The following circuit contains ideal operational amplifier, Vs voltage is sinusoidal with amplitude of 1Volt and frequency of 1kHz, where VE is a dc voltage of 2Volts. I am trying to use superposition principle to find the output voltage. Also I want to draw a diagram of Vs(t) and Vout(t) versus time. First, suppose we ignore positive and negative power supply of the op-amp(they are not shown on the circuit I was given).
Step 1: Let's ignore dc source and find the output. The equivalent circuit is:
So Vout1(t) = -(R2/R1) * Vs(t) = -Vs(t) (inverting amplifier)
Step 2: Let's ignore ac source and find the output. The equivalent circuit is:
So Vout2 = Vin * (1 + R1/R2) (non-inverting amplifier)
= VE * (R4/(R3 + R4)) * (1 + R1/R2)
= 2 * (2000/(2000 + 2000)) * (1 + 1)
Finally, Vout(t) = Vout1(t) + Vout2 = 2 - Vs(t) Is that method I followed correct?
Also, T = 1/f = 1/1000Hz = 0.001sec
So a graph I created is the following (supposing that Vs(t) is a sinusoidal signal with initial phase 0 degrees):
I know the graph is not very good but I want to know if it's correct. Thanks.