phaedrus
Member level 4
Hello ,
I have a problem with using a Diff OpAMP (using LM324) in unity gain. I need to measure voltage from 0~2.5V from an electrochemical cell.
I used a mV source to prelim check the equipment. I was able to read and display the voltage correctly.
But when I connect the electrolytic cell , the voltage is displayed as maximum.
I tried disconnecting the R76 ( 1M) pullup but the problem still remains. Pad8 and Pad9 are shorted.I cannot pull S11-1 directly to ground. This because the ground path has a current sense resistor connected in another part of the circuit.
All unmarked resistors in the circuit are 4k7.
Any ideas would be appreciated.
I have a problem with using a Diff OpAMP (using LM324) in unity gain. I need to measure voltage from 0~2.5V from an electrochemical cell.
I used a mV source to prelim check the equipment. I was able to read and display the voltage correctly.
But when I connect the electrolytic cell , the voltage is displayed as maximum.
I tried disconnecting the R76 ( 1M) pullup but the problem still remains. Pad8 and Pad9 are shorted.I cannot pull S11-1 directly to ground. This because the ground path has a current sense resistor connected in another part of the circuit.
All unmarked resistors in the circuit are 4k7.
Any ideas would be appreciated.