Non Inverting Op-Amp Circuit Analysis

  • #1

Homework Statement


For an input potential (Vin ) which is a 1V (peak) sinusoidal source. Calculate V1 and Vout
upload_2014-11-6_14-49-48.png

Homework Equations


- The laws for an op-amp
- NVM

The Attempt at a Solution


Here is my attempt not sure if correct.
upload_2014-11-6_15-2-34.png
 

Attachments

  • upload_2014-11-6_14-49-27.png
    upload_2014-11-6_14-49-27.png
    14.3 KB · Views: 462

Answers and Replies

  • #2
NascentOxygen
Staff Emeritus
Science Advisor
9,244
1,073
VB = VA otherwise the OP-AMP is not operating as an amplifier. Fix this and you should be right.

This is a non-inverting amplifier, the input being applied to the (+) input.
 
  • #3
VB = VA otherwise the OP-AMP is not operating as an amplifier. Fix this and you should be right.

This is a non-inverting amplifier, the input being applied to the (+) input.
Cool, just wondering why it is a negative terminal ?
 
  • #4
NascentOxygen
Staff Emeritus
Science Advisor
9,244
1,073
Cool, just wondering why it is a negative terminal ?
Why what is a negative terminal?
 
  • #6
NascentOxygen
Staff Emeritus
Science Advisor
9,244
1,073
On diagram it has (-) for non inverting input.
(-) is the inverting input of the OP-AMP, used here for negative feedback of some output to reduce the gain from its high open-loop value. The circuit's voltage input is applied to the (+) non-inverting input of the OP-AMP.
 
  • Like
Likes cavalieregi
  • #7
donpacino
Gold Member
1,439
283
in addition to Nascent's points, you did some math solving for Vb incorrectly.
you say V1-Vb=0

so that means V1=Vb
why invert Vb?
 
  • #8
psparky
Gold Member
884
32
Dont worry so much about what terminal is negative and so forth assuming this is an ideal amp.
To master op amps just stick to nodal analysis.
In this case, V1=A=B. They are all the same voltage.
We know that no current enters the op amp thru the + and - terminals.
Therefore we can easily find the voltage at A or V1 by using a simple voltage divdier. Vin X (10K/57K) = A
Now you know the voltage at B since the + and - terminals are equal in ideal amps.
Now use nodal analysis, (B / 1k) + (B - Vout)/ 10K = 0.
Solve and you are done.
 
  • Like
Likes Dhruv Dhawan and cavalieregi

Related Threads on Non Inverting Op-Amp Circuit Analysis

  • Last Post
Replies
4
Views
2K
  • Last Post
Replies
3
Views
3K
Replies
3
Views
1K
  • Last Post
Replies
9
Views
1K
  • Last Post
Replies
11
Views
1K
Replies
15
Views
1K
  • Last Post
Replies
5
Views
2K
  • Last Post
Replies
11
Views
19K
  • Last Post
Replies
16
Views
2K
Top