Feedback Amplifier & Oscillators

Size: px
Start display at page:

Download "Feedback Amplifier & Oscillators"

Transcription

1 256 UNIT 5 Feedback Amplifier & Oscillators 5.1 Learning Objectives Study definations of positive /negative feedback. Study the camparions of positive and negative feedback. Study the block diagram and working of negative feedback types of negative feedback. Study the conditions to get oscillations,block diagram of positive feedback,derivation over all gain of an oscillator. Study of types of oscillators working,expressions of frequency of RC Phase shift, Collector tuned,heartly,collpits oscillators. Study of comparisions of RC and LC oscillators. Study of crystal oscillators working advantages. Study of applications of oscillators.

2 Paper - II Electronic Devices and Circuits Introduction of Feedback Amplifiers The phenomenon of feeding a portion of the output energy back to the input circuit is known as feedback. The effect results in a dependence between the output and the input and an effective control can be obtained in the working of the circuit. Feedback is of two types. 1. Positive Feedback 2. Negative Feedback Positive or regenerate feedback: When the feedback voltage or current, is in phase with the input signal, it is called positive or regenerative feedback. The positive feedback increases the amount of amplification. Negative or Degenerate feedback: When the feedback voltage or current,is out of phase to the input signal,it is called negative or degenerative feedback. Negative feedback decreases the magnitude of amplification. Its main advantage is the reduction in the distortion of the amplifier. Feedback: The process of injecting a fraction of output energy of some device back to the input is known as feedback. Depending upon whether the feedback energy aids or opposes the input signal, there are two basic types of feedbacks in amplifiers. These are. 1. Positive Feedback 2. Negative Feedback 1. Positive Feedback: In positive feedback, the feedback energy (voltage or currents), is in phase with the input signal and thus aids it. Positive feedback increases gain of the amplifier also increases distortion, noise and instability. Because of these disadvantages, positive feedback is seldom employed in amplifiers. But the positive feedback is used in oscillators. 2. Negative Feedback: In negative feedback, the feedback energy (voltage or current), is out of phase with the iput signal and thus opposes it. Negative feedback reduces gain of the amplifier. It also reduce distortion, noise and instability. This feedback increases bandwidth and improves input and output impedances. Due to these advantages, the negative feedback is frequetly used in amplifiers.

3 Comparision Between Positive and Negative Feed Back The difference between positive and negative feedback is, S.No Negative Feedback Feedback energy is out phase with their input signal Gain of the amplifier decreases Gain stability increases Noise and distortion decreases. Increase the band width Used in amplifiers Positive Feedback Feedback energy is in phase with the input signal. Gain of the amplifier increases Gain stability decreases Noise and distribution increases. Decreases bandwidth Used in Oscillators 5.2 Expression for the Gain of Feedback Amplifier The configuration of the feedback amplifer in its shortest form in shown in Fig 5.1 The feedback factor of the feedback network is given by = X f / X o where X f and X o are feedback and output signals respectively. The input to the amplifier is X s. The gain of the basic amplifiers is A. Therefore, Output sigal X o = AX i where X i is the input signal to the basic amplifier which is equal to difference signal X d. Therefore X o = AX d But for negative feedback X d = X s - X f = X i Therefore X o = A(X f - X f ) We know that = X f / X o or X f = X o Substituting this value is Eqn X o = A(X s - X o ) X o + A X o = AX s X o (1+A ) = AX s

4 Paper - II Electronic Devices and Circuits 259 X o = AX s / 1 + A The gain of feedback amplifier is A f = X o / X s = A / 1+A Here, A f is less than A giving in reduction in gain. If positive feedback employs, in deominator is - (minus) ad therefore gain increase. Fig. 5.1 Block Diagram of Simplified Single loop Negative Feedback amplifier Effects of Negative Feedback: The following are the advantages of negative feedback in amplifies. 1. Gain Stability: An important advantage of negative feedback is that the resultant gain of the amplifier can be made independent of transistor parameters or the supply voltage variations. A f = (A) /(1+ A ) The product of A is much greater than unity. Therefore in above relation 1 can be neglected as compared to A. Then, the expression becomes. A f = (A / A = (1 / It may seen that the gain now depends only upon feedback fraction. The feedback circuit is usually resistive network. Therefore, it is uneffected by changes in temperature variations in transistor parameters ad frequency. Hence, the gain of the amplifier is extremly stable. 2. Reduces Non-Linear Distortion: The negative feedback reduces,with the non linear distortion in large signal amplifiers. It can be proved mathematically,giventhat D f = (D) / (1 + A )

5 260 It is clear from the above equation that, a negative feedback reduces the distortion by factor 1 + A. 5.3 Types of Nagative Feedback Amplifiers The feedback amplifiers can be classified according to mixing and sampling employed to it as follows: 1. Voltage series feedback amplifier 2. Current series feedback amplifier 3. Current shunt feedback amplifier 4. Voltage shunt feedback amplifier 1. Voltage Series Feedback Amplifier: This uses output voltage sampling and series mixing. 2. Current Series Feedback Amplifier: This uses output current sampling and series mixing. 3. Current Shunt Feedback Amplifier: This uses output current sampling and shunt mixing. 4. Voltage Shunt Feedbac Amplifier: This uses output voltage sampling and shunt mixing. 5.4 Conditions of an oscillators - Barkhausen Criteron Oscillations produced by adequate positive feedback in an amplifier is called a feedback oscillator. Fig gives the block diagram of feedback oscillator. An amplifier is an essential part of an oscillator. Oscillations may be produced by adequate positive feedback in an amplifier. Fig. 5.2 Block diagram of an Oscillator

6 Paper - II Electronic Devices and Circuits 261 Consider an external signal Xs applied directly to the input terminals of the amplifier shown in Fig This results in an output signal X o. The output of the feedback network is. X f = X o = A X s This output of the mixing network is X 1 f = -X f = -A X s Let it be so arranged that X 1 is identical with X. If now the external source f s is removed and terminal 2 is connected to terminal 1, the amplifier continues to provide the same output voltage X o as before without any exteral input signal. The system then functions as an oscillator. The condition necessary for oscillations is that X 1 = Xs. Thus the instantaneous values f X1 and X are identical at all f s times. Since X 1 = -A X implies that -A =1 i.e., the loop gain must be equal to f s unity and phase angle of -A is zero. This condition for sustained oscillations is called the Barkhausen criterion. Barkhausen Criterion: 1. Sustained oscillations are produced in a sinusoidal oscillators at a frequency for which the total phase shift introduced,as the signal travels from the input terminal through the basic amplifier, feedback network and mixing network back to the input terminals its precisely zero or a integral multiple of 2 radians. 2. Sustained oscillations are not produced if at the oscillation frequency the magnitude of the loop gain i.e., the product of the transfer gain A, of amplifer and magnitude of the feedback factor of the feedback network is less than unity. Requisites of an Oscillator 1. Tank Circuit: It consists of inductor connected in parallel with capacitor C. The frequency of oscillations in the circuit depends upon the values of inductance (L) ad capacitace (C). In RC oscillators inductor replaced by resistor(r). 2. Transistor Amplifier: The transistor amplifier receives d.c power from the battery and changes it into a.c. power for supplying to the tank circuit. The oscillations occurring in the tank circuit are applied to the input of the transistor amplifier. The amplified output of oscillations is due to the d.c. power supplied by the battery. The output of the transistor can be supplied the tank circuit to meet the losses. 3. Feedback Circuit: The feedback circuit supplies a part of collector energy

