Switch on the dc voltage supply, adjust the voltage to any. To experimentally determine the resonance frequency in a series rlc circuit and compare this to the expected resonance value. Chapter 21 19 power in ac circuits ipower formula irewrite using icos. The energy in the circuit sloshes back and forth between the capacitor and the inductor the oscillations are damped out by the resistance in the circuit. Robertson, phillips, and the history of the screwdriver duration. Inductors and capacitors are energy storage devices. These include as buffers on large transmission lines to reduce energy surges, on a smaller scale. Rlc series circuit v the voltage source powering the circuit i the current admitted through the circuit r the effective resistance of the combined load, source, and components. Experiment 10 rlc series circuit resonance in an rlc series circuit objective. 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. A variable noninductive resistor, a variable capacitor, a variable inductor, a signal generator, an a. Lcr measurement primer 6 of 78 1 what is impedance. Calculate i 1, i 2, i 3 and vo for the circuit shown in figure 1 for f 1khz and f 10khz.
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. The quality factor or qfactor of a series resonant circuit is defined as the ratio of a voltage developed across the inductance or capacitance at resonance to the impressed voltage, which is. To maintain good voltage profile in long and medium distance power transmission capacitive and inductive compensation techniques are used. Introduction to lcr parallel circuits the lcr parallel circuit. It also provides you with further practice in computer modeling and introduces you to non. For the parallel circuit the half power frequencies are found by. Resonant circuits measuring inductance frederiksen. Below you can see the same lcr circuit in different order, e. Not only that, the series lcr circuit can magnify voltage, so the voltages. In general, the complex impedance is defined as follows. To study the variation in current and voltage in a series lcr circuit. Experiments for first year electrical engg lab 201516 dept of electrical engineering, shri ramdeobaba college of engineering and management, nagpur 4400 india page 3 procedure. Use the lcr meter to measure the inducance of the coil and the capacitance of the capacitor labeled as 330.
Construct the circuit shown in figure 1 and measure i 1, i 2, i 3 and vo. Introduction to lcr parallel circuits electronics for fun. It doesnt matter how beautiful your theory is, it doesnt matter how smart you are. 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. After performing this experiment you will be able to. The formula for determining the resonant frequency of a series lcr circuit is. They can be used to select a certain narrow range of frequencies from the total spectrum of ambient radiowaves. Quality factor lcr circuits consider an electrical circuit consisting of an inductor, of inductance, connected in series with a capacitor, of capacitance, and a resistor, of resistance. The capacitor charges when the coil powers down, then the capacitor discharges and the coil powers up and so on. The frequency corresponding to maximum current is noted and it is the resonant frequency f 0. The values for v0 and dv0dt from the circuit do not depend on whether the response is overdamped, underdamped, or critically damped. To measure the resonance frequency and the quality factor of a driven rlc circuit by creating a resonance frequency response curve. Lesson plan for electric circuits salt river project. The measurements will be compared with theoretical calculations of the same quantities.
The student will measure the circuit current, the voltages across the resistor and the. In our article about the types of circuit, we discussed that there two major types of circuit connection. Rlc circuits scilab examples differential equations. The mathematics underlying lcr circuit theory for ac currents is discussed. The purpose of this experiment was to observe and measure the transient response of. To find resonance frequency, bandwidth, q factor of rlc series circuit.
A circuit containing a resistor, a capacitor, and an inductor is called an rlc circuit or lcr, as shown in figure 1b. As a single, lumped element, inductors find many uses. We must take into account the different phase angles between voltage and current for each of the three components in the circuit. In effect, you have made a potential divider using a resistor the 100k whose resistance. The frequencies f 1 and f 2 corresponding to half power points is noted and from it the bandwidth, f 1 f2 is noted. The capacitance was varied and the periods of the oscillations were used to determine the inductance in the circuit. The behaviour of lcr lowpass filters are studied by measuring the frequency response and step response. Notes on electrical resonance in series lcr circuit and. Rlc circuit board pasco model ci6512 computer interface system pasco series 6500. The curve is based on the resonant rise in circuit current where i vr at resonance.
