What is Nodal analysis: Definition and 176 Discussions

In electric circuits analysis, nodal analysis, node-voltage analysis, or the branch current method is a method of determining the voltage (potential difference) between "nodes" (points where elements or branches connect) in an electrical circuit in terms of the branch currents.
In analyzing a circuit using Kirchhoff's circuit laws, one can either do nodal analysis using Kirchhoff's current law (KCL) or mesh analysis using Kirchhoff's voltage law (KVL). Nodal analysis writes an equation at each electrical node, requiring that the branch currents incident at a node must sum to zero. The branch currents are written in terms of the circuit node voltages. As a consequence, each branch constitutive relation must give current as a function of voltage; an admittance representation. For instance, for a resistor, Ibranch = Vbranch * G, where G (=1/R) is the admittance (conductance) of the resistor.
Nodal analysis is possible when all the circuit elements' branch constitutive relations have an admittance representation. Nodal analysis produces a compact set of equations for the network, which can be solved by hand if small, or can be quickly solved using linear algebra by computer. Because of the compact system of equations, many circuit simulation programs (e.g., SPICE) use nodal analysis as a basis. When elements do not have admittance representations, a more general extension of nodal analysis, modified nodal analysis, can be used.

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    Master Nodal Analysis with this KCL Question | Nodal Analysis Homework

    Homework Statement Homework Equations KCL The Attempt at a Solution I recognise that the voltage sources form supernodes. This produces: A - B = 10 -> A = 10 + B We also know that node C is 12v. I then form KCL equations: 6 + \frac{A - C}{12} = \frac{B}{40} + \frac {A}{24} When I...
  2. A

    Confused with Nodal Analysis and Voltage Sources! HELP!

    The question might be simple for you guys but the problem is that it is not for ME ! I have a circuit and I have to determine the node voltages by Nodal Analysis method. And the one which I learned was in cases when we had a current source, I could simply write the equations using KCL...
  3. S

    Solving V0 Using Nodal Analysis

    Homework Statement I have to solve for V0 , using nodal analysis. I am getting different answers in MATLAB and PSPICE. The circuit is below 2 supernodes ; or 1 big supernode Here are my nodal equations: v1-v3 = 12 v3 - v2 = 6 (v3)/6k + (v1)/4k - 6/k = 0 Matlab output is here...
  4. O

    Engineering Nodal analysis algorithm applied to a circuit without voltage sources

    Homework Statement I am having some trouble with the nodal analysis algorithm explained in this web page http://www.swarthmore.edu/NatSci/echeeve1/Ref/mna/MNA3.html My electrical circuits knowledge is very basic, and I need to get the equivalent resistance of a circuit for a non related...
  5. W

    Nodal Analysis using Complex Numbers

    Hi, I would be grateful of any advice on how to solve the problem below. My aim is to find the voltages at nodes 2, 3, and 4, by means nodal analysis and thus creating simultaneous equations and solving them using matricies or matrix in order to prove that these theories work. I...
  6. W

    Nodal Analysis Help using matrix

    Hi, I would be grateful of any advice on how to solve the problem below. My aim is to find the voltages at nodes 2, 3, and 4, by means nodal analysis and thus creating simultaneous equations and solving them using matricies or matrix I understand kirchhoffs law etc however its the...
  7. M

    Nodal analysis (Node-voltage method) for op-amps?

    Hi, I am just beginning to learn about op amps and I was wondering if there was a way to use the node voltage method (nodal analysis to some) to solve these circuit without replacing the op amp with its equivalent ideal amplifier. To me, it is much faster to use node voltage method than going...
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    Engineering Nodal Analysis Problem (Basic Circuit Analysis)

    Homework Statement Find v1 and v2 from the given picture. Homework Equations Ohm's law, V=IR Current Division The Attempt at a Solution I tried to use current division. The 6A source split into 2, giving 2A down the 8 ohm resistor and 4 amperes down the 4 ohm resistor. Since...
  9. N

    Understanding Nodal Analysis: How Voltage at Node D is Calculated

    Guys l would like to know how does the the voltage at node D become : Vd=-(Vc-Va)=Va-Vc
  10. C

    Engineering Need guidance on this circuit question using nodal analysis. Confused.

    http://i615.photobucket.com/albums/tt237/chaz0426/Problem2.jpg it asks to solve for V1 and V2 using nodal analysis however I'm not sure how to solve this particular one because there is a voltage source and a resistor between the reference node and V1and I'm not sure what to do. Here is what...
  11. A

    Can I Use My TI-84 for Nodal Analysis with Rectangle and Polar Form?

