# circuit to convert 30 mv to 5 v.

#### Sankalpsood

Joined Jan 19, 2016
9
people, i am trying to use thermo-electric cooler/generator to run a 5 volt dc motor. my problem is that the output of the TEG is as low as 30mv to 50mv. I know that an op amp can be used for the purpose but i need to confirm the ic number and the circuit please. I need to convert 30mv to 5 volt.
please tell me a circuit to complete this process. Or any other feasible method to do this.

#### Papabravo

Joined Feb 24, 2006
14,883
What you want to do is physically impossible. An opamp by itself will not produce the power required to run a motor. The power to run the motor has to come from an external power supply.

#### Sankalpsood

Joined Jan 19, 2016
9
thermoelectric fans have already been made. they are too using something or the other to do this function.

#### Papabravo

Joined Feb 24, 2006
14,883
thermoelectric fans have already been made. they are too using something or the other to do this function.
The problem is that you are assuming you know how to do it. Tell me how much power you think you can extract from a 30mV signal. A couple of microwatts -- maybe. Not enough to run a fan.

#### atferrari

Joined Jan 6, 2004
4,172
thermoelectric fans have already been made. they are too using something or the other to do this function.
Could you show a link to one you have precisely in mind?

#### JWHassler

Joined Sep 25, 2013
284
people, i am trying to use thermo-electric cooler/generator to run a 5 volt dc motor. my problem is that the output of the TEG is as low as 30mv to 50mv. I know that an op amp can be used for the purpose but i need to confirm the ic number and the circuit please. I need to convert 30mv to 5 volt.
please tell me a circuit to complete this process. Or any other feasible method to do this.
You might need to series a few of those to get enough voltage to run a boost-converter.
And maybe parallel a few to get enough power at the boosted voltage.
How much power does your motor require? That's your starting point .

#### Papabravo

Joined Feb 24, 2006
14,883
A boost converter will always have less power out than power in. Sometimes by a fairly wide margin. SMPS design is not for the faint of heart, and it is easy to make mistakes with smokey consequences.

#### MisterBill2

Joined Jan 23, 2018
7,769
The way to drive a fan motor or anything else from thermocouple power is already commercially an old product called a power-pile, I believe. My grandfather had one in his converted furnace back in 1955. There were a whole lot of thermocouples made from heavier wire, all in series, and they delivered enough power to drive a fan motor. So the solution is to simply have a whole lot of them in series. I came up with a similar idea to charge the battery in a generator set using the waste heat from the gas engine exhaust. It would have worked but it would probably not be cost effective.