Lc Definition and 167 Threads

  1. Kyuubi

    Current on Infinite Periodic LC Circuit

    I wrote down the equation of motion for In(t) and I'm trying to match it with infinite spring mass system equation solution. In the spring mass system, we consider A to be the equilibrium length of the springs, and we can thus write Xn(t) = X(nA,t) and put it back into the equation of motion...
  2. ermia

    Solving LC circuit with energy conservation

    krotovs solution is based on energy conservation. My question is that why the solution didn't consider inductors energy? the question: The solution:
  3. L

    I Explaining Current Behavior in an LC Circuit

    Without mathematical formulas, but only with a "Physical intuitive meaning", why if at t=0, I have a charged capacitor, and I connect it through a wire ,forming a closed path, to a inductor the current increasing with time and his derivative decreasing? To me seems like the inductor oppose "to...
  4. A

    Inductor Efficiency via LC Oscillator

    I want to create an LC circuit with varying inductors and compare those inductors for efficiency. Would it be accurate to suggest measuring the area under the curve of the first cycle of the resonant frequency would determine which of the inductors are most efficient? If the area is greater...
  5. LCSphysicist

    Signs of the voltage drops in this LC Circuit

    I have been studying electronical circuit. In general, it is not difficult and is more about to solve EDO. The main problem is, really, the signs. See as follows: $$V_{L} = L dI/dt, V_{c} = +- Q/C$$ ? Should i put a minus sign there? Or shout i maintain the signs? When do i know what sign to...
  6. LarryS

    EM Waves Generated by an LC Circuit?

    I am not an electrical or electronic engineer. I am trying to understand how a simple, series LC circuit running at it's resonant frequency can generate EM waves. I believe, based on what I have read, that the frequency of the generated EM waves will be the resonant frequency of the circuit...
  7. Andrei0408

    Equation Demonstration -- Comparing a pendulum's motion to an LC circuit

    I've just learned about simple harmonic motion and I've been given the following examples: The physical pendulum (for small oscillations sin(theta)~theta), with the formula (1st pic), and the LC circuit, with the formula (2nd pic). If possible, I need the demonstration for these 2 formulas...
  8. johnboyman

    Trouble working with LC circuits

    Hello. I am experimenting with LC Circuits. So far I know that 1/2*Pi *Sqrt(LC) will give you the frequency of the lc cricuit. So when i decide which components to use I can start with that. I was wondering though in a circuit with a 60 hertz supply. What is the minimum and maximum frequencies...
  9. J

    In an LC circuit the current does no drop to 0

    in an LC circuit the current does no drop to 0 but varies sinusoidally. The capacitor is recharged with a different polarization. Why is this so?
  10. A

    Series LC frequency/voltage dependance

    I think I have mistaken something here but does changes in voltage affect the frequency of a series LC or parallel LC circuit or not? Or is the frequency only dependent on capacitance and inductance of the circuit elements? And if the fed in frequency matches the resonant frequency then the LC...
  11. C

    Solve LC and LRC Circuits Kirchhoff's Rule Problem

    Problem Statement: A 300-V dc power sup- ply is used to charge a 25-μF capacitor. After the capacitor is fully charged, it is disconnected from the power supply and connected across a 10-mH inductor (at t = 0). (a) Assume that the resistance in the circuit is negligible. Apply Kirchhoff’s loop...
  12. Zack K

    How exactly do inductors work in an LC circuit?

    I understand Faraday's law and about induced electric fields created by a changing magnetic fields, etc. But what causes the current to oscillate in an LC circuit, with no battery? If you picture that there is current going into an inductor, and that current is decreasing over time, then you...
  13. sneakycooky

    Find the charge q(t) for an LC circuit

    Homework Statement An LC circuit consists of an 82 mH inductor and a 17 microfarad capacitor that initially carries a 180 microC charge. The switch is open for t < 0 and is then closed at t = 0. a. Find the frequency of the resulting oscillations. b. At t = 1 ms, find the charge on the...
  14. Nikhil Rajagopalan

    Charging and Discharging of a capacitor in an LC circuit

    In an LC circuit, the capacitor that is initially charged to a finite value starts to discharge cross the inductor, initially the current increases and the inductor opposes it, but as the current is supplied against the back emf, due to the discharging of the capacitor, won't it reduce the value...
  15. Shivang kohlii

    Current through source in AC circuit with R & LC in parallel

    Homework Statement In the circuit diagram shown , Xc = 100 ohm , XL = 200 ohm , R = 100 ohm , the effective current through the source is ? Homework Equations Z= √( R^2 + ( XL - Xc)^2) Vrms = Irms/ ZThe Attempt at a Solution I tried to draw the phaser diagram and calculate the relation...
  16. Laserray

    T Section Lowpass LC Filter Frequency Formula

    I have been trying to find out how the cutoff equation for the T section LC Lowpass filter is derived. I remember from college that f=1/(2pi√(LC)) for an LC circuit. But, with the T section, the cutoff frequency is given by f=1/(pi√(LC)), with L being the sum of the two inductors. My math has...
  17. S