    Hi, I was wondering if it's possible to solve nodal analysis problems that include rectangle and polar form using the TI-84. It just gives me an error when I put in "i" as in imaginary when trying to put up my matrix. I've read it's possible to do with the TI-89, but I'd really rather not...
  12. A

    Nodal analysis with 2 voltage sources

    Can someone solve this circuit Find v and i in the circuit. I know that we have to make somethng with supernode, but where the supernode is here? How to develop this problem? Please help me :) Btw it is nice forum, today i have found that. I hope I will be able to help you in other...
  13. A

    Electric Circuit to solve with nodal analysis

    Can someone solve this circuit Find v and i in the circuit. I know that we have to make somethng with supernode, but where the supernode is here? How to develop this problem? Please help me :) Btw it is nice forum, today i have found that. I hope I will be able to help you in...
  14. M

    Calculating Voltage and Power with Nodal Analysis

    Homework Statement Consider the circuit shown (attached). Calculate the voltage v and calculate the power for the 2A current source. In this particular case, is it supplying or absorbing power? Homework Equations The Attempt at a Solution I know that there is 2A flowing around...
  15. M

    Solving Circuit Analysis with Nodal Analysis - Help Needed!

    Hey guys. I have attached a circuit that i am trying to analyse using nodal analysis. This is how i am doing it: at node 2: (v2-v1)/1 + v2/4 + (v2-v3)/1 = 0 at node 3: (v3-v2)/1 + v3/2 = 4A at node 1: v1/25 = 2A but i am not getting the right results for v1, v2 and v3. Can...
  16. T

    How Do I Solve AC Nodal Analysis Equations on an HP 50g Calculator?

    I've got a small issue at hand right now. I need to solve simultaneous equations with unknowns in order to do mesh and nodal analysis problems. The issue is, i can't figure out how to enter the equations into get an answer out. My previous calculator was a t183+, so I'm not that well...
  17. J

    Solving Question 1(b) Using Nodal Analysis

    Homework Statement i haVE tried to solve it no. of ways but i didn't get the right answer. Please have a look on the question 1(b) in attachment Figure 1(a), I want to know that how can i solve this question by using nodal analysis. Please explain your answer as well so i could clear my...
  18. A

    Master Loop and Nodal Analysis with Expert Tips and E-books

    Could u guys reccomend some e books for loop and nodal analysis . I am having some problems implenting the methods to solve poblems. or may be u could give me some tips
  19. V

    I really need to learn how to do Nodal Analysis by Inspection before Wednesday

    I really need to learn how to do "Nodal Analysis by Inspection" before Wednesday! My Prof. told us (very quickly) about some easy method for circuit analysis called "Inspection". Can someone explain, in detail, how this is done? If you want a circuit to demonstrate on, just check my old posts...
  20. D

    Engineering Nodal Analysis For Circuits class

    Homework Statement Hi guys, I solved this problem out. I'm just curious as to see if my work is valid. I strongly believe it is, but perhaps you can help me. I do have a quick question... once I've found all the voltages at specific nodes, I_o is the difference of the voltage / resistance...
  21. R

    Simple Nodal Analysis: Solving Homework

    Homework Statement http://img258.imageshack.us/img258/2152/screenshot01kf5.th.jpg Homework Equations KCL KVL V = IR The Attempt at a Solution I used 4 nodes at the top, one reference node at the bottom. I have it labeled V1, V2, V3, V4, starting from the far left -> right. My nodal...
  22. V

    Engineering Solve V_0 & I_0 in Circuit w/ Nodal Analysis

    Homework Statement Using nodal analysis, find v_0 and I_0 in the circuit below. http://img248.imageshack.us/img248/7325/chapter3problem301dy.jpg Homework Equations KVL, KCL, V = i R, Super-nodeThe Attempt at a Solution So I added 3 current variables, 3 node markers (V_1\,-\,V_3), a super...
  23. V

    Engineering Solve V_A in Circuit with Nodal Analysis

    Homework Statement Use nodal analysis to find V_A in the circuit below. http://img180.imageshack.us/img180/7004/chapter3problem236vy.jpg Homework Equations KVL, KCL, v = i R, super-node?The Attempt at a Solution I made a few currents and showed the obvious KVL loop...
  24. V

    Understanding Nodal Analysis: Exploring Voltage Distribution in Circuits

    Hi, I just have a quick question about nodal analysis in the attached file. At v1 and v3, is it not necessary to take into account the current going to the right and left respectivley? So at v1, -6V + (v1 - v2 / 6k) and at v3, 24V + (v2 - v3/4k) Thanks a lot!
  25. V

    Solving for v_1, v_2, and v_3 with Nodal Analysis

    Find v_1,\,v_2,\,and\,v_3 in the circuit below using nodal analysis: My work so far: I\,=\,\frac{v_1}{2\Omega},\,\,I_1\,=\,\frac{v_2}{4\Omega},\,\,I_2\,=\,\frac{v_3}{3\Omega},\,\,I_3\,=\,\frac{v_1\,-\,v_3}{6\Omega} KVL @ loop1 => -I\,(2\Omega)\,+\,10\,V\,+\,I_1(4\Omega)\,=\,0...
  26. D

    Determining Frequency Response Using Nodal Analysis

    I am trying to find the frequency response for the given circuit. My instructor recomended using a nodal analysis method. However, while attempting to use the nodal analysis I end up with all my variables equaling zero (Va = 0, Vin = 0 and Vout = 0). Is there something I'm missing or over...
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