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EXPERIMENT 4: RC, RL and RD Circuits
Laboratory 4: The RC Circuit EXPERIMENT 4: RC, RL and RD CIRCUITs Equipment List An assortment of resistor, one each of (330, 1k,1.5k, 10k,100k,1000k) Function Generator Oscilloscope 0.F Ceramic Capacitor 100H Inductor LED and 1N4001 Diode. Introduction We have studied D.C. circuits with resistors and batteries and discovered that Ohm’s Law governs the relationship between current through and voltage across a resistance. It is a linear response; i.e., 푉 = 퐼푅 (1) Such circuit elements are called passive elements. With A.C. circuits we find other passive elements called capacitors and inductors. These, too, obey Ohm’s Law and circuit loop problems can be solved using Kirchoff’ 3 Laws in much the same way as with DC. circuits. However, there is one major difference - in an AC. circuit, voltage across and current through a circuit element or branch are not necessarily in phase with one another. We saw an example of this at the end of Experiment 3. In an AC. series circuit the source voltage and current are time dependent such that 푖(푡) = 푖푠sin(휔푡) (2) 푣(푡) = 푣푠sin(휔푡 + 휙) where, in this case, voltage leads current by the phase angle , and Vs and Is are the peak source voltage and peak current, respectively. As you know or will learn from the text, the phase relationships between circuit element voltages and series current are these: resistor - voltage and current are in phase implying that 휙 = 0 휋 capacitor - voltage lags current by 90o implying that 휙 = − 2 inductor - voltage leads current by 90o implying that 휙 = 휋/2 Laboratory 4: The RC Circuit In this experiment we will study a circuit with a resistor and a capacitor in m. -
Chapter 7: AC Transistor Amplifiers
Chapter 7: Transistors, part 2 Chapter 7: AC Transistor Amplifiers The transistor amplifiers that we studied in the last chapter have some serious problems for use in AC signals. Their most serious shortcoming is that there is a “dead region” where small signals do not turn on the transistor. So, if your signal is smaller than 0.6 V, or if it is negative, the transistor does not conduct and the amplifier does not work. Design goals for an AC amplifier Before moving on to making a better AC amplifier, let’s define some useful terms. We define the output range to be the range of possible output voltages. We refer to the maximum and minimum output voltages as the rail voltages and the output swing is the difference between the rail voltages. The input range is the range of input voltages that produce outputs which are not at either rail voltage. Our goal in designing an AC amplifier is to get an input range and output range which is symmetric around zero and ensure that there is not a dead region. To do this we need make sure that the transistor is in conduction for all of our input range. How does this work? We do it by adding an offset voltage to the input to make sure the voltage presented to the transistor’s base with no input signal, the resting or quiescent voltage , is well above ground. In lab 6, the function generator provided the offset, in this chapter we will show how to design an amplifier which provides its own offset. -
JRE SCHOOL of Engineering
JRE SCHOOL OF Engineering PUT EXAMINATION SET-A MAY 2015 Subject Name Microwave Engineering Subject Code EEC 603 Roll No. of Student Max Marks 100 Max Duration 3 hrs Date 02/05/2015 Time 10:00 a.m. to 1:00 p.m. For Branches: EC Branch only (6th sem) Q. 1 Attempt any FOUR from the following. All question carry equal marks. (5 X 4 = 20) a) A TE11 wave is propagating in a air-filled circular waveguide of diameter 12cm at 2.5GHz, find the cutoff frequency, guide wavelength, wave impedance in the guide. b) Show that TM01 and TM10 modes do not exist in a rectangular waveguide. c) What is a microstrip line? Compare microstrip lines with striplines. Write advantages and disadvantages of both. Microstrip Transmission Line: It is also called open strip line because of the openness of its structure. It has very simple geometry. It is an unsymmetrical strip line that is nothing but a parallel plate transmission line having dielectric substrate, the on face of which is metallised ground and the other (top) face, has thin conducting strip of certain width ‘w’ and thickness ‘t’. The top ground plate is not present and so cover plate is used for shielding purpose. Modes are only quasi TEM, thus the theory of TEM coupled lines applies only. Losses: (i) Dielectric loss in substrate (ii) ohmic skin losses in conductor strip and ground plane. Advantages: (i) Simple construction (ii) easier integration with semiconductor device (iii) fabrication cosh is lower (iv) package and unpacked semiconductor chips can be attached to these lines. -
