Node voltage Definition and 61 Threads

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.

View More On Wikipedia.org
  1. D

    Simple Node voltage method problem

    Homework Statement Use the node voltage method to find v in the circuit shown. (picture of circuit attached) Homework Equations The Attempt at a Solution v1 + (v1 - v2)/8 = 4.5 (v2 - v1)/8 + (v2)/12 + (v2 - 30)/4 = 0 Solving for v1 and v2 I get: v1 = 6 V v2 = 18 V I...
  2. J

    How can Kirchhoff's Laws be used to find node voltage in a circuit?

    Hi.. I'm trying to figure out how to find voltage over nodes in a circuit can anyone give me a crash course or just explain it... I've been using KCL to find it but my voltages are always out of whack... any suggestions would be helpful
  3. S

    How do I know when to use the Mesh Current Method or Node Voltage Method?

    These two methods seem like they can be applied to the same situations, and I don't really know when I should apply one over the other. I've only just learned the methods so I'm not very familiar with either though. I'd appreciate any help from general guidelines to specific examples.
  4. Z

    Determining node voltage using Mesh Analysis and Thevenin's Theorem

    Homework Statement Using mesh analysis work out the currents flow through each of the three meshes. From these current values calculate the voltage of node A, and node B with respect to the ground node. Find equivalents of sub circuits A-G, B-G, A-B by applying Thevenin's theory. Then...
  5. M

    Understanding Sign Conventions in Node Voltage Analysis

    There is one thing i can't seem to figure out and it is the sign convention for circuits. On one side my textbook says that it is arbitrary and a neg sign in some cases means that we didnt chose the correct polarity and in some cases i feel like it is some kind of vodoo magic. I don't get how...
  6. D

    Help with Node Voltage Analysis

    Say you are analyzing a circuit. Will the node voltages depend on where you set your reference node? Because, i did a circuit problem and set the reference node to a different node each time and, i got the same answer overall, but my potential across a certain node was different each time. Am...
  7. P

    How Do You Calculate Equivalent Resistance Using Node Voltage Analysis?

    Find the equivalent resistance looking into terminals a-b for the network. Hint: first connect a 1A current source across terminals a and b. The solve the network by the node-voltage technique. The voltage across the current source is equal in value to the equivalent resistance. So I've...
  8. N

    Node Voltage Method in Circuit Analysis

    I really don't understand exactly how they got the term highlighted in yellow. We want to get all values for all of the currents coming into or out of the node...so why does it have what appears to be the voltage across the 1 ohm resistor divided by the equivalent resistance of the 1 ohm and...
  9. S

    Understanding Op Amp Node Voltage Analysis: Equation Differences at Node D

    Hey, I think I need a little help understanding node voltage analysis with ideal op amps. For the circuit I've attached, at node D, I wrote the equation ((1/1000) + (1/1000))Vd - (1/50000)Vc - (1/1000)Ve = 0 However my prof's equation for node D is: ((1/1000) + (1/1000))Vd - (1/1000)Ve = 0...
  10. L

    Solve Node Voltage Equations for Circuit w/ 10V Power Source

    Can anyone help me find node-voltage equations for this circuit. The 10V power source is throwing me. Thanks.
  11. L

    Understanding Conventional vs Electron Flow in Node Voltage Analysis

    The question asks me to find i_o and V_o I'm not sure how to do it since I don't know which way the current goes on the 8 ohms resistor. any ideas?
Back
Top