Thevenin Definition and 318 Threads

  1. James889

    How to Calculate Thevenin Equivalent with a Dependent Source?

    Hello, I have the following circuit [PLAIN]http://img143.imageshack.us/img143/2213/theveningdependantsrc.png I need to calculate the Thevenin equivalent circuit. I don't really know where to start. Can i zero the independent source and calculate the resistance? Or do you start by...
  2. E

    Help with thevenin - dependent sources

    Homework Statement It is not so important for my question Homework Equations So first of all, sorry to just barge in and post this question, but I am not sure how to solve it. I have attached images of the circuits. The task is to find the equivalent thevenin or norton generator. My problem...
  3. T

    Solving Thevenin Equivalents: Techniques and Steps

    Homework Statement Compute the values of the Thévenin equivalent seen by the 20 kΩ resistor using circuit analysis techniques. Draw the equivalent circuit and list the values. Homework Equations V=IR Nodal analysis mesh analysis The Attempt at a Solution I know a Thévenin...
  4. L

    Engineering Finding Thevenin Equivalent Circuit for Complex Network

    Homework Statement I wish to obtain the Thevenin equivalent for the network show in the attachment between the terminals a and b. 2. The attempt at a solution First I considered the voltage source alone (replaced current source by an open circuit). I = \frac{V}{Z_T} =...
  5. H

    Open Circuit Voltage, Thevenin Equivalent

    Homework Statement Find the open circuit voltage across A & B: Homework Equations V = IR The Attempt at a Solution If I0 is the current leaving the voltage source and passing through the first resistor, I1 is the current through the left resistor in parallel, and I2 through...
  6. M

    Solving Thevenin Equivalent with 1 Point & Ground

    Hey I can't figure out how to convert the below circuit into its thevenin equivalent. I am used to having two points to work with, but in this circuit there is only one and a ground. http://img715.yfrog.com/i/13332492.jpg/ for some reason the image doesn't show up on my screen; if that's the...
  7. E

    Thevenin equivalent q. (AC analysis)

    Homework Statement ^We're asked to find the "Thevenin's equivalent circuit for the source" The Attempt at a Solution I'm a bit unsure how to start this problem. What i initially thought was that i'd combine all my impedances in parallel to the point where it's them combined plus the...
  8. R

    Engineering Circuits Question: Thevenin Equivalent

    Homework Statement Find thevenin equivelent of this circuit with respect to a and b Homework Equations Mesh Currents The Attempt at a Solution Here I will try to find V(open circuit) = Vth = Vab ((I think this anyways)) I apply mesh currents (any faster methods are welcome if...
  9. V

    How can I solve a Thevenin problem involving two batteries?

    Homework Statement Hi there, I got this question from an old test. I would say I have limited knowledge of electronics and would ask for guidance into what approach to take with this question. Homework Equations The Attempt at a Solution No attempt yet. I thought of breaking it...
  10. P

    Engineering How do I solve for the voltage across a and b in this Thevenin circuit problem?

    Homework Statement V1 = 15 V V2 = 4 V I = 2 A R1 = 3 Ohm R2 = 4 Ohm R3 = 8 Ohm R = 2 Ohm In this part of the question, I have to solve for the voltage across a and b R isn't listed as a resistor in this circuit because that comes in a later part of the question (which I can do). Homework...
  11. M

    Why Can't I Solve for Is Using the Left Loop in Thevenin Voltage Problems?

    Hi, this isn't homework, just a practice problem (for which the solution is given)I found online that I am trying to prepare for my midterm next week: My question is why can't I simple solve for is using the left loop. So 5V-500is-400(6ma)=0, which gives is=5.2ma...alternatively I didn't...
  12. M

    What is the Thevenin Equivalent for a Circuit with a Voltage-Controlled Source?

