What is Node voltage: Definition and 61 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.
Hello.
I'am practicing circuit analisis about the norton and thevenin's circuits and I can't seem to manage to get the right thevenin's voltage using the node voltage for a)
resolution
1) I did source transformation turning the current source(2A) into a voltage source (10V)
applied node voltage...
Hello.
Can someone give m e pointers on how to find the value of vx given that it is inside a supernode(will it be the valueof the voltage inside or the difference of potential between the two nodes?): here's the exercise and what I've done so far attached.
Your time and attention are deeply...
Hi!
I'm trying to understand and solve this circuit by Node Voltage Method. I have to calculate u(t). In my mind, I don't have any idea if any current should go through Z1 in my calculations.
I would be grateful if you could write even equations for this circuit. Is 'a' just a prefix to multiply...
I am given that all the BJTs are the same.
First of all, when finding node voltages like Vref should I make the node voltage a voltage source first and then do circuit analysis? If so then I would use KVL but that does not give me Vref = 2Vbe.
I do know that Vref = Vb1 = Vb2. What am I doing...
Hello,
Here's the example I'm looking at now.
I am wondering if I swap ground and Node C... will this still be correct? I can see how it's more useful to have ground where it is above, but I'd still like to know if it would work for a swap of C and GND.
Here's my work trying this:
Does...
Homework Statement
For the given circuit (see below), find the voltage across resistor 3.
Homework Equations
n-1 Kirchhoff's Current Laws for n nodes.
The Attempt at a Solution
Can anyone verify whether my KCL equations are correct? The mixture of source voltages with node voltages may...
For the B) part, I don't get why is it that for calculating voltage between collector an the emitter (Vce) I take into account diode on base (0.7V), whereas for part A) it's ignored?
Why is Vce in part A and part B are calculated differently? Why is it that in part A voltage of 0.7V isn't taken...
is= 1.2 mA
i submitted my solution but it was wrong,can someone please explain why?
/* i just wanted to check if my solution is correct so i don't lose marks on my homework
did i do any mistakes ?
if so please explain.*/
my solution:
Okay, so why is it that Vc assumed to be 12v - 0.7v (D1), how about contribution from the 9v battery?? Why is this not affecting the voltage at node C?
Why Vc isn't 9v - 0.7v (D2) = 8.3v?
Homework Statement
I am wondering if in this circuit Vb will be 0V?
Homework EquationsThe Attempt at a Solution
I have found all the other ones, but I am unsure if Vb will be 0 or not, and if it is then what is the logic behind it?
1. Homework Statement
The circuit is driven by a voltage source,
Vs(t)= 8.2 cos(1.8 t − 0.25 )V .
The circuit elements are given as follows.
G1= 5 S,G2= 7.6 S,G3=3.8 S
(Gi is the conductance of corresponding resistor Ri)
L1= 20 H,C1= 5×10−2 F
If we select Node 4 as the reference node...
Homework Statement
Homework Equations
Node Voltage Method
V=IR
The Attempt at a Solution
So I have never worked with a bridge/ladder circuit before and I am not sure if I am doing it correctly. My professor never gave us an example of a bridge/ladder so I'm kinda winging it. Anyway can I...
Homework Statement
Find the voltage, V, across the 6A current source
Homework Equations
V=IR
Node Voltage Method
The Attempt at a Solution
Did I set this up correctly to find my voltage?
Homework Statement
Hi all, how do I know how the current direction are through each elements after solving a circuit (finding node voltages w.r.t GND)?
I think my understanding in electricity is rather incomplete. For example, I know that current should flow from a higher potential to a lower...
[Mod note: Post moved to new thread, so template not included]
Hello there again!
I started working on the second problem but I think I am doing it wrong so I thought I would post the first step and do this one step at a time to see where the mistake was.
So the task is to determine UR3 and...
Homework Statement
Find V1. I attached a picture for the circuit.
Homework EquationsThe Attempt at a Solution
This is what I did (Refer to Fig. 1):
-2A + (V1)/(50) +(V1-45)/(1) = 0
But when I looked at the solution my professor posted this is what he did (Redrew Fig.1 as Fig.2):
-2A +...
