An RLC circuit is an electrical circuit consisting of a resistor (R), an inductor (L), and a capacitor (C), connected in series or in parallel. The name of the circuit is derived from the letters that are used to denote the constituent components of this circuit, where the sequence of the components may vary from RLC.
The circuit forms a harmonic oscillator for current, and resonates in a similar way as an LC circuit. Introducing the resistor increases the decay of these oscillations, which is also known as damping. The resistor also reduces the peak resonant frequency. In ordinary conditions, some resistance is unavoidable even if a resistor is not specifically included as a component; an ideal, pure LC circuit exists only in the domain of superconductivity, a physical effect demonstrated to this point only at temperatures far below and/or pressures far above what are found naturally anywhere on the Earth's surface.
RLC circuits have many applications as oscillator circuits. Radio receivers and television sets use them for tuning to select a narrow frequency range from ambient radio waves. In this role, the circuit is often referred to as a tuned circuit. An RLC circuit can be used as a band-pass filter, band-stop filter, low-pass filter or high-pass filter. The tuning application, for instance, is an example of band-pass filtering. The RLC filter is described as a second-order circuit, meaning that any voltage or current in the circuit can be described by a second-order differential equation in circuit analysis.
The three circuit elements, R, L and C, can be combined in a number of different topologies. All three elements in series or all three elements in parallel are the simplest in concept and the most straightforward to analyse. There are, however, other arrangements, some with practical importance in real circuits. One issue often encountered is the need to take into account inductor resistance. Inductors are typically constructed from coils of wire, the resistance of which is not usually desirable, but it often has a significant effect on the circuit.
A series RLC circuit is connected to a 5 V supply, the frequency of the supply is adjusted to give a maximum current of 11.9 mA at 2.5 kHz. The Q factor is 70. Determine the component values of the circuit.
R= 5/.0119=420.2 Ohm
Q = (1/R)*(sqrt L/C)
70 = (1/420.2)*(sqrt L/C)
70/(1/420.2)=...
Voltage V(t)=V1 Re{eiwt} produces a current I(t)=I1 Re{e(iwt+θ). Determine I1 and θ.
The circuit is AC so do I treat it the same as an SHM question? Is π/2? And what do I need to do to find I1? I don't know where to start.
Homework Statement
Hello all,
Representing RLC circuits via differential equations is rather new to me, in fact differentials as an entirety are new for me. Essentially I am looking for clarification regarding this type of question and whether or not I am doing it right. Thanks in advance...
Hi, I need to write a c++ program that calculates the total impedance of a simple RLC circuit. I'm given the values of each component (resistance, coil, condenser). The programming part is not a issue however I can't find the formulas for the impedance on the internet. Can someone help me out...
hi
i have a textbooks that says that if you have a driven RLC at its resonance frequency and now you increase the inductance, then you would measure a phase difference between the external emf and the voltage at the capacitor that is now greater than pi/2
unfortunately, i do not know how to...
Not really sure whether this question belongs here or not (if it doesn't, help move?).
So I was reading my electronic circuits textbook and am at the section of underdamped RLC unforced response, and the book mentions the natural response as
v_{n} = e^{-\alpha\cdot t}(A_{1}\cdot...
The link below shows a circuit and the s-domain equation for I1(s) that I have derived; My question is on the portion of the equation containing the "(s+a)" terms. I am trying to arrive at the time-domain equation for I1(s) but instead of arriving at the Laplace transform pair shown in the...
Homework Statement
An RLC circuits consists of R1 a 10-ohm resistor, R2 a resistor that takes 50 W, C1 a capacitor with 5-ohm reactance, and L1 an inductor that takes 100 var. Find the value of R1, R2, and Xl (inductive reactance).Homework Equations
P = (I^2)R
Xc = 1/(2∏fC)
Xl = 2∏fL
Z =...
I am having difficulties with phasor diagram for Is and Vs of an parallel RLC circuit. I have calculated all values but not sure how to use phasors.
Impedance Z has angle +65°. Current Isupply +30° and Vsupply is Z*Is= Vs at angle 95°
But with parrallel network V is the reference so I guess it...
Homework Statement
Please check picture
http://i.imgur.com/YMQBR.png
Homework Equations
The Attempt at a Solution
Shouldn't all the energy be 0 at beginning?
Thanks!
Hi there, we recently completed a laboratory session on MATLAB relating to an RLC Circuit and arrive at a code and relevant inputs and got our graphs as shown below.
I was just wondering if anyone know if these are correct and make any sense? Or any other comments appreciated.
We also have...
Quick Question...
Given:
Can I still use the general impedance equation for parallel RLC circuits even though the resistors are not in parallel with the other components? Substituting the two resistors for a single resistor with the equivalency resistance?