7 262 to the tank circuit in correct phase to aid the oscillations i.e., it provides positive feed back. In oscillator is to satisfy Barkhausen criteria has to get sustained oscillations. 5.5 Classification of Oscillators The oscillators can be classified in the following ways. 1. According to the generated waveform. (a) Sine wave oscillators. (b) Relaxation or non-sinusoidal oscillators. 2. According to the fundemental mechanism involved (a) Feedback oscillators. (b) Negative resistance oscillators. 3. According to the associated circuit components (a) RC oscillators (b) LC oscillators (c) Cyrstal oscillators 4. According to the frequency range: (a) Audio frequency (AF) oscillators (b) Radio frequency (RF) oscillators (c) VHF or microwave oscillators A > 1 When the total phase shift around a loop is 0 0 or and A >1, then the output oscillates but the oscillations are of growing type. The amplitude of oscillations goes on increasing as shown in Fig. 5.3 Fig. 5.3 Growing type of Oscillations

8 Paper - II Electronic Devices and Circuits A = 1 As stated by Barkhausen criterion, when total phase shift around a loop is 0 0 or ensuring positive feedback and A = 1 then the oscillations are with constant frequency and amplitude called sustained oscillations. Such oscillations are shown in Fig A < 1 Fig. 5.4 Sustained Oscillations When total phase shift around a loop is 0 0 or but A < 1 then the oscillations are of decaying type i.e. such oscillation amplitude decreases exponentially and the oscillations finally cease. Thus circuit works as an amplifier without oscillations. The decaying oscillations are shown in Fig 5.5. Fig. 5.5 Exponentially decaying Oscillations

9 264 Classification of Oscillators As type of tank circuit employ to the amplifier circuit in positive feedback the following oscillators. 1. RC Phase Shift Oscillator 2. Collector Tuned Oscillator 3. Hartley Oscillator 4. Collpitt s Oscillator 5.6 RC Phase Shift Oscillator Fig.5.06 shows the circuit of a phase shift oscillator. It consists of a conventional single transistor amplifier and a RC Phase shift network. The phase shoft network consists of three sections R 1 C 1, R 2 C 2 and R 3 C 3. At some particular frequency f 0, the phase shift of each section is 60 0, so that the total phase-shift produced by the RC network is (3 x 60) = The frequency of oscillations is given by f o = ( 1 ) / ( 2 RC 6) where R 1 = R 2 = R 3 = R C 1 = C 2 = C 3 = C Figure 5.6 RC Phase Shift Oscillator

10 Paper - II Electronic Devices and Circuits 265 With the circuit is switched ON, it produces oscillations. The output E 0 of the amplifier is feedback to RC feedback network. This network produces a phase shift of and a voltage E 1 appears at its output which is applied to the transistor amplifier. The feedback factor = E 1 / E 0. It can be shown that the feedback factor of the RC network is = 1/29. This expression has an important significance. For self starting the oscillations we must have A >1. It means that gain A of the amplifier must be greater than 29. Only then the oscillations can start. The feedback phase is correct. A phase shift of is produced by the transistor amplifier. A further phase shift of is produced by the RC network. As a result, the phase around the entire loop is Advamtages : 1. It does not require transformers or inductors. 2. It can be used to produce very low frequencies. 3. The circuit provides good frequency stability. Disadvantages : 1. It is difficult for the circuit to start oscillations as the feedback is generally small. 2. The circuit gives small output. 5.7 Tuned Collector Oscillator The tuned collector oscillator contains tuned circuit L 1 -C 1 in the collector load.the feedback coil L 2 in the base circuit is magnetically coupled to the tank circuit coil L 1.and hence the name. The frequency of oscillations depends upon the values of L 1 and C 1 and is given by f = ( 1 ) / (2 L 1 C 1 ) The figure coil L 2 in the base circuitis magnetically coupled to the tank circuit L 1. In practice L 1 and L 2 form the primary and secondary of the transformer. The biasing is provided by potential divider arrangement. The capacitor C connected in the base circuit provides low reactance path to the oscillations.

11 266 Circuit Operation: Fig. 5.7 When switch S is closed. Collector current starts increasing and charges the capacitor C 1. When this capacitor is fully charged, it discharges through Coil L 1, setting up oscillations of frequency. f = ( 1 ) / (2 L 1 C 1 ) These oscillations induce some voltage in coil L 2 by mutual induction. The frequency of voltage of coil L 2 is the same as that of tank circuit but its magnitude depends upon the number of turns of L 2 and coupling between L 1 and L 2. The voltage acaross L 2 is applied between base and emitter and appears in the amplified form in the collector circuit, thus overcoming the losses occurring in the tank circuit. The number of turns of L 2 and coupling between L 1 and L 2 are so adjusted that oscillations across L 2 are amplified to a level just sufficient to supply losses to the tank circuit. It may be noted that the phase of feedback is correct i.e., energy supplied to the tank circuit is in phase with the generated oscillations. A phase shift of is created between the voltages of L 1 and L 2 due to transformer action. A further phase shift of takes place between base-emitter and collector circuit due to transistor properties. As a result the energy feedback to the tank circuit is in phase with the generated oscillations. 5.8 Hartly Oscillator Hartly oscillator is very popular and is commonly used as a local oscillator in radio receivers. Fig.5.8 shows the circuit of Hartley oscillator. The tank circuit is made up

12 Paper - II Electronic Devices and Circuits 267 of C L 1 and L 2. The coil L 1 is inductively coupled to coil L 2, the combination functions as auto-transformer. The self bias is provided here for biasing. the capacitor C b blocks the d.c. component. When the power is ON, collector current starts rising and charges the capacitor C. When the capacitor is fully charged, it discharges through coils L 1 and L 2 setting up oscillations of frequency. f = ( 1 ) / ( 2 (L 1 +L 2 ) C) Fig. 5.8 Hartley Oscillator The oscillations across L 1 are applied to the base-emitter junction and appears in the amplified form in the collector circuit. The coil L 2 couples the collector circuit energy back into the tank circuit by means of mutual inductance between L 1 and L 2. In this way, energy is being continuously supplid to the tank circuit to overcome the losses occurring in it. It may be seen that the phase of feedback is correct. The capacitor C and L 1 - L 2 are out of phase. A further phase shift of is produced by transistor circuit. In this way, energy feedback to the tank circuit is in phase with oscillations. Advantages : 1. Easy to tune. 2. Adaptability to a wide range of frequencies. 5.9 Colpitt s Oscillator Fig 5.9 shows the circuits of colpitt s oscillator. The tank circuit is make up

13 268 of C 1 C 2 and L. The biasing is provided by self biasing. When power is ON, collector current starts rising and charges the capacitors C 1 and C 2. These capacitors discharges through coil L setting up oscillations. The frequency of oscillations is given by f = (1) / (2 LC T ) where C T = (C 1 C 2 ) / (C 1 + C 2 ) The oscillations across C 1 are applied to the base-emitter junction and appear in the amplified form in the collector circuit and supply losses to the tank circuit. The amount of feedback depends upon the relative capacitance values of C 1 and C 2. Fig. 5.9 Collpitt s Oscillator It may be noted that the phase of feedback is correct. The capacitors C 1 and C 2 act as a simple alternating voltage divider. Therefore the tank circuit of L C 1 C 2 produce phase shift. A further phase shift is produced by the transistor. In this way feedback is properly phased to produce continuous undamped oscillations Oscillators Frequency Equations as Follows a) Collector tuned oscillator frequency f = (( 1 ) / (2 C T L 1 ) b) RC Phase Shift Oscillator frequency fo = ((1) / (2 RC 6)