KVL Example Resistor Voltage Divider • Consider a Series of Resistors And
KVL Example Resistor Voltage Divider • Consider a series of resistors and a voltage source • Then using KVL V −V1 −V2 = 0 • Since by Ohm’s law V1 = I1R1 V2 = I1R2 • Then V − I1R1 − I1R2 = V − I1()R1 + R2 = 0 • Thus V 5 I1 = = = 1 mA R1 + R2 2000 + 3000 • i.e. get the resistors in series formula Rtotal = R1 + R2 = 5 KΩ KVL Example Resistor Voltage Divider Continued • What is the voltage across each resistor • Now we can relate V1 and V2 to the applied V • With the substitution V I 1 = R1 + R 2 • Thus V1 VR1 5(2000) V1 = I1R1 = = = 2 V R1 + R2 2000 + 3000 • Similarly for the V2 VR2 5(3000) V1 = I1R2 = = = 3V R1 + R2 2000 + 3000 General Resistor Voltage Divider • Consider a long series of resistors and a voltage source • Then using KVL or series resistance get N V V = I1∑ R j KorKI1 = N j=1 ∑ R j j=1 • The general voltage Vk across resistor Rk is VRk Vk = I1Rk = N ∑ R j j=1 • Note important assumption: current is the same in all Rj Usefulness of Resistor Voltage Divider • A voltage divider can generate several voltages from a fixed source • Common circuits (eg IC’s) have one supply voltage • Use voltage dividers to create other values at low cost/complexity • Eg. Need different supply voltages for many transistors • Eg. Common computer outputs 5V (called TTL) • But modern chips (CMOS) are lower voltage (eg. 2.5 or 1.8V) • Quick interface – use a voltage divider on computer output • Gives desired input to the chip Variable Voltage and Resistor Voltage Divider • If have one fixed and one variable resistor (rheostat) • Changing variable resistor controls out Voltage across rheostat • Simple power supplies use this • Warning: ideally no additional loads can be applied. -
Ohm's Law and Kirchhoff's Laws
CHAPTER 2 Basic Laws Here we explore two fundamental laws that govern electric circuits (Ohm's law and Kirchhoff's laws) and discuss some techniques commonly applied in circuit design and analysis. 2.1. Ohm's Law Ohm's law shows a relationship between voltage and current of a resis- tive element such as conducting wire or light bulb. 2.1.1. Ohm's Law: The voltage v across a resistor is directly propor- tional to the current i flowing through the resistor. v = iR; where R = resistance of the resistor, denoting its ability to resist the flow of electric current. The resistance is measured in ohms (Ω). • To apply Ohm's law, the direction of current i and the polarity of voltage v must conform with the passive sign convention. This im- plies that current flows from a higher potential to a lower potential 15 16 2. BASIC LAWS in order for v = iR. If current flows from a lower potential to a higher potential, v = −iR. l i + v R – Material with Cross-sectional resistivity r area A 2.1.2. The resistance R of a cylindrical conductor of cross-sectional area A, length L, and conductivity σ is given by L R = : σA Alternatively, L R = ρ A where ρ is known as the resistivity of the material in ohm-meters. Good conductors, such as copper and aluminum, have low resistivities, while insulators, such as mica and paper, have high resistivities. 2.1.3. Remarks: (a) R = v=i (b) Conductance : 1 i G = = R v 1 2 The unit of G is the mho (f) or siemens (S) 1Yes, this is NOT a typo! It was derived from spelling ohm backwards. -
Thyristors.Pdf
THYRISTORS Electronic Devices, 9th edition © 2012 Pearson Education. Upper Saddle River, NJ, 07458. Thomas L. Floyd All rights reserved. Thyristors Thyristors are a class of semiconductor devices characterized by 4-layers of alternating p and n material. Four-layer devices act as either open or closed switches; for this reason, they are most frequently used in control applications. Some thyristors and their symbols are (a) 4-layer diode (b) SCR (c) Diac (d) Triac (e) SCS Electronic Devices, 9th edition © 2012 Pearson Education. Upper Saddle River, NJ, 07458. Thomas L. Floyd All rights reserved. The Four-Layer Diode The 4-layer diode (or Shockley diode) is a type of thyristor that acts something like an ordinary diode but conducts in the forward direction only after a certain anode to cathode voltage called the forward-breakover voltage is reached. The basic construction of a 4-layer diode and its schematic symbol are shown The 4-layer diode has two leads, labeled the anode (A) and the Anode (A) A cathode (K). p 1 n The symbol reminds you that it acts 2 p like a diode. It does not conduct 3 when it is reverse-biased. n Cathode (K) K Electronic Devices, 9th edition © 2012 Pearson Education. Upper Saddle River, NJ, 07458. Thomas L. Floyd All rights reserved. The Four-Layer Diode The concept of 4-layer devices is usually shown as an equivalent circuit of a pnp and an npn transistor. Ideally, these devices would not conduct, but when forward biased, if there is sufficient leakage current in the upper pnp device, it can act as base current to the lower npn device causing it to conduct and bringing both transistors into saturation. -