Hey,
Quick question for you guys. How do you find alpha (damping coefficient, Neper frequency) for a circuit that's not strictly parallel or in series? For instance, α for a series RLC circuit is R/2L whereas α for a parallel circuit is 1/2RC; but what if it's different?
Homework...
Homework Statement
A series RLC circuit has an electromotive force given by E=200e^(-100t) V, a resistor of 80 ohms, an inductor of 0.2 H, and capacitor of 5x10^-6 F. If the initial current and charge on the capacitor are zero, find the current at any time t>0.
Homework Equations
...
A series RLC circuit has an electromotive force given by E=200e^(-100t) V, a resistor of 80 ohms, an inductor of 0.2 H, and capacitor of 5x10^-6 F. If the initial current and charge on the capacitor are zero, find the current at any time t>0.
How on Earth do i start this?!
Homework Statement
For RLC circuit determine and solve differential equation. R, L, C, E0 values are constants, E = E(t) = E0*sin(ω*t) (E is marked as V in the image). Then make program which calculates values of I(t) when R, L, C, E0, ω are given.
In short, I need to get function I(t), so I...
I have been given the task of building an RLC circuit that is driven at 10kHz, has an output amplitude of 1/sqrt(2) and is 45 degrees out of phase from the input voltage.
I am not really even sure where to get started.
Any tips will be greatly appreciated.
Homework Statement
Given a series RLC circuit with a sinusoidal voltage input, find the effective voltage across each element.
Given:
1) If the effective value of the source voltage is 1 V, the effective value of the current is 1 amp.
2) i(t) lags v(t) by 45 degrees
3) L=1H
4) w=2...
Homework Statement
Hey guys.
So we've been working on a RLC circuit, where the subject is oscillations. We accomplished to work out a differential equation, for this specific circuit, however solving it is a completely other part of the problem. We're completely stuck here and hopefully...
I'm looking at this question and I can't seem to come up with an answer, don't the VL (inductive voltage) and Vc (capacitor voltage) just cancel each other out leaving you with Vr (resistance voltage) as the source voltage, but I don't see why VL and Vc are much higher than the source voltage...
Homework Statement
Consider a RLC circuit.
a) Suppose the parameters are chosen to give critical damping. The capacitor is charged to a voltage of V₀ and at time equal to zero the switch is closed. Find the time at which the magnitude of the current reaches a max, and find the value of the...
the general form of state space output is y=cx+du which means that output is linear combination of state variables and inputs my question is can we write output in this form when our output is not combination of state variable for example in rlc circuit state variables are vc and IL now if we...
Consider the circuit show below, where V1 = V_{peak}sin(\omega t - 36^\circ)
http://img195.imageshack.us/img195/9687/rlc.png
I wish to find an expression for I in the time domain and in phasor form and then sketch the magnitude/phase vs frequency plots. I already managed to get a solution...
Does anyone have a formula for the current in a series RCL circuit, if I have the: resonance frequency, current at resonance, capacitance (only one resistor, one capacitor, and one inductor), the voltage of the battery attached, and resistance?
oké, I'm ghaving a hard time with this one, bt it should be really simple acutally:
picture shows RLC circuit:
by kirchhoff law we can stat that:
+V-R*i(t)-(1/C)*integral(i*dt)-L*(di/dt)=0
I do understand V, R*i(t) and )-(1/C)*integral(i*dt), because those voltage physically...
1. Consider a series RLC circuit. The applied
voltage has a maximum value of 160 V and
oscillates at a frequency of 53 Hz. The circuit
contains a variable capacitor, a 760 Ω resistor,
and a 5.7 H inductor.
Determine the value of the capacitor such
that the voltage across the capacitor is...
Homework Statement
here is the circuit >>> http://www.4shared.com/photo/F3ewfm_3/22_online.html
the whole question is here >>> http://www.4shared.com/document/Qwxgzq78/Circuits_for_Modeling.html
whats assigned to me is #22.
anyways, what we need to get here is the differential equations...
Homework Statement
I'm trying to determine this insane circuit's |Z| so I can use an AC voltage to find the current as a function of time.
This is my circuit (the switch is closed, and ignore the values): http://i.imgur.com/mA55I.png
Homework Equations
Impedances for each of the RLC...
Hey everyone,
Ive been learning RLC circuits recently and all is ok now in the understanding side of things. We have also been learning about AM transmition and LCAM. Also how LCAM uses just a diode, capacitor and resistor to demodulate as that circuit will trace the peaks and recreate the...
Hi guys I really need some help to finish this on time,
1. A circuit with V volts and a 2 ohm resistor and a 2mH inductor and a 500uF capacitor in series.
There is a graph of current through circuit over time, starting at 0 current icnreases to 20 amps in 1 mS stays there for 1 ms then goes...
