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Design >> Analog Design >> Difference amplifier with a difference.
https://designers-guide.org/forum/YaBB.pl?num=1245218690

Message started by Riotpack on Jun 16^th, 2009, 11:04pm

Title: Difference amplifier with a difference.
Post by Riotpack on Jun 16^th, 2009, 11:04pm

Hello,

I am trying to design a circuit but one small aspect is holding me back.

I have two signals, we will call them A and B.

I want signal A to always appear at the output

I want signal B to be subtracted from signal A if they are common

But what I dont want is signal B at the output. That sensor is there to pickup vibration and cannot be at the output for instance if it raises to a higher peak to peak voltage or has different information then sensor A.

So it is like a difference amp, except one input is there for subtraction only.

Signal A has varying DC offset as it is a Load Cell, it is the superimposed AC signal due to vibrations I am looking at.

How is this achieved, I have been thinking about it for an hour now.

Thank you for any suggestions.