A power amplifier is designed to provide maximum power output and is used to amplify weak signals to a level sufficient to drive a loudspeaker or other output device. It consists of multiple stages, with the final stage designed specifically for high power output. Power amplifiers use power transistors that can handle large currents and dissipate significant heat. They are classified based on the operating mode of the transistors, including class A, B, AB, and C power amplifiers. Transformer coupling is commonly used to match impedances in power amplifier circuits.
This directional over current relay employs the principle of actuation of the relay....It has a metallic disc free to rotate between the poles of two...
Part of Lecture series on EE321N, Power Electronics-I delivered by me during Fifth Semester of B.Tech. Electrical Engg., 2012
Z H College of Engg. & Technology, Aligarh Muslim University, Aligarh
Please comment and feel free to ask anything related. Thanks!
The bridge uses for measuring the value of unknown resistance, inductance and capacitance, is known as the AC Bridge. The AC bridges are very convenient and give the accurate result of the measurement.The construction of the bridges is very simple. The bridge has four arms, one AC supply source and the balance detector. It works on the principle that the balance ratio of the impedances will give the balance condition to the circuit which is determined by the null detector.
This directional over current relay employs the principle of actuation of the relay....It has a metallic disc free to rotate between the poles of two...
Part of Lecture series on EE321N, Power Electronics-I delivered by me during Fifth Semester of B.Tech. Electrical Engg., 2012
Z H College of Engg. & Technology, Aligarh Muslim University, Aligarh
Please comment and feel free to ask anything related. Thanks!
The bridge uses for measuring the value of unknown resistance, inductance and capacitance, is known as the AC Bridge. The AC bridges are very convenient and give the accurate result of the measurement.The construction of the bridges is very simple. The bridge has four arms, one AC supply source and the balance detector. It works on the principle that the balance ratio of the impedances will give the balance condition to the circuit which is determined by the null detector.
To turn on a Thyristor, there are various triggering methods in which a trigger pulse is applied at its Gate terminal. Similarly, there are various techniques to turn off a Thyristor, these techniques are called Thyristor Commutation Techniques.
Technical presentation on protection distance protectionSujith Mohandas
This is a sample PPT on Basics Distance protection. For more professional ppt's, Electrical Projects, Excel VBA Programming, Electrical Calculation spreadsheets, MATLAB Programs, Dissertation & thesis assistance please mail the requirements to SMDASacademics@gmail.com
The performance obtainable from a single-stage amplifier is often insufficient for many applications, hence several stages may be combined forming a multistage amplifier. These stages are connected in cascade, i.e. output of the first stage is connected to form input of second stage, whose output becomes input of third stage, and so on.
thank u
Hansraj MEENA
To turn on a Thyristor, there are various triggering methods in which a trigger pulse is applied at its Gate terminal. Similarly, there are various techniques to turn off a Thyristor, these techniques are called Thyristor Commutation Techniques.
Technical presentation on protection distance protectionSujith Mohandas
This is a sample PPT on Basics Distance protection. For more professional ppt's, Electrical Projects, Excel VBA Programming, Electrical Calculation spreadsheets, MATLAB Programs, Dissertation & thesis assistance please mail the requirements to SMDASacademics@gmail.com
The performance obtainable from a single-stage amplifier is often insufficient for many applications, hence several stages may be combined forming a multistage amplifier. These stages are connected in cascade, i.e. output of the first stage is connected to form input of second stage, whose output becomes input of third stage, and so on.
thank u
Hansraj MEENA
Power Amplifier circuits.
Output stages of types of power amplifier (class A, class B, class AB, class C, class D)
Distortions( Harmonic and Crossover).
Push-pull amplifier with and without transformer.
Complimentary symmetry and Quasi- complimentary symmetry push pull amplifier.
in this slide you will learn what are classes of amplifiers and what is main difference between all classes of amplifier
and after reading this slide you will be able to explain all clases of amplifier
A voltage amplifier circuit is a circuit that amplifies the input voltage to a higher voltage. So, for example, if we input 1V into the circuit, we can get 10V as output if we set the circuit for a gain of 10. Voltage amplifiers, many times, are built with op amp circuits.
