Lc Definition and 167 Threads

  1. Rugile

    Average power in series LC circuit

    Homework Statement A voltage source is connected to a series LC circuit. The frequency of the source is resonant. The voltage amplitude of capacitor is 1V. Find the average power in the circuit. Homework EquationsThe Attempt at a Solution I realize that if there is no active resistance the...
  2. L

    Model Scope Probe Ground & Signal Lead Impedances

    I am trying to figure out how to model a scope probe ground lead and signal lead. Both leads would have some impedance and the probe would have some pf capacitance. How to deal with both the inductances?
  3. K

    What happens when a battery is connected to an ideal LC circuit?

    Hi All , I was thinking about the time domain unit step response of ideal series LC crcuit. If both cap and inductor are ideal and unchrged initially and I am looking at voltage across capacitor. Connecting a battery to LC circuit at t=t1 , would the circuit oscillate ? I am not able to...
  4. Y

    Understanding Kirchhoff's Law in LC Circuits: Exploring the Confusion

    I am confused with explanation about Kirchhoff's law in LC circuit. Please refer to the file I attached for the LC circuit. First, the switch was connected to the emf and the capacitor was charged to its full capacitance. Then the switch is connected to the capacitor, the capacitor will start to...
  5. nmbr28albert

    The Lagrangian Solution of an LC Circuit

    One way to solve the simple LC circuit with 1 inductor and 1 capacitor is to use the Lagrangian formulation of mechanics and consider charge q as the generalized coordinate. When writing down your Lagrangian, the energy of the inductor \frac{1}{2}L(\frac{dq}{dt})^2 is treated as the kinetic...
  6. C

    Solving for Angular Frequency in Series R to Parallel LC

    This is my first post here. I hope I have found the correct place to do it. This is not actual coursework, but as it is this type of work, I am posting here per the guidelines. Homework Statement I am trying to solve for angular frequency for a given output voltage, so I am seeking to...
  7. R

    Making Bode Amplitude Plot of LC Filter in Matlab

    Homework Statement I'm trying to make a theoretical Bode Amplitude plot of the following circuit in Matlab: The transfer functions is given by ##T=\frac{V_{out}}{V_{in}}=\frac{R_2}{R_2+z_p}## ##z_p=R_p|| j \omega L || \frac{1}{j \omega C} = \frac{R_p}{1+ j R_p (\omega C -...
  8. J

    Laplace analysis of simple LC tank (no resistance)

    I am stumped by an exercise in using Laplace transforms to analyze the voltage and current in simple LC tank. My issue is with the correct sign of the voltage across the capacitor ...let me pose the problem. A circuit consists of a voltage source V, 2 switches, a cap C and an inductor L. The...
  9. B

    Series parallel LC tank circuit Resonant Frequency equation?

    Hi How would I calculate a series-parallel LC circuit for resonance? I added up all the μH and pF for the equation, would that be correct? The inductors are in parallel, and the capacitors in series.
  10. A

    Solve Freq of Coupled LC Circuit with Inductor

    Homework Statement I have to find the normal frequencies of a coupled LC circuit. However, this LC circuit is coupled by an inductor, not a capacitor. __|C|________|C|__ |...|...| ^I(1)...|...^I(2) |...|...| {L}...{L'}...{L} |...|...| |...|...| -------------------- I'm sorry, I didn't have a...
  11. dwn

    How Do You Calculate Charge and Current Change Rate in LC Circuits?

    I'm having a difficult time finding any information in regards to LC circuits. The total energy in an circuit is 5.0*10^-6 J. If C= 15 microfarads, what is the charge on the capacitor? the ans is 12 microC An circuit has an inductance of 15 mH and a capacitance of 10 µF. At one...
  12. amjad-sh

    Electomagnetic oscillation in lc circuit

    Hi, We know that when we connect a charged capacitor to a coil, the capacitor will discharge in the coil that means that the current will flow in the circuit in decreasing manner with respect to time .So an emf will be created in a way that oppose the decrease. Bin will has the same...
  13. G

    LC Filter Voltage Drop Considerations

    Hi, I've gotten a little confused and would like some guidance and confirmation, I've designed an H-Bridge inverter which should output 100A at 20Vrms onto a 200mΩ load. The current target output peak voltage (with max duty cycle of 98% considered) is 28.86V. The LC filter is made up of a...
  14. Crazymechanic

    Lc Circuit Question: Understanding Oscillations and Polarity Changes

    So I have a question about the circuit. Now we know that when the C is discharging there is a current through the inductor , now there can be these oscillations because the inductor time delays the current (because of back emf) that wants to run to the other side of the capacitor as it would...
  15. D

    How can the added inductors and capacitor in this LC circuit create a harmonic?

