- #1
aiswarya reddy
- 1
- 0
Can I use a thermocouple which has a temperature difference of 1 degree to generate current to run a very small led.
Thermocouple Applications to generate current to run a very small led ?
- Thread starter aiswarya reddy
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Discussion Overview
The discussion centers on the feasibility of using a thermocouple with a minimal temperature difference to generate sufficient current to power a very small LED. It explores theoretical and practical aspects of thermocouples and thermopiles in generating electricity from temperature differentials.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
Main Points Raised
- One participant questions whether a thermocouple with a 1 degree temperature difference can generate enough current to run a small LED.
- Another participant suggests that while a significant heat flow and increased voltage might theoretically work, in practice, it is unlikely due to the minimum voltage requirement of LEDs.
- A participant provides a graph showing the millivolts produced by various thermocouple types at different temperatures, indicating limited voltage change per degree Celsius.
- One contributor recalls a project involving a series of thermocouples wired as a thermopile to power a small radio, noting historical uses of similar setups.
- Another participant mentions commercially available thermopiles for gas appliances, highlighting their low voltage output and the impracticality of using a 1 degree temperature difference.
- A participant humorously notes that a large number of thermocouples would be needed to generate sufficient voltage from a 1 degree difference and mentions Peltier devices as an alternative for generating voltage from temperature differences.
Areas of Agreement / Disagreement
Participants express differing views on the practicality of using a thermocouple with a minimal temperature difference to power an LED, with no consensus reached on the feasibility of the initial proposal.
Contextual Notes
Participants note limitations related to the voltage requirements of LEDs and the effectiveness of thermocouples at small temperature differentials, as well as the need for significant heat flow to generate usable voltage.
- #2
mfb
Mentor
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If you find some way to have a huge heat flow and if you can increase the voltage by orders of magnitude: maybe. In practice, probably not. LEDs need a minimal voltage (depending on the color, but at least ~2V) to work.
- #3
dlgoff
Science Advisor
Gold Member
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Here's a graph showing the Millivolts produced at various temperatures for several common Thermocouple types. Not much change in voltage per ºC change in temperature.
- #4
Mike_In_Plano
- 700
- 35
When I was a kid, there was a project in an encyclopedia that used a series of thermocouples to power a small radio. By
wiring thermocouples in series, you get what's termed a thermopile.
The design I read about used a lamp socket and candle along with a bunch of thermocouples.
Later I learned that Russians often used a similar arrangement to power radios.
wiring thermocouples in series, you get what's termed a thermopile.
The design I read about used a lamp socket and candle along with a bunch of thermocouples.
Later I learned that Russians often used a similar arrangement to power radios.
- #5
jim hardy
Science Advisor
Homework Helper
Dearly Missed
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Home supply stores carry thermopiles for gas appliances.
They come in 0.03 and 0.75 volt
https://customer.honeywell.com/en-U...=Thermocouples+and+Thermopiles&catpath=1.2.12
but they have to be immersed in a flame, your 1 degree isn't going to work.
They come in 0.03 and 0.75 volt
https://customer.honeywell.com/en-U...=Thermocouples+and+Thermopiles&catpath=1.2.12
but they have to be immersed in a flame, your 1 degree isn't going to work.
- #6
Mike_In_Plano
- 700
- 35
Yes, LOL, you'll need a zillion thermocouples to make it from 1 degree C or F.
Piltier devices (used for 12 volt coolers) offer a simple means of getting voltage from a temperature difference.
I've applied 12 volts to one, allowed it to settle, and then used it to power a small 6v bulb for a short time. Fun!
Piltier devices (used for 12 volt coolers) offer a simple means of getting voltage from a temperature difference.
I've applied 12 volts to one, allowed it to settle, and then used it to power a small 6v bulb for a short time. Fun!
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