The RC Circuit
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Electrical Circuits Lab. 0903219 Series RC Circuit Phasor Diagram
Electrical Circuits Lab. 0903219 Series RC Circuit Phasor Diagram - Simple steps to draw phasor diagram of a series RC circuit without memorizing: * Start with the quantity (voltage or current) that is common for the resistor R and the capacitor C, which is here the source current I (because it passes through both R and C without being divided). Figure (1) Series RC circuit * Now we know that I and resistor voltage VR are in phase or have the same phase angle (there zero crossings are the same on the time axis) and VR is greater than I in magnitude. * Since I equal the capacitor current IC and we know that IC leads the capacitor voltage VC by 90 degrees, we will add VC on the phasor diagram as follows: * Now, the source voltage VS equals the vector summation of VR and VC: Figure (2) Series RC circuit Phasor Diagram Prepared by: Eng. Wiam Anabousi - Important notes on the phasor diagram of series RC circuit shown in figure (2): A- All the vectors are rotating in the same angular speed ω. B- This circuit acts as a capacitive circuit and I leads VS by a phase shift of Ө (which is the current angle if the source voltage is the reference signal). Ө ranges from 0o to 90o (0o < Ө <90o). If Ө=0o then this circuit becomes a resistive circuit and if Ө=90o then the circuit becomes a pure capacitive circuit. C- The phase shift between the source voltage and its current Ө is important and you have two ways to find its value: a- b- = - = - D- Using the phasor diagram, you can find all needed quantities in the circuit like all the voltages magnitude and phase and all the currents magnitude and phase. -
Time Constant of an Rc Circuit
ECGR 2155 Instrumentation and Networks Laboratory UNIVERSITY OF NORTH CAROLINA AT CHARLOTTE Department of Electrical and Computer Engineering EXPERIMENT 10 – TIME CONSTANT OF AN RC CIRCUIT OBJECTIVES The purpose of this experiment is to measure the time constant of an RC circuit experimentally and to verify the results against the values obtained by theoretical calculations. MATERIALS/EQUIPMENT NEEDED Digital Multimeter DC Power Supply Alligator (Clips) Jumper Resistor: 20kΩ Capacitor: 2,200 µF (rating = 50V or more) INTRODUCTION The time constant of RC circuits are used extensively in electronics for timing (setting oscillator frequencies, adjusting delays, blinking lights, etc.). It is necessary to understand how RC circuits behave in order to analyze and design timing circuits. In the circuit of Figure 10-1 with the switch open, the capacitor is initially uncharged, and so has a voltage, Vc, equal to 0 volts. When the single-pole single-throw (SPST) switch is closed, current begins to flow, and the capacitor begins to accumulate stored charge. Since Q=CV, as stored charge (Q) increases the capacitor voltage (Vc) increases. However, the growth of capacitor voltage is not linear; in fact it is an exponential growth. The formula which gives the instantaneous voltage across the capacitor as a function of time is (−t ) VV=1 − eτ cS Figure 10-1 Series RC Circuit EXPERIMENT 10 – TIME CONSTANT OF AN RC CIRCUIT 1 ECGR 2155 Instrumentation and Networks Laboratory This formula describes exponential growth, in which the capacitor is initially 0 volts, and grows to a value of near Vs after a finite amount of time. -
The Accuracy Comparison of Oscilloscope and Voltmeter Utilizated in Getting Dielectric Constant Values
Proceeding The 1st IBSC: Towards The Extended Use Of Basic Science For Enhancing Health, Environment, Energy And Biotechnology 211 ISBN: 978-602-60569-5-5 The Accuracy Comparison of Oscilloscope and Voltmeter Utilizated in Getting Dielectric Constant Values Bowo Eko Cahyono1, Misto1, Rofiatun1 1 Physics Departement of MIPA Faculty, Jember University, Jember – Indonesia, e-mail: [email protected] Abstract— Parallel plate capacitor is widely used as a sensor for many purposes. Researches which have used parallel plate capacitor were investigation of dielectric properties of soil in various temperature [1], characterization if cement’s dielectric [2], and measuring the dielectric constant of material in various thickness [3]. In the investigation the changing of dielectric constant, indirect method can be applied to get the dielectric constant number by measuring the voltage of input and output of the utilized circuit [4]. Oscilloscope is able to measure the voltage value although the common tool for that measurement is voltmeter. This research aims to investigate the accuracy of voltage measurement by using oscilloscope and voltmeter which leads to the accuracy of values of dielectric constant. The experiment is carried out by an electric circuit consisting of ceramic capacitor and sensor of parallel plate capacitor, function generator as a current source, oscilloscope, and voltmeters. Sensor of parallel plate capacitor is filled up with cooking oil in various concentrations, and the output voltage of the circuit is measured by using oscilloscope and also voltmeter as well. The resulted voltage values are then applied to the equation to get dielectric constant values. Finally the plot is made for dielectric constant values along the changing of cooking oil concentration. -
