I have a confusion understanding one of the basic assumption used for operational amplifiers which is Vin = 0 or difference of inputs = 0.(adsbygoogle = window.adsbygoogle || []).push({});

Take for example an ideal amplifier with inputs V+ and V-

V+ = 1

V- = 0.5 * Vout

Supply Voltage = +-9

Vin = V+ - V-

At start V+ = 1 and V- = 0, providing us a Vin of 1V. Since gain is infinite, Vout = +9.

Now V+=1 and V- = 4.5, providing us a Vin of -3.5. Since gain is infinite, Vout = -9

Now V+=1 and V- = -4.5, providing us a Vin of 5.5. Since gain is infinite, Vout = +9

Now V+=1 and V- = 4.5, providing us a Vin of -3.5. Since gain is infinite, Vout = -9

My question is in this example Vin doesnt approaches 0. So can you explain how does an operational amplifier will work in this situation to make Vin = 0?

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# A question regarding electronic negative feedback

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