1. Présentation LTspice est un logiciel professionnel de simulation des circuits électroniques analogiques. Circuit RC en régime transitoire 4. Circuit RL en. admissible de V. Quelle était l’intensité du courant circulant en régime permanent au temps t = 0 Régime transitoire 1°) Montrer que l’ impédance complexe du circuit peut se mettre sous la forme Z = R + jX(ω) avec . Filtre RC. La tension transitoire de rétablissement (TTR, ou TRV de l’anglais Transient Recovery Voltage) . Pour faciliter la coupure de faibles courants inductifs des circuits RC ou des varistances sont . de défaut, tend à rejoindre la tension du réseau avec un régime transitoire dont la fréquence vaut plusieurs kilohertz ( figure 7).
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The primary goal of this assignment is to quickly review what you regume know about capacitors, inductors, and AC circuits and to extend your new circuit analysis skills to cover sinusoidal signals.
The assignment draws from Chapters of your text. You will also learn how to use Spice to simulate time dependent effects and to analyze frequency dependent response in AC circuits. We increasingly conceive of circuits in terms of terminal behavior.
That is, we label the source signal and the potential difference between some other pair of nodesand we think of the network of devices between the input and output terminals to be a filter that transforms into. Measuring C and L: Series RC and RL circuits. First, measure the resistance of the resistor by any means you like.
Drive the circuits with a square wave signal from the function generator. Measure with the other channel to look at the natural and step response of the circuit.
Measuring the half time and converting to the time constant may be easier than trying to measure the time constant directly. Use the time base magnification feature of the oscilloscope to improve the precision of your time measurements. Give the uncertainties in your results. Simulation Use a transient analysis. You can measure the voltage levels and rise and fall times of the function generator with the oscilloscope to possibly produce a more realistic simulation.
Compare and contrast the voltage plot from your simulation with your measured oscilloscope traces. To model a real inductor, include an internal resistance in series with the inductor, and include this resistor in the voltage drop across the inductor. Use your expression for to find an expression for the inductance in terms of,and. It should be noted that there is nothing about this general approach that is specific to inductors. It works just as well for measuring capacitance.
Simulation Use a small signal AC analysis to generate a plot of vs. Include the internal resistance of the inductor.
Set up the simulation, guessing values for and. You will refine it as you work through the following experiment. Experiment First, measure the internal resistance of the inductor. Give an uncertainty with your result. Presumably, you know the resistance of the resistor you are using. If not, measure that, too. Then, use the function generator to drive your series RL circuit with a sinusoidal wave form. Use one channel of the oscilloscope to measure and the other to measure. Compare and at various frequencies.
How well do your measurements compare with your theoretical calculation and spice simulation? Use a measurement of in your theoretical calculation to find.
Report an uncertainty with your result. Be sure to measure your value at good frequency. Can this discrepancy be attributed to ignoring the internal resistance of the inductor? RLC Resonance Exercise At resonance, the capacitive and inductive reactances cancel, the phase angle is 0, and the voltage across the resistor is maximal as are the current and.
Derive an expression for the resonant frequency of a series RLC circuit in terms of and. Produce plots of and as a function of frequency, and note the predicted resonant frequency. Investigate and report on the dependence of the plots and the resonant frequency on the resistanceand explain.
Measure the voltage across the source with one channel the oscilloscope and with the other. Dial up X-Y mode on the time base knob to plot vs. At resonance, these two signals are in phase. In X-Y mode, this looks like a straight line.
At any other frequency, the oscilloscope trace resembles an ellipse. In time base mode, you can look for the frequency at which the voltage across the resistor is maximal. Report an uncertainty in your result. Compare your result with your theoretical prediction using your best measured values of and.
One is a low pass filter, meaning that it transmits low frequency signals to its output terminals favorably. Another is a high pass filter, transmitting high frequency signals favorably. There is also a band pass filter that transmits signals in a frequency band. On this basis, classify each of these networks as a low pass, high pass, or band pass filter. Use this expression to produce a plot of vs. Experiment Set up the band pass filter, driving it with a sinusoidal wave form from the the function generator.
Also measure the cutoff frequencies of the filter. A half wave rectifier. In order to convert an AC current that spends equal amounts of time flowing in opposite directions into a DC current flowing in only one direction, we need a device that responds differently to applied voltages of different polarities. The standard device used for this purpose in modern electronics is the semiconductor diode.
Are you surprised by the peak voltage across the load? Make note of this. Also compare your observations with a Spice simulation a transient analysis. If they agree, just hand in a graph of the simulation. Otherwise, also sketch your observed oscilloscope traces. In your Spice simulation, do not explicitly include the transformer. Simply treat it as a sinusoidal voltage source. In order to use diodes in a circuit, include the following statement somewhere in your circuit file.
A half wave rectifier with a filter. You should have found that the load is not being driven by a particularly steady DC signal, although the current always moves in one direction.
If you did not, perhaps we should look at what you discovered together. The next step is to use a large capacitor to filter out most of the unwanted variation or ripple in the signal across the load resistor.
Since the diode does not allow current to flow back through to the transformer, the capacitor discharges through the load resistor with a time constant. Assuming derive an expression for the peak to peak magnitude of the ripple in the output signal in terms of and. Using the best filter capacitor you can find 3measure the DC level and the magnitude of the ripple across the load.
Use the DC direct coupling mode of the oscilloscope or a DVM to measure the the DC level, and use the AC active coupling mode of the oscilloscope to remove the DC component of the signal and zoom in on the ripple.
File:RLC série soumis à échelon de tension – réponse apériodique critique en uC – bis.png
Then change the load resistance, and determine whether the ripple changes as expected. Full Wave Rectifier Figure A full wave rectifier with a filter.
It is also a full wave rectifierbecause it does not throw away any part of the input signal. Consequently, the filter for this circuit requires roughly half the time constant of the half wave rectifier. Otherwise, also sketch your observed oscilloscope transitoirr.
Électricité/Les circuits RL, RC, LC et RLC — Wikilivres
Measure the magnitude of the ripple, change the load resistance, and determine whether the ripple changes as expected. A full wave rectifier with a voltage regulator. This supply is a full wave rectifier with a filter and a device called a voltage regulator that removes the remaining ripple. This device is an integrated circuit Clrcuit that contains lots of very small resistors, capacitors, diodes and transistors manufactured on a single silicon wafer.
Poke around carefully with the oscilloscope. The filter capacitor is physically the largest capacitor. It also has the largest capacitance. The other two capacitors, labelled and are recommended by reegime manufacturer of the voltage regulator.
Électrotechnique I + II
Measure the DC and ripple voltages both at the output and at the filter capacitor. Check your calculations against a Spice simulation.
Find transtoire Thevenin equivalent voltage and impedance for the output terminals indicated. Comment on the function of the circuit as a filter converting into. Posted by Movies Live Posted on 5: Share to Twitter Share to Facebook. Newer Post Older Post Home. Le bilan se presente sous f