Arduino Forum

Using Arduino => General Electronics => Topic started by: amundsen on Jan 27, 2013, 01:13 pm

Title: Small power source for one century
Post by: amundsen on Jan 27, 2013, 01:13 pm
Hello,

Is there a possibility to power a circuit to be put inside a time capsule for 100 years ? The power source should feed a timer and an audio circuit with a small audio amp. The audio amp would be triggered at the end of the century by the timer. Therefore during 100 years the power source should power only a clock.

Is there any possibility outside say a nuclear reactor ? Batteries ?

Thank you in advance.
Title: Re: Small power source for one century
Post by: billroy on Jan 27, 2013, 01:23 pm
These guys have some ideas…

http://longnow.org/clock/

Solar for the win.

If you think about it, you're asking for a power supply that lasts longer than we have had commercially deployed electricity.

-br
Title: Re: Small power source for one century
Post by: MarkT on Jan 27, 2013, 01:27 pm
That is highly specialised requirement, offhand can't think of any battery chemistry that lasts anything like that long.   And you'd
not be able to test it...  You would have to engineer the whole system to avoid tin-whisker growth too.
Title: Re: Small power source for one century
Post by: amundsen on Jan 27, 2013, 03:27 pm
Yes this is quite a challenge. Thanks anyway.
Title: Re: Small power source for one century
Post by: tack on Jan 27, 2013, 04:45 pm
It's not just the power source you have a problem with, it's the whole device. There is no hard and fast data to prove that any electronics will actually last that long. At the very least you'd need some kind of hermetically sealed container to have a good chance of working preservation, IF you had confidence in a reliable power source.

The chances are that one of the crucial link components will fail way before that 100 year period is up.

Without some form of regular check and maintenance, I'm doubtful you'd get anywhere near the longevity you require.
Title: Re: Small power source for one century
Post by: harshvardhan on Jan 27, 2013, 04:53 pm
ok
this seems pretty far fetched

but rolex (as far as i recall ) had come up with a way to run a watch perpetually(it said something about utilizing atmospheric pressure ). that means it require no extra mehanical power to run.

u could understnd how that works, and use it as the switch .   

as for the amp. try using bells' model
(it ran mechanically ).


u will havt to wound up the amp. and the switch will be triggered, running the discs.

(i have remove all the electronics out of it though :P )
Title: Re: Small power source for one century
Post by: retrolefty on Jan 27, 2013, 04:53 pm

It's not just the power source you have a problem with, it's the whole device. There is no hard and fast data to prove that any electronics will actually last that long. At the very least you'd need some kind of hermetically sealed container to have a good chance of working preservation, IF you had confidence in a reliable power source.

The chances are that one of the crucial link components will fail way before that 100 year period is up.

Without some form of regular check and maintenance, I'm doubtful you'd get anywhere near the longevity you require.


I'm not so sceptical about the electronic components not lasting that long if the power source life can be solved.
At the refinery I worked at before retirement we still had some equipment at or more then 40 years old that had semiconductor components (diodes, SCRs, transistors, etc) still operational, so I don't think 100 years life output of semiconductors is a automatic show stopper. Especially if it's in some kind of 'sleep' mode that only wakes up say once day or week or month to check the date and then goes back to sleep if 100 years has not elapsed.

Lefty
Title: Re: Small power source for one century
Post by: Shpaget on Jan 27, 2013, 05:00 pm
lefty
I would be surprised if today's consumer electronics lasted more than 20 years. As the old saying goes: "They don't make 'em like they used to."
Title: Re: Small power source for one century
Post by: retrolefty on Jan 27, 2013, 05:09 pm

lefty
I would be surprised if today's consumer electronics lasted more than 20 years. As the old saying goes: "They don't make 'em like they used to."



Well the project in question is not a typical 'consumer product' now is it? It's designed to 'deep sleep' for 100 years and only then turn fully on and work all it's functions. I think if the power 'problem' can be solved the rest would not be show stoppers.

Lefty

Title: Re: Small power source for one century
Post by: dhenry on Jan 27, 2013, 05:50 pm
I think the electronics can be challenging (more so from a reliabilty / redundance point of view), but the power sources are more so.

