Introduction free oscillations in lc and rlc circuits for purposes of clarity, these experiment instructions will use lowercase letters, qt and it to denote timevarying circuit quantities. In effect, you have made a potential divider using a resistor the 100k whose resistance. Instead of analysing each passive element separately, we can combine all three together into a series rlc circuit. Try changing the amplitude and repetition frequency of the generator and observe. Use pspice to determine i 1, i 2, i 3, and vo in figure 1 at f 1khz and f 10khz. With both an inductor and capacitor in the same circuit, an lrc circuit essentially acts as a bandpass filter, a filter that only allows a narrow range of frequencies to pass. Also, compute and record the percent deviation between experimental and theory in table 1. Ac circuits rlc circuit introduction an inductor l is an important component of circuits, on the same level as resistors r and capacitors c. Since the current is common to all three components it is used as the horizontal reference when constructing a voltage triangle. The circuit forms an oscillator circuit which is very commonly used in radio receivers and televisions. To see the phase relationships between driving voltage and driven current in such a circuit at, below, and above the resonance frequency. Circuits laboratory experiment 3 ac circuit analysis 3. The analysis of a series rlc circuit is the same as that for the dual series r l and r c circuits we looked at previously, except this time we need to take into account the magnitudes of both x l and x c to find the overall circuit reactance.
The name rlc circuit is derived from the starting letter from the components of resistance, inductor, and capacitor. All the initial variables and values are remained the same. Before examining the driven rlc circuit, lets first consider the simple cases where only one circuit element a resistor, an inductor or a capacitor is connected to a sinusoidal voltage source. Natural response of parallel rlc circuits the problem given initial energy stored in the inductor andor capacitor, find vt for t. Circuits laboratory experiment 5 circuits containing inductance 5.
To measure the resonance frequency and the quality factor of a driven rlc circuit by creating a resonance frequency response curve. The text shows that if we start with the battery connected to the lr circuit, after a long time the current reaches a steadystate value, i 0 v 0 r. Construct the circuit shown in figure 1 and measure i 1, i 2, i 3 and vo. Voltage and current in rlc circuits iac emf source. An rlc circuit consists of a resistor with resistance, an inductor with inductance, and a capacitor with capacitance. Calculate i 1, i 2, i 3 and vo for the circuit shown in figure 1 for f 1khz and f 10khz. Ac circuits rlc circuit introduction an inductor l is an important component of circuits, on the same level as resistors r and the capacitors c.
The student will measure the circuit current, the voltages across the resistor and the. 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. A model circuit with an inductor and resistor if we call t 0 the time when we suddenly throw the switch to remove the battery. An inductor l is an important component of circuits, on the same level as resistors r and capacitors. Next, plot the total input of the series resonant rlc tank circuit. Using ni multisim to design and simulate rlc series resonance. In a series rlc circuit containing a resistor, an inductor and a capacitor the source voltage v s is the phasor sum made up of three components, v r, v l and v c with the current common to all three. The effective impedance of the circuit is nothing more than r, and the current drawn from the source is in phase with the voltage. The circuit has two initial conditions that must be satisfied, so the solution for vt must have two constants. This experiment will be used to examine the sinusoidal frequency response of the series and parallel to see at what frequency the current through an rlc series becomes or the voltage across a parallel rlc circuit reaches maximum value. Again we will do this by placing a charge on the capacitor since there is a resistor in the circuit now there will be losses as the energy passes through the resistor. There is an exact analogy between an rlc circuit and a harmonic oscillator mass attached to spring. Similarly, v crms is the rms voltage across the capacitor.
Index terms remote experiment, rlc circuit, phasor. The inductor is based on the principle of inductance that moving charges create a magnetic eld the reverse is also true a moving magnetic eld creates an electric eld. The v o voltage on the resistor is proportional to the series rlc circuit current. An illustrative example is given with spice simulation. Experiment 10 rlc series circuit resonance in an rlc series circuit objective.
Using ni multisim to design and simulate rlc series. Pdf lab 8 rlc resonance margaret wettergreen academia. The circuit should reach steady state very quickly, in much less than one second. Lets continue the exploration of the frequency response of rlc circuits by investigating the series rlc circuit shown on figure 1. These include as buffers on large transmission lines to reduce energy surges, on a smaller scale. Rc rlc filters and labview description and background in this lab you will a manipulate instruments manually to determine the inputoutput characteristics of an rc filter, and then b use an instrument control system called labview made by national instruments, inc. The series rlc resonance circuit introduction thus far we have studied a circuit involving a 1 series resistor r and capacitor c circuit as well as a 2 series resistor r and inductor l circuit. V rc, rl and rlc circuits v university of michigan.
The student will measure the circuit current, the voltages. We are now ready to introduce one of the most important components of a radio, the ac lrc circuit. Series rlc circuits wolfram demonstrations project. 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 parallel rlc circuit is the exact opposite to the series circuit we looked at in the previous tutorial although some of the previous concepts and equations still apply. The v o voltage on the resistor is proportional to the series rlc circuit. Eytan modiano slide 4 state of rlc circuits voltages across capacitors vt currents through the inductors it capacitors and inductors store energy memory in stored energy state at time t depends on the state of the system prior to time t need initial conditions to solve for the system state at future times e. A rlc circuit as the name implies will consist of a resistor, capacitor and inductor connected in series or parallel.
