# Questions tagged [thevenin]

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

507 questions
Filter by
Sorted by
Tagged with
53 views

### Thevenin's Theorem and maximum power

The solution to the question is: Why is the thevenin's equivalent Zth = R and not R-j as they are both in series?
67 views

### What should I do to find the Thevenin voltage and resistance for large circuits?

I have the following circuit and I'm asked to find the Thevenin resistance between points A and B. I tried to solve it by creating an open circuit between the points, as usual, thus removing the ...
68 views

### The reason why Thevenin voltage source is in SERIES with Thevenin resistor and why Norton current source is in PARALLEL with Norton resistor

As you know, in Thevenin's theorem Thevenin voltage source is in series with Thevenin resistor and in Norton's theorem Norton current source is in parallel with Norton resistor. COULDN'T Thevenin ...
48 views

### How to find an equivalent LC circuit from a combination LC circuit [closed]

I have a circuit containing a number of L and C, both in parallel and series. How can I find the equivalent LC circuit (with a single L and C) for such a circuit? Kirchhoff or Thevenin can give me the ...
1 vote
45 views

### Obtain Thevenin Equivalent with two voltage sources in parallel

I want to get the Thevenin equivalent of the circuit above. simulate this circuit – Schematic created using CircuitLab I applied source transformation, and now i have two voltage sources in ...
60 views

### How to find Thevenin's Equivalent Resistance

I am asked to find the thevenin equivalent of this circuit but I am having trouble. The solution says that: Rth=2(RxRy)/(Rx+Ry) Vth= (VxRy+VyRx)/(Rx+Ry) Can someone please explain to me how to arrive ...
31 views

### trouble understanding thevenin equivalent

I really don't understand how the middle ciruit is the thevenin equivalent of the left-most circuit, any help?
53 views

### Thevenin Resistance by dropping independent sources

Original Question After dropping the sources The solution So my understanding is, once you drop the load resistor over a-b, the voltage at a and voltage at b are both 10 so the thevenin voltage is ...
1 vote
57 views

### How to get Thevenin Resistance of this circuit?

I have the following circuit: And i need to calculate the Thevenin Resistance. when I shorted the source and removed the R5(Load resistor), I got I thought the result was (R1 || R3) || (R2 || R4) ...
48 views

### how to calculate the output voltage of specific circuit using superposition law

Hi, How to calculate the output voltage of the circuit is shown below. Using the superposition principle is the best or the one that you recommend. I'm using strain gauges based on the Wheatstone ...
108 views

### Finding the Thevenin Voltage with respect to terminals A and B using Nodal analysis

Was doing this problem and I got -1V for the Thevenin voltage, but my lecturer got 5V. The resistors are actually measured in Ohms and not kilo ohms, my lecturer made a mistake. I was wondering if she ...
56 views

### Analysis circuit using Thevenin theorem

in the book "Engineering Circuit Analysis", example 5.9, i don't understand few things, hope someone can clear up for me: Why does the dependent current can't flow through resistor 3k? If ...
175 views

### RC low pass filter for NTC

I want to measure temperature using an NTC resistor and ADC (of an MCU). A low pass input filter is required with a certain cutoff frequency. Here is the recommended schematic: So I replace ...
1 vote
87 views

### Thevenin equivalent in a diode circuit with ground between resistors [closed]

I'm trying to find the Thevenin equivalent of this circuit with respect to the diode. I know the steps needed to find Vth and Rth and I was able to find Rth already (2.2222k) but I'm having a hard ...
73 views

### Calculating and Simulating Voltage dependent source circuit in LTSPICE - What am I doing wrong?

I'm trying to calculate the total resistance seen by the source v1 in this circuit and we have a voltage dependent voltage source in this circuit with a gain of 0.1 (v1) which is the voltage across ...
1 vote
87 views