    Homework Statement I am being asked to draw the Thevenin equivalent for and to calculate the voltage that would appear across RL if it were connected across the 2 output terminals. Using Kirchoff's law I found that the voltage across RL is -12.5 V. However I am really suppose to do it using...
  13. I

    Norton and thevenin equivalent

    Homework Statement The circuit is attached as a jpg image. How can i find the norton equivalent when both current sources and voltage sources are present? please help Homework Equations The Attempt at a Solution
  14. R

    Solve Thevenin & Diodes Homework with Ideal Diode

    Homework Statement http://img444.imageshack.us/img444/5601/scan0001my.th.jpg Hey, I'm trying to solve this problem using thevenin's method. As you can see in method 1 I was able to solve for the correct output voltage of 7.5 volts. When I try Thevenin's method I get 4 volts. I have a...
  15. M

    Engineering Introductory circuit analysis - thevenin circuits

    Homework Statement Homework Equations Thevenin stuff, right? The Attempt at a Solution So, I tried to re-write everything and make it a bit easier to understand: I ended up getting Rth completely fine and everything, but I can't seem to get Eth. So from there, I...
  16. C

    Find Thevenin Equivalent at A-B in Circuit

    Homework Statement Find the Thevenin equivalent at terminals A-B of the circuit below. http://img5.imageshack.us/img5/1723/thevenin.jpg Homework Equations The Attempt at a Solution
  17. N

    Need help calculation Thevenin equivalent

    On the first image i have to find the thevenin equivalent viewed from terminals x, x' & y, y' i get the Req as 7.32ohms but now i am having trouble calculating the vth, i have no I to calculate thanks in advance
  18. C

    Thevenin equivalent circuit with a load

    Homework Statement Show that if a battery of fixed emf E and internal resistance R1 is connected to a variable external resistance R, the maximum power is delivered to the external resistor when R=R1 Homework Equations Power = R * I^2 The Attempt at a Solution We can think of...
  19. Y

    Thevenin voltage and resistance

    Homework Statement Calculate the Thevenin voltage Vt and the Thevenin resistance Rt. Homework Equations V=(Vt*R)/(Rt+R) I=Vt/(Rt+R) The Attempt at a Solution I'm thinkin that my R is 1 ohm but I can't figure out how to simply the rest of the resistors to get Rt. If I can get...
  20. N

    Current Proportionality and Thevenin Equivalence

    Homework Statement For the linear circuit shown, given that the current I in the 0.9 K\Omega is 10mA when Vs = 100V: (a) Predict I using the proportionality property for: Vs = 25V, -12V, and 145 V respectively. (b) Use Thevenin’s theorem across terminals a and b. Find I in terms of Vs and...
  21. B

    Engineering Check my work please - Circuits Thevenin Thm Prob

    Not sure if I am using the right technique or even using the technique correctly... http://img8.imageshack.us/img8/6346/practiceprob.th.jpg http://img44.imageshack.us/img44/8479/workedpracticeprob.th.jpg
  22. D

    Quick question about finding Thevenin equivalents

    Homework Statement When finding the Thevenin resistance for a circuit, there is a method involving applying either a test voltage source or a test current source at the terminals a and b. My teacher didn't really go into this in very much detail so I was wondering if you can specify any value...
  23. M

    Finding Thevenin and Norton question

    Homework Statement Finding the Thevenin and Norton equivalent circuit The Attempt at a Solution Just wondering whether i have done it right? So the Thevenin circuit has a voltage supply of 12V, in series with an 8 Ohm resistor, while the Norton circuit has a current supply of 1.5A in...
  24. Q

    Find Thevenin Equivalent Resistance for Network

    Homework Statement Find the Thevenin Equivalent resistance for the network below: http://img27.imageshack.us/img27/8508/circuit.png Homework Equations R=(1/R1+1/R2)^-1 The Attempt at a Solution Hi all, to find the resistance i short circuited the volage sources and...
  25. S

    Thevenin and Norton Equivalent Circuits problem

    Hi, I found this question from a textbook: Suppose there are two black boxes, Box A has a 1V voltage source and 1ohm resistance (Thevein Circuit); and Box B has a 1A current source and 1ohm resistance (Norton Circuit). You only have access to the two terminals. How do you know which is which...
  26. S