Figure 1 shows a driven rlc circuit where vo is the. The voltage v in volts and current in milliamperes ma are shown in the plot over. This complete solution is designed for use with pasco capstone software. The resonance property of a first order rlc circuit. To show the three equivalent response of a series rlc circuit ii. Ac circuits laboratory report experiment 4 series rlc circuit. A sinusoidal voltage is applied individually to a resistor, a capacitor, and an inductor. Using 12 switches, different connections between a resistor, an inductor and a. Series rlc circuits consist of a resistance, a capacitance and an inductance connected in series across an alternating supply. Rlc natural response derivation our mission is to provide a free, worldclass education to anyone, anywhere.
These types of circuits are also called as rc filters or rc networks since they are most commonly used in filtering applications. Parallel rlc circuit and rlc parallel circuit analysis. The output of input impedance of series rlc tank circuit. The complete solution for examining the response of a series lrc circuit with various driving frequencies. This laboratory is about studying resonance in rlc series and parallel circuits. Record the experimental inductor voltage in table 1. The resonant rlc circuits are connected in series and parallel. Rc, rl and rlc circuits 2 procedure to learn how to operate the oscilloscope and function generator, set the function generator for square wave output and connect the generator to the vertical input of the oscilloscope. Discharge of a capacitor procedure y assemble the circuit shown in figure 5 function generator. This can be verified using the simulator by creating the above mentioned parallel lcr circuit and by measuring the current and voltage across the inductor, capacitor and resistor. You can vary the frequency in hz, the resistance in ohms, the inductance in millihenries mh, and the capacitance in microfarads. The properties of the resonant circuit can be examined using this arrangement because the impedance of a resonant circuit is frequency dependent. Chapter 21 2 voltage and current in rlc circuits iac emf source.
Once the capacitor is discharged, the inductor resists any change in the. Rlc circuits it doesnt matter how beautiful your theory is, it doesnt matter how smart you are. However, the analysis of a parallel rlc circuits can be a little more mathematically difficult than for series rlc circuits so in this. Richard feynman 19181988 objectives to observe free and driven oscillations of an rlc circuit. Repeat the experiment using for the series resonant circuitry in figure 3, and use l 33mh and c 0. It is also very commonly used as damper circuits in analog applications. The voltage through an rlc series circuit will be measured as a function of frequency for a fixed applied voltage. It doesnt matter how beautiful your theory is, it doesnt matter how smart you are. To observe free and driven oscillations of an rlc circuit. The transient behavior of rc circuits is also tested. In the experiment will plot these quantities, and you will find a resonance, as shown in figure 114. The circuit can be thought of as being in two parts. Rlc circuit no generator like the lc circuit some energy must initially be placed in this circuit since there is no battery to drive the circuit. To experimentally determine the resonance frequency in a series rlc circuit and compare this to the expected resonance value.
In the execution of the experiment, highest benefit is gained if someone can distinguish. The current in an rlc series circuit is determined by the differential equation. First, the generation, transmission, distribution, and consumption of electric energy occur under essentially sinusoidal steadystate conditions. Rlc natural response intuition article khan academy. If it is set by your instructor, use the moodle course. Procedure y assemble the circuit shown in figure 5. The response of a series lrc circuit is examined at driving frequencies above, below, and at the resonant frequency. Rlc series circuit introduction the objective of this experiment is to study the behavior of an rlc series circuit subject to an ac input voltage. In both cases, it was simpler for the actual experiment to replace the battery and switch with a signal generator. Jun 18, 2016 rlc circuit in simulinksimpowersystem. An rc circuit can be used to make some crude filters like lowpass, highpass and bandpass filters.
Adjust the oscilloscope to obtain each of the patterns shown in figure 3. Frequency response of resonant rlc circuit here will find the voltage across the resistor, vr, as a function of frequency, for the rlc circuit shown in figure 112. In this demonstration, the amplitude is set to 10 volts v. Theory overview the dc steady state response of rl and rc circuits are essential opposite of each other.
This paper presents the remote experiment serial and parallel rlc circuit. The internal resistance of the function generator will affect the damping of an rlc circuit to which it is connected. Construct the rlc filter with r 10k, c 1uf and l 10mh and connect the. In both cases, it was simpler for the actual experiment to replace the battery and switch with a signal generator producing a square wave. This is an rlc circuit, which is an oscillating circuit consisting of a resistor, capacitor, and inductor connected in series. Write another function to calculate the total input current of series rlc tank circuit as shown in figure 3. Solve rlc circuit for i 1t and i 2t using the node or loop method we will use node method in our examples note that the equations at e 1 and e 2 give us i 1 and i 2 directly in terms of e 1, e 2, e 3 also note that v 1 e 1 and v 2 e 2 equation at e 3 gives e 3 in terms of e 1 and e 2 we. To determine the impedance of a series rlc circuit used in ac application. Pdf this article explains the analysis of series rlc circuit driven by a step voltage input. Circuits laboratory experiment 3 ac circuit analysis. The rc circuit resistor capacitor circuit will consist of a capacitor and a resistor connected either in series or parallel to a voltage or current source. Rcrlc filters and labview description and background in this lab you will a manipulate instruments manually to determine the inputoutput characteristics of an rc filter, and then b use an instrument control system called. Note, currents are measured indirectly by measuring the voltage across an. Copy and paste the link address wherever it is asked.
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