    I'm trying to better understand this circuit: https://www.circuitlab.com/circuit/qnxkke/lc-chopper/ and how the added inductors (L3, and L4) and Capacitor create a harmonic. I fully understand how to calculate the resonance for the main circuit but how would I calculate the harmonic that the...
  16. M

    Low-pass LC butterworth filter cutoff frequency question

    I am designing a 5-pole low-pass butterworth filter to have a cutoff frequency of ~50 Hz. It has a source impedance of ~1 Ohm, and a load impedance of ~50 Ohm (The load impedance can be changed around if that will help later). Because of these, I am using the "T" configuration. I used the table...
  17. R

    Engineering Proving the Form of a Homogenous LC Circuit?

    Homework Statement I have a circuit with input source x(t), which contains also an inductor and a capacitor in series which I have found to be related to the output voltage y(t) (across the capacitor) like so: LC*d2y/dt2 + y(t) = x(t). I have also found its roots through the quadratic...
  18. skate_nerd

    LC circuit, space between dielectric plates

    Homework Statement If the max E-field in the capacitor is E=1.2(103) N/C and the space between the plates is filled with a dielectric of constant 100,000, what is the separation between the plates? Homework Equations I know C=kεoA/d where k is the dielectric constant, A is the area of...
  19. P

    AP Physics E&M MC: Electric Field, Induction, LC Circuit

    Homework Statement Answer is B. Answer is E. Answer is E. Homework Equations E=F/q E=V/d Right hand rule for inductors The Attempt at a Solution Quite confused for these problems. For number 18, I'm quite baffled as to where the 0.04 meters even comes from. What I had...
  20. H

    Using a spectrum analyzer to find LC resonance?

    Hi everyone, I am using a signal generator in series with a RLC circuit, generating an AC signal at 1kHz. I have my probes connected across the resistor When I change the timescale the Fres bandwidth changes on the spectrum analyzer. At 1mS the resonant bandwidth is from 25kHz-50kHz At...
  21. R

    Finding resistance in an LC Circuit (FM Radio)

    Homework Statement The figure shows a simple FM antenna circuit in which L = 8.22 µH and C is variable (the capacitor can be tuned to receive a specific station). The radio signal from your favorite FM station produces a sinusoidal time-varying emf with an amplitude of 12.2 µV and a frequency...
  22. S

    Solving the Equation for a Simple LC Circuit

    In a simple LC circuit, How do i set up the differential equation? Following Walter Lewin's teaching that 0) Use Maxwell-Faraday Equation instead of Kirchhoff Rule 1) if E field and dl are in the same direction, then I write a positive term. 2) There is no electric field in an...
  23. A

    Tuning an LC circuit to a particular EM wave.

    Hello Everyone, I am making an LRC circuit by having a Coil attached to a Capacitor attached to a Light-bulb which is attached to the Coil. Provided that the radio signal (of 2000 Mhz) I'm trying to "collect" is strong enough and the coil/capacitor is properly tuned I should see the...
  24. G

    Calculating the frequency based on LC circuit

    Hi all, I am currently building up a lightning detector based on this website: http://www.techlib.com/electronics/lightningnew.htm as the diagrams shows, the resonance tank included a 10mH inductor and a 10pF capacitor. As I want to calculate the resonant frequency (using the formula f =...
  25. I

    Maximum Charge in an LC circuit.

