# Op AMP Integrator Circuit

Discussion in 'Homework Help' started by slydog895, Apr 30, 2014.

1. ### slydog895 Thread Starter New Member

Apr 30, 2014
2
0
Hello everyone, I have a HW question with a simple op amp circuit and was wondering if I could get some help. Here is a quick glance at the problem:
http://tinypic.com/r/fbvqsj/8

and here is my attempt to solve it:
http://tinypic.com/r/2you7ts/8

I am not sure if my signs are correct when solving it. Also should I solve for Vo(t) for each case or did I do it correctly by solving for the formula for a general Vi and then graphing each result separately. Could I also receive some insight on part B. I am not sure how to go about it. the only thing I am thinking is that I multiply Vo(t) by tau and the RC's cancel out but this doesn't seem correct.

Any help appreciated. Thank you!

2. ### WBahn Moderator

Mar 31, 2012
18,087
4,917
First question that comes to mind. Why does your output voltage start where it does? What assumptions are you making about the initial conditions in the circuit?

3. ### slydog895 Thread Starter New Member

Apr 30, 2014
2
0
You are right. I did not state that at t=o Vin=o.

4. ### WBahn Moderator

Mar 31, 2012
18,087
4,917
Saying that Vin = 0V at t=0 is not enough to tell me what Vout is at t=0+.

The main question remains: Why have you chosen the initial value of Vout to be what you indicate in your solutions?