What is the flaw in this op-amp circuit?

pwdixon

Joined Oct 11, 2012
488
The thermocouple produces a voltage not a current for the circuit to work, as it does in fact point out, the thermocouple would need to source current into both inputs ie. it would be a current generator.
 

Thread Starter

rkbshiva

Joined Aug 1, 2015
5
The thermocouple produces a voltage not a current for the circuit to work, as it does in fact point out, the thermocouple would need to source current into both inputs ie. it would be a current generator.
Sorry!Can you please elaborate your answer.I can't get you
 

kubeek

Joined Sep 20, 2005
5,794
Both inputs act like a current source with the same polarity, so if you just connect them together you will get bogus results. You need to provide a way to close the loop for those currents.
 

crutschow

Joined Mar 14, 2008
34,281
Also, there needs to be a path for the op amp input bias currents to ground.
Op amps cannot operate with the inputs floating.
 
Top