### Find Thevenin equivalent of given circuit with two voltage sources

I have to find Thevenin equivalent circuit between M and N. So I understand that I have to get rid of R7, and find voltage of Vm and Vn, then Vth = Vm-Vn. But I don't understand how to calculate it. ...
90 views

### How is Thevenin's Theorem derived?

Thevenin's Theorem simplifies any linear circuit to an equivalent circuit with just a single voltage source and series resistance connected to a load. How is the theorem derived?
97 views

### Thevenin with coupled coils

I'm trying to solve this problem (to find the equivalent thevenin): where Xm (the mutual inductance) is 6 ohms. I've solve this circuit with nodal analysis, but I would like to solve it without is as ...
508 views

### How to find current through the 5 Ω resistor using Thevenin's theorem?

I tried to take the 5 Ω resistor as Rl but still couldn't find the answers as given in the green highlight. I'm pretty new at this and can only manage solving straightforward circuits. I managed to ...
1 vote
197 views

### What does it mean if the Thevenin voltage is 0?

Does it mean that we can't make an equivalent circuit using the Thevenin Theorem? My question specifically is when using theoretical circumstances on this image. Theoretically speaking the Vth = Vab = ...
88 views

### How to model the output signal of this circuit?

Following up this question: Thévenin equivalent: is this resistor useless? I've now changed the voltage source to a resistor since this is a photoresistor. However I have no idea now how to ...
118 views

### Thévenin equivalent: is this resistor useless?

I am doing a lab project that includes a sensor connected to a signal conditioning module. I am analyzing the circuit to understand more about how it works and I came across this: That voltage source ...
1k views

### How does this trick to finding the Thevenin Resistance work?

Here's a circuit for which I was asked to find the Thevenin Resistance: My professor said that there's a shorter way to do this. Apparently one could short-circuit voltage sources(in this case the 72 ...
1 vote
366 views

### Calculating resistor's current and voltage using Thevenin's theorem

I am trying to use Thevenin's theorem to determine the voltage and current of a certain resistor (625 Ω,) but somehow, nothing is really adding up. I measured the results in a simulation using Falstad,...
130 views

### BJT small-signal base resistor voltage

simulate this circuit – Schematic created using CircuitLab I am doing a small signal analysis of the following common-emitter BJT stage and I am trying to calculate the voltage across r_π (v_π). ...
66 views

### I tried to get Thevenin equivalence but keep failing

I found Thevenin equivalent capacitance easily. As all the capacitors are in parallel it comes as $$C_{eq} = 5 + 2 + 3 = 10\ \mathrm F$$ And I calculated Thevenin equivalent voltage as follows V_{...
1 vote
134 views

### Solution Verification: Thevenin Equivalent with Dependent Voltage Source

I am currently self-studying through MITs 6.002 Spring 2007 course. There are currently no solutions for the assignments afaik. Normally, this isn't an issue, but I am having some trouble with this ...
17 views

### Source Transformation Finding TEC

I have been trying to find the thevenin equivalent circuit with respect to nodes a and b using source transformation. I end up having this setup. What would possibly be the next step I should do? Can ...
550 views

### Determine Thevenin's equivalent circuit

I am doing my first year of engineering and have EE as a compulsory course. My teacher recently gave this question in an exam. He gave me a 5/10. He is not answering anybody's doubts. Can anyone tell ...
105 views

### If all the resistances inside a passive resistive network is multiplied by some factor, what will happen to the thevenin resistance?

Lets imagine an arbitrary passive resistive network, a black box. Let its Thevenin equivalent resistance across some terminals $a,b$ of the network be $R_{th}$ ohms. Now lets imagine another ...
158 views

### Why do two different approaches give different results about choosing resistances for voltage divider of emitter follower circuit?