Apart from electronic applications,there are many applications in electric power transmission. The radio is used to illustrate the concepts of resonance and variable capacitance. Engineering physics lab experiment lcr series circuits. The values of the components are tuned so that we have a smooth rolloff of the middriver towards higher frequencies. A network is in resonance when the voltage and current at the network input terminals are in phase and the input. The lcr circuit can appear to be just a capacitor, just an inductor, or solely a resistor. Most students complete part a in week one and part b in week two.
Unless stated otherwise, for this experiment use the inductor without the steel core in its center. Electrical impedance z, is the total opposition that a circuit presents to alternating current. Lcr circuits electrical impedance series and parallel circuits. Such a circuit is known as an lcr circuit, for obvious reasons. The circuit can be thought of as being in two parts. With this context, let us discuss the lcr circuit and its analysis in detail. Series lcr circuit has applications in radio and communication engineering. Lcr circuit analysis of lcr circuit series circuit. Lcr circuits, damped forced harmonic motion physics 226 lab. Complex numbers are used to convert differential equations to algebraic equations. 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. From the article, we understood that a series circuit is one in which the current remains the same along with each element. How to design a transistor circuit that controls lowpower devices. Use the display button and the format button found in the.
The effective impedance of the circuit is nothing more than r, and the current drawn from the source is in phase with the voltage. From the values of f 0, f 1 and f 2, the quality factor, q is calculated. An lcr circuit, also known as a resonant circuit, tuned circuit, or. They differ in that a capacitor stores energy as accumulated charge voltage potential and an inductor stores energy in a magnetic field that is due to. Rlc circuits it doesnt matter how beautiful your theory is, it doesnt matter how smart you are. Lcr circuit series and parallel psbrahmacharys blog.
Lcr circuit 420600 includes the following components. In introducing the lcr series circuit, one of the most useful combinations of passive components in electronics, module 9 set the groundwork for module 10. In both cases, it was simpler for the actual experiment to replace the battery and switch with a signal generator. In both cases, it was simpler for the actual experiment to replace the battery and switch with a signal generator producing a square wave. Amfm radio with analog tuners use a rlc circuit to tune a radio frequency. Lc, rc, and lcr filter circuits in this experiment we will measure the gain and the phase shift of some simple. We measured the time varying voltage across the capacitor in a rlc loop when an external voltage was applied. The frequency of applied ac at which resonance takes place or current is maximum. Note, currents are measured indirectly by measuring the voltage across an. The name of the circuit is derived from the letters that are used to denote the constituent components of this circuit, where. Also to find the quality factor and band width in lc r series circuit. What is the value of z in lcr series circuit at resonance.
Experiments for first year electrical engg lab 201516. The voltage through an rlc series circuit will be measured as a function of frequency for a fixed applied voltage. On this page you can read or download grade 12 electric circuits experiment in pdf format. 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. Impedance changes according to the components in the circuit and the frequency of the. Circuits laboratory experiment 5 circuits containing inductance 5.
The purpose of this experiment was to observe and measure the transient response of rlc circuits to external voltages. Ac circuits rlc circuit introduction an inductor l is an important component of circuits, on the same level as resistors r and capacitors c. The amount of charge on the capacitor in this circuit is described by the differential equation e. Above is seen an lcr circuit, a notch filter, suppressing a peak in the treble range of the middriver.
Richard feynman 19181988 objectives to observe free and driven oscillations of an rlc circuit. Use pspice to determine i 1, i 2, i 3, and vo in figure 1 at f 1khz and f 10khz. If you dont see any interesting for you, use our search form on bottom v. To see the phase relationships between driving voltage and driven current in such a circuit at, below, and above the resonance frequency. Electricity and magnetismdriven lcr circuits by learnonline through ocw. Lcr in weak damping limit, energy of such a circuit, quality factor has been discussed.