    Homework Statement A circuit is constructed with a resistor, two inductors, one capacitor, one battery and a switch as shown. The value of the resistance is R1 = 481 Ω. The values for the inductances are: L1 = 281 mH and L2 = 163 mH. The capacitance is C = 85 μF and the battery voltage is V...
  26. D

    Engineering Multisim Transient Analysis for LC parallell circuit

    Homework Statement The main problem is that I need help using Multisim for transient analysis of a simple LC parallell circuit. I am doing something wrong. C= 3*10^-5 F L= 3*10^-3 H The Capacitor is charged to 10V What happens to the energy of the capacitor when we connect it in...
  27. B

    Finding the Resonant frequency in an LC circuit

    Homework Statement The figure opposite shows a free oscillator composed of an LC circuit. Derive an expression for the resonance frequency. Show all of your working. Homework Equations d2x/dt2 + ω2x = 0 The Attempt at a Solution First I tried using Kirchoffs Voltage Law to set...
  28. B

    Building an LC Circuit powered by 60Hz AC Current

    Hey guys, So I'm working on this project, and I'm trying to make two coils of different diameters to be tuned to the same resonance frequency. I got the equation ω=1/(LC)^0.5 for the frequency. My thinking was that the frequency of the wall power shouldn't matter because the resonance...
  29. A

    Engineering Capacitor voltage of series LC circuit (inductor and capacitor)

    Homework Statement I have a series LC circuit that consists of a 1V DC voltage supply, an inductor and a capacitor. The inductance of the inductor is 2mH and the capacitance of the capacitor is 1μF. I performed a transient analysis using a simulation software and I observed the trace of the...
  30. W

    Can I replace an LC circuit with a crystal?

    Hello all, I am trying to make an FM transmitter that operates at only 1 frequency. I need the frequency tolerance to be very high, so I'd like to choose a crystal instead of an LC circuit. This is the circuit I'm building: http://cappels.org/dproj/FMdist/fmdis.htm If I were to replace...
  31. N

    Why in a LC circuit does the current reverse ?

    So I was learning about the LC circuit and I know that an inductor would oppose the change in current through it, so if I connect a charged capacitor with an inductor, the charges on the capacitor would want to flow to the other side and neutralize the two plates like it does when the two plates...
  32. H

    LC Circtuit finding Q across an element for given time

    Homework Statement A circuit is constructed with two capacitors and an inductor as shown. The values for the capacitors are: C1 = 513.0 μF and C2 = 68.0 μF. The inductance is L = 265.0 mH. At time t =0, the current through the inductor has its maximum value IL(0) = 106.0 mA and it has the...
  33. Crazymechanic

    Can a Series LC Circuit Effectively Drive MOSFET Gates?

    Hi, I have built some stuff before mainly amplifiers and some power supply modules, tell me what you think of this. I want to ask is it possible to have a series lc circuit that is powered from the rectified + rail through a resistor that gives me the correct voltage and transorb that would make...
  34. Q

    Engineering LC circuit analysis problems with 2 voltage sources

    Homework Statement . In the following transient circuit, assume at t<0, the circuit is at steady state. Find v0(t) for t>0 http://sphotos-b.xx.fbcdn.net/hphotos-ash3/c0.0.354.354/p403x403/546839_509413575744829_42997155_n.jpg Homework Equations The Attempt at a Solution The...
  35. O

    Calculating Capacitance of LC Circuit

    1. Homework Statement Calculate capacitance of LC Circuit where: Inductor - 30H Capacitance voltage fully charged goes to zero in 20 seconds 2. Homework Equations Main Eq: V=V. *cost(ωt) where V is final Voltage, V. = Voltage initial, ω = resonant angular frequency ω = 1/√(LC)...
  36. O

    Calculating Capacitance of LC Circuit

    Homework Statement Calculate capacitance of LC Circuit where: Inductor - 30H Capacitance voltage fully charged goes to zero in 20 seconds Homework Equations Main Eq: V=V. *cost(ωt) where V is final Voltage, V. = Voltage initial, ω = resonant angular frequency ω = 1/√(LC) = 2∏f f. =...
  37. T

    Where does the phi come from in the charge of a capacitor in an LC circuit?

