Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [thevenin]

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

5
votes
3answers
2k views

Thevenin Equivalent Voltage: why ignore the 3-kΩ resistor?

In order to find the Thevenin voltage here, why is it that the 3k Οhm resistor is ignored and no current goes through it? (hence \$V_{TH}=8mA \cdot 7kΩ = 56V\$)
2
votes
3answers
48 views

Norton <-> Thévenin equivalents with complex impedances

Given a Thévenin equivalent circuit, it's pretty easy to convert to the Norton equivalent, or vice versa: simulate this circuit – Schematic created using CircuitLab Although the value of the ...
0
votes
1answer
61 views

How can I find the short circuit current across a and b?

In order to find R thevenin, I need to find Isc across a and b since there's a dependent source. Based on my calculations, Vth=500/3V. I've spent countless hours thinking about Isc,please help.
0
votes
1answer
26 views

Understanding CMOS Circuit Behaviour with Resistive Loads using Thevenin theorem

I have been reading the Digital Design: Principles and Practices 3rd Edition as a hobby. Unfortunately, I am stuck at page 103 of Section 3.5.2: Circuit Behavior with Resistive Loads. In Figure 3-27: ...
0
votes
3answers
52 views

why would Ix would be 0?

Current coming out of the 5V source would never be 0 so what would make the current coming out of the 3v dependent source 0?
0
votes
3answers
45 views

Redrawing circuit diagram for Thevenin's theorem

We're looking for Uo voltage but that's not the issue (yet). My problem is I don't know how to redraw this diagram in a way so that I'm able to see the resistors connections and compute the equivalent ...
0
votes
1answer
32 views

Dependent sources removal

In thevenin's and norton's theorem why do we dont remove the dependent sources in calculating the thevenin's resistance. And secondly,why do we only use 1 ampere/1 volt source to find the thevenin's ...
1
vote
1answer
52 views

Understanding some mistakes, when trying to find the Thevenin equivalent

I was asked to find the Thevenin-Norton equivelant, and I got stuck on some things that I can't quite understand. I don't know if i need to be more specific. What's wrong with the following? And why ...
0
votes
2answers
85 views

Thevenins theorem + two diodes and a resistor using graphical solution

I've got a homework to solve this circuit by a thevenin's theorem and get a current and tension of the diodes using graph. I've looked all around the Internet and couldn't find one single video that ...
0
votes
1answer
29 views

For the circuit shown find the Thevenin’s equivalent circuit between terminals A and B

Here I began with Vth making mesh equations : 48-6I1-12(I1+I2)=0 12(I1+I2)+42+8I2=0 With which I get I1=4A & I2=-2A Then I considered the open circuit part AB to use the 2 mesh currents there ...
-1
votes
1answer
38 views

How to find thevenin's eq circuit from the given figure? [closed]

So I started with finding Rth shorting all voltage sources and opening all current sources getting at 10||5 case getting it as 10/3 = 3.33 ohms. After that using source transformation I changed the ...
0
votes
2answers
55 views

Combining perfect voltage and current sources

I am attempting to reduce the circuit shown into a form of a single voltage source and resistance in series using Thevenin and Norton conversions. I approached the problem by first considering a ...
-1
votes
0answers
39 views

Thevenin Equivalent in case of dependent source

In this circuit I was needed to find the Thevenin equivalent across the terminals AB. But the problem is that when we open circuit the 2 ohm resistance, we get a dependent source(CCVS) at the terminal ...
1
vote
2answers
89 views

Why maximum power transfer condition is suitable for communication system but not for transmission of electricity?

A fundamental concept that i have learned from basic electrical circuit study is to receive maximum power by a load of resistance RL from a source the necessary ...
2
votes
1answer
42 views

Calculate the Norton Resistance and Current and the Thevenin Voltage of the following circuit

U=10 V, R=10 ohm I calculated the resistance as such: 1/Rt = 1/R + 1/R <=> Rt = R/2 = 5 ohm To calculate the voltage I did KVL as such: U - 2Ur = 0 <=> Ur = 5V, where Ur is the voltage in the ...
0
votes
2answers
47 views

Calculating the Thevenin Voltage of this circuit

What I did was apply kirchoff's voltage law to the closed network with the 2 resistors and the voltage source to calculate the voltage of the resistors. I got U - 2*Uresistor =0 <=> Uresistor =5V ...
1
vote
1answer
52 views