Hi!
Recently I did an experiment of an RLC circuit nearing resonance, and I found a substantial amount of loss of both current and voltage (30%). (More so than a different kind of AC circuit)
My question is, why is this so? Or is this just a coincidence/human error?
Some of...
Homework Statement
Consider an RLC circuit with very large Resistance.
a) when t = 0, q(0) = 0
b) When t = TL q(TL) = 2Q(1+e)-1cosh(TL/TC)
Where TL and TC are the inductive and capacitive time constants, respectively.
Show that the charge as a function of time is given by:
q(t) =...
Homework Statement
Solve the differential equation(for voltage uc(t) on the end of the capacitor in some electric circuit)
http://pokit.etf.ba/get/402e740f4c35317784c20c0acd656de5.jpg
for independent starting conditions
http://pokit.etf.ba/get/?f840b445d268567428ada50ed466c4f6.jpg
and...
hi guys
I am trying to fined Vo and Io using mesh analysis for the following cct
The formulas I made from the cct using mesh analysis don't seem right
here is what I have-
loop1
2(I1 - I2) = 0
loop2
2(I2 - I1) + I2(j4) - 3Vo = 0
loop3
3Vo + I3(-2j) = 0
and
I1 = 4<-30
vo...
Hey guys
I'm just wondering if I'm on the right track for the problem. I have started analysing the circuit, but I'm really unsure of my method of analysis. Did I use the formulas correctly? :confused:
The circuit switches from position "a" to position "b" at t=0
and I'm trying to fined...
Consider a series RLC circuit. The applied voltage has a maximum value of 120 V and oscillates at a frequency of 81 Hz. The circuit contains a variable capacitor, an 820 \Omega and a 3.7 H inductor. Determine the value of the capacitor such that the voltage across the capacitor is out of phase...
Homework Statement
At resonant frequency of 2,459 Hz for an RLC circuit, average power of circuit is 74 Watts when connected to a voltage source with a maximum voltage of 58 volts. If capacitance is 3 micro-Farads, what is maximum current, in amps, at 1,759 Hz? Answer is 2.14.Homework Equations...
Homework Statement
A brief description of the current condition here; I'm in confusion.
The question states that there are 2 unknown components in a circuit and we are to find it using the given data. The voltage, current and frequency are irrelevant for the time being.
I'm more interested...
Homework Statement
Calculate the impedance Zab across ab.
w=0.75 Hz
wo=1 Hz.
L=1 H
R=1 Ohm
C=1 F
Inductor and Capacitor are in series, and together are in parallel with the resistor.
circuit looks like a capital A, but square on top, and rotated 90 degrees clockwise.. if that...
I am trying to model an oscilloscope probe(active probe).
The voltage source in the circuit is from the device under measurement.
Let's say a 100MHz clock.
The probe signal and ground lead inductance are represented by 2 inductors, then a small series resistor. I made up the value of the...
Electrical oscillations are initiated in a series circuit containing a capacitance C, inductance L, and resistance R.
a) If
R << \sqrt{\frac{4L}{C}}
what time interval elapses before the amplitude of the current oscillation falls to 50.0% of its initial value?
b)Over what time interval does...
Homework Statement
I'm struggling to figure out what vectors I use for my phasor diagram for an RLC series circuit.
Homework Equations
VC = 1/j\omegaC
VL = j\omegaL
VR = IZ
The Attempt at a Solution
I know how to add vectors, so that's not a problem, transfer my circuit from the time...
Guys,
Let's suppose we have RLC series circuit feeded by tension source initially with no energy stored. When we apply an unitary step of tension at t=0 at the terminals of the circuit, we observe a current of i(t)=(125/24) * exp(-700t)* Sin(2400t) mA that goes around the circuit for...
The energy of an RLC circuit decreases by 1.00% during each oscillation when R=2.00 ohms. If this resistance is removed, the resulting LC circuit oscillates at a frequency of 1.00 kHz. Find the values of inductance and capacitance.
Hello All,
I have a bit of a problem with a series RLC circuit with no supply voltage. In the process of actually solving the second order differential equation for the voltage across the capacitor I have lost a handle on what it actually represents in terms of the circuit.
I have attached...
What type of power rating does a wattmeter measure in an AC RLC circuit? Is the power measured the apparent power or active power, and is this reading the rms value?
Also which current value is taken by an ammeter in an AC rlc circuit? is this also rms value?
I have design this circuit from the book on the software "Electronic Work Bench" but see the 1st peak voltage in the attached image,
why it is in Giga Volts ?
the 1% of 1st peak voltage should be equal to the last peak voltage but this condition is not fulfilling here ...why ?
i have...