Part 2 - Condenser Testers and Testing Correctly Part1 Condenser Testers and Testing Correctly.Doc Rev
Part 2 - Condenser Testers and Testing Correctly Part1_Condenser_Testers_And_Testing_Correctly.doc Rev. 2.0 W. Mohat 16/04/2020 By: Bill Mohat / AOMCI Western Reserve Chapter If you have read Part 1 of this Technical Series on Condensers, you will know that the overwhelming majority of your condenser failures are due to breakdown of the insulating plastic film insulating layers inside the condenser. This allows the high voltages created by the “arcing” across your breaker points to jump through holes in the insulating film, causing your ignition system to short out. These failures, unfortunately, only happen at high voltages (often 200 to 500Volts AC)….which means that the majority of “capacitor testers" and "capacitor test techniques" will NOT find this failure mode, which is the MAJORITY of the condenser failure you are likely to encounter. Bottom line is, to test a condenser COMPLETELY, you must test it in three stages: 1) Check with a ohmmeter, or a capacitance meter, to see if the condenser is shorted or not. 2) Assuming your condenser is not shorted, use a capacitance meter to make sure it has the expected VALUE of capacitance that your motor needs. 3) Assuming you pass these first two step2, you then need to test your condenser on piece of test equipment that SPECIFICALLY tests for insulation breakdown under high voltages. (As mentioned earlier, you ohmmeter and capacitance meter only put about one volt across a capacitor when testing it. You need to put perhaps 300 or 400 times that amount of voltage across the condenser, to see if it’s insulation has failed, allowing electricity to “arc across" between the metal plates when under high voltage stress. -
Phasor Analysis of Circuits
Phasor Analysis of Circuits Concepts Frequency-domain analysis of a circuit is useful in understanding how a single-frequency wave undergoes an amplitude change and phase shift upon passage through the circuit. The concept of impedance or reactance is central to frequency-domain analysis. For a resistor, the impedance is Z ω = R , a real quantity independent of frequency. For capacitors and R ( ) inductors, the impedances are Z ω = − i ωC and Z ω = iω L. In the complex plane C ( ) L ( ) these impedances are represented as the phasors shown below. Im ivL R Re -i/vC These phasors are useful because the voltage across each circuit element is related to the current through the equation V = I Z . For a series circuit where the same current flows through each element, the voltages across each element are proportional to the impedance across that element. Phasor Analysis of the RC Circuit R V V in Z in Vout R C V ZC out The behavior of this RC circuit can be analyzed by treating it as the voltage divider shown at right. The output voltage is then V Z −i ωC out = C = . V Z Z i C R in C + R − ω + The amplitude is then V −i 1 1 out = = = , V −i +ω RC 1+ iω ω 2 in c 1+ ω ω ( c ) 1 where we have defined the corner, or 3dB, frequency as 1 ω = . c RC The phasor picture is useful to determine the phase shift and also to verify low and high frequency behavior. The input voltage is across both the resistor and the capacitor, so it is equal to the vector sum of the resistor and capacitor voltages, while the output voltage is only the voltage across capacitor. -
Lab 5 AC Concepts and Measurements II: Capacitors and RC Time-Constant
Sonoma State University Department of Engineering Science Fall 2017 EE110 Laboratory Introduction to Engineering & Laboratory Experience Lab 5 AC Concepts and Measurements II: Capacitors and RC Time-Constant Capacitors Capacitors are devices that can store electric charge similar to a battery (but with major differences). In its simplest form we can think of a capacitor to consist of two metallic plates separated by air or some other insulating material. The capacitance of a capacitor is referred to by C (in units of Farad, F) and indicates the ratio of electric charge Q accumulated on its plates to the voltage V across it (C = Q/V). The unit of electric charge is Coulomb. Therefore: 1 F = 1 Coulomb/1 Volt). Farad is a huge unit and the capacitance of capacitors is usually described in small fractions of a Farad. The capacitance itself is strictly a function of the geometry of the device and the type of insulating material that fills the gap between its plates. For a parallel plate capacitor, with the plate area of A and plate separation of d, C = (ε A)/d, where ε is the permittivity of the material in the gap. The formula is more complicated for cylindrical and other geometries. However, it is clear that the capacitance is large when the area of the plates are large and they are closely spaced. In order to create a large capacitance, we can increase the surface area of the plates by rolling them into cylindrical layers as shown in the diagram above. Note that if the space between plates is filled with air, then C = (ε0 A)/d, where ε0 is the permittivity of free space. -