    Engineering Solve LC Circuit Problem: Examples & Resources

    Homework Statement An image of the problem is attached. I have to find 2 currents in an LC circuit. Homework Equations V = L(di/dt) The Attempt at a Solution [/B] I have no clue how to do this type of problem. Are there any examples problems similar to this online? Or can someone give me...
  18. E

    Dispersion equation for an LC Circuit

    Need the dispersion equation for chain consisting of cell units ( LC unit scheme in attachments). I know I need to make complex Kirchhoff equations and after get the dispersion equation but absolutely don't know how to do it. All examples that I find in web very poor including books, articles...
  19. E

    Pulsating DC supply to LC circuit

    I have a very basic question for the professionals here, but I am having a small issue with my parallel LC circuit. I have an inductor that is 6.425mH, a capacitor that is 217uF (it is two 470uF aluminum electrolytic caps connected in series to make one non-polar 217uF cap). I am supplying the...
  20. K

    B LC Oscillation: Current Flow & Charge Polarity

    when in LC oscillation current flow from inductance to capacitor and charge is opposite polarity. why don't current flow in reverse of it and charging the capacitor in same manner as it was earlier.
  21. E

    How to know when an LC circuit hits resonance

    I have been having issues with a series LC circuit. I have a supply voltage of 6.96 volts, across the inductor is 7.04 volts and the capacitor voltage is 7.17 volts. The capacitor has a capacitance of 45uFarad and a supply frequency of 250 hertz. I don't know what the inductance is of the...
  22. Paul Colby

    Voltage Monitor for an LC circuit

    Hi, I have an air wound 0.736 mH coil in series with a 3.5pF capacitor being driven with a function generator. Ideally the series resonant frequency should be around 3.13 MHz. The internal impedance of the function generator is 50 ohms or so. At resonance the voltage across the cap should be...
  23. S

    LC circuits in series with Diodes

    I need help understanding what will happen when the switch in closed in this circuit. What I want to happen is for Cap B to charge first and then discharge into Cap C. When the charged capacitor begins to discharge, will it charge Caps B and C at the same time? It will have to overcome the...
  24. yuvalidan

    What is the Hamiltonian for an LC circuit?

    Homework Statement Hi i got a problem in lc circuit, I need to find the hamiltonian to this circuit , I think that I did well but I am not sure, the problem and my attempt in the following file. Homework EquationsThe Attempt at a Solution
  25. J

    LC Reactive elements cancel cause huge V drop. High voltage

    Hello all, I am a senior electrical engineering student at Purdue University and I am working on my senior capstone project. One of the aspects of my project is to measure voltage and current waveforms as well as the relative phase shift between them. I need to get these waveforms into a data...
  26. T

    Filter Performance Assessment Using Basic Equipment: A Practical Guide

    Hi, Say I have a design for a filter, is there a method of bench-marking it's attenuation over a variety of loads and types of harmonics? (or even common and differential noises) For instance, say I wanted to compare a filter to an LC filter or a π filter, how does one evaluate how much better...
  27. G

    B Build a Dipole Antenna with LED: Charge Imbalance Explained

    Hi. In this video around 6:45, this guy builds a simple dipole antenna with an LED and capacitor in parallel in the center. The LED flickers when close to a transmitting cellphone. Since the LED only let's current pass in one direction, shouldn't this quickly lead to a charge imbalance between...
  28. clamatoman

    Solving for Imax and Energy in an LC Circuit: Homework Help

    Homework Statement 4700uF Capacitor is initially charged to 9.0V, then the voltage source is removed and the capacitor is connected across a 1.50H inductor. Solve for: Energy of the Circuit, Imax, and Time after Circuit connected whed Energy of the capacitor =Energy of the inductor Homework...
  29. A

    How to Find i(t) for an Inductor in an LC Circuit?

    Homework Statement In the figure given, find i(t) for the inductor My problem is though when we found i(t) with a source we find the transient response and the steady state response... I know how to do the transient response of an RLC circuit not an LC one... do i just consider R to be 0...
  30. O

    Engineering What is the time constant in an LC circuit.

    Homework Statement I wrote an exam today and a question worth quite a bit of points asked Determine the value of a capacitor in a series circuit that will give a time constant of 4.0 ms and is isn series with an inductance of 3mH Homework EquationsThe Attempt at a Solution I do not believe...
  31. R

    LC circuit -- Calculate the work done

    1. The problem statement, all variables and given/known data In an oscillating circuit consisting of of a parallel-plate capacitor and an inductance coil with negligible active resistance the oscillations with energy ##W## are sustained. The capacitor plates were slowly drawn apart to increase...
  32. T

    I have some problems with LC -3 assembly language

    Hi guys, I'm new to this language. When studying I'm really confused and don't know where to start, even with a simple example. I have read the book Introduction to Computing System but it doesn't help much. Can you show me some ways or books that can help me ?
  33. A

    LC Circuit Problem Homework: Calculate Values of L & R

    Homework Statement When the current in the portion of the circuit shown in the figure below is 4.00 A and increases at a rate of 0.500 A/s, the measured voltage is ∆ = 15.0 V. When the current is 4.00 A and decreases at the rate of 0.500 A/s, the measured voltage is ∆ = 10.0 V. Calculate the...
  34. M

    What Is the Voltage Across the Resistor in an LC Circuit with Given Parameters?

