I'm wondering if this makes sense
You have an oil lamp as a source of heat. Then you have a thermoelectric generator coupled thermally to it. (Could be a cooler run backwards.) then you connect that to a led. Presto, a lantern! Could add a storage battery also.
A cogeneration lantern.
That's how they power some satellites.. replace lamp w/ some radioactive heat source. As long as you don't melt the solder in the TEC it would work. but if you have an oil lamp, why do you need a weak wimpy led? (I did try getting power out of a TEC.. not very much...) In general heat engines aren't very good unless you get 'em hot.
George H.
-Lasse
The lamp is hot and bulky. If you wanted cold light in a very specific - and small - area, the LED might be handy.
In Russia in the 1920's they reputedly used a similar lamp/TEC combination to power a radio to keep people in remote villages more or less informed.
Or big - preferably both.
-- Bill Sloman, Sydney
It is doable but you either need a heck of a lot of junctions to power a LED or a step up transformer/DC to DC converter. Semiconductor based Peltier coolers are the easiest way to do it.
Chromel-constantan is good for about 70uV/K and good to 750C so you might hope to get 50mV per junction. It is amusing to check USPTO to see what risible patents they grant these days in 2003 no less.
Keeping the cold junctions cold is somewhat tricky. The moron who filed this example clearly failed to understand this as his cooling fins are way too small to maintain a decent power output at equilibrium.
Here are some examples from the days when the idea was relatively new. The Russians had such kerosene powered lamp generators in production around 1959 and it did 90v @ 12mA and 1.5v @ 125mA or 250mA.
I have done it as a demo with a candle (output about 100W) heating an aluminium plate driving a high temperature TEC coupled to a lower temperature one with a heatsink. It will briefly provide enough power to light an LED if the cold side heatsink comes out of the deep freeze. Much easier with single chip high efficiency step up of voltage.
Using the latest generation of high efficiency LED the light output might even exceed that of the candle. It isn't a child friendly science demo as the hot side is well above the melting point of soft solder.
Fans using TECs that go on top of wood burning stoves work pretty well since the fan also cools down the heat sink as well.
-- Regards, Martin Brown
Dude told me thtt in the Amish community, a guy had a fan on top of his stove. He stoked ai and al that to get heat, but here was this little electric fan on top of it running. Apparently.
It was at just the right angle so the convection of the air drove the fan blades and actually worked the oscillating gears.
That's right, the thing paqnned the room.
You hve seen fans like this I am sure, but I never saw one run without electricity.
Don't gt me wrong, the guy doid not make this up and I understand, the convection was running it.
I thinik it is cool as hell. I would go down there just to see it except, umm, forget it why...
One of my friends has one of those. It sits on top of the oven and only starts when it is warm (runs of the heat of the oven). It is placed to draw heat from the pipe so that less heat is exiting the house via the chimney
Cheers
Klaus
Nice! Thanks for the links. The Russian lamp was 2-4% efficient! (pretty good) and now this,
Reading this whole thread, I'm wondering if you wouldn't get better performance out of a Stirling engine run by the lantern.
-- Tim Wescott Wescott Design Services http://www.wescottdesign.com
There are also modern ones that work from a Peltier device powering a small DC motor.
Advantage of Peltier or Seebeck effect is no moving parts. Space probes use Pu238 self heating as a reliable power source. They are toying with the idea of using it to steal back a few watts from car exhaust gasses. I hope the weight and complexity doesn't annul any gains.
Strikes me as a lot of effort for a tiny return.
I have a hand made Stirling engine that will run off a cup of coffee - it is tetchy about starting on that small a temperature difference.
You can easily make one to drive a fan off a wood burning stove, but all the modern ones are Peltier device, low voltage motor and a fan.
-- Regards, Martin Brown
Wrap a lot of bafflegaff about it, get 10 or so megabucks funding. do an IPO and get paid $500K/yr or so. Bail out with the golden parachute for a few million bucks a few months after the IPO and chuckle about all of the fools that followed. Then with that experience,run for Congress!
