Hi guys,
I have made a difference amplifier (subtractor) based upon OP-AMPs as below pic.
The whole 4 resistors which I used were 10K. I have just a problem by it. When I connect a sine input to the V1 the said sine wave just drops in volatge by say a factor of 2!! But when I connect the said sine signal to the V2, The signal does not drops at all!
By the way When I increasing the feedback resistor to a higher one the signal at V1 is less dropped!?
What is the problem please and how to solve it?
I myself guess that the input impedances at V1 and V2 are not the same, even by using the same resistors for them though It is very strange and should not be correct!? But I am not sure?!
I have made a difference amplifier (subtractor) based upon OP-AMPs as below pic.
The whole 4 resistors which I used were 10K. I have just a problem by it. When I connect a sine input to the V1 the said sine wave just drops in volatge by say a factor of 2!! But when I connect the said sine signal to the V2, The signal does not drops at all!
By the way When I increasing the feedback resistor to a higher one the signal at V1 is less dropped!?
What is the problem please and how to solve it?
I myself guess that the input impedances at V1 and V2 are not the same, even by using the same resistors for them though It is very strange and should not be correct!? But I am not sure?!
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