Questions tagged [passive-networks]

Use this tag for circuits that only contain passive components, such as resistors, capacitors, and inductors. This includes RC, RL, LC, and RLC circuits.

Filter by
Sorted by
Tagged with
0
votes
2answers
56 views

Why does the \$ Q\$-factor depend on the resonant frequency?

The \$Q\$-factor is defined as $$Q=\frac{\omega_{0}}{\Delta \omega},$$ where \$ \Delta \omega\$ is the bandwidth around the resonant frequency \$ \omega _{0}\$. For a series RLC circuit, $$\Delta \...
0
votes
2answers
74 views

Calculating Differential equation RLC Circuit

Hi, I tried to find the voltage on the capacitor as a function of time, Vc(t). In the initial condition (t<0) the switch was closed and the current source was open circuit, so I found the initial ...
-1
votes
2answers
91 views

Design a passive amplifier

I am trying to increase the amplitude of my generated electrical signal by a passive amplifier. I have seen so many complex RLC circuits. But I have limited space for design, therefore, can I use a ...
0
votes
2answers
47 views

Derivation needed

I am using a chip that has the following circuit in it where V_in is inputted on the left and V_out is measured on the right. This circuit is sometimes called the "lumped-element delay lines." I was ...
0
votes
1answer
90 views

Initial Condition in Series RLC Circuit

I have the following RCL circuit simulate this circuit – Schematic created using CircuitLab After using the Laplace transform my lecture notes mention that we get the following circuit ...
0
votes
4answers
100 views

How to model a load as combination of RLC (resistance, inductance capacitance?)

I have a constant voltage DC power source and a load connected accross it. The load consists of various sensors, modems, some small actuators, and something else which I don't know (mostly resistive.)...
0
votes
3answers
50 views

Controlling brushed motor speed with variable load with a PWM

I am considering driving a brushed motor driver with an H-bridge and PWM. I'd like to roughly control the motor speed regardless of the motor's load (envision a small robot climbing/descending hills). ...
1
vote
1answer
78 views

Substitution + Superposition with RLC circuits

Consider the following circuit: simulate this circuit – Schematic created using CircuitLab \$E\$ is a constant voltage source. The switch is closed at time \$t = 0\$. The request is to ...
3
votes
1answer
54 views

How does an LC network enable a shoot through state for an inverter

I was researching about inverters when I came across the Z source inverter. The Z source inverter is unique in a sense that it enables a shoot-through or a short circuit condition by closing any two ...
1
vote
1answer
57 views

RLC equivalent model and Impedance Smith Chart

I have done some impedance measurements on an unknown 1 port device. I have measured its impedance at different frequencies (from 10 MHz to 600 MHz) and I have seen it on the normalized (on 50 Ohm) ...
0
votes
0answers
54 views

Generate identical positve going and negative going pulses/spikes at the same time

I am interested in building a circuit to generate a sharp positive pulse and an identical negative pulse at the same time with a peak of about 10 to 200 V. So when I say sharp I would like a rise time ...
0
votes
1answer
56 views

Mosfet LC oscillator

I'm looking at the following circuit: simulate this circuit – Schematic created using CircuitLab It consists of an oscillation whose frequency depends on the tank circuit (C1, L1 and L2). When ...
9
votes
4answers
2k views

The Intuition for RLC circuits

I'm reading through Hayt's Engineering Circuit Analysis 9e and it does a fairly good job of giving the intuition for "where" the energy is going in a damped RLC circuit, but I'm hoping that someone ...
0
votes
2answers
32 views

Query on writing KVL equation for an RL circuit

Say I have the inductor in the following circuit with certain current already in the circuit flowing in the specified direction: simulate this circuit – Schematic created using CircuitLab If I ...
0
votes
2answers
46 views

What does a simple passive circuit to simulate an impedance mismatch look like?

I am trying to learn some of the basics of circuit design. One thing I am curious to make a filter/schematic of is what happens when a voltage source hits an impedance mismatch. eg. A high impedance ...
0
votes
0answers
27 views

Initial conditions in multi-state Tesla Coil circuit

Half a year ago I posted this quesion about a Tesla Coil resonant circuit which got an amazing answer that helped me understand the resonant frenquency of such circuit. Now I've returned to that ...
0
votes
0answers
29 views

Infinite hexagonal impedance network with loads at specific nodes

It's been a couple weeks already that I am trying to solve this network on the paper. It consists on a infinite/periodical hexagonal lattice but with some peculiarities. First of all, this is not the ...
0
votes
2answers
72 views