Block diagram of a typical op-amp – characteristics of ideal and practical op-amp - parameters of opamp – inverting and non-inverting amplifier configurations - frequency response - circuit stability.
Common emitter amplifier by YEASIN NEWAJYeasinNewaj
This slide has been created for students who are studying electrical engineering and who want to gain knowledge of basic electronics. The topic is COMMON EMITTER AMPLIFIER OF BJT
Wire Splicing
A wire spice is when two pieces of electrical wire are taken and join them together with a crimp, butt-splice, or heat shrink to make a complete electrical connection.
Importance of Wire Splicing
The Splicing or jointing is required since the wires are manufactured in 100 metres lengths and the total length of wire used for house wiring may be more than 100 metres.
The jointing conductors and wires should always be carried out at outlets i.e. in switches,ceiling roses using the looping in system or in junction boxes.
Splicing should never be done in conduit runs but sometimes necessary when repairing old works.
This document is by explosives industry in which document discussed manufacturing process and flow charts details by nitric acid and sulfuric acid and tetra benzene and step by step details of explosive industry explosives industry is produced raw materials and manufacture it by manufacturing process
Forklift Classes Overview by Intella PartsIntella Parts
Discover the different forklift classes and their specific applications. Learn how to choose the right forklift for your needs to ensure safety, efficiency, and compliance in your operations.
For more technical information, visit our website https://intellaparts.com
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
Learn about the cost savings, reduced environmental impact, and minimal disruption associated with trenchless technology. Discover detailed explanations of popular techniques such as pipe bursting, cured-in-place pipe (CIPP) lining, and directional drilling. Understand how these methods can be applied to various types of infrastructure, from residential plumbing to large-scale municipal systems.
Ideal for homeowners, contractors, engineers, and anyone interested in modern plumbing solutions, this guide provides valuable insights into why trenchless pipe repair is becoming the preferred choice for pipe rehabilitation. Stay informed about the latest advancements and best practices in the field.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Online resume builder management system project report.pdfKamal Acharya
This project aims at the Introduction to app Service Management.
This software is designed keeping in mind the user’s efficiency & ease of handling and maintenance , as and secured system over centralized data handling and providing with the features to get the complete study and control over the business.
The report depicts the basics logic used for software development long with the Activity diagrams so that logics may be apprehended without difficulty.
For detailed information, screen layouts, provided along with this report can be viewed.
Although this report is prepared with considering the results required these may be across since the project is subjected to future enhancements as per the need of organizations.
Toll tax management system project report..pdfKamal Acharya
Toll Tax Management System is a web based application that can provide all the information related to toll plazas and the passenger checks in and pays the amount, then he/she will be provided by a receipt. With this receipt he/she can leave the toll booth without waiting for any verification call.
The information would also cover registration of staff, toll plaza collection, toll plaza collection entry for vehicles, date wise report entry, Vehicle passes and passes reports b/w dates.
Halogenation process of chemical process industries
Power Amplifier
1. Department of Electrical and Electronic Engineering
Khulna University of Engineering & Technology
Khulna-9203
Power Amplifier
Course code : EEE-1215
Analog Electronics
Presented By
Amit Kumer Podder
3. A practical amplifier always consists of a number of stages that amplify a weak signal until
sufficient power is available to operate a loudspeaker or other output device.
The first few stages in this multistage amplifier have the function of only voltage
amplification.
However, the last stage is designed to provide maximum power. This final stage is known
as power stage.
A transistor amplifier which raises the power level of the signals is known as transistor
power amplifier. In general, where amount of power involved is 1W or more, the
amplifier is termed as power amplifier.
A transistor that is suitable for power amplification is generally called a power transistor
Power amplifier
7/3/2020 Amit Kumer Podder 3
4. Where does the power come from?
All these power losses appear as heat which affects the efficiency and temperature of
the circuit as well
An amplifier converts d.c. power drawn from d.c. supply VCC into a.c. output power
7/3/2020 Amit Kumer Podder 4
5. A power amplifier is required to deliver a large amount of power and as such it has to
handle large current.
(i) The size of power transistor is made considerably larger in order to dissipate the heat
produced in the transistor during operation.
(ii) The base is made thicker to handle large currents. In other words, transistors with
comparatively smaller β are used.
