- #1
Jy158654
- 7
- 0
- Homework Statement
- How does the difference between V- and V+ reduce and eventually become zero?
- Relevant Equations
- G = G0/(1+G0)
The book says that " The op-amp multiplies the potential difference between V+ and V- by the open-loop voltage gain to produce Vout."
So my first question is, since we say we assume open-loop voltage gain is infinite, so does that mean the Vout produce will be infinite too?
Then, the book says that "As Vout is 'fed back' to V-, the value of V- increases and this reduces the difference between V- and V+. Very quickly this difference becomes zero again and Vout = Vin." The problem is, I have checked some websites and all of their photo of negative feedback amplifier consists of resistors to attenuate and take some fraction of the voltage to the V-, but the photo shown in this book doesn't consist any of the resistors, so if Vout = infinite, doesn't that mean V- in this example also has infinite value without any attenuation??
And also, this example says that the initial input, Vin was +0.1V, and Vout/V- was 0V, so how does the increase in V- result to reduce the difference between V- and V+ and becomes zero in difference at the end? I am a little confused over this part here.
Hope there's someone who can help me in my confusion. Thank you.