2nd order Low-Pass Output Impedance and Phase difference

I am trying to calculate the output filter impedance and the phase difference of the inverter that I am designing. However not sure how to construct a formula for both the output impedance and phase ...
0
votes
1answer
24 views

Solving a series RLC DC step response circuit

I got two different answers to this RLC problem when using a method shown in class. What am I doing wrong? Edit: I graphed each answer. I'm assuming the answer for Vc on the right is correct, as the ...
1
vote
0answers
53 views

RLC Circuit with Dependent Source

I am trying to solve the attached practice problem from Hayt's 8e of Engineering Circuit Analysis but I am struggling to find a solvable differential equation for the circuit. I am trying to use KVL ...
0
votes
1answer
81 views

Low pass LC filter goes “wrong” with capacitive load

I have been experimenting with this circuit: simulate this circuit – Schematic created using CircuitLab Vin has a lower frequency ripple of 2V and a high frequency (switching?) noise of 6.5V. ...
0
votes
3answers
83 views

Why is the impedance zero at cutoff frequencies in a series RLC resonance circuit?

I see that, in many derivations in the frequency analysis of series RLC circuits, \$X_L - X_c = R\$ or \$Xc - X_L = R\$ is considered at lower and higher cutoff frequencies. So does that mean that the ...
1
vote
1answer
63 views

Finding current in RLC circuit

I am given the following circuit: Thanks for any help.
0
votes
0answers
36 views

Using Thévenin to find I3 current

i'm an engineering student and i've come across this problem i have to use Thévenin method, even though i could find Zth by "short circuiting" the power sources and opening the circuit at I3, i'm ...
1
vote
1answer
64 views

Ambiguity in the Definition of Resonance Frequency

we know that in a series LC circuit the resonance frequency is defined as that frequency in which the total impedance offered by the circuit is zero. We also know that in a parallel LC circuit the ...
0
votes
0answers
29 views

RFI filter modeling in LTspice w/ triac

I have a few questions about modeling an RFI filter in LTspice with a triac-based dimmer circuit. I'm referencing the circuit described in Figure 11 in Triac Principles and Circuits -- Part 2 (Nuts &...
2
votes
2answers
58 views

State variable equations for a RLC circuit

What are the state variable equations of this RLC circuit? How do I write the final matrix? I tried to write the equations for the capacitor and inductor: $$L\frac{di_3}{dt}=v_1-v_C \leftrightarrow \...
1
vote
2answers
93 views

What of value of R result in V=0

As shown the answer is 15 Ohm's . I don't get the trick of the question. can anyone explain to me how we can get the value of R Thank you all!
0
votes
1answer
86 views

LC CIRCUIT ISSUE

I am high school boy doing his homework on the circuit, I came across this question , I need to find maximum current that will flow in the circuit What I have tried :) It's a weird one because ...
0
votes
1answer
35 views

RLC initial conditions

I am working on the following series RLC circuit: Let the circuit have non-zero initial conditions \$I(0^+)= 6\text{A}\$ and a voltage across the capacitor of \$V(0^+)=-12\text{V}\$. What are \$\...
1
vote
3answers
108 views

Computing the voltage across a parallel LC component at resonance?

Problem For the circuit illustrated below, I am trying to compute the sinusoidal voltage across resistor \$R_{1}\$ when the parallel LC component is in resonance: I setup my problem with the ...
0
votes
1answer
48 views

How to find Vo in a circuit with two voltage sources

I do not know how to find Vo in this circuit. According to my notes about how to take node voltage, I get 0 = Va + 6.857 V + 0V Vo = Va But that doesn't sound right. And I get a different answer ...
0
votes
2answers
79 views

555 Timer - How to quickly discharge RC capacitor

I'm using a 555 timer to turn off an LED with delay. Here is the circuit. All I want to implement is, to get the input voltage changes in output with a constant delay. When I close the switch, the ...
0
votes
0answers
27 views

What does it mean, for poles and zeroes to alternate; Foster's Theorem

I'm currently learning Foster's reactance theorem; The most general driving-point impedance Z obtainable by means of a finite resistance-less network is a pure reactance which is odd rational ...
1
vote
0answers
80 views

Struggling to get an amplified sine wave over a small inductor at low frequencies

I am building a power amplifier circuit to amplify a sine wave over an inductor from a function generator. However because the inductor is small and i'm running at a low frequency I am getting ...
1
vote
1answer
77 views