You probably will need to make some assumptions, without spending a lot of money. I would think of a few back-ups, like solar, geo-thermal, mechanism (wind + water), battery + capacitors, etc.

If all the device does is to keep time + go to sleep, its current consumption cannot be that big (ua range).
Title: Re: Small power source for one century
Post by: AWOL on Jan 27, 2013, 05:53 pm
Quote
Solar for the win.

Not in the UK - we haven't seen the damn thing for months.
Title: Re: Small power source for one century
Post by: retrolefty on Jan 27, 2013, 05:58 pm

Quote
Solar for the win.

Not in the UK - we haven't seen the damn thing for months.


Doesn't matter, solar for 100 years is a no go. Lighting strike, vandals steals the panel or paints it black, etc. Same for wind generation. The whole assembly must be self contained and sealed up securely. He did state " time capsule " now didn't he?

Lefty
Title: Re: Small power source for one century
Post by: Shpaget on Jan 27, 2013, 06:19 pm

Doesn't matter, solar for 100 years is a no go. Lighting strike, vandals steals the panel or paints it black, etc. Same for wind generation. The whole assembly must be self contained and sealed up securely. He did state " time capsule " now didn't he?

Lefty


Nuclear it is then.

Seriously now. Where will the device be situated? Can you guarantee that the building/bunker/mountain that will hold it will be there in 100 years?
I'm thinking some sort of thermoelectric device, hooked up to a water flow on one side and something that fluctuates in temperature on other. The batteries would need to be capable of sustaining the device for a few months (which is possible), and would be recharged during summer and winter when there is difference in water/something other temperature.
Title: Re: Small power source for one century
Post by: BulletMagnet83 on Jan 27, 2013, 06:43 pm
I wonder could you do it with bacteria somehow? Bacteria + shitload of food for them = heat.
Title: Re: Small power source for one century
Post by: JimboZA on Jan 27, 2013, 06:45 pm

shitload of food for them


Great technical detail there BM  8)

(PS, where in South of England? I'm from Crawley originally)
Title: Re: Small power source for one century
Post by: AWOL on Jan 27, 2013, 06:45 pm
That reminds me of the Cold War nuclear land mine, that was going to use chickens to keep the electronics warm...

Maybe cockroaches, and a treadmill?
Title: Re: Small power source for one century
Post by: BulletMagnet83 on Jan 27, 2013, 06:47 pm
I'm still working on getting it made a recognised SI unit ;)

Hampshire, at the moment... until the work runs out anyway! My landlord used to do a lot of work around Crawley.
Title: Re: Small power source for one century
Post by: DirtBiker on Jan 27, 2013, 06:51 pm
There are batteries based on tritium that are supposed to (theoretically, not promised) last hundreds of years.  Just google "Nano tritium battery"

You need deep pockets though.  I think I read somewhere they were nearly $2000 each.
Title: Re: Small power source for one century
Post by: BulletMagnet83 on Jan 27, 2013, 06:59 pm

There are batteries based on tritium that are supposed to (theoretically, not promised) last hundreds of years.  Just google "Nano tritium battery"

You need deep pockets though.  I think I read somewhere they were nearly $2000 each.


http://www.betavoltaic.co.uk/citylabs20yearnanotritiumbattery.html  these? That dip package looks so cool :D
Title: Re: Small power source for one century
Post by: EVP on Jan 27, 2013, 07:25 pm
If the time capsule is buried in the ground then there is the possibility of using a heat pump coupled with some novel alloy and neodymium magnets?

http://en.wikipedia.org/wiki/Geothermal_heat_pump (http://en.wikipedia.org/wiki/Geothermal_heat_pump)

http://www.popsci.com/technology/article/2011-06/new-alloy-can-convert-heat-directly-electricity (http://www.popsci.com/technology/article/2011-06/new-alloy-can-convert-heat-directly-electricity)


Title: Re: Small power source for one century
Post by: 0AlphaOmega on Jan 27, 2013, 07:43 pm
The electronics could be very simple - just count equinox using the alignment of the sun (we don't have a specific date in mind), Stonehenge style.
So charging could be very low current, providing charge is greater than leakage.

Mmm, maybe that is what Stonehenge is? It will pop open soon, spouting confetti....