    Thevenin with Variables: Finding Thev Eq for Nodes A and B and C and D

    Homework Statement For the circuit shown: Find the Thev Eq between nodes A and B and then for nodes C and D. I worked the second half of the equation but am stuck on how to begin the analysis for the opposite end of the circuit. I have attatched the image as well as posting it as I am having...
  27. J

    Thevenin Equivalent Resistance for a Black Box

    Homework Statement I am trying to find the theoretical Thevenin equivalent resistance for a black box that I used in an experiment. The measured Thevenin equivalent resistance was roughly 4786\Omega. However, I have tried several times to solve the problem, but keep arriving at a theoretical...
  28. J

    Thevenin Equivalent Resistance for a Black Box

    Homework Statement I am trying to find the theoretical Thevenin equivalent resistance for a black box that I used in a circuits experiment. The measured Thevenin equivalent resistance was roughly 4786\Omega, so the theoretical should be somewhere around that. However, I have tried several...
  29. S

    Thevenin Equivalent: Solve DC Power Supply 30V/400mA, 27V/600mA

    Homework Statement Find the Thev Eq circuit for a DC power supply that has a 30-volt terminal voltage when delivering 400mA and a 27-volt terminal voltage when delivering 600mA. Homework Equations KVL: Vs=IsR1+IsR2 Vth=Isc*Rth The Attempt at a Solution Assuming that each 3volt...
  30. S

    Engineering What is the Thevenin Equivalent Circuit for a Car Battery?

    Homework Statement A car battery has an open-circuit terminal voltage of 12.6 volts. The voltage drops to 10.8 volts when the battery supplies 240 amps to the car's starter motor. What is the Thevenin eq for this battery? Homework Equations I think the root of my problem is the setup of...
  31. B

    Thevenin without removing load resistor

    I'm having trouble with Thevenin models, specifically this question where the V_oc is not given. The problem: Assume an unknown circuit provides the specified current through the load resistors as given below: 100k - 2.3mA 1.2M - 510uA Find a Thevenin model for the unknown circuit. All...
  32. S

    Thevenin Equal Resistance - Strange Circuit

    Homework Statement I want to find Rτ (Thevenin Equal Resistance) if the load is R4 in the attached image's circuit. As easy it may seem, I get confused because it asks for the equal resistance between A and B. Homework Equations The Attempt at a Solution We remove the voltage sources and...
  33. S

    Engineering Thevenin Equivalent for circuits with dependent sources

    Hi! Good day! I was studying Circuit Theorems when I stumbled upon this circuit that has a dependent current source asking for a Thevenin equivalent. Up until now, I was only familiar with solving circuits with independent sources so this has me having a hard time. I tried using...
  34. T

    How can I understand the Thevenin Theorem and its formula for e?

    Homework Statement hey guys. I am new to the board. I've seen this problem on a website of which i'll list below. I am not sure how came up with that formula for e. http://hyperphysics.phy-astr.gsu.edu/HBASE/electric/thevenin.html -> is the link to the page. i understand the rest of...
  35. A

    Finding Thevenin Equivalent: 6 Ohm Resistor

    I have to find the thevenin equivalent of the following circuit in order to find the current and potential difference across the 6 ohm resistor. I can not get to know that where should I start. Should I divide the circuit into 2 parts or what? http://img141.imageshack.us/img141/2690/416qr1.th.jpg
  36. C

    Thevenin impedance with mutual inductance

    Homework Statement I have a part of circuit with 2 inductors (L1, L2) of given values having a given mutual inductance, and a (capacitor+inductor L3) parallel to L2. Please find attached the circuit.Homework Equations Find the impedance of this part of the circuit.The Attempt at a Solution (all...
  37. L

    Thevenin equivalent circuit problem

    I start with the Thevenin equivalent. \hat{R} = R_2 + R_4 || R_1 = 6 \Omega R_{Th} = R_3 + \hat{R} || R_5 = 8 \Omega The correct answer here should be 2 \Omega
  38. J

    Finding Thevenin Equivalent of Circuit

    Finding the thevenin equivalent of the above circuit This is what I did, I set the current source to zero, no current passes through so the Rth is the resistor on farthest right // with another 2 in series with 4. so it is 5ohms? Finding the open circuit voltage, I use a current...
  39. P

    Engineering Why Does My Thevenin Resistance Calculation Differ from the Expected Result?