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. -
Relaxation Oscillators and Networks
In J.G. Webster (ed.), Wiley Encyclopedia of Electrical and Electronics Engineering, Wiley & Sons, vol. 18, pp. 396-405, 1999 Relaxation Oscillators and Networks DeLiang Wang Department of Computer and Information Science and Center for Cognitive Science The Ohio State University Columbus, OH 43210-1277 Relaxation oscillations comprise a large class of nonlinear dynamical systems, and arise naturally from many physical systems such as mechanics, biology, chemistry, and engineering. Such periodic phenomena are characterized by intervals of time during which little happens, interleaved with intervals of time during which considerable changes take place. In other words, relaxation oscillations exhibit more than one time scale. The dynamics of a relaxation oscillator is illustrated by the mechanical system of a seesaw in Figure 1. At one side of the seesaw is there a water container which is empty at the beginning; in this situation the other side of the seesaw touches the ground. As the weight of water dripping from a tap into the container exceeds that of the other side, the seesaw flips and the container side touches the ground. At this moment, the container empties itself, and the seesaw returns quictly to its original position and the process repeats. AAA AAA Figure 1. An example of a relaxation oscillator: a seesaw with a water container at one end (adapted from (4)). Relaxation oscillations were first observed by van der Pol (1) in 1926 when studying properties of a triode circuit. Such a circuit exhibits self-sustained oscillations. van der Pol discovered that for a certain range of the system parameters the oscillation is almost sinusoidal, but for a different range the oscillation exhibits abrupt changes. -
50 Simple L.E.D. Circuits
50 Simple L.E.D. Circuits R.N. SOAR r de Historie v/d Radi OTH'IEK 50 SIMPLE L.E.D. CIRCUITS by R. N. SOAR BABANI PRESS The Publishing Division of Babani Trading and Finance Co. Ltd. The Grampians Shepherds Bush Road London W6 7NI- England Although every care is taken with the preparation of this book, the publishers or author will not be responsible in any way for any errors that might occur. © 1977 BA BAN I PRESS I.S.B.N. 0 85934 043 4 First Published December 1977 Printed and Manufactured in Great Britain by C. Nicholls & Co. Ltd. f t* -i. • v /“ ..... tr> CONTENTS U.V.H.R* Circuit Page No. 1 LED Pilot Light......................................... 7 2 LED Stereo Beacon.................................... 8 3 Stereo Decoder Mono/Sterco Indicator . 9 4 Subminiature LED Torch........................... 10 5 Low Voltage Low Current Supply............ 11 6 Microlight Indicator .................................. 12 7 Ultra Low Current LED Switching Indicator 13 8 LED Stroboscope....................................... 14 9 12 Volt Car Circuit Tester........................... 15 10 Two Colour LED......................................... 16 11 12 Volt Car “Fuse Blown” Indicator.......... 17 12 LED Continuity Tester............................... 17 13 LED Current Overload Indicator.............. 18 14 LED Current Range Indicator................... 20 15 1.5 Volt LED “Zener”................. '............ 22 16 Extending Zener Voltage........................... 22 17 Four Voltage Regulated Supply................. 23 18 PsychaLEDic Display.................................. 24 .19 Dual Colour Display.................................... 25 20 Dual Signal Device....................................... 26 21 LED Triple Signalling.................................. 27 22 Sub-Miniature Light Source for Model Railways . 28 23 Portable Television Protection Circuit . 29 24 Improved Portable TV Protection Circuit 30 25 LED Battery Tester.............................. -
NAME Experiment 7 Frequency Response ______PARTNER