    Homework Statement In the following figure(Figure 1) switch S1 is closed while switch S2 is kept open. The inductance is L = 0.360 H, the resistance is R = 31.0 Ω , and the emf of the battery is 22.0 V . At time t after S1 is closed, the current in the circuit is increasing at a rate of di/dt =...
  35. Luek

    Energy stored in a LC circuit

    Homework Statement Energy in the circuit remains constant. When the current is flowing, the energy stored is all stored in the inductor. When the current stops flowing, it is because all the energy is stored in the capacitor. Find the fraction of energy stored in the inductor when half of the...
  36. S

    Electric Discharge acts as in LC Circuits?

    For the most part, do electric discharges behave as tank circuits? For example, an air capacitor; when the electric field causes the air to breakdown and conduct, will the discharge alternate at a frequency defined by the inductance of the plasma channel and the capacitance of the capacitor?
  37. S

    Can a Center Tapped LC Circuit Reduce Potential Difference Across the Inductor?

    My objective is to make a lc circuit that will have a potential difference across the inductor that is lower than that of the capacitor. A spark gap must also be used. Will this work and will the resonant frequency be the same as if it was wired conventionally?
  38. L

    B Why aren't standard rods and clocks affected by LC and TD?

    Are measuring rods and clocks(the ones that are used as reference to ascertain LC and TD of the relatively moving rods and clocks) left out of the theory in principle?
  39. B

    Impedances of R, L, C, RL, RC, LC and RLC circuits

    Homework Statement In first place, ignore the source in each circuit, ignore if make sense or not. I placed one sorce in each circuit just for the circuit be more visible. In second place, ignore the numerical values of the sources, resistors, capacitors and inductors. Think R, L and C in...
  40. A

    Why LC tank only oscillates at resonant frequency?

    I am wondering why LC tank only oscillates at resonant frequency not other frequencies? Is there a physics explanation for that?
  41. E

    Calculate LC Lowpass Filter Output Signal

    Hi! Here is my task: Lowpass filter circuit is given: Input signal to this circuit is: L=36.4mH, C=85.4nF. Calculate and draw output signal. My idea is to: 1) Represent input signal in term of Fourier series (complex form), 2) Calculate transfer function for given circuit (for n-th...
  42. DoobleD

    Solving a parallel LC circuit with DC current

    Take the following circuit (capacitor initially not charged) : I am trying to solve for the current everywhere as a function of time. I set up the following equations (are they right ?) : Then, any way I try it, I end up with some messy integrals. Even using wolfram alpha to get those...
  43. B

    RLC, RL, RC and LC circuits and ODE

    Look this schematic picture: S means source and can be a current source or a voltage source. C_1, C_2 and C_3 are linear components, can be resistor, capacitor and inductor. In the everycircuit, I tried set up all possible combination and the everycircuit denied some combinations, but...
  44. R

    Engineering LC circuit (Differential Equation)

    Homework Statement An inductor with value L and a capacitor with value C are connected in series to a power source. At time t, the voltage of the power source (i.e. the voltage across both the inductor and capacitor) is given by ## v(t)=Asin(\frac{2t}{\sqrt{LC}}) ##. If the voltage across the...
  45. S

    LC series oscillator with DC supply

    Hi, I have a question about LC series oscillators. Specifically when a DC supply is applied. Solving the differential equation for such circuit using as initial conditions at t=0 that Vc=0 and I=0 I get as a solution that the circuit oscillates and the voltage across the capacitor has an...
  46. Dorian Black

    Limitations of LC Circuit Charging with Constant EMF

    Hi, A capacitor has both its terminals connected together using a wire in a rather lengthy circular fashion, hence acting as a significant inductance. If the area encircled by this 'circuit' is subjected to a linearly rising magnetic field (B=k x t) where k is a constant, the emf induced -due...
  47. PratyashAstro

    Derivation of self inductance formula in an LC circuit

    My observation is to verify self inductance formula by measuring the resonant frequencies of different coils in an LC circuit.For this, I am asked to use this formula by my mentor : L = 1/(4π^2 . f^2 . C) Here, f = different resonant frequencies, C = capacitance of the capacitor in the LC...
  48. F

    LC circuit in external static magnetic field

    Homework Statement What effect would placing an LC circuit in a steady magnetic field have have on its resonant frequency? The inductor contains a paramagnet. This is asked about at very low temperature. Homework EquationsThe Attempt at a Solution Apart from initial changes due to Lenz's Law...
  49. I

    Series lc circuit and clamp-on ammeter

    In a series LC resonant circuit the capacitor acts to cancel out the inductance of the the circuit. With no inductance in the circuit the magnetic field will collapse. So my question is, with this collapse of the magnetic field will it be be harder to measure the current in the circuit with a...
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