This just seemed appropriate in the "Candle Power" forums:
http://www.youtube.com/watch?v=0_GqE5aDR68
http://www.youtube.com/watch?v=0_GqE5aDR68
Candle powered LED
- Thread starter TEG
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kuksul08
Enlightened
thermocouples generate voltage when their junction is exposed to a temperature higher than ambient. I think it's just doing that.
bshanahan14rulz
Flashlight Enthusiast
I wonder how much power can be generated that way. Is power related to how hot it gets or how much heat flows through the thermocouple?
LukeA
Flashlight Enthusiast
Looks like a Peltier junction between the heatsink and candle.
Now I know what to use that Peltier junction I bought :candle:
Now I know what to use that Peltier junction I bought :candle:
Looks like a Peltier junction between the heatsink and candle.
Now I know what to use that Peltier junction I bought :candle:
I looked at the website that was on the video... it is different that your normal Peltier Junction... It uses a new thinner design with a new material.. I would guess it is more efficent?
I have a couple of Peltier Junctions laying around as well..... I actually hooked one up to a heat sink and was able to make a little ice cube in a aluminum cup on top of it! LOL
Gryloc
Enlightened
Just make sure you keep the cold side of the peltier cold or else your power output would drop. Our college has a club where we design what you would call a "BUV", or a Basic Utility Vehicle, that would be used in countries in need of basic transportation. These vehicles would be basic, 10 HP engine powered carts that could be used to transport supplies, school children, or even injured people. These would be used in places with primitive road systems, and built from common car parts (like Toyota Corrola front ends or transmissions) and other construction parts from a kit (these are low cost, build it yourself vehicle kits). One of our designs called for a setup that excluded an alternator and battery for cost reasons. I thought that a peltier-Cree setup would work for great indicator lighting (the front headlights could still be useful, of course). The peltier would be mounted to the exhaust pipe somewhere, and on the other side, would be practically any flat chunk of metal available (a member of the frame, some steel sheeting, or possibly a decent aluminum heatsink found in the kit).
I demonstrated by crudely slapping a 40mm X 40mm peltier to an old Pentium heatsink, then I used a small pencil torch to heat the other side. The current that came from the peltier was enough to power an old Cree P4 bin emitter at a decent current (maybe a bit past 350mA). With a cheap DX reflector I had laying around, I was able to cast a noticeable beam on the wall of the well-illuminated shop. Imagine either larger peltiers or several in series (or parallel for redundancy) to power a bunch of cheap, newer generation emitters (Rebels, XP-Es, etc). You would have a decent basic lighting system that does not have to be recharged, and it operates without worry while the motor is running. In colder climates, you may have to put a current-limiting resistor in there, or just deal with the extra light. At lower speeds (~20mph) and with a couple of Cree emitters behind basic reflectors, you should get plenty of light to see the path ahead comfortably, right? If not, you can be seen by other vehicles and pedestrians, and have enough light to see the edges of the path.
[FONT="]I would like to see others work with higher-powered LED arrays that get its power from an engine, a small fire, or a chemical source of heat. This would not be a very efficient setup, but atleast there are no battery maintenance and moving parts to worry about. :twothumbs
-Tony
[/FONT]
I demonstrated by crudely slapping a 40mm X 40mm peltier to an old Pentium heatsink, then I used a small pencil torch to heat the other side. The current that came from the peltier was enough to power an old Cree P4 bin emitter at a decent current (maybe a bit past 350mA). With a cheap DX reflector I had laying around, I was able to cast a noticeable beam on the wall of the well-illuminated shop. Imagine either larger peltiers or several in series (or parallel for redundancy) to power a bunch of cheap, newer generation emitters (Rebels, XP-Es, etc). You would have a decent basic lighting system that does not have to be recharged, and it operates without worry while the motor is running. In colder climates, you may have to put a current-limiting resistor in there, or just deal with the extra light. At lower speeds (~20mph) and with a couple of Cree emitters behind basic reflectors, you should get plenty of light to see the path ahead comfortably, right? If not, you can be seen by other vehicles and pedestrians, and have enough light to see the edges of the path.