5 RC Circuits
Physics 212 Lab Lab 5 RC Circuits What You Need To Know: The Physics In the previous two labs you’ve dealt strictly with resistors. In today’s lab you’ll be using a new circuit element called a capacitor. A capacitor consists of two small metal plates that are separated by a small distance. This is evident in a capacitor’s circuit diagram symbol, see Figure 1. When a capacitor is hooked up to a circuit, charges will accumulate on the plates. Positive charge will accumulate on one plate and negative will accumulate on the other. The amount of charge that can accumulate is partially dependent upon the capacitor’s capacitance, C. With a charge distribution like this (i.e. plates of charge), a uniform electric field will be created between the plates. [You may remember this situation from the Equipotential Surfaces lab. In the lab, you had set-ups for two point-charges and two lines of charge. The latter set-up represents a capacitor.] A main function of a capacitor is to store energy. It stores its energy in the electric field between the plates. Battery Capacitor (with R charges shown) C FIGURE 1 - Battery/Capacitor FIGURE 2 - RC Circuit If you hook up a battery to a capacitor, like in Figure 1, positive charge will accumulate on the side that matches to the positive side of the battery and vice versa. When the capacitor is fully charged, the voltage across the capacitor will be equal to the voltage across the battery. You know this to be true because Kirchhoff’s Loop Law must always be true. -
Capacitance and Dissipation Factor Measurementst from 1 Khz to 10 Mhz " Presenter: A
Capacitance and Dissipation Factor Measurementst from 1 kHz to 10 MHz " Presenter: A. D. Koffman NIST, 220/B162, Gaithersburg, MD 20899 (301) 975-4518 Paper Authors A. D. Koffman, B. C. Waltrip, N. M. Oldham National Institute of Standards and TechnologY: Gaithersburg, MD S. Avramov-Zamurovic U.S. Naval Academy Annapolis, MD Abstract: A measurement technique developed by K. Yokoi et al. at Hewlett-Packard Japan, Ltd. has been duplicated and evaluated at the National Institute of Standards and Technology (NIST) to characterize four-tenninal pair capacitors. The technique is based on an accurate three-terminal measurement made at 1 kHz using a capacitance bridge and wideband single-port measurementsmadebetween30MHzand200 MHz usinga networkanalyzer. The measurement data are fitted to the four-tenninal pair admittance model defmed by R. Cutkosky to compute capacitance and dissipation factor at any frequency up to 10 MHz. Capacitors characterized using this technique will be used as impedance reference standards for a general- purpose digital impedance bridge recently developed at NIST to calibrate inductors and ac resistors. The technique could also lead to a future NIST Special Test for dissipation factor. INTRODUCTION Recent efforts by the Electricity Division at the National Institute of Standards and Technology (NIST) to develop improved impedance comparison methods from 20 Hz to 1 MHz (1)have made it necessary to fmd a means to evaluate the reference impedances used in such comparisons. The impedance-characterization method discussed in this paper is described by Suzuki, et al. (2)and is based on the four-tenninal pair impedance work of Cutkosky (3)and Jones (4,5) The four-terminal pair impedance, Z4tp'of a device is defined as a combination of its real component, R, and its imaginary component, X: Z41p= R+ jX. -
EE 462G Laboratory #1 Measuring Capacitance
EE 462G Laboratory #1 Measuring Capacitance Drs. A.V. Radun and K.D. Donohue (1/24/07) Revised by Samaneh Esfandiarpour and Dr. David Chen (9/17/2019) Department of Electrical and Computer Engineering University of Kentucky Lexington, KY 40506 I. Instructional Objectives Introduce lab instrumentation with linear circuit elements Introduce lab report format Develop and analyze measurement procedures based on two theoretical models Introduce automated lab measurement and data analysis II. Background A circuit design requires a capacitor. The value of an available capacitor cannot be determined from its markings, so the value must be measured; however a capacitance meter is not available. The only available resources are different valued resistors, a variable frequency signal generator, a digital multi-meter (DMM), and an oscilloscope. Two possible ways of measuring the capacitor’s value are described in the following paragraphs. For this experiment, the student needs to select resistors and frequencies that are convenient and feasible for the required measurements and instrumentation. Be sure to use the digital multi-meter (DMM) to measure and record the actual resistance values used in each measurement procedure. III. Pre-Laboratory Exercise Step Response Model 1. For a series circuit consisting of a voltage source v(t), resistor R, and capacitor C, derive (show all steps) the complete solution for the capacitor voltage vc(t) when the source is a step with amplitude A and the initial capacitor voltage is 0. 2. Assume the source v(t) is a function generator, where the source voltage can only be measured after the 50 Ω internal resistance. -
