New challenge is here! It's AQQ259 related to a tunable or adjustable amplifier:

The above circuit is a tunable or adjustable gain amplifier. The opamp used is
considered as ideal (i.e. infinite open loop gain, infinite input resistance and
zero output impedance).
Questions:
1. For given R1, R2 and P, at which wiper position α, Vout = 0 volt?
2. Versus Vin, what is the dynamic range of Vout?
Good luck! And try to be among the first ones!
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1. Vout is 0V at α = R2/(R1+R2)
2. at α = 0: Vout = -Vin * R2/R1
at α = 1: Vout = Vin * (1-(R2/R1))
...and of course, Vout is limited to +Ecc max. / -Ecc min.
1. Vout is 0V at α = R2/(R1+R2)
2. at α = 0: Vout = -Vin * R2/R1
at α = 1: Vout = Vin * (1-(R2/R1))
...and of course, Vout is limited to +Ecc max. / -Ecc min.
Thanks Roland! Agree with your answer 1. But are you sure about question 2? You probably made a typo in an equation when calculating Vout for alpha=1... May be you can recheck?
Oops, I see: The correct answer for α = 1 is Vout = Vin
... but this is only true as long as R1 / R2 is > 0 ...
And if R1=R2 you have a nice use case: With the potentiometer you can adjust the gain from +1 to -1. In the mid position the gain is 0.
Well recovered ADIApproved