[FONT="]I would like to see others work with higher-powered LED arrays that get its power from an engine, a small fire, or a chemical source of heat. This would not be a very efficient setup, but atleast there are no battery maintenance and moving parts to worry about. :twothumbs
-Tony
[/FONT]
Illum
Flashaholic
Looks like a Peltier junction between the heatsink and candle.
Now I know what to use that Peltier junction I bought :candle:
Look up "Radioisotope Thermoelectric Generator"
then go to "thermoelectric effect"
the efficiency sucks, not to mention the hazards, but betavoltaics still has their place:shakehead
Ryanrpm
Enlightened
Nice find! I've passed that video around to several people. Gotta love tech improvements...
gillestugan
Enlightened
Especially those inventions made almost 200 years ago...
Ryanrpm
Enlightened
Thanks for your sarcasm.
Besides, I wasn't there to appreciate it 200 years ago.
Besides, I wasn't there to appreciate it 200 years ago.
gillestugan
Enlightened
sorry, it was just too tempting
Besides, it is not until recently they have become commercially available, so there sure have been a lot of tech improvements to make this happen. Now ju can buy those peltier based fridge boxes just about anywhere.
Besides, it is not until recently they have become commercially available, so there sure have been a lot of tech improvements to make this happen. Now ju can buy those peltier based fridge boxes just about anywhere.
Illum
Flashaholic
well, you can buy the peltier junction as a stand alone item...
a 40mm Peltier heatpump runs around $15
127 thermocouples in a 40mm square
Tmax=79degC
Vmax=16.1V
40MM x 44MM x 3.3MM
Qmax=80.6W
Imax=8.1A
I have no idea what kinda power you can get if you apply heat to it, but given the power needed for it to function...I can't imagine to efficiency to be high
a 40mm Peltier heatpump runs around $15
127 thermocouples in a 40mm square
Tmax=79degC
Vmax=16.1V
40MM x 44MM x 3.3MM
Qmax=80.6W
Imax=8.1A
I have no idea what kinda power you can get if you apply heat to it, but given the power needed for it to function...I can't imagine to efficiency to be high
LukeA
Flashlight Enthusiast
The efficiency is infinite. You're turning waste power into useful power. There previously was zero recovered power, and now there's some. You're dividing by zero. You're getting power effectively from nowhere.
Mine produces power at a ratio of about 15Ohm.
Illum
Flashaholic
infinite? Efficiency cannot be 100%, it has to be less than 100% therefore definite
in terms of consumed fuel to output...if both were converted to watts...there has to be losses...
in terms of consumed fuel to output...if both were converted to watts...there has to be losses...
spencer
Enlightened
Lets say in this case efficiency is defined by energy in to energy out. Heat energy can be measured in joules and joules can be converted to watt hours. So if the candle is releasing x amount of joules, then how much power in watt hours is being generated? Is it 1/100x? 1/1000x? 1/10,000x? 1/100,000x? I think this is what Illum was asking and I believe he is right in believing that the efficiency is not infinite.
NeSSuS-GTE
Newly Enlightened
Clearly Illum is correct. But that doesn't defeat the spirit of Luke's post. It seems worthwhile to try and capture that wasted energy.
But when I was running alternate energy experiments in school with Peltier's in sunlight, we developed the best temperature differential conditions we could muster with lab components and could only generate power in the miliVolt range per 40x40mm junction.
After much collaboration and many redesigns, we deemed it infeasible because we couldn't get worthwhile output for the effort and cost. But that was for sunlight conditions... which of course is dominated by a different power generation technology.
Now I only use Peltiers for cooling purposes... and I'm quite happy with that. :thumbsup:
But when I was running alternate energy experiments in school with Peltier's in sunlight, we developed the best temperature differential conditions we could muster with lab components and could only generate power in the miliVolt range per 40x40mm junction.
After much collaboration and many redesigns, we deemed it infeasible because we couldn't get worthwhile output for the effort and cost. But that was for sunlight conditions... which of course is dominated by a different power generation technology.
Now I only use Peltiers for cooling purposes... and I'm quite happy with that. :thumbsup:
