I'm studying for an exam and i'm struggling to understand op amps, here's my problem:(adsbygoogle = window.adsbygoogle || []).push({});

I understand that for an op amp to have a controllable gain, the difference between the input terminals must be very very close to zero (and you can assume it is zero). And to do this you use negative feedback. For example a non inverting op amp http://upload.wikimedia.org/wikipedia/commons/6/66/Operational_amplifier_noninverting.svg

If the voltage divider sends half the voltage from the output to the inverting terminal, then the output will need to be twice as big as Vin in order for the input terminals to be the same. So the amp will have a gain of 2.

A lot of website explain this by saying the op amp "Wants" the inputs to be the same, so it adjusts the output so that they are.

What I don't understand is why the op amp "Wants" the inputs to be the same. Obviously it doesn't actually "Want" anything, but how does the circuit stabilize and manage to produce the desired output?

Thanks

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# Why does negative feedback stabilize an operational amplifier?

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