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Peltier / thermoelectric module.

12/20/2009 1:36 AM

I know the common peltier devices used to warm or cool 12 vdc coolers will also produce electricity when one side is hotter than the other side. I know this, because when the cold side on the one i have gets cold, and the outside heat sink gets warm, i can unplug the 12 volt power lead and the fan continues to spin for several minuits, although it spins much slower. I would like to use a few of the peltiers i have laying around here to produce enough power to at least light up a few 3 vdc l.e.d. bulbs. Does anyone know the optimum and/or maximum temperature these can be run on the hot side without damaging them? Or, what is the proper/best temp to try to maintain across the 2 sides of the peltier. I have a few heatsinks,too, in case theyre needed. I know one side has to be cooler than the other, but what is the right temp range between the hot and cold side? Thanks.Charles

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#1

Re: Peltier / thermoelectric module.

12/20/2009 9:33 AM

The specification or data sheet for these devices will tell you all that information....

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#2
In reply to #1

Re: Peltier / thermoelectric module.

12/20/2009 11:19 AM

when you roadkill peltiers from discarded coolers, they rarely come with a spec sheet or manufacturer data. These were intended for cooling, not electrical production, therefore the spec sheet would be useless anyway. Does anyone in here know the right temp range to run them at for electric generation.

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#3
In reply to #2

Re: Peltier / thermoelectric module.

12/20/2009 12:19 PM

Nope. Not a clue. Can't you measure the output while running through the temp range available? You should be able to find the most efficient operating temp. that way.

Cheers.

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#8
In reply to #3

Re: Peltier / thermoelectric module.

12/21/2009 12:23 AM

Yes, i think i may just have to resort to the ancient chineese electric skillet thermostat trick. You see, i have wood heat. I also have 5-55 gallon drums of water encircling my stove to distribute the heat better and more evenly. I heat about 1300 sq feet with 2-3 armloads of firewood for 24 hours I was just trying to figure out if they should be placed on the stove, barrels of water, or the exhaust stack. I can bring cool outside air in along their heatsinks if i have to to get the right temps, as soon as i can find out the right temps,lol. I am trying to avoid burning any of them up.

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#10
In reply to #2

Re: Peltier / thermoelectric module.

12/21/2009 6:44 AM

Once the RS Components Ltd had a wide range of Peltier devices & a detailed Application Note was available with the order.

Try if they still have.

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#4
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Re: Peltier / thermoelectric module.

12/20/2009 4:19 PM

WRONG!!!

Look up any data sheet on peltier devices, they will always tell you the information you need.

You may have to estimate the number of junctions and size of your scavenged parts but the temperature range and operating characteristics will be similar.

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#6
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Re: Peltier / thermoelectric module.

12/20/2009 10:55 PM

"Look up any data sheet on peltier devices, they will always tell you the information you need."

I tried doing that. It's not a trivial task! Could you provide a link? From what I found, generally the ∆T can be around 50K (50°C), although I gather that there do exist high temperature units that can withstand up to 200K.

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#7
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Re: Peltier / thermoelectric module.

12/21/2009 12:15 AM

NOT WRONG, different peltiers are made from different metals therefore have different thermal charachteristics, that much i do know. And i dont plan to destroy them and have them assayed to learn what they WERE made of. And these things are sealed up, so they only have 2 junctions, one for the positive wire and one for the neg wire.If you dont have numbers, you have nothing to offer. Thank you for your input. c

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#5

Re: Peltier / thermoelectric module.

12/20/2009 10:39 PM

Most TE coolers are assembled with low temperature solder that limits the hot side temperature to about 90 degrees C.

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#9
In reply to #5

Re: Peltier / thermoelectric module.

12/21/2009 12:25 AM

Thank you welderman. I only have a few, and didnt want to disable any of them through trial and error.

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#11

Re: Peltier / thermoelectric module.

12/21/2009 6:51 AM
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Guru
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#12
In reply to #11

Re: Peltier / thermoelectric module.

12/21/2009 10:33 AM

GA for a good link....

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#13
In reply to #11

Re: Peltier / thermoelectric module.

12/21/2009 11:35 PM

Thank you for more good info.

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#14

Re: Peltier / thermoelectric module.

12/22/2009 3:50 AM

Thanks for GA

Electroman and ageniusforhire !!!!!

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