ELECTRICAL CIRCUIT ANALYSIS Lecture Notes
ELECTRICAL CIRCUIT ANALYSIS Lecture Notes (2020-21) Prepared By S.RAKESH Assistant Professor, Department of EEE Department of Electrical & Electronics Engineering Malla Reddy College of Engineering & Technology Maisammaguda, Dhullapally, Secunderabad-500100 B.Tech (EEE) R-18 MALLA REDDY COLLEGE OF ENGINEERING AND TECHNOLOGY II Year B.Tech EEE-I Sem L T/P/D C 3 -/-/- 3 (R18A0206) ELECTRICAL CIRCUIT ANALYSIS COURSE OBJECTIVES: This course introduces the analysis of transients in electrical systems, to understand three phase circuits, to evaluate network parameters of given electrical network, to draw the locus diagrams and to know about the networkfunctions To prepare the students to have a basic knowledge in the analysis of ElectricNetworks UNIT-I D.C TRANSIENT ANALYSIS: Transient response of R-L, R-C, R-L-C circuits (Series and parallel combinations) for D.C. excitations, Initial conditions, Solution using differential equation and Laplace transform method. UNIT - II A.C TRANSIENT ANALYSIS: Transient response of R-L, R-C, R-L-C Series circuits for sinusoidal excitations, Initial conditions, Solution using differential equation and Laplace transform method. UNIT - III THREE PHASE CIRCUITS: Phase sequence, Star and delta connection, Relation between line and phase voltages and currents in balanced systems, Analysis of balanced and Unbalanced three phase circuits UNIT – IV LOCUS DIAGRAMS & RESONANCE: Series and Parallel combination of R-L, R-C and R-L-C circuits with variation of various parameters.Resonance for series and parallel circuits, concept of band width and Q factor. UNIT - V NETWORK PARAMETERS:Two port network parameters – Z,Y, ABCD and hybrid parameters.Condition for reciprocity and symmetry.Conversion of one parameter to other, Interconnection of Two port networks in series, parallel and cascaded configuration and image parameters. -
(ECE, NDSU) Lab 11 – Experiment Multi-Stage RC Low Pass Filters
ECE-311 (ECE, NDSU) Lab 11 – Experiment Multi-stage RC low pass filters 1. Objective In this lab you will use the single-stage RC circuit filter to build a 3-stage RC low pass filter. The objective of this lab is to show that: As more stages are added, the filter becomes able to better reject high frequency noise When plotted on a Bode plot, the gain approaches two asymptotes: the low frequency gain approaches a constant gain of 0dB while the high-frequency gain drops as 20N dB/decade where N is the number of stages. 2. Background The single stage RC filter is a low pass filter: low frequencies are passed (have a gain of one), while high frequencies are rejected (the gain goes to zero). This is a useful filter to remove noise from a signal. Many types of signals are predominantly low-frequency in nature - meaning they change slowly. This includes measurements of temperature, pressure, volume, position, speed, etc. Noise, however, tends to be at all frequencies, and is seen as the “fuzzy” line on you oscilloscope when you amplify the signal. The trick when designing a low-pass filter is to select the RC time constant so that the gain is one over the frequency range of your signal (so it is passed unchanged) but zero outside this range (to reject the noise). 3. Theoretical response One problem with adding stages to an RC filter is that each new stage loads the previous stage. This loading consumes or “bleeds” some current from the previous stage capacitor, changing the behavior of the previous stage circuit. -
Capacitance Meter MUDIT AGARWAL
Capacitance Meter MUDIT AGARWAL Nasiha Ali The principle of operating is counting the pulse oscillator during a fixed time interval produced by another lower frequency oscillator. This oscillator uses the capacitor being measured as the timing element. The capacitance measurement is proportional during pulse counting during a fixed time interval. The astable oscillator formed by IC1c K K K K K K K K K K K K K K K K K K K K K 1 1 1 1 1 1 1 9V 1 1 1 1 1 1 1 1 1 1 1 1 1 1 + + 9V produces a pulse train of constant frequency. Gate 13 12 11 10 9 15 14 3 3 13 12 11 10 9 15 14 13 12 11 10 9 15 14 3 IC4 IC5 IC6 4 4 8 8 4 IC1a also form oscillator whose oscillation period 4511 4511 8 4511 16 5 6 2 1 7 16 16 5 6 2 1 7 6 2 1 7 5 is given approximately by the equation: T=0.7RC. 1C1c Period T is linearly dependent on the capacitance 4093 9 6 5 4 3 2 14131211 10 8 6 5 4 3 16 2 IC2 IC3 10 1 1 C. This period is used as the time interval for one 4518 4518 8 9 7 15 7 15 9 1.5M measurement. The differentiator network following 2K C1 the oscillator creates the negative spikes shaped in 1C1a 9V + 220pf 4093 14 K 1 5 1 9 3 4 R K narrow pulses by IC1b NAND Schmitt trigger.