I have read this page from the Practical Electronics for Inventors book. What I don't understand is about the calculation of R1 and R2. Approach 1: This approach is author's idea and the result is R1 =...
50 views

### Question regarding equivalent resistance

I am looking at an example in my text regarding Thevenin circuits and when they set the voltage source on the most left hand side to zero and solve for the equivalent resistance they get the following:...
592 views

### How do we derive the values for these Thévenin equivalent circuits?

I am currently studying the textbook The Art of Electronics, third edition, by Horowitz and Hill. Appendix D Thévenin's Theorem says the following: In Chapter 1 we stated (but did not "prove&...
31 views

### Finding thevenin voltage

When finding Thevenin voltage am I able to simplify the circuit to make it easier? For example if there were resistors in a series am I able to combine them to reduce the amount of nodes I am dealing ...
214 views

The answer is Vth=0.839 V and Rth=3.77 ohm but I can't get the right answer. Please give me the steps to find it. what i did to find Rth: removed RL and 6V, 6 & 8 ohm are in parallel, which gives ...
87 views

### Finding resistance and voltage from Thevenin equivalent

I am stuck on a homework problem where the objective is to compute the top and bottom resistance of a potentiometer and the voltage of the source. I've gotten this far, but now I am stuck and am ...
611 views

### How to find Thevenin equivalent resistance with dependent sources?

For this problem, Vs and Io are not given. Beta is equal to 8. I want to learn how to find the Thevenin equivalent resistance with respect to terminals a and b. The correct answer is 27.33 kilo-ohms, ...
261 views

### Thevenin equivalent resistance of a complex circuit

I have a complex circuit. I have found the thevenin equivalent voltage V_t, by making two equations. Its V_t=3.877 V Now I have to find the thevenin quivalent resistance. I was thinking of short ... 1 vote
154 views

### Thévenin's theorem exercise

I tried to do an exercise from my textbook where I have to apply the Thevenin theorem, but can't solve it. I got stuck at one point. Given the circuit in the picture find the V0, Vth and Rth. I tried ...
46 views

### Calculating current -- Thevenin?

Can someone please remind me how to solve this very basic calculation? I've got a Wye configuration of resistors and am giving DC values 1V, 2V, and 4V to points A, B, and C respectively. I want to ...
122 views

### Why would these two resistors make a parallel connection?

The circuit on the left is the one that is given and the circuit on the right is the way that I visualize the circuit. Could someone explain why the equivalent resistance would be 5kΩ?
112 views

### Big confusion about the very fundamentals of circuit analysis

First, let's call IR3 the current flowing from A to B, IR4 the current flowing from B to C, IR5 the current flowing from C to (-V2). What's the proof that IR3>0, IR4>0 and IR5>0? I know this ...
217 views

### Thevenin of DC circuits with inductors and capacitors

Can I use Thevenin's theorem for DC circuits containing an inductor or capacitor upon application of Laplace transform - bringing the entire circuit to the $s$ frequency?
1 vote
145 views

### Why do we treat R1 and R2 as though they're parallel in this circuit?

I'm working on a homework problem and I need to solve for the base current Ib, and I know to do that I need to find the Thevenin equivalent at the transistor base. My professor solves for it as though ...
176 views

### Thevenin equivalent or mesh-current in a diode circuit

I've been stuck on a problem for a couple days and many hours now and see no other option than to ask here and see if you can help me or give me a lead. What I have been stuck on is this: My initial ...
121 views

### For the sake of finding the thevenin and norton equivalent circuits, how do I calculate the Isc and Voc in this circuit?

I was taught to do it with a longer method which I understand, by moving the Va and Vb terminals up to the source and gradually moving further back while finding equivalent circuits. I want to do it ...
56 views

### RL Transient Analysis confusion

simulate this circuit – Schematic created using CircuitLab When I am using Thevenin's circuit and deriving inductor currents equations i am getting different Time constant $\tau$ from what I ...
131 views

### What would be the Open Circuit Voltage and Thevenin Resistance in this Circuit?

I am hoping someone can help me understand Open Circuit voltage and Thevenin Resistance. To test my understanding I created the attached circuit and ran a transient analysis using LTSpice. With a ...