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.
Amplifier gain ##A_V## is defined as the ratio of an amplifier's output voltage to its input voltage,
i.e. ##\displaystyle\frac{V_R}{V}=\frac{IR}{IZ}=\frac{R}{R}=0.5## at 200 Hz.
But this is absurd. Where have I gone wrong? Please nudge me in the right direction.
Good morning,
I need some help solving those two question. I've attached my attempted solution below. Could i solve the transfer function any further?
Thank you for your help
Hello guys,
LRC circuits with an AC source are having the best over me... had some confusion in class with respect to which method is best using(phasors diagram, reactances or complex impedances) which I am trying to desperately sort out before my exam; here I will show you my best attempt on...
a) An inductor should be added because that would cancel out the lag of the voltage with the current so that P = IV is at a maximum since V is ahead of I in an inductor
b) ##cos(\phi) = \frac{R}{Z}##, ##R = Zcos(\phi) = 60\times 0.5 = 30 ohms##
##X_l - X_c = \sqrt{Z^2 - R^2} = \sqrt{60^2 -...
(An even longer-winded version was written and deleted out of mercy.)
Assume an AC voltage at zero degrees applied to an ideal parallel RLC circuit.
For a predominantly inductive circuit, the vector diagram for current should show the supply current in the fourth quadrant (i.e. with lagging...
Hi Guys
When I use lumped RLC in HFSS, I find that its size can influence the simulation result. How do I set the sheet size of lumped RLC? Make it square is better? Thanks.
Hi all,
I understand the standard solution where charge in an RLC circuit decreases from +Q to 0, for a capacitor with starting charges +Q and -Q. May I know what the terminal charge on a capacitor in an RLC circuit is, when it’s original charges are 2Q and 0?
I am thinking it will be +Q and...
So am trying to find the current in the RLC series circuit ,but i think i have done something wrong ,if anyone could tell me where i went wrong ,it would be great ,thank you
Resistor-100ohms
Capacitor-0.01uF
Inductor-25mH
Voltage Source-50v a.c
1kHz
Hi
i want to know just how to approach this question.
i know the omega=100 then should i find XL and XC? and then find the voltage in points c and d?
also how do i find the current that enters point c?
thanks a lot.
Hi,
I've a doubt about how to the energy is stored in a 'real' RLC parallel resonant network feeds from a sinusoidal source. Take a 'real' RLC parallel network having a resistor ##R_s## in series with the inductor ##L_s## (modeling its loss) with the capacitor C in parallel and consider it in...
Summary:: About resonant frequencies
A series RLC circuit with R = 250 ohms and L = 0.6 H results in a leading phase angle of 60° at a frequency of 40 Hz. At what frequency will the circuit resonate?
Answer is 81.2 Hz but i got a different answer. May someone please correct me.
Hello, this is my working. My professor did not give any answer key, and thus can I check if I approach the question correctly, and also check if my answer is correct at the same time.
for t < 0,
V(0-) = V(0+) = 60V
I(0) = 60 / 50 = 1.2A
When t > 0,
$$α = \frac{R}{2L}$$
$$α =...
Hello, this is my working. My professor did not give any answer key, and thus can I check if I approach the question correctly, and also check if my answer is correct at the same time.
When t < 0, capacitor acts as open circuit,
$$V(0-) = V(0+) = 9V$$
When t = infinity,
$$V( ∞) = 5V$$ (because...
the impedance of the parallel RLC circuit is shown as attached.
The equation above is the impedeance of RLC circuit in series, how can I convert that in parallel? Thanks.
These are my attempts at doing this question, and I was wondering if I am correct so far.
At t= 0-, i(L) will be 0A, since the capacitor acts as a open circuit.
However, I'm not sure why V(c) at t=0- will be -20V as given by the answers. Won't it be 0V?
Moving on, since current in inductor and...
If a voltage source is sinusoidal, then we can introduce a phasor map and come up with equations like$$V_0 e^{i \omega t} = I(R + i\omega L + \frac{1}{\omega C} i)$$where ##I## would also differ from ##V## by a complex phase.