Measuring the quality factor RLC circuit

I am trying to get the Q factor for this circuit but I don't know how to simulate it properly. I did a frequency sweep from 1 Hz - 30 MHz. The oscillating frequency is 16 MHz. I can't get the ...
0
votes
1answer
61 views

Help me see if I understand this RLC circuit

The switch closes at t=0 I need to determine the current and the voltage of Capacitor at t=0.25s at t<0 the switch is open there is no current and no voltage at t=0 the switch closes the current ...
-1
votes
1answer
70 views

Capacitors capacity in an RLC circuit that is in resonance [closed]

So if its in resonance that means XL=XC right? anyway thats how I started I∠=Irms∠=7.07/sqrt2 ∠30° A ω=10^3 Z1=R+jXL=1+1∠90°=sqrt2∠45° Z2=-jXC=1∠-90° Ztotal=(1/Z1+1/Z2)^-1=sqrt2∠-45° U∠=I∠*...
5
votes
1answer
124 views

How does the second order time constant affect circuit behavior?

I learned that the transfer function of a second order circuit can be expressed in the following standard way: $$ \frac{K}{\tau_s^2 s^2 + 2 \zeta \tau_s s + 1} $$ Where: \$K\$ is the gain \$\zeta\$ ...
0
votes
1answer
48 views

Are these valid transformations, Please guide

Please help check if the transformations in the pink are allowed, when solving a circuit. For the given circuit the goal is to find the current I1 which could be found using nodal without taking care ...
0
votes
1answer
186 views

Is my circuit solution correct?

simulate this circuit – Schematic created using CircuitLab I have to calculate the energy of the inductors magnetic field at t = 6 ms. I am given: E = 50 V, R1 = 10 Ω, R2 = 15 Ω, R3 = 20 Ω and ...
0
votes
2answers
58 views

I have to find all the voltages and current in the circuit

I am given Uab=100V XL=6Ω XC=3Ω R=4Ω This is how I started X=XL+XC=9Ω Ztotal=sqrt(R^2+X^2)=9.84Ω Zab=R+jXL=4+j6=7.21∠56.30 I=Uab/Zab=100/7.21=13.86A but obviously I made a mistake somewhere ...
0
votes
2answers
447 views

RLC circuit: how to find voltage/current derivatives and derive differential equation

Trying to resolve differential equations for RLC-networks, I'm always stumbling upon the voltage/current derivatives. Here I would like to give two examples from the same textbook and explain my ...
0
votes
1answer
77 views

Differential equation for a notch filter RLC circuit

I'm trying to write and solve a differential equation for this simple RLC notch filter and I'm not sure what I'm doing wrong. simulate this circuit – Schematic created using CircuitLab So ...
1
vote
1answer
183 views

Parallel RLC Circuit: how to write differential equation?

Please consider the following circuit: At t>0 this circuit will be transformed to source-free parallel RLC-circuit, where capacitor voltage is Vc(0+) = 0 V and inductor current is Il(0+) = 4. Now is ...
1
vote
4answers
103 views

What are AC and DC transients, rather do we even classify transients that way?

We are provided a syllabus in our university stating "Unit III - Transient responses of RL,RC,RLC circuits, DC and AC sinusoidal input". As far as I can see, "transients" are the response a circuit ...
1
vote
1answer
75 views

Find Io(t) of RLC circuit (from Electric Circuits, Nilsson )

My question is from the Electric Circuits, Nilsson 10th edition. My solution is For \$t < 0\$, we get \$i_o(0) = 2 \mathrm{A}\$ and \$v_o(0) = -400 \mathrm{V}\$. For \$t > 0\$, the circuit ...
0
votes
1answer
34 views

Should we include Source and Load Impedance while calculating two port parameters?

While calculating the \$Z\$, or \$Y\$ or \$h\$ parameters of a two port network, should we include the source impedance and load impedance or not? In other words, for finding \$Y_{11}\$, we short the ...
0
votes
2answers
76 views

Kirchoff's Law Problem

We were given a circuit with 7 resistors and 3 voltage sources For emf sources, \$E_1=120V\$, \$E_2=60V\$, and \$E_3=30V\$ while for resistors in ohms,\$R_1=10\$, \$R_2=5\$, \$R_3=20\$, \$R_4=8\$, \$...
0
votes
4answers
100 views

Quality factor in arbitrary RLC resonance circuits

I am looking for a way to calculate the quality factor in arbitrary RLC circuits not just standart series or parallel circuits. It would be great, if anybody could provide a formula and some further ...

1 2 3 4 5 11