The output of Op-Amp[LM324] has error as non-inverting Amp

jjw said:

The gain is 1+R2/R1 ~ 5.5
Input offset voltage is max. 5mV and it could explain the results.

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JimB said:

Try drawing a graph of Input Volts vs Output Volts, is it linear?

Consider that you may have the wrong expression for the the gain. Gain = 1+ R2/R1 may give better results.

JimB

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Tony Stewart said:

Your false assumption is the output resistance of Op Amp is 0, which it is not, so that must be considered when choose Rf.

Try scaling up your values x10 to x1000 and try again and observe Vo vs Io to compute ESR or see Imax and plan on using much less.

From your data, you can now compute internal ESR of OA output.
got it?

if not...
Calculated gain is 1 + Rf/Rin = 5.5069124423963133640552995391705
using 1% R values this becomes 5.507 +/-2%

You got applied 0.15v to the input and got 0.94v in the output. then the gain is 6.26667.
which using Rin=217
Av(-) = 5.267 Rf= 5.267 * 217 = 1143 Ω
But your design used 978 Ω,

so the Op Amp ESR must be 1143-978 = 165 Ω but since you used DMM to measure R accuracy is 0.1%

which is typical for an op Amp. Rail to Rail CMOS types are much higher (kΩ)

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crutschow said:

You should increase the resistor values to that their sum is at least 2kΩ.

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What would happen if that would not be linear?

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JimB said:

You thought the gain was varying.
I plotted your values on a graph, it was linear, so the gain was constant, but there was an offset.

Try some higher values of resistors as other have suggested, do some more measurements and see what happens.

JimB

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