14 Paper - II Electronic Devices and Circuits 269 where R 1 = R 2 = R 3 = R C 1 = C 2 = C 3 = C c) Hartly Oscillator frequency (formula) where f o = ((1) / (2 CL 1 ) where L 1 = L 1 + L M d) Colpitt s Oscillator frequency f o = ((1) / 2 CT L ) where C T = C 1 C 2 / C 1 +C Comparison of LC and RC Oscillators: S.No. Particulars LC Oscillators RC Oscillators 1. Requirements of Inductor / transformer Yes No 2. Cost More Less 3. Output Frequency High Low 4. Frequency stability Poor Good 5. Output voltage More Less 5.12 Piezo Electric Crystals Certain crystalline materials, exhibit the piezo-electric effect i.e., when we apply an a.c. voltage across them, they vibrate at the frequency of the applied voltage. Conversely, if the crystals are forced mechanically to vibrate, they generate an emf at the fundamental frequency of the crystal. This nature is found in materials namely: Rochelle salt, quartz and tourmaline. Of the various piezoelectric crystals quartz is most commonly used. The advantages of quartz crystal is. 1. Optimum value of mechnical strength 2. Inexpensive 3. Readily available in nature

15 270 The nature shape of the quartz crystal is a hexagonal prism. The useful crystal is obtained by cutting the nature crystal. The crystal is usually mounted in an oscillator circuit to vibrate best at one of its resonant frequencies, usually the fundamental frequency. The formula of the fundamental frequency of crystal is given by. where f = k / t t = Thickness of crystal k = constant that depends o its cut and other physical factors. In order to use crystal in an electronic circuit, it is placed between two metal plates. A crystal can be conveniently replaced by an electrical equivalent circuit. When the crystal is not vibrating, it is equivalent to capacitance Cm because it has two metal plates separated by a dielectric (crystal). However when crystal is vibrating, it is equivalent to series tuned circuit RLC. Therefore, the electrical equivalent circuit of the crystal is shown in Fig In this figure. C m = Mounting capacitance C s = Series capacitance introduced by air gap R-L-C : Electrical equivalent of vibrational characteristics of crystal. Fig The series resonant frequency of crystal is the resonant frequency of LCR branch is given by f s = ((1) / (2 LC s )) The parallel resonant the frequency of the crystal is the frequency at which the loop current il reaches the maximum value. Since C is in series with C m the loop capacitance C T equal to (C m C) / (C + C m ). So the parallel resonant frequency is given by f p = ((1) / 2 LC T ))

16 Paper - II Electronic Devices and Circuits Transistor Crystal Oscillator The Fig.5.11 shows the crystal oscillator. This circuit is same as Colpitt s oscillator. In this circuit the crystal is mounted to act as an inductor which forms the tuned circuit with C 1 and C 2. The positive feedback is provided by the capacitive voltage divider network. The crystal now acts as an inductor that resonants with C 1 and C 2 and the oscillating frequency of the circuit now lies in between series and parallel resonant frequencies of the crystal. The resistors R 1, R 2 for biasing and R E for stabilization. The C E configured transistor provides phase shift where as the remaining phase shift is provided by the feedback network. Advantages Fig Crystal Oscillator 1. It can produce highest oscillating frequencies. 2. The quality factor (Q) of the crystal is very high. The Q factor of the crystal may be as high as 10,000 compared to about 100 of LC tank circuit. 3. They have a high order of frequency stability. 4. Low cost. 5. Simple in construction.

17 272 Disadvantages : 1. They are fragile and consequently can only be used in low power circuits. 2. The frequency of oscillation cannot be changed appreciably. Summary Oscillator Circuit or Tank Circuit: A circuit which produce electrical oscillations of any desired frequency is known as an oscillatory circuit. Frequency of oscillations is given by f = (1) / (2 LC) Feedback Oscillator : Oscillations produced by adequate positive feedback in an amplifier is called a feedback oscillator. Barkhensans Condition for Sustained Oscillations: 1. A = 1 2. Phase angle of - A is zero. Colpitt s Oscillator : The tank circuit of this oscillator is made up of C 1 C 2 and L. The frequency of oscillations is given by f = (1) / (2 LC T ) where C T = (C 1 C 2 ) / (C 1 + C 2 ) Hartley Oscillator : The tank circuit of this oscillator is made up of CL 1 and L 2. The frequency of oscillations is given by f = 1 / (2 (L1+L2) C) RC Phase Shift Oscillator : The phase shift network of this oscillator consists of three identical RC sections. The phase shift of each session is Frequency of oscillations is given by f = (1) / RC 6) Crystal Oscillator : It is used to get high frequency stability. This is possible by employing crystal in a transistor oscillator. Relaxation Oscillator : An oscillator which produces non-sinusoidal wavesl like square, sawtooth, rectangular, triangular etc., is called a relaxation oscillator.

18 Paper - II Electronic Devices and Circuits 273 Short Answer Type Questions 1. Define an oscillator. 2. Explain how oscillations produce in tank circuit. 3. Explain the condition for oscillation. 4. Explain the classifications of oscillators. 5. State the requisites of an oscillator. 6. Draw the circuit of a Collpitt s oscillator and explain its working? 7. With a near diagram explain the action of Hartley oscillator. 8. Draw the circuit diagram of an RC phase shift oscillator and explain. 9. Mention the advantages and disadvantages of phase shift oscillator. 10. List the applications of oscillators. 11. Draw the circuit diagram of crystal oscillator and explain its working. Also list its advantages and disadvantages. 12. Draw the circuit diagram of UJT relaxation oscillator and explain its working. 13. What are the requisites of an oscillators? Long Answer Type Questions 1. Write camparisions of negative and positive feedback. 2. Draw and explain positive feedback. 3. What are the requirements a transister amplifier works as an oscillator. Explain?. 4. Explain working of RC phase shift oscillator. 5. Explain working of tuned collector oscillator with neet diagram. 6. Explain working of Hartely oscillator. 7. Explain working of Colpitts oscillator. 8. Explain working of Crystal oscillator.

19 274 Practical/OJT Questions Study the oscillators-rc phase shift,hartely,colpitts,tuned collector and Crystal oscillators.

Chapter.8: Oscillators

Chapter.8: Oscillators Chapter.8: Oscillators Objectives: To understand The basic operation of an Oscillator the working of low frequency oscillators RC phase shift oscillator Wien bridge Oscillator the working of tuned oscillator

More information

DEFINITION: Classification of oscillators Based on the frequency generated Oscillator type Frequency range

DEFINITION: Classification of oscillators Based on the frequency generated Oscillator type Frequency range DEFINITION: An oscillator is just an electronic circuit which converts dc energy into AC energy of required frequency. (Or) An oscillator is an electronic circuit which produces an ac output without any

More information

Expect to be successful, expect to be liked,

Expect to be successful, expect to be liked, Thought of the Day Expect to be successful, expect to be liked, expect to be popular everywhere you go. Oscillators 1 Oscillators D.C. Kulshreshtha Oscillators 2 Need of an Oscillator An oscillator circuit

More information

Oscillators. An oscillator may be described as a source of alternating voltage. It is different than amplifier.

