Winter down under time

[cjdelphi]

I thought i'd create an emergency light using a candle 2 heatsinks and a sandwiched thermoelectic plate a peltier device..

I got thinking with a fan attached to the peltier connected to the cold side, the fan would help cool the cool side making the fan spin faster?

I'm wondering what kind of wattage i can get from a tealight while waiting for the heatsink cement dries so i can test it

 

[Bluejets]

Maybe see how long it takes to boil a jug of water and compare with electric heat time.

 

[cjdelphi]

Well today i got about 300ma from the stove cooker but the 2nd heat sink is just not big enough to disspate the heat, maybe water cooling and a pump

 

[hevans1944]

Just light some more candles for your "emergency light" and go read a book on thermionic energy conversion.

 

[KJ6EAD]

I thought i'd create an emergency light using a candle 2 heatsinks and a sandwiched thermoelectic plate a peltier device..

I got thinking with a fan attached to the peltier connected to the cold side, the fan would help cool the cool side making the fan spin faster?

I'm wondering what kind of wattage i can get from a tealight while waiting for the heatsink cement dries so i can test it

A candle flame produces approximately 50W, mostly heat but 2-5% light.

 

[oz93666]

I think you should define exactly what you are trying to achieve with this project .... if it's to educate yourself , develop skills in construction , then fine ...

If it's to create a practical emergency light , I would suggest this is a clumsy idea . Eyes are very sensitive to light , and small leds very efficient ... try a few experiments low power Leds and discarded batteries .... I have created a night light for my bedroom which consumes less than a milliwatt but it produces enough light for what I want.

 

[BobK]

I had this same idea, but my plan was to epoxy the Peltier to to bottom of a tin can, and fill the can with snow. I actually made it, but I used a clamp to hold the Peltier to the can while gluing and the pressure destroyed it. I have not tried it again, but I might. It is an intriguing idea. I would love to know if you can actually get significantly more light out of it than the candle alone. AK's assertion that only 2% of the energy goes into light makes me hopeful. If you could just get 10% efficiency from the heat to light, you would get nearly 5X the light out of the candle.

Bob

 

[hevans1944]

Even filling the can with water, and insulating the outside, would help. No snow necessary, just dump the water and re-fill the can after the water gets hot.

My boss at my former employer bought one of those Peltier thingys that generate electricity, just to "experiment" with and perhaps increase his limited understanding of things electronical. I think he intended to respond to a Phase I Small Business Innovative Research (SBIR) Request for Proposal (RFP). These are always good for funding a year's worth of salary, and he was quite good at writing winning RFPs. The device sat on a table in his office for years, untouched to the best of my knowledge.

I have a similar one stashed here somewhere, attached to a large, finned, aluminum heat sink with white heat-sink paste, so maybe I can try to repeat Bob's failed experiment. Not sure how well the Peltier junctions would tolerate a candle flame though. I will have to do a bit of research on that first, since I can't afford to run out and buy another one if I brick the only one I own.

 

[BobK]

Well, melting ice (latent heat) sucks up a lot more heat than just heating water. And our power outages tend to be during blizzards.

I glued a U shaped piece of sheet metal to the bottom of the Peltier so the flame would not be directly on it.

I might have to try this again.

Bob

 

[hevans1944]

Yeah, snow. I am hoping to avoid that real soon now. And rethinking this, forget about insulating the can: we want the heat to be be dissipated to the environment, not trapped inside the can. I wonder if there isn't some luminescent substance that magically converts infrared energy into visible light energy. Wow! You could just paint that pixie dust onto the can and heat the can. No Peltier junctions required.

 

[73's de Edd]

Excluding its FRAGILITY factor . . . . a Coleman lanterns mantel activated by the strategically placed candle flame underneath it, puts out a hell of a lot of white light.

 

[hevans1944]

Two Coleman lanterns have been our go-to camping lights for many years, and one of our sources for emergency light at home. I always keep a few spare mantles in the carrying cases we bought for the lanterns, along with a can or two of Coleman fuel and a spare lantern generator. Not only do they produce a lot of light, they also produce a lot of heat. You do need to be aware that good ventilation is always necessary to avoid carbon monoxide poisoning. We never use these lanterns in confined areas such as a tent because of the fire hazard and CO poisoning. But, other than that, what's not to like?

We do keep a few flashlights handy too, most with LEDs, but some with a halogen lamp. The latter accept three D-cells and the aluminum case makes a fair club to beat off zombie attacks. And we have lots of disposable alkaline cells and re-chargeable NiMH cells. It would be very handy to have a few Peltier voltage sources with suitable circuitry to recharge a NiMH cell or two from a tea candle or maybe a solar concentrater. We always pack a few hundred tea candles in our "emergency" kit, but solar concentraters are easy to throw together from cardboard and aluminum foil. What I would really like to have is a small gas turbine generator with capability to operate on natural gas and propane. Not likely to find that on eBay though.