Or non-electronic, pure mechanical, use rise/fall of groundwater changed by tides to run a clock. Electronics could then be turned on during event day, release chemicals into a battery, and play happy birthday etc. One is only concerned with shelf-life. Bearings etc in the "clock" would only receive two 'ticks' per day, so little wear.
Title: Re: Small power source for one century
Post by: John_S on Jan 27, 2013, 08:17 pm
Have a little crank on the outside of the time capsule that turns a generator and charges a battery. Put a sign that reads "Please turn crank".

Someone ought to turn it within 100 years. :D

On a serious note, if you can sleep your processor and it uses 0.35 uA (http://www.gammon.com.au/forum/?id=11497), it would require a 306.6 mAH battery. This assumes a zero internal discharge rate, and some form of battery chemistry that can last 100 years.
Title: Re: Small power source for one century
Post by: BulletMagnet83 on Jan 27, 2013, 09:46 pm
John, that is actually an awesome idea :P Crowdsourced power. The one thing you won't run out of in the next hundred years is curious people.
Title: Re: Small power source for one century
Post by: harshvardhan on Jan 28, 2013, 01:55 am
u should go ahead with the perpetual idea :D
Title: Re: Small power source for one century
Post by: A4kash on Jan 28, 2013, 02:10 am
I think NASA can make it.the battery that are being used in mars rovers last for almost 20 yrs.if there will be a competition,nasa will make it.
Title: Re: Small power source for one century
Post by: John_S on Jan 28, 2013, 03:04 am
The one thing you won't run out of in the next hundred years is curious people.
Reminds me of when my brother was little, he made a small wooden box with a slot in the top. He wrote "Insert Coin Here". Of course when ever we had guests over, they all had to insert a coin to see what happens  XD
Title: Re: Small power source for one century
Post by: cjdelphi on Jan 28, 2013, 03:34 am
How much power is the device going to need?..  leave a solar cell, sealed up and pull it out and use it at the end of the period of time?.

or a mechanical device, a rolled up coil which releases it's energy once a year and after 100 years it triggers off lol

Title: Re: Small power source for one century
Post by: westfw on Jan 28, 2013, 04:05 am
The military uses some pretty exotic batteries that I think are supposed to have near-forever shelf-life (well, 20 years, anyway.)  In missiles and fuzes and things.  They're essentially solid and inert at room temperature and need to be activated by a pyrotechnic charge to melt the relevant parts.  After which they produce plenty of power, for long enough for the device to reach the target.   http://en.wikipedia.org/wiki/Molten_salt_battery

Come to think of it, there's a slightly similar class of water-activated batteries, and a near equivalent in the zinc-air batteries commonly used in hearing aids.  I suspect that if you can build a storage container that will hold vacuum for 100 years, a circuit with OTS Zinc-air batteries might still work after 100 years once you let air (and moisture) in.
Title: Re: Small power source for one century
Post by: Shpaget on Jan 28, 2013, 07:43 am

-snip-


But how do you figure out when the 100 years is up so you can trigger the battery? What triggers the battery?
Title: Re: Small power source for one century
Post by: Chagrin on Jan 28, 2013, 08:04 am


-snip-

But how do you figure out when the 100 years is up so you can trigger the battery? What triggers the battery?

Another molten salt battery. To trigger that battery you'd just use another molten salt battery.... and then eventually a turtle.
Title: Re: Small power source for one century
Post by: cjdelphi on Jan 28, 2013, 08:14 am
how about this for idea...

what left for 100 years would create a battery? ...
Title: Re: Small power source for one century
Post by: amundsen on Jan 28, 2013, 08:57 am
The time capsule is a metal box and it wil contain 100 objects. It will probably be stored in an attic. The circuit to be triggered after 100 years will be an audio circuit (maybe with a surface transducer sticked to the metal of the case).

Therefore I don't see a possibility with solar power.

