Solving Op amp with nodal equations

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    Amp Nodal Op amp
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Discussion Overview

The discussion revolves around solving a circuit problem involving an operational amplifier (op amp) using nodal equations. Participants are attempting to find the output voltage (V0) and output current (i0) while sharing their approaches and challenges in applying Kirchhoff's Current Law (KCL).

Discussion Character

  • Homework-related, Technical explanation, Exploratory

Main Points Raised

  • One participant expresses difficulty in solving the problem and requests guidance on current direction.
  • Another participant asks for a demonstration of the user's attempts to provide appropriate help.
  • A participant mentions that if the op amp operates in the linear region, the voltage at the inverting input should be 0V.
  • One participant shares their results but indicates that the calculated current (i0) is incorrect, seeking strategies for solving such problems.
  • Another participant notes that while the current was calculated correctly in a subsequent attempt, its direction was wrong, highlighting confusion about determining current direction at nodes.
  • A participant points out a potential oversight regarding the determination of a voltage (V3) needed for the equations.
  • Another participant identifies that the circuit is an inverting amplifier and specifies that V3 will be -6V.

Areas of Agreement / Disagreement

The discussion reflects multiple competing views and uncertainties regarding the correct approach to solving the circuit problem, particularly in terms of current direction and the application of nodal analysis.

Contextual Notes

Participants have not reached a consensus on the correct method for solving the problem, and there are unresolved questions about the assumptions made in their calculations.

Alex Santos
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Homework Statement


Find V0 and i0 of the circuit.

Homework Equations


KCL

The Attempt at a Solution


I tried multiple times and never got the right answer.
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Hello, I am having trouble solving a problem. I will link a picture of the problem with answers, but it just seems I can't get it right. Also if someone has a good rule of thumb when applying direction of current it would be highly appreciated to get to know it.
 

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Can you show us at least one of your attempts? It's a Forum requirement that before you can receive help you must show some attempt in order that helpers can evaluate the level of help you need.
 
Pleas show as your attempt. And do you know that if op amp works in linear region the voltage at inverting input will be 0V.
 
Yes of course I am trying to do this once again, I will post my results and show you.
 
Here is my attempted result, as you can see the current I0 is incorrect and therefor the rest of the problem is incorrect. Any tips on strategy how to solve those problems is welcome.
Thank you for taking the time to help me.
 

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Here is another attempt, This time I got the current right but in the wrong direction, It confuses me how to determine the direction of current, It always seems like its flowing out of the node all the time at every node.
ieG5LtL.jpg
 
I don't see where you determined V3 to plug into the last equation. Otherwise you seem to be doing okay.
 
It's an inverting amplifier, so V3 is going to be -6V here.
 

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