Oscillators. An oscillator may be described as a source of alternating voltage. It is different than amplifier. Oscillators An oscillator may be described as a source of alternating voltage. It is different than amplifier. An amplifier delivers an output signal whose waveform corresponds to the input signal but

More information

EE301 ELECTRONIC CIRCUITS CHAPTER 2 : OSCILLATORS. Lecturer : Engr. Muhammad Muizz Bin Mohd Nawawi

EE301 ELECTRONIC CIRCUITS CHAPTER 2 : OSCILLATORS. Lecturer : Engr. Muhammad Muizz Bin Mohd Nawawi EE301 ELECTRONIC CIRCUITS CHAPTER 2 : OSCILLATORS Lecturer : Engr. Muhammad Muizz Bin Mohd Nawawi 2.1 INTRODUCTION An electronic circuit which is designed to generate a periodic waveform continuously at

More information

The Hartley Oscillator

The Hartley Oscillator The Hartley Oscillator One of the main disadvantages of the basic LC Oscillator circuit we looked at in the previous tutorial is that they have no means of controlling the amplitude of the oscillations

More information

Figure 1: Closed Loop System

Figure 1: Closed Loop System SIGNAL GENERATORS 3. Introduction Signal sources have a variety of applications including checking stage gain, frequency response, and alignment in receivers and in a wide range of other electronics equipment.

More information

Feedback and Oscillator Circuits

Feedback and Oscillator Circuits Chapter 14 Chapter 14 Feedback and Oscillator Circuits Feedback Concepts The effects of negative feedback on an amplifier: Disadvantage Lower gain Advantages Higher input impedance More stable gain Improved

More information

NOORUL ISLAM COLLEGE OF ENGG, KUMARACOIL. DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGG. SUBJECT CODE: EC 1251 SUBJECT NAME: ELECTRONIC CIRCUITS-II

NOORUL ISLAM COLLEGE OF ENGG, KUMARACOIL. DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGG. SUBJECT CODE: EC 1251 SUBJECT NAME: ELECTRONIC CIRCUITS-II NOORUL ISLAM COLLEGE OF ENGG, KUMARACOIL. DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGG. SUBJECT CODE: EC 1251 SUBJECT NAME: ELECTRONIC CIRCUITS-II Prepared by, C.P.SREE BALA LEKSHMI (Lect/ECE) ELECTRONICS

More information

EC202- ELECTRONIC CIRCUITS II Unit- I -FEEEDBACK AMPLIFIER

EC202- ELECTRONIC CIRCUITS II Unit- I -FEEEDBACK AMPLIFIER EC202- ELECTRONIC CIRCUITS II Unit- I -FEEEDBACK AMPLIFIER 1. What is feedback? What are the types of feedback? 2. Define positive feedback. What are its merits and demerits? 3. Define negative feedback.

More information

Design of a Regenerative Receiver for the Short-Wave Bands A Tutorial and Design Guide for Experimental Work. Part I

Design of a Regenerative Receiver for the Short-Wave Bands A Tutorial and Design Guide for Experimental Work. Part I Design of a Regenerative Receiver for the Short-Wave Bands A Tutorial and Design Guide for Experimental Work Part I Ramón Vargas Patrón rvargas@inictel-uni.edu.pe INICTEL-UNI Regenerative Receivers remain

More information

V out A v. Feedback Circuit

V out A v. Feedback Circuit Oscillators V out A v Feedback Circuit Figure.: Positive Feed Back The feedback network in an oscillator an input to the amplifier, which in turn an input to the feedback network. Since positive feedback

More information

Table of Contents Lesson One Lesson Two Lesson Three Lesson Four Lesson Five PREVIEW COPY

Table of Contents Lesson One Lesson Two Lesson Three Lesson Four Lesson Five PREVIEW COPY Oscillators Table of Contents Lesson One Lesson Two Lesson Three Introduction to Oscillators...3 Flip-Flops...19 Logic Clocks...37 Lesson Four Filters and Waveforms...53 Lesson Five Troubleshooting Oscillators...69

More information

MAHALAKSHMI ENGINEERING COLLEGE TIRUCHIRAPALLI

MAHALAKSHMI ENGINEERING COLLEGE TIRUCHIRAPALLI MAHALAKSHMI ENGINEERING COLLEGE TIRUCHIRAPALLI-621213. QUESTION BANK DEPARTMENT: EEE SUBJECT CODE: EE2203 SEMESTER : III SUBJECT NAME: ELECTRONIC DEVICES &CIRCUITS UNIT 4-AMPLIFIERS AND OSCILLATORS PART

More information

Oscillators. Hartley, Colpitts, UJT relaxation. ECE/MEA Engg College S.R.K. 9/13/2007 Authored by: Ramesh.K

Oscillators. Hartley, Colpitts, UJT relaxation. ECE/MEA Engg College S.R.K. 9/13/2007 Authored by: Ramesh.K Oscillators Hartley, Colpitts, UJT relaxation. S.R.K 9//007 Authored by: Ramesh.K This documents contains a brief note about the principle of sinusoidal oscillator and some general oscillator circuits

More information

Lecture # 12 Oscillators (LC Circuits)

Lecture # 12 Oscillators (LC Circuits) December 2014 Benha University Faculty of Engineering at Shoubra ECE-312 Electronic Circuits (A) Lecture # 12 Oscillators (LC Circuits) Instructor: Dr. Ahmad El-Banna Agenda The Colpitts Oscillator The

More information

MARIA COLLEGE OF ENGINEERING AND TECHNOLOGY, ATTOOR UNIT-1. Feedback Amplifiers

MARIA COLLEGE OF ENGINEERING AND TECHNOLOGY, ATTOOR UNIT-1. Feedback Amplifiers MARIA COLLEGE OF ENGINEERING AND TECHNOLOGY, ATTOOR DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING ELECTRONIC CIRCUITS-II 2 MARKS QUESTIONS & ANSWERS UNIT-1 Feedback Amplifiers 1. What is meant

More information

Lecture 28 RC Phase Shift Oscillator using Op-amp

Lecture 28 RC Phase Shift Oscillator using Op-amp Integrated Circuits, MOSFETs, OP-Amps and their Applications Prof. Hardik J Pandya Department of Electronic Systems Engineering Indian Institute of Science, Bangalore Lecture 28 RC Phase Shift Oscillator

More information

SIDDHARTH GROUP OF INSTITUTIONS :: PUTTUR (AUTONOMOUS) Siddharth Nagar, Narayanavanam Road QUESTION BANK

SIDDHARTH GROUP OF INSTITUTIONS :: PUTTUR (AUTONOMOUS) Siddharth Nagar, Narayanavanam Road QUESTION BANK SIDDHARTH GROUP OF INSTITUTIONS :: PUTTUR (AUTONOMOUS) Siddharth Nagar, Narayanavanam Road 517583 QUESTION BANK Subject with Code : Electronic Circuit Analysis (16EC407) Year & Sem: II-B.Tech & II-Sem

More information

UNIT - IV FEEDBACK AMPLIFIERS & OSCILATTORS

UNIT - IV FEEDBACK AMPLIFIERS & OSCILATTORS UNIT - IV FEEDBAK AMPLIFIES & OSILATTOS OBJETIVES i)the basics of feedback. ii)the properties of negative feedback. iii)the basic feedback topologies. iv)an example of the ideal feedback case. v)some realistic

More information

Communication Circuit Lab Manual

Communication Circuit Lab Manual German Jordanian University School of Electrical Engineering and IT Department of Electrical and Communication Engineering Communication Circuit Lab Manual Experiment 3 Crystal Oscillator Eng. Anas Alashqar

More information

CHAPTER 3 OSCILOSCOPE AND SIGNAL CONDITIONING

CHAPTER 3 OSCILOSCOPE AND SIGNAL CONDITIONING CHAPTER 3 OSCILOSCOPE AND SIGNAL CONDITIONING OUTLINE Introduction to Signal Generator Oscillator Requirement for Oscillation Positive Feedback Amplifier Oscillator Radio Frequency Oscillator Introduction