Maybe it will be easier to use the services of a bailiff.
Title: Re: Small power source for one century
Post by: fungus on Jan 28, 2013, 09:54 am
Set up a temple around it with a bunch of monks to care for it and organize a suitable ceremony when it opens.
Title: Re: Small power source for one century
Post by: JChristensen on Jan 28, 2013, 03:09 pm
No doubt the power source is the stickiest problem here, but I'd also design some redundancy into the electronics. Source all parts based on reliability. That probably puts the flaps down on those cheap capacitors from eBay :smiley-roll:
Title: Re: Small power source for one century
Post by: JChristensen on Jan 28, 2013, 03:40 pm
Perhaps some sort of electromagnetic energy harvesting (http://en.wikipedia.org/wiki/Energy_harvesting) approach?  Assuming an urban setting, the energy available might even increase over time.  And if there is none in 100 years, it's probably because there's no one left to open the time capsule anyway. :smiley-eek:
Title: Re: Small power source for one century
Post by: silverxxx on Jan 29, 2013, 02:58 am
A fuel cell could periodically charge a rechargeable battery or supercapacitor , therfore neutralising each other's shortcomings. I have a feeling you will end up needing a lot of power. Suppose the rechargeble could stay charged for 10 years, then the fuel cell should be able to work 11 times. This seems doable to me. Or you could use a wet battery and just replace the electrolyte with fresh one periodically.

Maybe temperature gradient exploitation using peltier devices?

I was going to suggest a radioisotope generator, but I doubt you can get one.

Or , someone mentioned a turtle. Don't they live 100 years? How much food could a turtle possibly eat in 100 years?
Title: Re: Small power source for one century
Post by: westfw on Jan 29, 2013, 05:01 am
You could rig up a little generator, based on a DC or stepper motor.  "Turn crank" or "pull string" to activate...
Title: Re: Small power source for one century
Post by: fungus on Jan 29, 2013, 01:37 pm
Over 100 years you could probably harvest the EMP from lightning strikes and the kinetic energy from tectonic movement/earthquakes.

Title: Re: Small power source for one century
Post by: Docedison on Jan 29, 2013, 06:56 pm
If there is no one to open the box in a hundred years, Who cares... But a water activated battery and some stored water and some instructions to "Pour Water Here to Activate" should work... All sealed in an inert gas? Nitrogen?, Neon, Argon to avoid corrosion. If the water contained a mild acid, Zinc and copper would serve well and I'm sure that there are better methods than what 2 minutes consideration gave me.

Bob
Title: Re: Small power source for one century
Post by: fungus on Jan 29, 2013, 08:04 pm
Assuming somebody is there to see what's in the box when it opens, why not put in a hand crank? They can use it to open the box manually.

The curiosity of passers-by will make sure the crank is turned once in a while. You can use that energy to charge a capacitor to run the Arduino for a while until the next person turns it.

The principle is basically the same as those water pumps (http://www.google.es/search?q=playpump) that are connected to a children's playground. The infinite energy of children makes sure that no adult ever has to pump water manually.
Title: Re: Small power source for one century
Post by: 0AlphaOmega on Jan 29, 2013, 10:42 pm
Going out on a limb here, but if it's in the loft of a house, why not tap into the house wiring? I've done some math, I think it could work.
Title: Re: Small power source for one century
Post by: Obereon on Jan 29, 2013, 11:02 pm
Most terrestrial batteries suffer from degradation from not being used as well as wear from use.

One of the longest known standalone power supplies would be the Radioisotope Thermoelectric Generators (RTGs) used in the Voyager spacecraft. Thirty-four years after launch, they are providing 57% of their rated output. Based on that, they will most not likely reach one century of operation.

There is the possibility of coupling a mechanical drive system to some form of generation. In the case of a time capsule, if it was suitably located hydroelectric generation would be a possibility. Depending on the environment for storage, a thermocouple might be usable to supplement the primary power.

In order to reach the goal of a century, a mechanical watch mechanism might be a better bet for the timing - if you can find a power source with sufficient shelf life to wait to be activated.

No matter which method you use to power it, you will have to take a note from spacecraft design, and make the entire system redundant, such that a failure of 50% of the components would still leave it in a usable state.
Title: Re: Small power source for one century
Post by: Shpaget on Jan 29, 2013, 11:03 pm
Going out on a limb here, but if it's in the loft of a house, why not tap into the house wiring?  I've done some math, I think it could work.

You've actually done math on this? On which part exactly? Does it include the centennial lifespan of 5V transformer?
Title: Re: Small power source for one century
Post by: SirNickity on Jan 29, 2013, 11:33 pm
Have a little crank on the outside of the time capsule that turns a generator and charges a battery. Put a sign that reads "Please turn crank".


