Troubleshooting Nodal Analysis for a 2 PSU Resistor Circuit

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Discussion Overview

The discussion revolves around troubleshooting a nodal analysis (NA) problem related to a circuit with two power supply units (PSUs) and multiple resistors. Participants are attempting to set up and solve the equations governing the circuit behavior, focusing on the application of Kirchhoff's Current Law (KCL) at various nodes.

Discussion Character

  • Homework-related
  • Technical explanation
  • Mathematical reasoning

Main Points Raised

  • The initial equations set up by the original poster (OP) for the nodes are questioned, particularly the equation for Node 4, which the OP believes cannot be solved.
  • Some participants suggest simplifying the circuit to make the analysis easier, proposing that certain resistors are in parallel and can be combined.
  • Others argue that simplifying the circuit may lead to the loss of important nodes, specifically Node 4, which is crucial for the analysis.
  • One participant provides a KCL equation for Node 1, indicating a different approach to the analysis, while noting that their method may differ from the OP's.
  • There is a recognition that the equations for Nodes 1 and 2 may need to be verified for correctness, especially after the OP realizes they omitted some resistors in their calculations.

Areas of Agreement / Disagreement

Participants do not reach a consensus on whether simplifying the circuit is beneficial. There are competing views on the necessity of maintaining all nodes in the analysis versus the potential simplification of the circuit.

Contextual Notes

There are indications of missing assumptions regarding the circuit configuration and the treatment of resistors, as well as unresolved mathematical steps in the equations presented by the OP.

Who May Find This Useful

Students and individuals working on circuit analysis, particularly those interested in nodal analysis and the application of KCL in electrical engineering contexts.

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Homework Statement



see attached

Homework Equations





The Attempt at a Solution


Hey, I'm having trouble with a 2 PSU resistor NA circuit. here is what I've done:
N1=V1
N2=v2
N3=v3 = 0V
N4=v4

0=(10-v1)/4K7-V2/10k-(V1-V2)/1K

0=(V1-V2)/1K-(V2-V4)/470-(V2-V4)/1K

0=(V4-5)/10K-V4/10K

there's at least something wrong with eq 3 because it can't be solved?

Thanks for any help
 

Attachments

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Perhaps you can simplify the circuit first? I think that R4 and R5 are in parallel and the resulting R45 in series with R2.
 
Shouldn't it be easy enough without simplifying + I lose node 4 if I do that.
 
Do a KCL at Nodes 1-4.

Hah...just read it and saw you did already I think.

But as an example at Node 1...

(Vx1-10)/R1 + (Vx1-Vx3)/10K + (Vx1-Vx2)/1K = 0

I think in your KCLs you worked backwards compared to me so not sure if this will help or confuse you.
 
thats the same as mine I think, V3=0V

node 4 is what I have wrong I think.

Thanks
 
Node 4:
(Vx4-5)/10K + (Vx4-Vx3)/10K + (Vx4-Vx2)/470R + (Vx4-Vx2)/1K = 0

Should be right for that node.
 
arhh I forgot to include the R's up the top, can you tell me if my EQ's for N1 AND 2 are correct.

thanks
 

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