Thevenin equation of a circuit with two voltage sources, one on an open circuit

I am incredibly sorry, as I'm sure this specific example has been asked before, but I missed the class on it and the professor hasn't yet uploaded the video to his website. I need to know how to find ...
0
votes
1answer
39 views

Finding the energy over the capacitor in DC

I tried using Thevenin to solve this and found Rth = 3 and Vth = 12 but this is way off the correct energy of the capactor (the energy is 4J).
1
vote
2answers
61 views

Modelling a temperature measurement system

The accuracy of a measurement system can be significantly reduced by loading effects in the system. A thermocouple is used together with an indicator to measure temperatures. The thermocouple has a ...
0
votes
1answer
42 views

Thevenin and resistance problem

I had a problem finding the Thevenin equivalent resistance of this circuit. If anyone could help me, I would be very thankful.
0
votes
2answers
30 views

Thévenin's theorem exercise, resistances

I've some problem identifying the \$R_{th}\$ simulate this circuit – Schematic created using CircuitLab Removing the load and short circuiting the Voltage source we get : simulate this ...
0
votes
2answers
31 views

Source transformation violation

Using thevenins or norton theorem, we can easily find current through the resistor as 1 amps. But if we convert the current source to voltage source , current turns out to be zero amps . Why?
1
vote
1answer
43 views

Finding Thevenin equivalent circuit and using that circuit when terminals inside circuit

Sorry for the bad title, but I'm trying to get the Thevenin equivalent circuit and then use that circuit to calculate a current i. The problem I'm having is I'm not sure what to get the open circuit ...
1
vote
1answer
47 views

Circuit Analysis in Non-Closed Systems

So I'm fairly confident in my ability to do circuit analysis on closed circuits, that is, circuits where all loops, sources, and elements are given. However I still find myself getting stuck on ...
0
votes
3answers
109 views

how can we solve a circuit with two opposing voltage sources using thevenin theorem

i have been asked to solve a circuit using thevenin theorem but when i try to solve it to find Vth by loop analysis, i realized that both voltages are in opposing directions and i can't understand ...
0
votes
2answers
79 views

Struggling with Thevenin Equivalent Problem

I had asked this question before and thought I had found the help I needed, but unfortunately I found myself unable to solve the problem fully when I attempted it. The problem: For the Thevenin ...
0
votes
1answer
96 views

Can a Dependent source be dependent on itself?

I am looking for the Thevenin Resistance here. However, I have no clue what to do with \$i_b\$ and the source dependent on it. This is the entire circuit. \$i_b\$ is the current through the 5\$k\...
0
votes
1answer
79 views

This circuit is two parallel resistances of 10Ω. Convince me otherwise

I'm trying to find the Thévenin equivalent resistance of a circuit - one that resembles a Wheatstone bridge, but is not at balance. The load in question is where the galvanometer would appear. Anyway,...
0
votes
2answers
208 views

Thevenin Equivalent Network: How to treat Capacitor across 0v potential, with Dependent Sources?

We were given this question in our intro to EE course: Find the Thevenin equivalent network between points a and b for the circuit shown in the image below: For the short-circuit current, I redrew ...
1
vote
2answers
87 views

Confusion with short circuits, and when you can ignore a loop

For the image above, when t<0, howcome it's safe to ignore the loop with the 50V source, and the 60 and 200 ohm resistors? How do you know when you can ignore a loop, or when to ignore a part of ...
0
votes
1answer
46 views

Is my approach for the RL circuit correct?

For the image above, i(0+) = i(0-) = 0A, and to get the IL(t) function, you solve for Rth, which is 50ohms. Afterwards, i'm confused with how to approach getting IL(t).
0
votes
1answer
21 views

Question concerning equivalent capacitance

For the question above, i'm confused as to why the 6uF and 3uF capacitors have the same charge. Also, for part b, would you have to find v(t) at the 10uF capacitor? If not, what would be the other ...
0
votes
0answers
271 views

How to determine maximum power transfer and load impedance?