    I'm reading University Physics 13e by Young and Freedman and we're given this equation: -L(di/dt)-q/C=0 So we know that i, current, is, i=dq/dt. So the first equation can be read, after some simplification, as q''+(1/LC)q=0 where q prime means the derivative of q (charge) with...
  38. P

    LC circuit with variable capacitor

    Homework Statement An oscillating LC circuit is designed to operate with a maximum current of 31 mA. The inductance is fixed at 42 mH, and the frequency is changed by means of a variable capacitor C. (a) If the highest voltage that the capacitor can handle is 50 V, can the circuit be operated...
  39. C

    Engineering Black box Conumdrum: CL or LC order in a RLC circuit

    Hey everyone. Since it is nearest the end of the summer semester for the Lab component of my classes, Our professor is having do the 'Black Box' project. From the information he gave us, there are three component in a L-configuration, an inductor, capacitor, and a resistor. The Box itself had...
  40. F

    Maximum Charge on a Capacitor in an LC Ciruit

    Homework Statement A charged capacitor is connected to an ideal inductor to form an LC circuit with a frequency of oscillation f = 1.6 Hz. At time t = 0 the capacitor is fully charged. At a given instant later the charge on the capacitor is measured to be 3.0 μC and the current in the circuit...
  41. D

    Max Harge on a Capacitor in LC Circuits

    Homework Statement An oscillating LC circuit consisting of a 1.2 nF capacitor and a 3.3 mH coil has a maximum voltage of 2.6 V. (a) What is the maximum charge on the capacitor? Homework Equations Q=CV The Attempt at a Solution I tried Q=CV but this did not work I got the answer...
  42. M

    Solving LC Circuits: Time Interval Between Max Current & Voltage

    Homework Statement The total energy stored in an LC circuit is 2J. The inductance is 10^-2 H and the capacitance is 100 μF. What is the time interval between a maximum current through the inductor and a maximum potential difference in the capacitor?Homework Equations T = 2∏/ω ω = √(1/LC)The...
  43. M

    Basic question about TD and LC

    Hello, I have basic confusion about Time Dilation and Length Contraction. I have struggled much, but I haven't succeed. Please. help me to clear it. In A frame I have [t_{a1}, x_{a1}] and [t_{a2}, x_{a2}]. If I assume c=1 and x_{a1}=x_{a2}, and if I transform it to B frame which is moving...
  44. B

    Series or Parallel connection for LC circuit

    I'm trying to make a wireless energy experiment by using LC circuits as resonators. But within this circuit you can either make the inductor and capacitor in series or in parallel. What do the different combinations do to the circuit? Is there one that is ideal for some circumstances?
  45. C

    How Do Infinitely Long LC Circuits Behave?

    Homework Statement I'm curious about infinitely(?) long LC Circuits. Say you have a circuit (and I am going to describe this sort of like a matrix) with capacitors on the top row, inductors on the bottom row, and one inductor in each column. Assume a current with value "i" is going up...
  46. N

    How does LC phase shift oscillator work?

    Heya Everyone :blushing: Im slightly confused as to how LC phase shift oscillator work ? Its a circuit consisting of 1 op-amp ( used as oscillator), 1 LC loop, few resistors. The op-amp has a reference voltage applied to the non-inverting end (+ve). The inverting end has a feedback...
  47. G

    Pspice Schematics LC resonance graph

    Hi!:smile: I have a LC circuit in pspice schematics, i want to simulate graph: input voltage versus frequency,to see resonance voltage. To simulate at least something i must give power source (VAC) some value,so when i choose to trace voltage in power source at the graph, its the constant value...
  48. cepheid

    What is the purpose of the second inductor in a T-section LC low pass filter?

    I have a dumb question about "T-section" filters like the one shown on this page: http://www.radio-electronics.com/info/rf-technology-design/rf-filters/simple-lc-lowpass-filter-design.php If the output it taken across the two rightmost terminals, then what is the point of the second...
  49. T

    Engineering Why Is There a Phase Shift in an LC Tank Circuit at Resonance?

    In a lab session we were investigating the LC tank circuit of a superhet radio. The tank consisted of a ferrite coil antenna connected in parallel with a variable capacitor. A signal generator was connected to a second ferrite antenna (the drive antenna) and placed close to the first in order to...
  50. M

    Maximazation of current in LC circuit

    Hello guys This is my first post and i am glad to be a member of this forum. There is something bugging me for a lot of time. I have a problem understanding why the current of an LC oscilator circuit is maximized when the capacitor is fully discharged. Of course when it is explained from the...
Back
Top