FTFY:  "Please DO NOT turn crank."

That should guarantee it gets turned once a week or so.

Seriously, though.  It's going in an attic?  Has anyone owned an attic for 100 years?  Maybe I'm just American, but after 60 years or so, houses tend to get remodeled and/or demolished.
Title: Re: Small power source for one century
Post by: 0AlphaOmega on Jan 30, 2013, 12:19 am

Seriously, though.  It's going in an attic?  Has anyone owned an attic for 100 years?  Maybe I'm just American, but after 60 years or so, houses tend to get remodeled and/or demolished.

Seriously, we have cowsheds older than America ;) The pier I walked on this afternoon was built in 1867, it looks pretty much the same as when it was built. And the pub I visited after has been a pub since late 1700's, it was however  remodelled then as it was formally a place where cider was made. Not everything is pulled down every 60 years. So I reckon, a European loft has a good chance of surviving another 100 years (we gotta keep our chickens somewhere!)
Title: Re: Small power source for one century
Post by: SirNickity on Jan 30, 2013, 01:19 am
LOL.  OK, OK.. I withdraw the question.  :-)  I just read about the capitol building in my state that is one little earthquake away from shedding its brick-wall skin and marble pillars.  It's all of 80 years old.
Title: Re: Small power source for one century
Post by: DirtBiker on Jan 30, 2013, 01:28 am

Seriously, we have cowsheds older than America ;)


LOL, The phrase "North American culture" is a bit of an oxymoron when compared to most of the rest of the world. :smiley-mr-green:
Title: Re: Small power source for one century
Post by: retrolefty on Jan 30, 2013, 02:00 am


Seriously, we have cowsheds older than America ;)


LOL, The phrase "North American culture" is a bit of an oxymoron when compared to most of the rest of the world. :smiley-mr-green:


Most, really? I've always felt so very luck to have been born and raised in my part of North America, compared to my admittedly somewhat limited travel experiences I have had experiencing other 'cultures'. But then again it all comes down to opinions I guess, and most people have opinions.  ;)

Lefty
Title: Re: Small power source for one century
Post by: DirtBiker on Jan 30, 2013, 02:34 am

Most, really?


Well, I am also a product of NA.  However, I am open to discussion.  Given that the predominant culture in the Americas is well less than 600 years old, can you think of some other place of significance that is also significantly younger?
Title: Re: Small power source for one century
Post by: retrolefty on Jan 30, 2013, 02:47 am


Most, really?


Well, I am also a product of NA.  However, I am open to discussion.  Given that the predominant culture in the Americas is well less than 600 years old, can you think of some other place of significance that is also significantly younger?



So the age of a culture is it's dominate attribute?

Lefty
Title: Re: Small power source for one century
Post by: westfw on Jan 30, 2013, 02:49 am
"In Europe, 100 miles is a long distance.  In America, 100 years is a long time."

There are two sets of answers showing up.  One assumes that the device needs power (at least enough for "standby") FOR 100 years, and the other assuming that the device will be completely inactive, and only needs power AFTER 100 years.

BTW, I don't know that modern semiconductors are expected to remain operational after 100 years.  Diffusion of dopants might render PN junctions non-working, and insulating gates non-insulating...
Title: Re: Small power source for one century
Post by: SirNickity on Jan 30, 2013, 03:05 am
So the age of a culture is it's dominate attribute?


Age, type of bacteria, and whether the fruit is at the bottom, or stirred in.
Title: Re: Small power source for one century
Post by: DirtBiker on Jan 30, 2013, 03:16 am


So the age of a culture is it's dominate attribute?

Lefty


Well (at the risk for wandering too far off topic), by definition, quite simply, yes.  It takes time to develop culture.

To take things to an extreme for purposes of demonstration, if I created a town tomorrow, how deep would you say it's unique cultural attributes would be, by say, Sunday, when compared to a place like Athens, or Lagos (current name not withstanding), or Alexandria?
Title: Re: Small power source for one century
Post by: DirtBiker on Jan 30, 2013, 03:18 am

So the age of a culture is it's dominate attribute?


Age, type of bacteria, and whether the fruit is at the bottom, or stirred in.


Yes, quite! (LOL)
Title: Re: Small power source for one century
Post by: teckel on Jan 30, 2013, 07:13 am


Most, really?