Edit: I realized my solution is invalid due to the dependent source. Upon further reading, I learned that only the independent sources get disabled, and \$R_L\$ transforms into a short circuit. ...
0
votes
3answers
119 views

Thevenin Equivalent Resistance of complex circuit

I'm trying to find the Thevenin equivalent of a circuit of which I have already found the Thevenin voltage. Unfortunately I can't figure out how these series parallel combinations work to find the ...
0
votes
0answers
64 views

Confusion about finding the Thevenin Resistance

Good day everyone, I'm really confuse on how can I find the Thevenin Resistance that is seen by the 2k ohm resistor. The original circuit looks like this. simulate this circuit – Schematic ...
0
votes
1answer
218 views

RC circuit analysis with parallel capacitances (using Thevenin equivalent)

I am trying to determine the voltage across capacitor C3 (voltmeter VM1) with respect to time. I believe that simplifying the circuit to its Thevenin equivalent is the correct way to proceed but I'm ...
0
votes
1answer
48 views

Thévenin equivalent of a Norton equivalent

A very simple question. When solving circuits, and you need to solve it using the mesh analysis, you want the circuit to only have voltage generators.I wonder if for an independent current generator ...
0
votes
1answer
80 views

Do a Thevenin source and its equivalent Norton source always supply equal power?

Power supplied by a Thevenin source $$P_{Thevenin} = V_{Th}^2 \frac{1}{R_{Th}+R_L}$$ Power supplied by its equivalent Norton source $$\begin{eqnarray} P_{Norton} & = & I_N^2 \frac{R_{Th} ...
0
votes
1answer
53 views

Find Thevenin equivalent voltage - Circuit Analysis

I am trying to understand how to calculate Vth (between the blue Volt meter and the grey volt meter). I have calculated the current correctly using KVL. However, I can't find a way to calculate Vth. ...
1
vote
1answer
68 views

Does a voltage source produce current on an open branch?

I am supposed to find the Thevenin equivalent of this circuit however the branch with the 30V source is confusing me. I know that if there was only a resistor in that branch then no current would flow ...
0
votes
1answer
52 views

Finding a current through a short circuit (Thevenin)

I am working through a question that involves superposition. I have attached a picture of the question I am working through. I am having difficulty doing question e) and f). I was hoping you someone ...
2
votes
3answers
102 views

Finding current when short-circuiting the terminals

I am working with the circuit shown below. I am having trouble with the situation where: if a short circuit is connected between Terminals A and B. what current would flow through the short circuit ...
0
votes
2answers
107 views

Thevenin Equivalent Voltage and Resistance with Multiple Parallel Sources [closed]

I am looking for help with finding the Thevenin equivalent voltage in the circuit pictured, basically 2c on the list of problems. I have so far done the loop equations and have come out with the ...
0
votes
3answers
330 views

Finding the open circuit voltage

I am asked to find the open circuit voltage v(AB). So far, I have found the current, I(1) by using the current divider, and I got approximately: 0.307A. Except, I am not sure where to go on from ...
0
votes
1answer
67 views

question with rl circuit

I have an assignment in my electronics 1 class: http://prntscr.com/jcdz1m My idea was to find a Thevenin equivalent, convert it to Norton then i would get Io and calculate the graph for I1 and I2 for(...
0
votes
2answers
128 views

Thevenin equivalent circuit with external loop

I am tasked with the following exercise: I am still finding Thevenin equivalent circuits challenging, and this example looks a bit daunting since it seems to have an external loop. Hopefully, I ...
0
votes
1answer
28 views

Question with using Isc -> Any errors?

For the picture below, the answer for Voc is 7.5V, but when I add an Isc at terminals AB, and use KCL, I get Voc = 3.75V. Here are my steps/equations: (1) 15 = 4I1 - 2Isc (2) 0 = 3Isc - 2I1 I get ...
0
votes
2answers
42 views

Thevenin Norton Concept

For the below circuit, assuming I add a short circuit between terminals A and B (let's call it Isc), howcome I can't use a KVL equation for the left loop, along with the right loop (IsR1 - IscR2 = 0)?
0
votes
1answer
40 views

Question about voltage in the open circuit

I have this circuit here, and I'm trying to its Thevenin equivalent voltage and resistance, using superposition. When I "kill" the \$V_{0}\$ source, it becomes a wire and the voltage across the gap is ...
0
votes
1answer
353 views

Thevenin resistance for bridge circuit

So I've been at this question for a few hours now and i can't seem to get the final answer for a). I know how to find the the resistance of a basic Wheatstone bridge, but i don't know how to find the ...