More information

Low frequency tuned amplifier. and oscillator using simulated. inductor*

Low frequency tuned amplifier. and oscillator using simulated. inductor* CHAPTER 5 Low frequency tuned amplifier and oscillator using simulated inductor* * Partial contents of this Chapter has been published in. D.Susan, S.Jayalalitha, Low frequency amplifier and oscillator

More information

UNIT 1 MULTI STAGE AMPLIFIES

UNIT 1 MULTI STAGE AMPLIFIES UNIT 1 MULTI STAGE AMPLIFIES 1. a) Derive the equation for the overall voltage gain of a multistage amplifier in terms of the individual voltage gains. b) what are the multi-stage amplifiers? 2. Describe

More information

TUNED AMPLIFIERS 5.1 Introduction: Coil Losses:

TUNED AMPLIFIERS 5.1 Introduction: Coil Losses: TUNED AMPLIFIERS 5.1 Introduction: To amplify the selective range of frequencies, the resistive load R C is replaced by a tuned circuit. The tuned circuit is capable of amplifying a signal over a narrow

More information

The steeper the phase shift as a function of frequency φ(ω) the more stable the frequency of oscillation

The steeper the phase shift as a function of frequency φ(ω) the more stable the frequency of oscillation It should be noted that the frequency of oscillation ω o is determined by the phase characteristics of the feedback loop. the loop oscillates at the frequency for which the phase is zero The steeper the

More information

TUNED AMPLIFIERS. Tank circuits.

TUNED AMPLIFIERS. Tank circuits. Tank circuits. TUNED AMPLIFIERS Analysis of single tuned amplifier, Double tuned, stagger tuned amplifiers. Instability of tuned amplifiers, stabilization techniques, Narrow band neutralization using coil,

More information

Oscillator Principles

Oscillator Principles Oscillators Introduction Oscillators are circuits that generates a repetitive waveform of fixed amplitude and frequency without any external input signal. The function of an oscillator is to generate alternating

More information

VALLIAMMAI ENGINEERING COLLEGE

VALLIAMMAI ENGINEERING COLLEGE VALLIAMMAI ENGINEERING COLLEGE SRM Nagar, Kattankulathur 603 203. DEPARTMENT OF ELECTRONICS & COMMUNICATION ENGINEERING SUBJECT QUESTION BANK : EC6401 ELECTRONICS CIRCUITS-II SEM / YEAR: IV / II year B.E.

More information

CHAPTER 3: OSCILLATORS AND WAVEFORM-SHAPING CIRCUITS

CHAPTER 3: OSCILLATORS AND WAVEFORM-SHAPING CIRCUITS CHAPTER 3: OSCILLATORS AND WAVEFORM-SHAPING CIRCUITS In the design of electronic systems, the need frequently arises for signals having prescribed standard waveforms (e.g., sinusoidal, square, triangle,

More information

Signal Generators and Waveform-Shaping Circuits

Signal Generators and Waveform-Shaping Circuits CHAPTER 18 Signal Generators and Waveform-Shaping Circuits Figure 18.1 The basic structure of a sinusoidal oscillator. A positive-feedback loop is formed by an amplifier and a frequency-selective network.

More information

Question Bank EC6401 ELECTRONIC CIRCUITS - II

Question Bank EC6401 ELECTRONIC CIRCUITS - II FATIMA MICHAEL COLLEGE OF ENGINEERING & TECHNOLOGY Madurai Sivagangai Main Road Madurai - 625 020. [An ISO 9001:2008 Certified Institution] SEMESTER: IV / ECE Question Bank EC6401 ELECTRONIC CIRCUITS -

More information

SKP Engineering College

SKP Engineering College SKP Engineering College Tiruvannamalai 606611 A Course Material on Electronics Circuits-II M.Jerin Jose Associate Professor Electronics and Communication Engineering Department By Electronics and Communication

More information

State the application of negative feedback and positive feedback (one in each case)

State the application of negative feedback and positive feedback (one in each case) (ISO/IEC - 700-005 Certified) Subject Code: 073 Model wer Page No: / N Important Instructions to examiners: ) The answers should be examined by key words and not as word-to-word as given in the model answer

More information

21/10/58. M2-3 Signal Generators. Bill Hewlett and Dave Packard s 1 st product (1939) US patent No HP 200A s schematic

21/10/58. M2-3 Signal Generators. Bill Hewlett and Dave Packard s 1 st product (1939) US patent No HP 200A s schematic M2-3 Signal Generators Bill Hewlett and Dave Packard s 1 st product (1939) US patent No.2267782 1 HP 200A s schematic 2 1 The basic structure of a sinusoidal oscillator. A positive feedback loop is formed

More information

UNIT 1. 9 What is the Causes of Free Response in Electrical Circuit. 12 Write the Expression for transient current and voltages of RL circuit.

UNIT 1. 9 What is the Causes of Free Response in Electrical Circuit. 12 Write the Expression for transient current and voltages of RL circuit. SUB: Electric Circuits and Electron Devices Course Code: UBEE309 UNIT 1 PART A 1 State Transient and Transient Time? 2 What is Tansient State? 3 What is Steady State? 4 Define Source Free Response 5 Define

More information

Positive Feedback and Oscillators

Positive Feedback and Oscillators Physics 3330 Experiment #5 Fall 2011 Positive Feedback and Oscillators Purpose In this experiment we will study how spontaneous oscillations may be caused by positive feedback. You will construct an active

More information

OSCILLATORS AND WAVEFORM-SHAPING CIRCUITS

OSCILLATORS AND WAVEFORM-SHAPING CIRCUITS OSILLATORS AND WAVEFORM-SHAPING IRUITS Signals having prescribed standard waveforms (e.g., sinusoidal, square, triangle, pulse, etc). To generate sinusoidal waveforms: o Positive feedback loop with non-linear

More information

BHARATHIDASAN ENGINEERING COLLEGE

BHARATHIDASAN ENGINEERING COLLEGE BHARATHIDASAN ENGINEERING COLLEGE DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING EC6401 - ELECTRONIC CIRCUITS - II QUESTION BANK II- YEAR IV SEM ACDEMIC YEAR: 2016-2017 EVEN SEMESTER EC6401 ELECTRONIC

More information

LECTURE NOTES ELECTRONIC CIRCUITS II SYLLABUS

LECTURE NOTES ELECTRONIC CIRCUITS II SYLLABUS FATIMA MICHAEL COLLEGE OF ENGINEERING & TECHNOLOGY Madurai Sivagangai Main Road Madurai - 625 020. [An ISO 9001:2008 Certified Institution] LECTURE NOTES EC6401 ELECTRONIC CIRCUITS - II SEMESTER: IV /

More information

Power Amplifiers. Class A Amplifier

Power Amplifiers. Class A Amplifier Power Amplifiers The Power amplifiers amplify the power level of the signal. This amplification is done in the last stage in audio applications. The applications related to radio frequencies employ radio

More information

Chapter 13 Oscillators and Data Converters

Chapter 13 Oscillators and Data Converters Chapter 13 Oscillators and Data Converters 13.1 General Considerations 13.2 Ring Oscillators 13.3 LC Oscillators 13.4 Phase Shift Oscillator 13.5 Wien-Bridge Oscillator 13.6 Crystal Oscillators 13.7 Chapter

More information

MAHALAKSHMI ENGINEERING COLLEGE TIRUCHIRAPALLI UNIT III TUNED AMPLIFIERS PART A (2 Marks)

