Hi.
See pic:
http://www.flickr.com/photos/67251822@N0…
What is the voltage between the inverting and non inverting inputs?
Also, what is the voltage across the 1k resistor.
Isn´t the gain of the circuit 9?
Some explanations would be much appreciated.
Thank you.
See pic:
http://www.flickr.com/photos/67251822@N0…
What is the voltage between the inverting and non inverting inputs?
Also, what is the voltage across the 1k resistor.
Isn´t the gain of the circuit 9?
Some explanations would be much appreciated.
Thank you.
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The voltage between the input terminals is essentially zero. Therefore, the current through the 1k resistor is Vin/1k. The current through the 9k resistor is the same. Thus Vout=Vin+(Vin/1k)*9k=Vin(1+9)=10*Vin.
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If you work out the math, Vout = Vin * (R2 + R1) / R1 where R1 is your 1k and R2 is your 9k so the gain is 10.
The voltage between the two inputs is extremely small for an ideal op amp. cheap op amps could have 1 or 2 milliVolts offset, down to mico Volts for good op amps.
The voltage between the two inputs is extremely small for an ideal op amp. cheap op amps could have 1 or 2 milliVolts offset, down to mico Volts for good op amps.