Questions tagged [thevenin]

Thévenin's theorem for linear electrical networks to simplify the analysis of complex electrical circuits.

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How to analyze and simplify a voltage divider with a second voltage source?

How do I simplify the circuit below? simulate this circuit – Schematic created using CircuitLab I know that R2 and R3 form a voltage divider, but I can't figure out the input impedance that In ...
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Finding Thevenin voltage and resistance [closed]

I am struggling to find the Thevenin voltage and resistance across terminals A and B of the given circuit. I got as far as writing KCL at nodes 2 and 3, which gave this: v_\text{AB} = - G_2/G_1 e + ...
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Thevenin Impedance of a Circuit with Multiple Dependant and Independant Sources

I am attempting to find the Thevenin impedance or the output impedance of the circuit shown in the following image. I have tried simplifying the circuit into two parallel impedances, one of which is ...
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How to find current for Thevenin equivalent circuit

I'm trying to figure out how to calculate the Thevenin equivalent circuit for a voltage divider like the following one: I understand that V_th is obtained by opening the terminals of the output, so ...
57 views

Thevenin equivalent voltage of an AC source circuit

In the given circuit, I can't understand how voltage division is performed to find voltage across 5 ohm resistance. I have already solved the problem by another method, I just want to know how voltage ...
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AC Circuit Analysis - Thevenin and Norton Circuit

I am having a difficult time answering this exam question so I can asking for help. I've been asked to find the Thevenin equivalent in which I think I am correct. When I convert to Norton I come ...
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How to solve maximum transfer question?

I am a student studying electrical engineering. While solving the maximum transfer problem, there was something I didn't know, so I posted a question. I would really appreciate your help. Two ...
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1 vote
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How to find Thévenin voltage with dependent voltage source

I am not an electrical engineer, so I lack fundamentals. I was trying to solve for the Thévenin voltage, that is Vout at the open terminals A and B, but what makes it significantly difficult for me is ...
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Thevenin Voltage BJT two DC sources

I'm trying to find the thevenin voltage at the base of Q1, but I can't seem to properly work out the value. It's just something in the basics I have a misunderstanding of: That's the circuit, and I'...
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1 vote
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Circuit without Thevenin equivalent?

(I edited heavily my original post because it was based on my serious misunderstanding of a textbook exercise. However the main question remains valid as explained below.) It appears to me (and also ...
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1 vote
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Thevenin Termination - Calculating $I_{OH}$

I am trying to see if my driver can drive the following circuit. The spec for the driver is $V_{OH,min} = 1.62 V$ and $V_{OL,max} = 0.18 V$ at $I_{OH}/I_{OL} = +/-4 mA$. So the $V_T = 0.9V$ ...
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BJT four-resistor bias circuit analysis, parallel resistors

I don't understand why R1 and R2 are in parallel. I need to find the Thévenin resistance of the circuit, and my textbook says that R1 and R2 are in parallel, but I don't understand why. I really ...
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How can I find Thévenin equivalent circuit of the NFB op-amp input? [closed]

I need to find the Thévenin equivalent of the right side of the circuit by looking into node E and F. How can I find it?
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Finding Thévenin resistance in a circuit with dependent sources which depend on a different loop

I have this circuit: I want to find Thévenin's resistance for this. From what I was taught, the way to do this (since there is a dependent source) is to connect a 1 V source across terminal ab, short ...
136 views

How to solve Thevenin and Norton circuit?

This is the circuit for the problem in finding Vth and Rth. Analyzing this circuit yields Vab=−35V and Ia=0. If 10V is connected to Vab, then Ia=1.125A From what I remember, you need to short the ...
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1 vote
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I'm trying to find Vth, somehow my Vx gets cancelled out but my Vth is wrong

I'm trying to find out how to solve for the Thevenin equivalent. I tried to use a 1A test source, but it didn't seem to work. Anyone can help please? Much appreciated.
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Currents in short circuit wires connected in parallel

simulate this circuit – Schematic created using CircuitLab There were two inductors at I1 and I2 which at steady state became short-circuited. What would be their currents? I am confused as to ...
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Thévenin: Weird instructions

Our professor provided us instruction on how to determine the Thévenin equivalent. The only problem is that the method prescribed seems weird. Here are the instructions: R1=1k, R2=2k, R3=3k, R4=4.3k, ...
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Stuck in a Thévenin's Theorem exercise

I'm practicing applying Thévenin's Theorem, and I'm struggling with computing $R_{th}$ in the following circuit: My attempt: after removing voltage and current sources, and combining resistors in ...
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Min and max resistance of this network with potentiometer

As the 20 kΩ pot is adjusted from A to B, any idea what the minimum and maximum Thévenin resistance is between C and D? Any thoughts on some equations?
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I don't get what I am doing wrong with this Thévenin question [closed]

I understand that the Thévenin voltage is zero because there are only dependent sources, but finding the Thévenin resistance doesn't seem to work. My work for finding the Thévenin resistance is below. ...
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Failing to compute Thévenin voltage

I tend to struggle computing the Thévenin voltage. Here is a simple example in which I reason wrongly. After open-circuiting, we reach the following: simulate this circuit – Schematic created ...
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How can there be no Thévenin voltage with only a dependent voltage source? [closed]

I don't understand why the Thévenin equivalent is equal to zero in this case because, if the load is a resistance, then yes, the circuit would be dead as there would be no voltage drop across Vx. But ...
1 vote
117 views

Thévenin equivalent of circuit with two voltage sources

I'm trying to figure out the Thévenin equivalent of the circuit shown in the circuit diagram below. The circuit is from a book on electronic circuits. It would be great if somebody can show how to ...
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Hysteresis on inverting terminal for comparator circuits?