MAHALAKSHMI ENGINEERING COLLEGE TIRUCHIRAPALLI UNIT III TUNED AMPLIFIERS PART A (2 Marks) MAHALAKSHMI ENGINEERING COLLEGE TIRUCHIRAPALLI-621213. UNIT III TUNED AMPLIFIERS PART A (2 Marks) 1. What is meant by tuned amplifiers? Tuned amplifiers are amplifiers that are designed to reject a certain

More information

Sub Code & Name: EC2251- ELECTRONIC CIRCUITS II Unit : I Branch : ECE Year:II

Sub Code & Name: EC2251- ELECTRONIC CIRCUITS II Unit : I Branch : ECE Year:II Unit : I Branch : ECE Year:II Page 01 of 06 UNIT 1 FEEDBACK AMPLIFIERS 9 Block diagram, Loop gain, Gain with feedback, Effects of negative feedback Sensitivity and desensitivity of gain, Cut-off frequencies,

More information

An induced emf is the negative of a changing magnetic field. Similarly, a self-induced emf would be found by

An induced emf is the negative of a changing magnetic field. Similarly, a self-induced emf would be found by This is a study guide for Exam 4. You are expected to understand and be able to answer mathematical questions on the following topics. Chapter 32 Self-Induction and Induction While a battery creates an

More information

6.776 High Speed Communication Circuits and Systems Lecture 14 Voltage Controlled Oscillators

6.776 High Speed Communication Circuits and Systems Lecture 14 Voltage Controlled Oscillators 6.776 High Speed Communication Circuits and Systems Lecture 14 Voltage Controlled Oscillators Massachusetts Institute of Technology March 29, 2005 Copyright 2005 by Michael H. Perrott VCO Design for Narrowband

More information

Sri venkateswara college of engineering. Department of ECE. EC Electronic Circuits II. 2 mark questions unit wise. UNIT I Feedback Amplifiers

Sri venkateswara college of engineering. Department of ECE. EC Electronic Circuits II. 2 mark questions unit wise. UNIT I Feedback Amplifiers Sri venkateswara college of engineering Department of ECE EC -6401 Electronic Circuits II 2 mark questions unit wise UNIT I Feedback Amplifiers 1. Define feedback? A portion of the output signal is taken

More information

Lesson Plan. Electronics 1-Total 51 Hours

Lesson Plan. Electronics 1-Total 51 Hours Lesson Plan. Electronics 1-Total 5s Unit I: Electrical Engineering materials:(10) Crystal structure & defects; Ceramic materials-structures, composites, processing and uses; Insulating laminates for electronics,

More information

EMT212 Analog Electronic II. Chapter 4. Oscillator

EMT212 Analog Electronic II. Chapter 4. Oscillator EMT Analog Electronic II Chapter 4 Oscillator Objectives Describe the basic concept of an oscillator Discuss the basic principles of operation of an oscillator Analyze the operation of RC, LC and crystal

More information

EC6202-ELECTRONIC DEVICES AND CIRCUITS YEAR/SEM: II/III UNIT 1 TWO MARKS. 1. Define diffusion current.

EC6202-ELECTRONIC DEVICES AND CIRCUITS YEAR/SEM: II/III UNIT 1 TWO MARKS. 1. Define diffusion current. EC6202-ELECTRONIC DEVICES AND CIRCUITS YEAR/SEM: II/III UNIT 1 TWO MARKS 1. Define diffusion current. A movement of charge carriers due to the concentration gradient in a semiconductor is called process

More information

Lab 4 : Transistor Oscillators

Lab 4 : Transistor Oscillators Objective: Lab 4 : Transistor Oscillators In this lab, you will learn how to design and implement a colpitts oscillator. In part II you will implement a RC phase shift oscillator Hardware Required : Pre

More information

Electronic Circuits EE359A

Electronic Circuits EE359A Electronic Circuits EE359A Bruce McNair B206 bmcnair@stevens.edu 201-216-5549 Lecture 16 404 Signal Generators and Waveform-shaping Circuits Ch 17 405 Input summing, output sampling voltage amplifier Series

More information

A Course Material on. Electronics Circuits II

A Course Material on. Electronics Circuits II A Course Material on Electronics Circuits II By MS. R.P. MEENAAKSHISUNDHARI PROFESSOR DEPARTMENT OF ELECTRONICS & COMMUNICATION ENGINEERING SASURIE COLLEGE OF ENGINEERING VIJAYAMANGALAM 638 056 QUALITY

More information

MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC Certified) Summer 2016 EXAMINATIONS.

MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC Certified) Summer 2016 EXAMINATIONS. Summer 2016 EXAMINATIONS Subject Code: 17321 Model Answer Important Instructions to examiners: 1) The answers should be examined by key words and not as word-to-word as given in the answer scheme. 2) The

More information

Test Your Understanding

Test Your Understanding 074 Part 2 Analog Electronics EXEISE POBLEM Ex 5.3: For the switched-capacitor circuit in Figure 5.3b), the parameters are: = 30 pf, 2 = 5pF, and F = 2 pf. The clock frequency is 00 khz. Determine the

More information

Input and output coupling

Input and output coupling Input and output coupling To overcome the challenge of creating necessary DC bias voltage for an amplifier's input signal without resorting to the insertion of a battery in series with the AC signal source,

More information

Scheme Q.1 Attempt any SIX of following: 12-Total Marks a) Draw symbol NPN and PNP transistor. 2 M Ans: Symbol Of NPN and PNP BJT (1M each)

Scheme Q.1 Attempt any SIX of following: 12-Total Marks a) Draw symbol NPN and PNP transistor. 2 M Ans: Symbol Of NPN and PNP BJT (1M each) Q. No. WINTER 16 EXAMINATION (Subject Code: 17319) Model Answer Important Instructions to examiners: 1) The answers should be examined by key words and not as word-to-word as given in the model answer

More information

VETRI VINAYAHA COLLEGE OF ENGINEERING & TECHNOLOGY THOTTIAM, TIRUCHIRAPPALLI Department of Electronics and communication Engineering Question

VETRI VINAYAHA COLLEGE OF ENGINEERING & TECHNOLOGY THOTTIAM, TIRUCHIRAPPALLI Department of Electronics and communication Engineering Question VETRI VINAYAHA COLLEGE OF ENGINEERING & TECHNOLOGY THOTTIAM, TIRUCHIRAPPALLI-621215 Department of Electronics and communication Engineering Question Bank EC6401: ELECTRONIC CIRCUITS II (Regulation 2013)

More information

Understanding VCO Concepts

Understanding VCO Concepts Understanding VCO Concepts OSCILLATOR FUNDAMENTALS An oscillator circuit can be modeled as shown in Figure 1 as the combination of an amplifier with gain A (jω) and a feedback network β (jω), having frequency-dependent

More information

LABORATORY #3 QUARTZ CRYSTAL OSCILLATOR DESIGN

LABORATORY #3 QUARTZ CRYSTAL OSCILLATOR DESIGN LABORATORY #3 QUARTZ CRYSTAL OSCILLATOR DESIGN OBJECTIVES 1. To design and DC bias the JFET transistor oscillator for a 9.545 MHz sinusoidal signal. 2. To simulate JFET transistor oscillator using MicroCap

More information

INSTITUTE OF AERONAUTICAL ENGINEERING (AUTONOMUS) Dundigal, Hyderabad

INSTITUTE OF AERONAUTICAL ENGINEERING (AUTONOMUS) Dundigal, Hyderabad INSTITUTE OF AERONAUTICAL ENGINEERING (AUTONOMUS) Dundigal, Hyderabad - 00 0 ELECTRONICS AND COMMUNICATION ENGINEERING ASSIGNMENT Name : ELECTRONIC CIRCUIT ANALYSIS Code : A0 Class : II - B. Tech nd semester

