that the long hand counts 1-10 years, the short hand shows 10s of years (up to 120), and the sweep hand shows (approx) weeks.
- Mechanical devices have obvious wear issues
it's a dial, not a counter :)Instead of a mech counter, how about taking a battery operated wall clock, replacing the scale so that the long hand counts 1-10 years, the short hand shows 10s of years (up to 120), and the sweep hand shows (approx) weeks.
How is that not a mech counter? >:D
Janekm is dead on the money with the odometer example, i have worked on a 1890's military jeep's instrument cluster, and based on the owners knowledge it had to be serviced and the entire gear set replaced every 30 years or so,
I wonder if Stanley or Doble ever made a 4 wheel drive? :)Janekm is dead on the money with the odometer example, i have worked on a 1890's military jeep's instrument cluster, and based on the owners knowledge it had to be serviced and the entire gear set replaced every 30 years or so,
A Jeep in 1890??? Steam powered?
Didn't the watchmaking industry solve this a while ago with jewelled bearings?
Any other ideas?I think some form of bistable electrowetting is the best bet.
If you do it as a clock where 24hrs = 120 years, wear won't be an issueDidn't the watchmaking industry solve this a while ago with jewelled bearings?
Apparently they still need lubrication. Possibly to slow down the wear of the metal? The jewels can have Mohs hardness 9 after all...
They claim infinite shell life :o
http://aquacellbattery.com/ (http://aquacellbattery.com/)
No datasheet, of course ::)
Sorry, 1920, should not have gone off memory alone,
Just an FYI some might find interesting: From wiki (https://en.wikipedia.org/wiki/Longplayer): Longplayer is a piece of music that is designed to last for one thousand years. It started to play on January 1, 2000, and if all goes as planned, it will continue without repetition until December 31, 2999. It will restart on that date.
"Longplayer" is based on an existing piece of music, 20 minutes and 20 seconds in length, which is processed by computer using a simple algorithm (https://en.wikipedia.org/wiki/Algorithm). This gives a large number of variations, which, when played consecutively, gives a total expected runtime of 1000 years.
It plays at Bow Creek Lighthouse at Trinity Buoy Wharf, London.
(http://longplayer.org/img/display_2_web.jpg)
using Tibetan (https://en.wikipedia.org/wiki/Tibet) singing bowls (https://en.wikipedia.org/wiki/Singing_bowl) and gongs (https://en.wikipedia.org/wiki/Gong) [not exactly a great way to go for 1000 years.] Check out Tom Scott's take on it How Do You Make Something Last 1,000 Years? (https://www.youtube.com/watch?v=uhtUYzubRHU)