Well, I am also a product of NA.  However, I am open to discussion.  Given that the predominant culture in the Americas is well less than 600 years old, can you think of some other place of significance that is also significantly younger?



The Americas have been occupied for tens of thousands of years.  Check your facts.

Tim
Title: Re: Small power source for one century
Post by: teckel on Jan 30, 2013, 07:23 am

"In Europe, 100 miles is a long distance.  In America, 100 years is a long time."

There are two sets of answers showing up.  One assumes that the device needs power (at least enough for "standby") FOR 100 years, and the other assuming that the device will be completely inactive, and only needs power AFTER 100 years.

BTW, I don't know that modern semiconductors are expected to remain operational after 100 years.  Diffusion of dopants might render PN junctions non-working, and insulating gates non-insulating...



Just being able to store battery power that can be used in 100 years seems unlikely.  May I suggest a gold record if you want something that will last 100+ years as well as instructions on how to play it.  NASA had this same problem to solve back during the Carter administration.  Was sending a precious metal a good idea on Voyager?  Maybe it's an advertisement?  We have gold, this is where we are, come get it!

Tim
Title: Re: Small power source for one century
Post by: Shpaget on Jan 30, 2013, 08:07 am
Maybe it's an advertisement?  We have gold, this is where we are, come get it!


Battlefield Earth?
Title: Re: Small power source for one century
Post by: 0AlphaOmega on Jan 30, 2013, 10:03 am
Quote
The Americas have been occupied for tens of thousands of years.  Check your facts.
In fact, don't you have some sort of celebration of the fact that you super-ceded them involving pumpkin pie?  :smiley-eek:
I first heard the 100 year/100 mile phrase a long time ago and it goes a long way to explain our differences.
I was of course just leg pulling, but some very funny responses :)

Back to the topic in hand. It's interesting how such a mundane problem can throw up so many problems.
My original idea of a ultra slow mechanical clock that effectively used the moon as a power source, and then activating the electronics at the last moment was intended to keep the electronics turned off until required thus preventing FWAT, this included the power supply.

Someone mentioned redundancy, well, yes of course, but one could take this a stage further and rather than simple majority voting, one could maybe use a learning (repairing) neural net that could "energise" new circuit parts as others failed. For time keeping, again use say a solar event (day) to count.

Power supplies are a problem if self contained, but, since we are in a loft of a house, why not use main power and indeed, every 10 years it could request human intervention to "swap-out" circuity.

A friend of mine has a small (electric) lamp that he keeps burning in memory his mother and is thinking of emigrating to Oz, and wanted to power the lamp during the the move and sea voyage. His requirements were very stringent the light must not fail! And yet when I asked him what currently happened about power cuts, or the bulb blowing, he went quiet and didn't have an answer.
Title: Re: Small power source for one century
Post by: fungus on Jan 30, 2013, 11:32 am

Going out on a limb here, but if it's in the loft of a house, why not tap into the house wiring? I've done some math, I think it could work.


I was just about to say that ^

If it's in a house then what's the chances of the house being a) abandoned without electricity and b) somebody being in the house to hear the siren?

Seems pretty small to me.

Title: Re: Small power source for one century
Post by: fungus on Jan 30, 2013, 11:34 am


Seriously, though.  It's going in an attic?  Has anyone owned an attic for 100 years?  Maybe I'm just American, but after 60 years or so, houses tend to get remodeled and/or demolished.

Seriously, we have cowsheds older than America ;) The pier I walked on this afternoon was built in 1867, it looks pretty much the same as when it was built. And the pub I visited after has been a pub since late 1700's, it was however  remodelled then as it was formally a place where cider was made. Not everything is pulled down every 60 years. So I reckon, a European loft has a good chance of surviving another 100 years (we gotta keep our chickens somewhere!)


To be fair, a lot American houses are made out of wood.

Maybe it's time we let the "free-thinking" young upstarts in on the secret of the Imperial British brick.
Title: Re: Small power source for one century
Post by: DirtBiker on Jan 30, 2013, 03:08 pm

The Americas have been occupied for tens of thousands of years.  Check your facts.