More information

Subject Code: Model Answer Page No: / N

Subject Code: Model Answer Page No: / N Important Instructions to examiners: 1) The answers should be examined by key words and not as word-to-word as given in the model answer scheme. 2) The model answer and the answer written by candidate

More information

Lab 4. Crystal Oscillator

Lab 4. Crystal Oscillator Lab 4. Crystal Oscillator Modeling the Piezo Electric Quartz Crystal Most oscillators employed for RF and microwave applications use a resonator to set the frequency of oscillation. It is desirable to

More information

EXPERIMENT #2 CARRIER OSCILLATOR

EXPERIMENT #2 CARRIER OSCILLATOR EXPERIMENT #2 CARRIER OSCILLATOR INTRODUCTION: The oscillator is usually the first stage of any transmitter. Its job is to create a radio-frequency carrier that can be amplified and modulated before being

More information

FGJTCFWP"KPUVKVWVG"QH"VGEJPQNQI[" FGRCTVOGPV"QH"GNGEVTKECN"GPIKPGGTKPI" VGG"246"JKIJ"XQNVCIG"GPIKPGGTKPI

FGJTCFWPKPUVKVWVGQHVGEJPQNQI[ FGRCTVOGPVQHGNGEVTKECNGPIKPGGTKPI VGG246JKIJXQNVCIGGPIKPGGTKPI FGJTFWP"KPUKWG"QH"GEJPQNQI[" FGRTOGP"QH"GNGETKEN"GPIKPGGTKPI" GG"46"JKIJ"XQNIG"GPIKPGGTKPI Resonant Transformers: The fig. (b) shows the equivalent circuit of a high voltage testing transformer (shown

More information

Emitter base bias. Collector base bias Active Forward Reverse Saturation forward Forward Cut off Reverse Reverse Inverse Reverse Forward

Emitter base bias. Collector base bias Active Forward Reverse Saturation forward Forward Cut off Reverse Reverse Inverse Reverse Forward SEMICONDUCTOR PHYSICS-2 [Transistor, constructional characteristics, biasing of transistors, transistor configuration, transistor as an amplifier, transistor as a switch, transistor as an oscillator] Transistor

More information

UART CRYSTAL OSCILLATOR DESIGN GUIDE. 1. Frequently Asked Questions associated with UART Crystal Oscillators

UART CRYSTAL OSCILLATOR DESIGN GUIDE. 1. Frequently Asked Questions associated with UART Crystal Oscillators UART CRYSTAL OSCILLATOR DESIGN GUIDE March 2000 Author: Reinhardt Wagner 1. Frequently Asked Questions associated with UART Crystal Oscillators How does a crystal oscillator work? What crystal should I

More information

Feedback (and control) systems

Feedback (and control) systems Feedback (and control) systems Stability and performance Copyright 2007-2008 Stevens Institute of Technology - All rights reserved 22-1/23 Behavior of Under-damped System Y() s s b y 0 M s 2n y0 2 2 2

More information

ELECTRONIC CIRCUITS - II BY A P GODSE, U A BAKSHI DOWNLOAD EBOOK : ELECTRONIC CIRCUITS - II BY A P GODSE, U A BAKSHI PDF

ELECTRONIC CIRCUITS - II BY A P GODSE, U A BAKSHI DOWNLOAD EBOOK : ELECTRONIC CIRCUITS - II BY A P GODSE, U A BAKSHI PDF Read Online and Download Ebook ELECTRONIC CIRCUITS - II BY A P GODSE, U A BAKSHI DOWNLOAD EBOOK : ELECTRONIC CIRCUITS - II BY A P GODSE, U A BAKSHI Click link bellow and free register to download ebook:

More information

Chapter 6. FM Circuits

Chapter 6. FM Circuits Chapter 6 FM Circuits Topics Covered 6-1: Frequency Modulators 6-2: Frequency Demodulators Objectives You should be able to: Explain the operation of an FM modulators and demodulators. Compare and contrast;

More information

FREQUENTLY ASKED QUESTIONS

FREQUENTLY ASKED QUESTIONS FREQUENTLY ASKED QUESTIONS UNIT-1 SUBJECT : ELECTRONIC DEVICES AND CIRCUITS SUBJECT CODE : EC6202 BRANCH: EEE PART -A 1. What is meant by diffusion current in a semi conductor? (APR/MAY 2010, 2011, NOV/DEC

More information

UNIT 2. Q.1) Describe the functioning of standard signal generator. Ans. Electronic Measurements & Instrumentation

UNIT 2. Q.1) Describe the functioning of standard signal generator. Ans.   Electronic Measurements & Instrumentation UNIT 2 Q.1) Describe the functioning of standard signal generator Ans. STANDARD SIGNAL GENERATOR A standard signal generator produces known and controllable voltages. It is used as power source for the

More information

GOVERNMENT OF KARNATAKA KARNATAKA STATE PRE-UNIVERSITY EDUCATION EXAMINATION BOARD II YEAR PUC EXAMINATION MARCH-2012 SCHEME OF VALUATION

GOVERNMENT OF KARNATAKA KARNATAKA STATE PRE-UNIVERSITY EDUCATION EXAMINATION BOARD II YEAR PUC EXAMINATION MARCH-2012 SCHEME OF VALUATION GOVERNMENT OF KARNATAKA KARNATAKA STATE PRE-UNIVERSITY EDUCATION EXAMINATION BOARD II YEAR PUC EXAMINATION MARCH-0 SCHEME OF VALUATION Subject Code: 0 Subject: Qn. PART - A 0. Which is the largest of three

More information

THIRD SEMESTER DIPLOMA EXAMINATION IN ELECTRICAL & ELECTRONICS ENGINEERING, MARCH 2013 ELECTRONIC DEVICES AND CIRCUITS

THIRD SEMESTER DIPLOMA EXAMINATION IN ELECTRICAL & ELECTRONICS ENGINEERING, MARCH 2013 ELECTRONIC DEVICES AND CIRCUITS REVISION-2010 Reg. No SUB CODE:3053 Signature THIRD SEMESTER DIPLOMA EXAMINATION IN ELECTRICAL & ELECTRONICS ENGINEERING, MARCH 2013 ELECTRONIC DEVICES AND CIRCUITS Time :3hours Maximum marks:100 PART

More information

Applied Electronics II

Applied Electronics II Applied Electronics II Chapter 4: Wave shaping and Waveform Generators School of Electrical and Computer Engineering Addis Ababa Institute of Technology Addis Ababa University Daniel D./Getachew T./Abel

More information

Linear electronic. Lecture No. 1

Linear electronic. Lecture No. 1 1 Lecture No. 1 2 3 4 5 Lecture No. 2 6 7 8 9 10 11 Lecture No. 3 12 13 14 Lecture No. 4 Example: find Frequency response analysis for the circuit shown in figure below. Where R S =4kR B1 =8kR B2 =4k R

More information

UNIT II- OSCILLATORS

UNIT II- OSCILLATORS UNIT II- OSCILLATORS Negative Resistance oscillator - Barhausen Criterion for oscillation in feedback oscillator - Mechanism for start of oscillation and stabilization of amplitude - Analysis of RC Oscillators

More information

MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC Certified)

MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC Certified) WINTER 16 EXAMINATION Model Answer Subject Code: 17213 Important Instructions to examiners: 1) The answers should be examined by key words and not as word-to-word as given in the model answer scheme. 2)

More information

Electronics Prof D. C. Dube Department of Physics Indian Institute of Technology, Delhi

