What is Rlc: Definition and 443 Discussions

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.

View More On Wikipedia.org
  1. F

    Values of RLC from S11 perameter

    Homework Statement Hi everyone. For a lab we have had to simulate a circuit with a "real" capacitor and review its S11 in order to re calculate back the values of R, L and C. The important result is obviously at resonant freq. So at 27.3GHz S11 = -0.989 also, for good measure, at...
  2. T

    Calculating Resonance Frequency and Amplitude in RLC Circuits

    Homework Statement I did an experiment using an RLC circuit (in series) and an oscilloscope to determine the resonance frequency and amplitude (in volts) of my components (R total = 2300ohm, L = 0.081H, C = 1.5E-8F). I plotted all the data I collected (V vs. f) and got a nice response curve...
  3. D

    What is the solution to a simple RLC circuit problem?

    Homework Statement I have some difficulties in parts 3 and 4 of the following problem: (1) A sufficient time has elapsed after closing the switch S, and a steady state is established in the circuit with a constant current I0 flowing. Find the expression for I0. (2) Then the switch S is...
  4. P

    Engineering Series RLC Circuit & Differential Equations

    Homework Statement I have a series RLC circuit, no values given, connected to a voltage source Vs(t). I am asked to write the differential equations for: a. that relates the inductor current iL(t) to the source voltage Vs(t). b. that relates the capactor voltage Vc(t) to the source...
  5. E

    Initial conditions for rlc series natural response

    Homework Statement Find v(t) across a cap. in a series rlc circuit with no driving force (initial v across cap: 24V) Homework Equations from the values of the components, \alpha > \omega_0, the circuit is overdamped, and the following equation can be used: v(t) =A_1 e^{s_1 t} + A_2...
  6. T

    What is the Thevinin's equivalent resistance in a series RLC circuit?

    hey guys, i was just wondering, in a series RLC circuit, is "R" the Thevinin's equivalent resistance at the "Capacitor and Inductor" terminals?, if not please correct me. Thanks.
  7. James889

    Parallel RLC, calculating phasors

    Hi, I have the following circuit: [PLAIN]http://img252.imageshack.us/img252/9470/phasor.png I need to find the current i(t). I have come to a point where i don't know how to proceed. I have the inductor and resistor in series. 40 +j120 in phasor form 126.5\angle 71.56 which...
  8. M

    What is the value of ω for a RLC AC circuit with given parameters?

    Homework Statement I am given a RLC circuit with a AC power source (e.g. signal generator), and i want to find the reactance of the capacitor. Given: R = 2200 Ohms, L = .025 H, C = (1 x 10-9) F, V0 = 5 V f = 3000 Hz Homework Equations edit: Sorry i wrote wrong formula.. here is...
  9. I

    What is the Relationship Between Bandwidth and RLC Circuit Parameters?

    Homework Statement and Homework Equations I am trying to get from: I_{max}=\sqrt{2}I=\frac{V}{\sqrt{R^2+(\omega L-\frac{1}{\omega C})^2}} to: \Delta\omega=\omega_1-\omega_2=\frac{R}{L} The Attempt at a Solution From the equation above: \sqrt{R^2+(\omega L-\frac{1}{\omega...
  10. 2

    Engineering RLC Circuit: Solving for IL(t) | Step-by-Step Guide and Explanation

    I need to find an expression for IL(t) i attached scans of what i have tried. I am not sure i did it right could you please take a look see post # 2 for my attempt at solution
  11. M

    Engineering Second Order Laplace Trasform For RLC Circuit

    Homework Statement The circuit below (please see attactment) shows an RLC filter circuit whereby RC = 1/2 and LC = 1/16. Determine the differential equation that describes the relationship beween the input voltage Vi(t) and output voltage Vo(t). If the initial conditions of the capacitor and...
  12. M

    Engineering RLC Circuit Differential Equation problem

    Homework Statement For a RLC circuit with RC = 1/2 and LC = 1/16 determine the differential equation that describes the relationship between the input and output voltages. An image of the circuit is shown with RLC all in series with the input voltage Vi(t) across all 3 components. The voltage...
  13. D

    Loop Antenna and RLC networks

    I am building a resonant RLC network in which the inductor is actually a loop antenna that will pick up changes in magentic fields and represent them as a voltage. Is this configuration actually feasible where the loop antenna is both the voltage source and the inductor? Also slightly related...
  14. R

    RLC Series/Parallel Impedance Near Resonance

    Hey, The impedance of the series and parallel RLC circuit both tend to R near the resonant frequency (one is a min/ one is a max) so if I expand the frequency around this point I should be able to show they are the same for \delta \omega small right? For some reason I can't get it to work. Any...
  15. B

    How Does Phase Angle Affect Current in an Undriven RLC Circuit?