If you examine 98% of circuits online that include hysteresis for a comparator, they always implement the hysteresis on the non-inverting input, like so: This is easy enough to calculate. However, ...
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Thévenin equivalent voltage: why ignore the 16 Ω resistor?

I am really confused by the concept of ignoring resistors while doing Thévenin theorem, especially for this problem. Some online videos, like this one, and other examples that I watched seem to ...
1 vote
136 views

Determining Thévenin voltage using nodal analysis

Here I want to determine $V_{th}$ without using mesh analysis and just by using nodal analysis. Now, $V_{th}$ is the same as the voltage across the $6\ \Omega$ resistor since no current passes ...
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Calculation of equivalent resistance

I need to calculate the equivalent resistor between knots A and B to then use it in Thevenin Generator; it says the result should be (R // Zl) + (R // R) however I don't quite get why that's the case.
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How do you find the RTH of this?

I suddenly got confused while practice solving using Thevenin method.
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Find Thevenin's voltage

How could I find Thevenin's voltage in this circuit? I can't use KVL since i don't know the voltage rise of the current source after removing the load.
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Is it wrong to use Thévenin's theorem on this memory circuit?

In my electricals beginner class I was given a paper about memory circuits. There was a small section about how writing data to a single memory cell worked. Here is the sketch of the memory cell: The ...
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Node equations for Thevenin voltage

I have the following circuit as shown in the picture below: I am interested only on finding the $V_{th}$ and not the Norton current. I choose to work with node analysis because I find it easier. In ...
1 vote
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Getting differing theoretical and simulated values of V{thevenin's} on LTSPICE

I got this question to find the thevenin's voltage across the load resistor RL when R = 5 ohm. I made the schematic circuit in LTSPICE and performed a DC op simulation on the circuit and got the value ...
71 views

Should resistance between a and b terminals be considered when computing Thévenin-equivalent resistance?

When attempting to find the Thévenin-equivalent circuit to the left of terminals a and b in the image below, should one consider the 4.7 kΩ resistor? Why or why not? When taking the 4.7 kΩ resistor ...
1 vote
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DC Thevenin voltage

The question I am trying to answer is: Find the Thevenin voltage Vth to the left of the 10-ohm resistor. I have determined Rth for the electrical circuit in the pictures (Rth = 5 ohms) but I am ...
1 vote
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Need help finding the thevenin voltage across the diode. Is my work correct?

I am admittedly really poorly versed in Thevenin's theorem and this is giving me a lot of trouble. I am having a hard time visualizing how to approach the problem, so any help would be appreciated.
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Thevenin Equivalent of a common emitter amplifier

Consider a CE (Common Emitter) Amplifier without the emitter capacity. After having determined the operating point we pass on to the small-signal analysis. It doesn't matter what model we use (...
329 views

Thevenin's Theorem: Finding Rth with Dependent Source

I was working on the problem below (which I was supposed to find Vo using Thevenin's Theorem) and tried to find R_TH but got the wrong answer. The issue is that there is a dependent current source, so ...
292 views

Thevenin/voltage logic

So, I'm trying to find the Thévenin voltage of this circuit. I understand that the resistors (R+3R) by node a are irrelevant as there's no current running and thus no voltage drop. However, I'm a bit ...
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How to derive the maximum power transfer theorem using the relation p=v²/R?

In most derivations of the Maximum power transfer theorem the derivation is done using the relation of power : P = i²R And on further derivation it comes out to be Pmax = Vth²/4Rth If I derive the ...
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1 vote
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Performing Node analysis with more

Following a previous question problem regarding the node analysis with dependent source in a circuit I made some extensions that I would appreciate some validation if someone know. I have the ...
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How can I perform Node Analysis with dependent source?

I have the following circuit as shown in the picture. My question is how can I perform Node analysis in this circuit in the node $V_{0}$? I want to find $i_{1}$ but without KCL or KVL. Just the ...
220 views

Finding the Thévenin and Norton equivalents for a circuit

I want to find the Thévenin and Norton equivalents for the circuit below. However I'm new to this and I would really appreciate some help. I start with a source transformation and naming all the ...
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Different results when using nodal and mesh analysis; application on a Thevenin equivalent problem [closed]

I need to find the Thevenin equivalent of the given circuit. The problem is that when I use Nodal analysis and mesh analysis I get different results. I know that Rth = 16 Ω. But when I use nodal ...