Electronics Prof D. C. Dube Department of Physics Indian Institute of Technology, Delhi Electronics Prof D. C. Dube Department of Physics Indian Institute of Technology, Delhi Module No. # 04 Feedback in Amplifiers, Feedback Configurations and Multi Stage Amplifiers Lecture No. # 03 Input

More information

Oscillations and Regenerative Amplification using Negative Resistance Devices

Oscillations and Regenerative Amplification using Negative Resistance Devices Oscillations and Regenerative Amplification using Negative Resistance Devices Ramon Vargas Patron rvargas@inictel.gob.pe INICTEL The usual procedure for the production of sustained oscillations in tuned

More information

for use Supervisor: on chip

for use Supervisor: on chip Local Oscillator for use in FM Broadcast Radio Receiver ETI 041: Radio Project Supervisor: Göran Jönsson Student: Yelin Wang and Hao Cai Master Program: System on chip Lund University Abstract Oscillator

More information

Chapter 2. The Fundamentals of Electronics: A Review

Chapter 2. The Fundamentals of Electronics: A Review Chapter 2 The Fundamentals of Electronics: A Review Topics Covered 2-1: Gain, Attenuation, and Decibels 2-2: Tuned Circuits 2-3: Filters 2-4: Fourier Theory 2-1: Gain, Attenuation, and Decibels Most circuits

More information

GATE: Electronics MCQs (Practice Test 1 of 13)

GATE: Electronics MCQs (Practice Test 1 of 13) GATE: Electronics MCQs (Practice Test 1 of 13) 1. Removing bypass capacitor across the emitter leg resistor in a CE amplifier causes a. increase in current gain b. decrease in current gain c. increase

More information

ELECTRONIC CIRCUITS LAB

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.

More information

An Oscillator is a circuit which produces a periodic waveform at its output with only the dc supply voltage at the input. The output voltage can be

An Oscillator is a circuit which produces a periodic waveform at its output with only the dc supply voltage at the input. The output voltage can be An Oscillator is a circuit which produces a periodic waveform at its output with only the dc supply voltage at the input. The output voltage can be either sinusoidal or non sinusoidal depending upon the

More information

Chapter 11. Alternating Current

Chapter 11. Alternating Current Unit-2 ECE131 BEEE Chapter 11 Alternating Current Objectives After completing this chapter, you will be able to: Describe how an AC voltage is produced with an AC generator (alternator) Define alternation,

More information

Paper-1 (Circuit Analysis) UNIT-I

Paper-1 (Circuit Analysis) UNIT-I Paper-1 (Circuit Analysis) UNIT-I AC Fundamentals & Kirchhoff s Current and Voltage Laws 1. Explain how a sinusoidal signal can be generated and give the significance of each term in the equation? 2. Define

More information

Crystal Oscillator. Circuit symbol

Crystal Oscillator. Circuit symbol Crystal Oscillator Crystal Oscillator Piezoelectric crystal (quartz) Operates as a resonant circuit Shows great stability in oscillation frequency Piezoelectric effect : When mechanical stress is applied

More information

Common-emitter amplifier, no feedback, with reference waveforms for comparison.

Common-emitter amplifier, no feedback, with reference waveforms for comparison. Feedback If some percentage of an amplifier's output signal is connected to the input, so that the amplifier amplifies part of its own output signal, we have what is known as feedback. Feedback comes in

More information

For the purpose of this problem sheet use the model given in the lecture notes.

For the purpose of this problem sheet use the model given in the lecture notes. Analogue Electronics Questions Todd Huffman & Tony Weidberg, MT 2018 (updated 30/10/18). For the purpose of this problem sheet use the model given in the lecture notes. The current gain is defined by a

More information

DHANALAKSHMI COLLEGE OF ENGINEERING DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING EC6202 ELECTRONIC DEVICES AND CIRCUITS

DHANALAKSHMI COLLEGE OF ENGINEERING DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING EC6202 ELECTRONIC DEVICES AND CIRCUITS DHANALAKSHMI COLLEGE OF ENGINEERING DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING EC6202 ELECTRONIC DEVICES AND CIRCUITS UNIT-I - PN DIODEAND ITSAPPLICATIONS 1. What is depletion region in PN junction?

More information

PartIIILectures. Multistage Amplifiers

PartIIILectures. Multistage Amplifiers University of missan Electronic II, Second year 2015-2016 PartIIILectures Assistant Lecture: 1 Multistage and Compound Amplifiers Basic Definitions: 1- Gain of Multistage Amplifier: Fig.(1-1) A general

More information

Lab 4. Crystal Oscillator

Lab 4. Crystal Oscillator Lab 4. Crystal Oscillator Modeling the Piezo Electric Quartz Crystal Most oscillators employed for RF and microwave applications use a resonator to set the frequency of oscillation. It is desirable to

More information

Electronic Measurements & Instrumentation. 1. Draw the Maxwell s Bridge Circuit and derives the expression for the unknown element at balance?

Electronic Measurements & Instrumentation. 1. Draw the Maxwell s Bridge Circuit and derives the expression for the unknown element at balance? UNIT -6 1. Draw the Maxwell s Bridge Circuit and derives the expression for the unknown element at balance? Ans: Maxwell's bridge, shown in Fig. 1.1, measures an unknown inductance in of standard arm offers

More information

Code: 9A Answer any FIVE questions All questions carry equal marks *****

Code: 9A Answer any FIVE questions All questions carry equal marks ***** II B. Tech II Semester (R09) Regular & Supplementary Examinations, April/May 2012 ELECTRONIC CIRCUIT ANALYSIS (Common to EIE, E. Con. E & ECE) Time: 3 hours Max Marks: 70 Answer any FIVE questions All

More information

VALLIAMMAI ENGINEERING COLLEGE

VALLIAMMAI ENGINEERING COLLEGE VALLIAMMAI ENGINEERING COLLEGE SRM Nagar, Kattankulathur 603 203 DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING QUESTION BANK IV SEMESTER EC6401 ELECTRONICS CIRCUITS-II Regulation 2013 Academic

More information

HIGH VOLTAGE ENGINEERING(FEEE6402) LECTURER-24

HIGH VOLTAGE ENGINEERING(FEEE6402) LECTURER-24 LECTURER-24 GENERATION OF HIGH ALTERNATING VOLTAGES When test voltage requirements are less than about 300kV, a single transformer can be used for test purposes. The impedance of the transformer should

More information

An active filter offers the following advantages over a passive filter:

An active filter offers the following advantages over a passive filter: ACTIVE FILTERS An electric filter is often a frequency-selective circuit that passes a specified band of frequencies and blocks or attenuates signals of frequencies outside this band. Filters may be classified

More information

ELECTRONIC CIRCUIT ANALYSIS LECTURE NOTES B.TECH (II YEAR II SEM) ( )

ELECTRONIC CIRCUIT ANALYSIS LECTURE NOTES B.TECH (II YEAR II SEM) ( ) ELECTRONIC CIRCUIT ANALYSIS LECTURE NOTES B.TECH (II YEAR II SEM) (2017-18) Prepared by: Mr. V. Shiva Rajkumar, Assistant Professor Mr. E. Mahendar Reddy, Assistant Professor Department of Electronics

More information

UNIT _ III MCQ. Ans : C. Ans : C. Ans : C

UNIT _ III MCQ. Ans : C. Ans : C. Ans : C UNIT _ III MCQ Ans : C Ans : C Ans : C Ans : A Ans : B Multiple Choice Questions and Answers on Transistor Tuned Amplifiers Q1. A tuned amplifier uses. load 1. Resistive 2. Capacitive 3. LC tank 4. Inductive

More information