    Homework Statement I am given a RLC circuit in series with a fully charged C. There is no applied voltage at this part of the problem. Using kirchhoff I arrive at a second order diff.eq which leads me to the (correct) solution for the charge in the capacitor: q(t) = Q0exp(-t/T)cos(wt + Ø)...
  16. X

    Pspice help RLC parrallel circuit.

    Hello everybody. I have an over-damped RLC parallel circuit. Using techniques taught, I solved for v(t) = 70e^(-10,000t)+20e^(-40,000t) V for t> zero. This indicates that my initial voltage is 90v. Using MATLAB (Part of the assignment) I verified this. I also found that Current as a function of...
  17. T

    Changing values of R in a RLC series circuit

    Homework Statement A television channel is assigned the frequency range from 54 MHz to 60 MHz. A series RLC tuning circuit in a TV receiver resonates in the middle of this frequency range. The circuit uses a 16 pF capacitor. Inductor is .487 micro Henries. In order to function properly, the...
  18. T

    Calculating Peak Current in a Series RLC Circuit

    Homework Statement A series RLC circuit consists of a 100 ohm resistor, a 0.10 H inductor, and a 100 micro farad capacitor. It is attached to a 120 V/60 Hz power line. What is the peak current, I? Homework Equations I=V/Z Z=sqrt(R^2+(omegaL - (omegaC)^-1)) omega=2pif The Attempt...
  19. E

    Understanding Characteristics of RLC Circuits

    speaking of R-L-C series and parallel circuits, can anyone tell me what is the physical meaning of characteristic frequency, damping ratio, overdamped, underdamped, critically damped circuits?
  20. P

    RLC circuit - total impedance,phasor analysis (mainly checks)

    Homework Statement A resistor, R = 100 Ω, an inductor, L = 0.20 H and a capacitor, C = 3 µF are connected in series across an ac source of VS = 100 V and frequency, f = 200 Hz. Calculate the following for this series circuit: in attempt at solution Homework Equations The Attempt...
  21. S

    Engineering Solving RLC Circuit Response: Converting to Phasor Notation and Troubleshooting

    the problem statement is attached. i've begun by converting everything into phasor notation but I'm not quite sure where to go from here. when i try to add the C and the L phasors, i get zero. this doesn't seem right. another problem is i have no idea what to do when i get the impedances of...
  22. Terocamo

    RLC Resonance: Understanding VL and VC Magnitudes

    Homework Statement The question ask if VL=VC if the circuit is under resonace The Attempt at a Solution I originally thought when resonance happens in RCL circuit, Vr=Vsupplied, therefore, by loops rule Vr+Vc+VL=Vsupplied, during reasonance Vr and Vsupplied canceled each other, so what's...
  23. L

    Resonance in RLC series circuit

    -Is the RCL circuit in resonant? Explain -Given that C is equal to 2X10-3F, find inductance, L. problems: -Is fo equal to 1...because the maximum value in the graph at t=1? -from the graph,how to know that the graph is resonant or not?...can i say that because the current and the voltage...
  24. P

    Calculating Impedance and Voltage Drop in an RLC Circuit

    Homework Statement A resistor, R = 100 Ω, an inductor, L = 0.20 H and a capacitor, C = 3 µF are connected in series across an ac source of VS = 100 V and frequency, f = 200 Hz. Calculate the following for this series circuit: a) the total circuit impedance (Zt) b) the total circuit current...
  25. P

    RLC circuit - total impedance,phasor analysis etc

    Homework Statement A resistor, R = 100 Ω, an inductor, L = 0.20 H and a capacitor, C = 3 µF are connected in series across an ac source of VS = 100 V and frequency, f = 200 Hz. Calculate the following for this series circuit: a) the total circuit impedance (Zt) b) the total circuit current (IS)...
  26. P