But if you set ##\omega = 0##, which would appear to correspond to...
Hello.
I have completed the following question.
My answer:
i)
Circuit Impedance
Reactance = XL = 2 x pi x F x L
= 2 x pi x 50 x 0.15
= 47.12 Ohms
Reactance of Capacitor = XC = 1/2 x pi x F x C...
Hello,
I have been thinking about this problem for a few hours, and I do not understand how I should proceed to solve it correctly. Section a is very simple, just substitute in the expression that gives us the values of L and C that the statement gives us.
However, when I get to section b, I...
Hi !
I'm trying to understand why does we say that RLC circuit is a dynamic system. An example of a dynamic system that i know is a pendulum. The swinging of a pendulum depends on the applied force but also on the past force. What about the output of RLC circuit ? What is the relation between...
One property of series resonance circuit is that at resonance, the voltage across circuit elements R,L and C may be larger than the source voltage. I can relate it to vector analogy where component vectors may have larger values than the resultant and the phenomenon is counter-intuitive. This...
Summary: Series RLC and Parallel RLC circuits
How can the voltage across a capacitor or inductor in a series RLC circuit be greater than the applied AC source voltage? The formula suggest that either can be larger than the source voltage but I still find it counter intuitive.
Also for...
Summary: Looking for guidance on how to model an RLC circuit with a system of ODES, where the variables are the resistor and inductor voltages.
This is a maths problem I have to complete for homework.
The problem is trying to prove that the attached circuit diagram can be modeled using the...
We know that the charge on capacitors as a function of time takes the general form of:
##Q(x,t)=qe^{ijka}e^{-i\omega t}##
The voltage at each capacitor:
##V_j = \frac 1 C (Q_j-Q_{i+1})##
From KVL we have differential equation of t-derivatives:
##LQ'' + RQ' = V_{j-1} - V_{j}##
##LQ''+RQ'= \frac...
Homework Statement
Homework Equations
V(t) = V(∞)+( V(0+) - V(∞) )e^-t/τ
3. The Attempt at a Solution
Hello again! I've already solved the problem depicted in the picture above and below are the following unknowns that I managed to solved:
These results checked out with the answers...
Homework Statement
The attempt at a solution
Constructing the total impedance of the circuit as follows,
$$\frac{1}{Z_T}=\frac{1}{Z_R}+\frac{1}{Z_C}+\frac{1}{Z_L}$$
where $Z_R=R$, $Z_C=-j\frac{1}{\omega C}$ and $Z_L=j\omega L$.
$$\frac{1}{Z_T}=\frac{1}{R}+j\omega C+\frac{1}{j\omega L}$$...
Homework Statement
10 v, 100 hz goes into a circuit of a 1o resistor, a 1o inductive reactance and a 1o capacitive reactance that are in series.
What is the current. What is the V across the cap.
Homework Equations and the attempt at a solution[/B]
So I know I = V/Z and Z = sqrt( R^2 +...
Hi, i need some help here. Can you help me?:sorry:
Here is the problem.
Exercise statement: The switch have been closed for a long time y is opened at t=0. Using Laplace's transtormation calculate V0(t) for t ≥ 0
This is what i made to solve it:
1) I know while the switch is closed, the...
Homework Statement
I have the following RLC circuit with an sinusoidal voltage generator and I want to verify the Kirchoff's first law with an oscilloscope. To measure the peak voltage in each of the components I just permute the positions between the component and the resistor.
The question...
Hello to everbody can you help me how come C6 to be 10p and c5 13.5 and and l1 to be 190n and L6 240n
i start with 100Meghz, with one circuits 50/XL or 50/XC now become three different thanks
i understand the first circuit, i understand the second circuit, but now they make three circuits
how...
Homework Statement
I'm reading the textbook section covering damped series RLC circuits (provided below). I'm wondering why the author stipulates "When R is small..."
Homework Equations
Given above.
The Attempt at a Solution
Given above.
Any gentle and courteous comments are welcome!
