Temperature to voltage sensor

[iscore]

Hi all,
I need a temperature to voltage sensor to convert body heat to voltage. But the sensors I came across require 3 to 5V input voltage supply. And the temperature to converted voltage is of millivolt range. So isn't it a waste of energy that supplying 5V to get millivolt output ??????
Please someone explain me ,In what way it is advantageous ..And if u know, please suggest me a sensor which consumes less input voltage ,may be in the range of millivolt.

Thank you..Have a nice day

 

[Usama Siddiqui]

its not like if it gives millivolts then it had consumed all the rest,actually theres a threshold for everything,lets say if you wana find the energy consumed thats in joules what we do is E=PT (power dissipated*Time) now the actual power dissipated is much less in case of many other things .suppose in your case the actual current drawn by the sensor is veryy low now its (I^2)*R here(R=internal resistance of that sensor is very low and actual source of power dissipation) therefore due to low current its squared times is much lower hence we may say that its energy consumption is much less due to the small magnitude of current it draws.

 

[iscore]

Hi Usama,
I just want to put the question in other way .Instead of Supplying 5V input for sensor, getting millivolt output and using it for some application, why cant we directly use the 5V supply itself to serve our application ??

 

[Usama Siddiqui]

Hi Usama,
I just want to put the question in other way .Instead of Supplying 5V input for sensor, getting millivolt output and using it for some application, why cant we directly use the 5V supply itself to serve our application ??

but how will you be able to sense the temperature difference?? i am not getting you,could you be a bit more brief?

 

[iscore]

i am not getting you,could you be a bit more brief?

My aim is to generate the voltage using the temperature sensor in order to use it for some application (say to blink an led) instead of using another voltage source. Now if I have to supply 5V(from a voltage regulator output) to the sensor circuitry then I can as well use this 5v for my application! So is it possible to do what I have said above, to be able to use sensor op for the application?
This is the sensor I checked https://bit.ly/11z9Lqf

Thanks!

 

[zsolt1]

hi,
LM35 is a good temperature sensor IC. It has a linear temp./voltage dependency on it's full measuring scale (see datasheet). The same 5V power supply can feed the LM35 and all other circuits you may have with no trouble

Ps : the only temperature sensor that generates voltage is the thermocuple , based on the seebeck effect

 

[shatruddha]

I dont know if I'm getting you right or not, but is it that you are saying you want to convert body heat to voltage?? (do you mean convert body heat to watt?? conversion of energy??)
If thats your question, then you are looking for a heat transducer. Look at this https://www.ehow.com/how_7781256_make-simple-heat-transducer.html Is this a solution for you or you actually want a converter like piezoelectric transducer which convert mechanical energy to electrical rather in your case you want its heat that should be converted to electrical?

 

[Usama Siddiqui]

My aim is to generate the voltage using the temperature sensor in order to use it for some application (say to blink an led) instead of using another voltage source. Now if I have to supply 5V(from a voltage regulator output) to the sensor circuitry then I can as well use this 5v for my application! So is it possible to do what I have said above, to be able to use sensor op for the application?
This is the sensor I checked https://bit.ly/11z9Lqf

Thanks!

yes bro you can do that,but its not a good practise ,what we do is that we use a microcontroller to interpret the signal of temp sensor and utilize in an any manner we like. but if you wanna use that directly then first of all you wud have to design a small opamp that could amplify the voltage and current (since the current of the temperature sensor's o/p is veryyyy low and it wont blink your LED ) and then you can do it,but before designing try lm741 it will do your job i guess.

 

[iscore]

I dont know if I'm getting you right or not, but is it that you are saying you want to convert body heat to voltage?? (do you mean convert body heat to watt?? conversion of energy??)

Yes, I'm interested in conversion of energy.

If thats your question, then you are looking for a heat transducer. Look at this https://www.ehow.com/how_7781256_make-simple-heat-transducer.html Is this a solution for you or you actually want a converter like piezoelectric transducer which convert mechanical energy to electrical rather in your case you want its heat that should be converted to electrical?

Thank you for the link, I need to check heat transducers. Yes, I can even add mechanical to electrical transducers in my project.

yes bro you can do that,but its not a good practise ,what we do is that we use a microcontroller to interpret the signal of temp sensor and utilize in an any manner we like. but if you wanna use that directly then first of all you wud have to design a small opamp that could amplify the voltage and current (since the current of the temperature sensor's o/p is veryyyy low and it wont blink your LED ) and then you can do it,but before designing try lm741 it will do your job i guess.

Thanks brother, I got your point.

 

[shatruddha]

oh wow
good to know I got your point correctly. So all you are looking for is something like this **broken link removed**
and keyword for your search should be "thin film heat flux sensor"

 

[iscore]

oh wow
So all you are looking for is something like this **broken link removed**

This looks nice, have you used them before? If yes, can you tell me its availability in India?

Thanks

 

[shatruddha]

I have not used it, but you can figure it out if its available in India. If you do not find, you can contact kitsnspares. They might be able to arrange it for you. (kitsnspares.com)

 

[iscore]

Thanks!