    RLC AC Circuit: Frequency & Impedance

    Homework Statement For which of the following AC circuits does impedance depend on frequency? A circuit with Check all that apply. a resistor and inductor. a resistor and capacitor. only a resistor. Homework Equations The Attempt at a Solution I think that for a capacitor...
  27. O

    RLC Circuit Problem: Finding Currents and Voltages Using Mesh Analysis

    Hello everybody, So I've been on this problem for nearly 4 hours now and am still blank at what i need to do as this book only has 2 RLC circuit examples that are not helping. --R1-----R2-- | | | Vs L C | | | ------------- (well...this diagram didn't...
  28. G

    Engineering RLC Circuit Second Order Differential and Laplace

    Homework Statement Derive the second order differential equation relating x(t) and y(t). Using the Laplace transform, find the total response as a function of the zero input response and the zero state response in the following form.Homework Equations Y(s)=Yzs(s) + Yzi(s) The Attempt at a...
  29. A

    RLC AC circuit can't get right answer

    Homework Statement R=250 L=6 C=15microf e(t)=300sin(50pi t) Find Z, phase angle, lead/lag, emf(215ms) (got all of this right) Voltage across inductor, capacitor and resistor, also show that the sum of the voltage across the elements at 215ms is equal to total emf at 215ms. Homework Equations...
  30. S

    Potential Difference Across an Inductor in an RLC circuit

    Homework Statement An alternating source drives a series RLC circuit with an emf amplitude of 6.0V, at a phase angle of +30deg. When the potential difference across the capacitor reaches its maximum positive value of +5.00V, what is the potential difference across the inductor? Homework...
  31. S

    Damoed Oscillation in an RLC circuit

    Homework Statement A single loop circuit consists of a 7.2 ohm resistor, a 12.0 H inductor, and a 3.20*10^-6 F capacitor. Initially the Capacitor has a charge of 6.20*10^-6 C and the current is zero. Find the charge on the capacitor N complete cycles later for a) N=5, b) N=10, and c) N=100...
  32. P

    Fit P(w) to determine Q,w, and R (Series RLC AC circuit)

    Homework Statement Fit P(w) to determine Q, and w_0, and R. You should put in Vrms as a known constant. Homework Equations P(\omega)={\frac{V_{rms}^{2}}{R(1+Q^2(\frac{\omega}{\omega_0}-\frac{\omega_0}{\omega})^2)} Q=\frac{\omega_0}{\Delta\omega} R=R_load+r The Attempt at a...
  33. 8

    Averag power of an RLC circuit

    Homework Statement 4.) Determine the average power in an RLC circuit. Derive an expression for the resonance frequency in terms of L and C. Is the average power a maximum or a minimum at the resonance frequency? Homework Equations The Attempt at a Solution I have circled in red...
  34. Y

    Archived Solve RLC Circuit Power Factor Problem: 3 x 10^3 Hz, 139V rms, 37.1A rms

    Homework Statement When the power factor of RLC circuit is equal to one, the frequency of the voltage source is 3 x 10^3 Hz. The rms value of the voltage source is 139 Volts and at a frequency of 3 x 10^3 Hz, the rms current in the circuit is 37.1 amps. If the inductive reactance at 3 x 10^3...
  35. G

    RLC Locus Diagrams Homework: Solve for Z,Y Variables

    Homework Statement In a series circuit V = V<0 @50hz with an R and C, show that the graph of the loci or the port impedance, Z, and port admittance, Y, as the resistance R is varied from 0 to inf ohms are as shown. http://ivila.net/prob.pnghttp://ivila.net/loci.png Homework Equations The...
  36. P

    Engineering Solve RLC Circuit w/Switch Homework Problem

    Homework Statement Provided in the picture below. Homework Equations The Attempt at a Solution So what I've done so far is use KVL to obtain Vc(t) +Vr(t) + Vo(t) = 1/2Vin(t). Could someone tell me if I started this problem correctly? Would I just take the derivative of the...
  37. N

    RLC Series Circuit Problem: Find V_source from V_R, V_L, V_C

    Homework Statement In an L-R-C series circuit, the rms voltage across the resistor is 32.0 , across the capacitor it is 90.1 and across the inductor it is 51.5 . What is the rms voltage of the source? Homework Equations Well there are lots of equations V_rms =V/sqrt(2) V_R=IR...
  38. U