    I don't know which node to take as zero voltage. Either C or B or both. Finding Out I-V characteristic of +V-. Considering Vb = 0. ASSUMING V IS SOME LOAD I = I2 - I3 I = ((Va - Vd)/10) - ((Vc - Vb)/10) I = ((7 - 5)/10) - ((Vc - 0)/10) I = 0.2 - Vc/10 Where Vc - Vb = V Considered Vb = 0 So Vc...
  40. J

    Engineering Thevenin Equivalent in AC circuit

    Hi All, My name is Joaquim and I'm new in this forums. I am a Electronic Engineer student (1st Year). I have a question about a Thevenin equivalent circuit in AC. I need someone to tell me if I'm doing the right math in finding the thevenin equivalent (AB point): Please see the...
  41. T

    Engineering Thevenin circuit, voltage problem

    Homework Statement Ok, i don't understand how they calculate the voltage. how are they getting the Vx? How do i read the circuit to know when to subtract, and add voltages? Also for Voc why do they add them together ? \
  42. T

    Engineering Find Rth in Thevenin Circuits: Use Resistors to Find Voc

    So to find Rth why did they choose these resistors. After choosing those resistors to find Rth , then i must use those resistors and go in a loop to find Voc ?
  43. J

    Engineering Calculating Current in Thevenin Equivalent Circuit?

    I trying to figure out a thevenin equivalent circuit I want to calculate the current I so I can't get the resistance for the thevenin equivalent. Im not 100% sure how to calculate I, can I use KCL on the node under the number -8.7V? http://img98.imageshack.us/my.php?image=curfc7.jpg
  44. D

    Engineering What is the Thevenin equivalent circuit?

    Homework Statement I really don't see how the Thevenin equivalent circuit is obtained from the one on the left. The way learned to find Thevenin equivalent circuit considers the circuit network in between 2 nodes. This one appears to have 3 nodes. And why is the thevenin resistance given as...
  45. W

    Engineering Phototransistor modeled as a Thevenin equivalent circuit

    Homework Statement you have a phototransistor that you have modeled as a Thevenin equivalent circuit. It has a output impedence(Thevenin Impedence) of 10kohm and produces a peak voltage o2 2V at a frequency of 80 MHz. The input impedence of the oscilloscope as this simple combination of input...
  46. J

    Why Does Superposition Give Different Results in PSPICE?

    Never mind, did superposition incorrectly. Homework Statement http://img258.imageshack.us/img258/9206/jesus2gn2.th.png Find Vload using superposition and thevenin's equivalent Homework Equations The Attempt at a Solution Well for network on the left of Rload, I found Vth...
  47. O

    Engineering Finding Thevenin Equivalent Circuit

    Hello, I am working on the following problem: http://img155.imageshack.us/img155/2478/thevpo9.jpg I am stuck on this seemingly simple circuit problem. I've worked many Thevenin circuit problems in my introductory circuit analysis. This problem is from a new class and seems different...
  48. D

    Thevenin Resistance Homework: Find max Power Transferred & Delivered

    Homework Statement Basically asking me to find the Thevenin/Norton's equivalent across a-b. Then figure out the maximum power transferred Then figure out max power delivered Homework Equations Maximum power is transferred when R_{l} = R_{th} . Max power delivered is \frac{V_2}{4R_{th}}...
  49. F

    Two source circuit thevenin and norton

    Can someone help me detemine The thevenin Voltage, the thevenin resistance and the Norton current of this circuit I can't solve it cause it has two current sources I have uploaded the picture Thank you
  50. K

    Electricity: Norton and Thevenin Theorem applications

    i've got a problem about the thevenin and Nortn models applications. i've been given a table giving 3 outpout voltages(v1= 200v,v2= 150V,v3 = 100v) from the voltage sources with their corresponding current(I1= 0A,I2= 12A,I3=22A). The question was to draw a V-I diagram and draw the...
Back
Top