Tim


I said predominant culture.  Check what I wrote, and check your attitude.
Title: Re: Small power source for one century
Post by: SirNickity on Jan 30, 2013, 08:49 pm
To be fair, a lot American houses are made out of wood.

Maybe it's time we let the "free-thinking" young upstarts in on the secret of the Imperial British brick.


Sure, sure... but the shipping would be atrocious!   XD
Title: Re: Small power source for one century
Post by: 0AlphaOmega on Jan 30, 2013, 09:12 pm

To be fair, a lot American houses are made out of wood.

Maybe it's time we let the "free-thinking" young upstarts in on the secret of the Imperial British brick.


Sure, sure... but the shipping would be atrocious!   XD

We could sell you the technology...
Title: Re: Small power source for one century
Post by: SirNickity on Jan 30, 2013, 09:42 pm
We could sell you the technology...


America's kinda strapped for cash right now.  Would you consider a payment plan?  Perhaps licensing royalties instead?  I hear you're a fan of royalty over there.
Title: Re: Small power source for one century
Post by: 0AlphaOmega on Jan 30, 2013, 11:15 pm
Clearly SirNickity, judging buy your name, a bit of a queen hugger yourself.
This is purely between the two of us, so keep it quiet, but the patent on the mud brick has expired, so licensing may pose problems, although her Maj is quite keen that you pay something, she say's you've already had Light Bulbs & Jet Engines for free (actually she had quite a long list but I distracted her by telling her that one of the Corgi's had managed to get out and was humping a guards leg). Although, she did say, as a sweeter, that she'd be happy to have you as subjects again providing you get out the tea-pots, quid pro quo and all that. I suppose you could translate it as Bricks & Tea offor Tax & Coolness. Oh, and I suggested that you get the ginger tosser back.... for free.
Title: Re: Small power source for one century
Post by: arduinoadrian on Jan 31, 2013, 03:06 am
I have been thinking in somekind of thermoelectric geneator for years that maybe can be used for this... There is a temp difference from the surface  down as you dig a hole. Maybe placing some bi-metal rods can havest some of the energy from the difference and it will be electrical energy already. If you go all CMOS and sleeping mode most of the time maybe you can use that energy to recharge something while sleeping or have two sets of batteies... Problem will be corrosion... but what if the rods are protected with vinyl or something like ceramic painting (like ovens)?. Maybe they produce enough power to supply the thing without a storage device. Remember spacecrafts use thermopiles (with a nuclear capsule for heating) to generate  electricity. You don't need that much energy so you don't need the reactor. Multiple rods in parallel and series (like batteies) may meet both voltage and current requierements even with small differences in temp. Maybe... Testing is the poblem.
I also think semiconductors should last that long specially because there will be negligible amounts of heat generated.
Title: Re: Small power source for one century
Post by: DVDdoug on Jan 31, 2013, 03:09 am
...a mechanical watch mechanism might be a better bet for the timing - if you can find a power source with sufficient shelf life to wait to be activated.
That's probably the most "practical" idea!    I THINK I've heard of mechanical clocks that only have to be wound once a year.    One hundred of these mechanisims with one triggering another in series could probably work.    And, for the "final action", probably a bigger spring-driven generator.   

You'd have to make sure there's no corrosion and that the lubrication won't dry-out.   

There are ways of generating electrcity with thermal differences, etc.   But you still need to STORE the energy in a battery (or capacitor) to continuously supply the clock.  It's the long-term reliability of the battery (with its nasty corrosive chemistry) that I'm worried about.

Title: Re: Small power source for one century
Post by: JChristensen on Jan 31, 2013, 03:23 am

I THINK I've heard of mechanical clocks that only have to be wound once a year.


Indeed, there are mechanical clocks that never need winding:
http://en.wikipedia.org/wiki/Atmos_clock
Title: Re: Small power source for one century
Post by: SirNickity on Jan 31, 2013, 03:33 am
I have absolutely nothing valuable to add, but this is a cool thread.

Whatever you do, let us know how it turns out, and if whatever you chose worked after 100 years.
Title: Re: Small power source for one century
Post by: arduinoadrian on Jan 31, 2013, 03:50 am
It's a good project you build your clock; but...
Also build a freezing chamber and I'll volunteer to get frozen to see if your thing pops after 100 yeas or not :D . Don't use the device to tigger my ice melting in case it fails...