Homework Statement
Use node voltage analysis to determine values for I1, I2, and I3. If a current has a negative value, then the reference direction chosen was incorrect and the current is positive in the opposite direction.
I attached a picture of the circuit. The things in blue (current ix...
Good evening people. Recently I started taking the "electric network analysis" course in my school. We already saw the mesh analysis method for solving circuits. Now we are seeing the node analysis method. I understand that the first step for this method is finding the number of nodes (and one...
Homework Statement
Determine the three node voltages, va, vb, and vc, when all the conductance's are equal to 1S
Circuit Diagram:
The labels are a bit cut off, hope you guys can see it. The current source parallel with G2 is 3A
Homework EquationsThe Attempt at a Solution
[/B]
I think their...
Homework Statement
From the above circuit find VCB and VDG
Know Data:
VE = 0 (ground)
Homework Equations
KCL and Ohm's Law are used in Node Voltage Method.
The Attempt at a Solution
I decided I would determine the node voltages then work out VCB and VDG afterwards.
1. KCL and Ohm's law at...
Homework Statement
Use the node-voltage method to find v0 in the circuit below.
Homework Equations
i1+i2+...in=0
i=v/R
The Attempt at a Solution
So I set my reference node to the top of the middle line(above 25Ω)
Equation...
24V/(20+80)Ω+v0/25+.004A=0
Now I can solve for...
In the attached picture, I have the problem and the equations I've come up with to solve for the requested variables. I have found seven equations for the seven unknowns, however, after plugging them into a calculator my answer is wrong. Which equation(s) is/are wrong, and why?
Relevant...
Homework Statement
(I added in the R values for reference)
Homework Equations
GV=I
KCL
The Attempt at a Solution
I am not concerned with the MATLAB portion of the problem, only the setup.
I think what the problem wants me to do is:
1) connect a 1A test current from the...
Hi, I am given a node voltage problem to find V1, V2, and V3 from this image below.
http://puu.sh/77Sg3.png
(v1+15)/20 + (v1-v2)/25 + (v3-v2)/50 + (v3 - 10)/10 = 0
18V1 - 12V2 + 24V3 = 50
V2: (v2-v1)/25 + v2/40 + (v2-v3)/50 = 0
17V2 - 8V1 - 4V3 = 0
15 = V3 - V1
Am I in...
I am having a hard time trying to determine the voltage at VA and VB. I know that VC = VD = 10V. At first I thought this would be a simple setup, but I'm unsure about how to set up an equation for VA considering that there is a resistor and a voltage source between it and the reference node...
Homework Statement
Find the voltage Vo using node voltage method specifically.Homework Equations
The Attempt at a Solution
I am able to get the correct answer when finding the equivalent impedance, then determining the current, and then finding the voltage at the first node V1 by subtrating...
Hey PF I need your help...again!
Homework Statement
Use Node Voltage Analysis to solve the unknowns in thishttps://dl.dropboxusercontent.com/u/53341615/Question.png
The Attempt at a Solution
Im quite confused and have had many attempts...
Homework Statement
Homework Equations
ƩCurrent(in) = ƩCurrent(out)
The Attempt at a Solution
----In situations like that, my book takes the node to be a positive voltage when the voltage source is connected like above. For some reason my professor takes it to be negative, is this why my...
Homework Statement
I'm having problems finding the power.
I should my work to get the node voltages. Apparently they are correct. I showed how I got to those answers as well just in case they were wrong but I don't think they are.
http://img547.imageshack.us/img547/8812/capturebu.png...
Hopefully it's ok if I post two questions
QUESTION 1
Homework Statement
Homework Equations
Node voltage analysis method
The Attempt at a Solution
First of all is this circuit equivalent?
(combining the 10 ohm and 4 ohm in parallel, and extending the ends of the protruding 10...
Hi everyone,
I currently stumped in the process of approaching a dependent voltage source problem using node voltages. Attached is the circuit.
