Im trying design a thermocouple circuit to measure temperature over a certain range. The thermocouple used produces milliamp voltage. Im using an op amp with a +Vsat of 5V and a grounded -Vsat.
The problem im having is the increments of temperature measured by the thermocouple only produce a small current and if i increase the gain of the op amp to the point where the Amplified increments are significant enough to measure accuratly I quickly reach saturation. and if I decrease it to the point where the point im not reaching Vsat. The l lowest output value of the op amp over my required range is around 3V.
In essence I want the op amp to work between 0 and 5V and consequently have the amplified thermocouple voltages be amplided over this range.
The problem im having is the increments of temperature measured by the thermocouple only produce a small current and if i increase the gain of the op amp to the point where the Amplified increments are significant enough to measure accuratly I quickly reach saturation. and if I decrease it to the point where the point im not reaching Vsat. The l lowest output value of the op amp over my required range is around 3V.
In essence I want the op amp to work between 0 and 5V and consequently have the amplified thermocouple voltages be amplided over this range.