ECE 241L Fundamentals of Electrical Engineering _____________________ NAME Experiment 7 Frequency Response _____________________ PARTNER A. Objectives: I. Measure frequency response of RC low-pass and CR high-pass filters II. Measure frequency response of an RLC frequency selective filter III. Measure uncalibrated inductance and capacitance B. Equipment: Breadboard, resistor(s), potentiometer, wire (student lab kit), wire stripper Digital Volt-Ohm Meter (DVM): Fluke 189 (or equivalent) Oscilloscope: Tektronix TDS3043 Digital Storage Scope Function Generator: Tektronix AFG310/320 Arbitrary Function Generator Inductor: 100 mH nominal Capacitors: 0.001 and 0.1 μF nominal C. Introductory Notes: Filters: Electric circuits can be used as filters to pass certain frequencies and stop others. For example the tone control on a radio is used to vary the amount of low frequencies (bass) and high frequencies (treble) in playing music. Frequency selectable filters are used to tune in a desired station and reject other stations. This experiment will demonstrate three standard types of filters: low-pass, high-pass, and band select. Simple filters can be designed using R, C, and L in voltage divider circuits. 1. LOW-PASS FILTER A low-pass filter can be constructed as a voltage divider with a resistance R and a capacitance C in series, with the output voltage across the capacitor. Figure E4-1 Voltage divider circuit to form an RC filter In this circuit, the low-pass filter frequency response |H(f)| is given by the (dimensionless) ratio of the voltage across the capacitor divided by the input voltage. |H| = [Vc]/[Vo] From the voltage divider formula and Kirchhoff's Voltage Law for a-c circuits [Vc] = [Vo] Xc/(R2 + Xc2)0.5 From the reactance of a capacitor Xc = 1/2π f C |H| = 1 / [1 + (f / Fc)2]0.5 FREQUENCY RESPONSE OF LOW-PASS FILTER Fc = 1/2πRC FILTER CUTOFF FREQUENCY (Hz) The graph of |H| as a function of frequency is sketched in Figure E4-2 Fc (cutoff frequency) f (frequency) (Hz) Figure E4-2 Frequency response of an RC low-pass filter. -
Electronic Circuits Lab
ELECTRONIC CIRCUITS LAB 1 2 STATE INSTITUTE OF TECHNICAL TEACHERS TRAINING AND RESEARCH GENERAL INSTRUCTIONS Rough record and Fair record are needed to record the experiments conducted in the laboratory. Rough records are needed to be certified immediately on completion of the experiment. Fair records are due at the beginning of the next lab period. Fair records must be submitted as neat, legible, and complete. INSTRUCTIONS TO STUDENTS FOR WRITING THE FAIR RECORD In the fair record, the index page should be filled properly by writing the corresponding experiment number, experiment name , date on which it was done and the page number. On the right side page of the record following has to be written: 1. Title: The title of the experiment should be written in the page in capital letters. 2. In the left top margin, experiment number and date should be written. 3. Aim: The purpose of the experiment should be written clearly. 4. Apparatus/Tools/Equipments/Components used: A list of the Apparatus/Tools/ Equipments /Components used for doing the experiment should be entered. 5. Principle: Simple working of the circuit/experimental set up/algorithm should be written. 6. Procedure: steps for doing the experiment and recording the readings should be briefly described(flow chart/programs in the case of computer/processor related experiments) 7. Results: The results of the experiment must be summarized in writing and should be fulfilling the aim. 8. Inference: Inference from the results is to be mentioned. On the Left side page of the record following has to be recorded: 1. Circuit/Program: Neatly drawn circuit diagrams/experimental set up. -
CLASS 331 OSCILLATORS January 2011
CLASS 331 OSCILLATORS 331 - 1 331 OSCILLATORS 94.1 MOLECULAR OR PARTICLE RESONANT 34 .Particular frequency control TYPE (E.G., MASER) means 1 R AUTOMATIC FREQUENCY STABILIZATION 35 ..Electromechanical (e.g., motor) USING A PHASE OR FREQUENCY 36 R ..Reactance device (e.g., SENSING MEANS variable capacitors, saturable 2 .Plural oscillators controlled inductors, reactance tubes, 3 .Molecular resonance etc.) stabilization 36 C ...Capacitor controlled AFC 4 .Search sweep of oscillator 36 L ...Inductor controlled AFC 5 .Magnetron oscillator 1 A .AFC with logic elements 6 .Klystron oscillator 37 BEAT FREQUENCY 7 ..Plural controls 38 .Plural beating 8 .Transistorized controls 39 ..Single channel 9 .Oscillator with distributed 40 .Frequency or amplitude parameter-type discriminator adjustment or control 10 .Plural A.F.S. for a single 41 .Frequency stabilization oscillator 42 .With particular signal combining 11 ..Plural comparators or means (e.g., cavity mixer) discriminators 43 ..With filter in mixer output 12 ...With phase-shifted inputs circuit 13 ..Motor control of oscillator 44 WITH FREQUENCY CALIBRATION OR 14 .With intermittent comparison TESTING controls 45 POLYPHASE OUTPUT 15 .Amplitude compensation 46 PLURAL OSCILLATORS 16 .Tuning compensation 47 .Oscillator used to vary 17 .Particular error voltage control amplitude or frequency of (e.g., intergrating network) another oscillator 18 .With reference oscillator or 48 .Adjustable frequency source 49 .Selectively connected to common 19 ..Spectrum reference source output or oscillator substitution