in given circuit R2 is the RTD (50ohm at ambient temp and 223.7 ohm at 450 degrees(maximum temp) at maximum temp the o/p is 3.583 volts and Vout gives to Arduino nano A0pin i want to change RTD with Thermocouple because that type of heater element is not available the o/p of Thermocouple is 5mV to 20mV what the change in given circuit will work......?

 

Hi mohsin
Welcome to AAC.
Look over this link, it will give you a starting example for a circuit design.
E
http://www.ecircuitcenter.com/Circuits/Thermocouple/Thermocouple2.htm

 

Hi mohsin
Welcome to AAC.
Look over this link, it will give you a starting example for a circuit design.
E
http://www.ecircuitcenter.com/Circuits/Thermocouple/Thermocouple2.htm

tnx for reply

 

hi m,
This is a basic LTSpice simulation of that type of circuit.
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tnx for fast replying the heating element in the attached circuit i want to change with themocouple

 

hi m,
That RTD circuit is totally unsuitable for a Thermocouple, also the LM358 OPA.
To increase the 5mV through 20mV to say 3.5Vout requires a Gain of ~175.
Do you have a part number or type name of the thermocouple that is available?
E

 

hi m,
This is a single power supply option.
E