What I know:
the Node north of the 60V supply with also be 60V
there are four nodes, two when supernodes are used
What I'm confused...
i solved this problem which asks to find the node voltages ,,
http://im12.gulfup.com/2012-02-19/1329666252272.png
and here is my sol :
http://im12.gulfup.com/2012-02-19/1329666252271.jpg
and finally i found that :
v1 = 226.25 volt
v2 = 20.92 volt
v3 = -63.07 volt
v4 =...
My teacher was going over a thevenin and norton circuit and i understand the thevenin and norton part of it, but the part that confused me was when he did the node voltage at the 2 circled nodes to find Ix. I understand why the bottom node would be zero because it is the reference node but why...
1. Find the power delivered by the 5V Voltage source in the network of Fig.
This is my attept at solution:
At node 1 V1...assuming current leaving V1:
KCL equation: -1A+1A+[(V1-5)/3]+[(V1-(V2-10))/2]=0
At node 2 V2...assuming current leaving V2:
KCL equation: -2A-1A+[V2-(V1+10)]=0...
Homework Statement
Here is the circuit
http://i.imgur.com/Xn2mc.jpg
The Attempt at a Solution
I've tried it a few ways, but the one I'm going for at the moment is this
Node 1: (v1-v2)/10 + (v1-v3)/15 + v1 /5 = 1
Node 2: (v2-v1)/10 + (v2-v3)/10 + v2 / 5 = 2
Node 3: 2Vx where Vx = (v2...
Homework Statement
Solve for V1, V2, V3 and V4 (in decimals) using node voltage analysis method for the following:
Homework Equations:
Node Voltage Analysis
The Attempt at a Solution:
For Node #1:
V_{1} = 6 V
For Node #4:
V_{4} = 16 V
For Node #2...
This question has been driving me crazy because i am unsure when i am able to apply voltage division to portions of a circuit i try to analyze.
I know the potiential difference across a voltage source always needs to be equal to the value of the voltage source but, if the branch coming out of...
Homework Statement
In the figure, use the node voltage method to find the voltage at point A with respect to ground.
Sorry for the crudely drawn picture.Homework Equations
Node voltage analysisThe Attempt at a Solution
First I added R3 and R4. Then I tried to find the current equations...
I have attached the problem and the worked out solution can a few people go over it and post if it's right and if not what is wrong with it.
Using node voltage method
When doing node voltage analysis with KCL. (eg sum of currents into each node = 0). Do we assume all the currents are going INTO the node, or out of the node.
maybe it's just my math but, assuming different things gives different answers. The textbook (hambley's) says that it's fine to select...
Homework Statement
See Figure
Homework Equations
\Sigma i_{out} = \Sigma i_{in}
The Attempt at a Solution
My attempt is in the figure.
Is this is what they are asking for? Or do I need to add something else? Is what I have correct?
Thanks again!
Homework Statement
A satellite is in circular orbit of radius R about a star of mass M . The star
suddenly undergoes an explosion in which one percent of its mass is blown spherically
symmetrically to a large distance. What are the new nearest and furthest distances of
the satellite’s...
Hi,
I have this circuit which i am trying to write KVL equations for, but i just can't seem to get it right...
[PLAIN]http://img146.imageshack.us/img146/3374/upg255.png
The equations i have written so far are:
For v1: \frac{v_1-v_2}{5} +\frac{v1}{10} +1 = 0
For v2: \frac{v_2-v_1}{5} -...
http://i39.tinypic.com/28akmfk.jpg
Ultimately, I am trying to find power dissipated by each resistor.
I already applied node voltage analysis to the circuit.
The picture shows the diagram of the problem and my attempted solution/ equations I came up with. In the diagram, I labeled...
Homework Statement
Find the node voltage
Homework Equations
Va = Vb x R1/(R1+R0)
The Attempt at a Solution
I didnt have the original picture of the question but this example is exactly same as the question that i had to solve. but I don't understand this thing from the first...
First off, I apologize if this belongs under homework help. It’s kind of a grey area I suppose...
Anyway, I just finished my linear circuits midterm. One of the questions on the midterm had a circuit we needed to solve using node analysis. That’s not the question, though. I’ve crudely redrawn...