Homework Statement
Homework Equations
I know for RL circuit T = L/R
For RC circuit it is RC
But how to go ahead for RLC circuit.The Attempt at a Solution
I calculated for RL as 1/4 = 0.25
And RC as 1
Then I added both time constant and got 1.25
Book answer is 0.5. How to solve this?
In...
I bolded the portions I need help with.
1. Homework Statement
A series circuit consists of a resistor with a resistance of 16 ohms, an inductor with inductance of 2 H, and a capacitor with a capacitance of 0.02 F.
At time t = 0 there is no charge on the capacitor and no current in the circuit...
Homework Statement
Find io for t≥0.
Express your answer in terms of t, where t is in milliseconds.
There is no energy stored in the circuit in (Figure 1) when the switch is closed at t = 0.
Homework Equations
##x(t)=x_f+[B_1cos(ω_dt)+B_2sin(ω_dt)]e^{-αt}##
The Attempt at a Solution
Let...
Hey guys, so I'm having trouble with this circuit analysis question. I need to find voltage across the capacitor as a function of time. I nearly finished analyzing but I'm having trouble solving for the initial value constants in the voltage equation. So first I used KCL to create the equation...
Homework Statement
Imagine you have two RLC circuits you are trying to scan for resonances. They have identical resonant frequencies, but circuit 1 has a very high Q-factor
(Q1 >> 1), and circuit 2 has a very low Q-factor (Q2 < 1). Let's assume you are already
on resonance and looking at V(out)...
Homework Statement
The answer in (algebraic form) is
Homework EquationsThe Attempt at a Solution
I'm not sure how to simplfy into the form required from here.
<Moved from a homework forum. Template removed.>
I can't find any documentation on how to do this. I remember in linear algebra how to find the incidence matrix of an electrical network of purely resistors. Put how do I find it of a RLC circuit with resistors, inductors, and capacitors? I can't...
How can taking voltage and current readings from an AC supplied CCT with either a resistive, capacitive or inductive load (gradually increasing the load for each) show the difference in phase angle between voltage and current for each component? Many thaks for any help.
Homework Statement
An RLC circuit contains the following components in series: a 15Ω resistor, a 200μF capacitor, and a 12mH inductor. What are the currents and voltages through each component?
It's known that the current through the resistor is 1.75A⋅cos(250πt)
Homework Equations
χL=ω*L...
I'm having trouble understanding RLC circuits. If I have a resistor, capacitor, and inductor connected in series and I'm GIVEN the current through the resistor, How do I find the currents through each component? Is it the current that was given for the resistor (since they're in series), or do I...
Homework Statement
here is my problem :
Homework Equations
like usual, the problem is related with RLC circuits and transients
The Attempt at a Solution
[/B]
from here, the solution is obviously wrong because from the solution, its alpha should be -300 and not -0.4...and from the...
Homework Statement
http://imgur.com/a/3xSYb
Homework Equations
RLC equations:
q= Qmax e ^ -Rt/2L cos wd t
wd = [ 1/LC - (R/2L)^2] ^ 1/2
The Attempt at a Solution
So, I am trying using Kirchoff law, but not sure what the question asks.
I thought it may be a trick and after a long...
Homework Statement
Homework Equations
Q(t) = Aei(wt+Φ); dQ/dt = i*w*Q(t); E = (L/2)(dQ/dt)2 + Q2/2C
i = √-1 E above is average energy
The Attempt at a Solution
When I plug in Q(t) & dQ/dt into equation above (E) I get:
A2L/2(w02-w2)cos[2(wt+Φ)]
w02 = 1/LC
After I plugged both of them in...
Homework Statement
Homework Equations
The Attempt at a Solution
I used the loop rule where ##ΣΔV=0## and junction rule.
From here I get 4 equations
##i_3=i_1+i_2##
##ε-i_3R_3-i_1R_1-L(di\dt)=0##
##ε-i_3R_3-i_2R_2-Q\C=0##...
Homework Statement
I want to find different parameters of series and parallel RLC
for series RLC we have this transfer function
and we know that transfer function of second order system is something like this:we can assume H0=1
but is wrong(when you use only denominator you find out that...