    RLC Circuit: Find Applied Source Voltage

    Homework Statement [PLAIN]http://img255.imageshack.us/img255/3048/56893213.jpg Find the voltage of the applied source. Homework Equations I=V/R Kirchoff's Voltage LawThe Attempt at a Solution Applying KVL. V= 40 + 50 +20 =110 Is this question that simple? Or am I missing something?
  39. Y

    RLC Circuit- Find average power in circuit

    Homework Statement When the power factor of RLC circuit is equal to one, the frequency of the voltage source is 3 x 10^3 Hz. The rms value of the voltage source is 139 Volts and at a frequency of 3 x 10^3 Hz, the rms current in the circuit is 37.1 amps. If the inductive reactance at 3 x 10^3...
  40. R

    Oscillating series RLC circuit

    Homework Statement In an oscillating series RLC circuit, with a 8.77 Ω resistor and a 15.0 H inductor, find the time required for the maximum energy present in the capacitor during an oscillation to fall to 1/8 its initial value. Homework Equations I know that for an RLC Circuit...
  41. R

    Engineering Plotting Impedance of Parallel RLC Circuit

    Homework Statement Plot |z| vs. f(Hz) of the circuit. R=100, C=600 pf = 6E-12 F, L=10E-6 H . All elements of the circuit are in parallel. Also identify the resonant frequency. Homework Equations ZR=R ZL=jwL ZC=1/(jwC)=-j/(wC) w=2(pi)f w0=1/sqrt(LC) f0=1/(2(pi)sqrt(LC)) G=1/R...
  42. M

    RLC parallel circuit; fourier components

    Homework Statement In my lab we did an experiment using an RLC parallel circuit, with the L and C in parallel. The voltage source was set at square waves. I am being asked to explain why there are frequencies, beyond the resonance, at which there is a peak voltage drop across the capacitor...
  43. M

    Kirchoff's Voltage Law in RLC circuit

    Homework Statement I am required to write KVL circuit equations for the following circuit I don't need to finish solving for I1, I2, I3 and I4 at the moment. I just need a bit of help setting up the equations. Thanks. Homework Equations Kirchoff's Voltage Law, which states that...
  44. M

    RLC Circuit (with variable frequency)

    Homework Statement Find the frequency at which the circuit becomes purely resistive and calculate the effective resistance. Here is the circuit with the given solution- The trouble is, whilst the solution is simple enough, there are many places to go wrong, and the whole process is...
  45. D

    Engineering How Do You Determine Thevenin Resistance in RLC Circuits for DC and AC?

    I want to know how to find the R thevenin of an RLC circuit. Do I short the inductor and open the capacitor? or do I remove both capacitor and inductors?
  46. L

    Parallel RLC Circuit: Find Current I & Resonance Condition

    Homework Statement For the following circuit: where R1 = 100k\Omega, R2 = 10\Omega, L = 0,1Hy, C = 200\muF. V gives a constant tension of 1V. Find the current I as function of the frecuence, the condition of resonance, and the condition R1 and R2 must have so that the Q factor = 0,5...
  47. fluidistic

    Impedance of an RLC series circuit when in resonance

    I don't find my notes right now, I'll try to use my memory on this. According to my notes, the impedance of an RLC series circuit is given by \frac{1}{\sqrt{R^2+\left ( \omega L-\frac{1}{\omega C}\right )^2 }}. So when in resonance, Z=\frac{1}{R} instead of Z=R. Also if I recall well, for...
  48. G

    Time Constant for an RLC circuit

    Can anyone please tell me what the Time Constant of an RLC (Resistor, Inductor, Capacitor) circuit is?
  49. P

    Max Power Dissipated in RLC circuit

    Homework Statement For this sample exam, we are given an RLC circuit, with an alternative emf of 1 V, connected all in series with a 500 ohm resistor, a .4 mH inductor, and two capacitors in parallel of 50 pF each. It asks for the "maximum power dissipated by the resistance" and at what...
  50. F

    RLC Circuits - Resonant Frequency, Power

    Homework Statement An AC circuit consists of an alternative emf of 1 V connected to a resistor of 500 Ohms, an inductance of 0.4 mH, and two capacitors connected in parallel of 50 pF each, We want to find the resonance frequency of this circuit, the maximum power dissipated by the...
Back
Top