Hi everybody
I'm trying to connect a thermocouple to an Op-Amp to amplify the output of a thermocouple. this is the circuit:
The Op-Amp is LM358N. when I use a potentiometer for the input(HEATER+) to test and check the circuit, everything work correctly but when I connect the circuit to the heater(or thermocouple because it's a soldering iron), the Op-Amp get freezed! I mean it just show a little and constant amount in the output (while the input is changing). why? something must be wrong.
I'm trying to connect a thermocouple to an Op-Amp to amplify the output of a thermocouple. this is the circuit:
The Op-Amp is LM358N. when I use a potentiometer for the input(HEATER+) to test and check the circuit, everything work correctly but when I connect the circuit to the heater(or thermocouple because it's a soldering iron), the Op-Amp get freezed! I mean it just show a little and constant amount in the output (while the input is changing). why? something must be wrong.