Someone has already beaten him to it. USPTO granted a patent on this prehistoric 1950's technology to someone in 2003! I kid you not!!!
It doesn't say much about USPTO's ability to search prior art!
-- Regards, Martin Brown
Or generate electricty with the sound from your stereo. Then use it to power the stereo.
Mark Harris
Yes, get kickstarter funding as "alternative energy," and then call it "Solyndra." At that point, jet around the world proclaiming that the earth will collapse soon if we burn oil. Then eat a $300 sushi dinner and talk about the need for income redistribution. Then jet off to Norway for a Nobel Prize. In your speech, condemn the non-believers and spoilers of the earth. Start a cable network to proclaim the truth of global warming. After a group of climate scientists get stranded in the ice, sell the cable network for 200 million and put that in your pocket. Exhausted and happy, declare victory and go on a well-deserved vacation without your wife. The End.
Hey Martin,
I posted this as a joke, if by "him" you mean me! I found it somewhat interesting thermodynamically - to see whether an led scavenger system can produce better light than a flame can.
Could a simple Seebeck generator charge your radio in an emergency? Yes.
What oil/wax has, the advantage, is it's a non-pareil energy storage medium. Lots of energy per unit volume and excellent storage stability. Nothing else is as good, unless you count radioactive materials.
So the complexity of a thermopile may give you a "WTF?" moment, but just consider the above advantages of oil/wax in your estimations!
I have tried a few years back and could not get an LED to be brighter than the candle flame that powered it back then. Maybe due for a rematch with the latest generation of new high efficiency power LEDs.
BTW My criticism wasn't aimed at you but at the hopeless USPTO who will grant patents for the blindingly obvious with clear prior art if the applicants dollars are green and supplied in the right quantities.
Though solar or wind power would be a lot more reliable off grid. Even one of those daft shake to charge it torches would be a better bet.
If you are serious about cogeneration these days then a methanol fuel cell is probably the most interesting route.
-- Regards, Martin Brown
ric generator coupled thermally to it. (Could be a cooler run backwards.) t hen you connect that to a led. Presto, a lantern!
o an IPO and get paid $500K/yr or so. Bail out with the golden parachute for a few million bucks a few months after the IPO and chuckle about all of the fools that followed.
Solyndra." At that point, jet around the world proclaiming that the earth will collapse soon if we burn oil. Then eat a $300 sushi dinner and talk a bout the need for income redistribution. Then jet off to Norway for a Nob el Prize.
Not a business plan that will attract many investors. Certainly not the one that the real Solyndra promoted. They touted copper indium gallium selenid e thin film solar cells, which were marginally more plausible.
Al Gore wasn't involved with Solyndra, and while his money-making antics ha ve been entertaining, his message on global warming is more or less accurat e, if a bit heavy on the photogenic polar bears, who turn out to be less do omed than he thought.
t a cable network to proclaim the truth of global warming. After a group o f climate scientists get stranded in the ice, sell the cable network for 2
00 million and put that in your pocket. Exhausted and happy, declare vict ory and go on a well-deserved vacation without your wife. The End.G.K.Chesterton's 1908 book "The Man who was Thursday" has an anarchist who reads up on bishops in the anarchist literature, and - based on that - trie s to pass himself off as a bishop. Real bishops turned out not to talk abou t grinding the faces of the poor.
Your idea of satire looks too much like Murdoch-press misinformation to be plausible enough to be funny.
-- Bill Sloman, Sydney
And Bill, believe me with all my heart, I don't find it funny either! While you sit on your little island, we are watching the biggest theft of a country's quality of life in the history of civilizations. Consider yourself lucky you aren't here. Say do you ever encounter roos on country walks? How fast can you run the 100 meter dash?
That's not a patent. It's an application, from someone in Belgium.
A quick search didn't find any grants (Solyndra got those ;-).
Cheers, James Arthur
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