(iii) Transformer coupling is used for impedance matching.
Difference Between Voltage and Power Amplifiers
7/3/2020 Amit Kumer Podder 5
Power amplifier
6. On the basis of the mode of operation, i.e., the portion of the input cycle during
which collector current flows, the power amplifiers may be classified as follows.
•Class A Power amplifier − When the collector current flows at all times during the
full cycle of signal, the power amplifier is known as class A power amplifier.
•Class B Power amplifier − When the collector current flows only during the
positive half cycle of the input signal, the power amplifier is known as class B
power amplifier.
•Class C Power amplifier − When the collector current flows for less than half
cycle of the input signal, the power amplifier is known as class C power amplifier.
There forms another amplifier called Class AB amplifier, if we combine the class A
and class B amplifiers so as to utilize the advantages of both.
.
7/3/2020 Amit Kumer Podder 6
Classification Based on Mode of Operation
8. Performance quantities of power amplifier
Collector efficiency. The main criterion for a power amplifier is not the power gain rather
it is the maximum a.c. power output. Therefore, the ability of a power amplifier to convert
d.c. power from supply into a.c. output power is a measure of its effectiveness.
The ratio of a.c. output power to the zero signal power (i.e. d.c. power) supplied by the
battery of a power amplifier is known as collector efficiency.
Distortion. The change of output wave shape from the input wave shape of an amplifier
is known as distortion.
Power dissipation capability. The ability of a power transistor to dissipate heat is known
as power dissipation capability.
7/3/2020 Amit Kumer Podder 8
9. [Here voltage and currents are in r.m.s value]
In terms of peak to peak value
Expression for Collector Efficiency
7/3/2020 Amit Kumer Podder 9
15. Transformer-Coupled Push–Pull Circuits
In this circuit, we use two complementary transistors in the output stage with one
transistor being an NPN or N-channel type while the other transistor is a PNP or P-
channel (the complement) type connected in order to operate them like PUSH a
transistor to ON and PULL another transistor to OFF at the same time. This push-pull
configuration can be made in class A, class B, class C or class AB amplifiers.
7/3/2020 Amit Kumer Podder 15
16. The construction of the class A power amplifier circuit in push-pull configuration is
shown as in the figure below. This arrangement mainly reduces the harmonic distortion
introduced by the non-linearity of the transfer characteristics of a single transistor
amplifier.
In Push-pull arrangement, the two identical transistors T1 and T2 have their emitter
terminals shorted. The input signal is applied to the transistors through the transformer
Tr1 which provides opposite polarity signals to both the transistor bases. The collectors of
both the transistors are connected to the primary of output transformer Tr2. Both the
transformers are center tapped. The VCC supply is provided to the collectors of both the
transistors through the primary of the output transformer.
The resistors R1 and R2 provide the biasing arrangement. The load is generally a
loudspeaker which is connected across the secondary of the output transformer. The turns
ratio of the output transformer is chosen in such a way that the load is well matched with
the output impedance of the transistor. So maximum power is delivered to the load by the
amplifier.
7/3/2020 Amit Kumer Podder 16
Construction of Push-Pull Class A Power Amplifier
17. When the a.c. input signal is applied, the base of transistor T1 is more positive while the base
of transistor T2 is less positive. Hence the collector current ic1 of transistor T1 increases while
the collector current ic2 of transistor T2 decreases. These currents flow in opposite directions in
two halves of the primary of output transformer. Moreover, the flux produced by these
currents will also be in opposite directions.
Hence, the voltage across the load will be induced voltage whose magnitude will be
proportional to the difference of collector currents i.e.
Similarly, for the negative input signal, the collector current ic2 will be more than ic1. In this
case, the voltage developed across the load will again be due to the difference
Circuit Operation
The polarity of voltage induced across load will be reversed.
7/3/2020 Amit Kumer Podder 17
18. The overall operation results in an a.c. voltage induced in the secondary of output
transformer and hence a.c. power is delivered to that load.
It is understood that, during any given half cycle of input signal, one transistor is being
driven (or pushed) deep into conduction while the other being non-conducting (pulled
out). Hence the name Push-pull amplifier. The harmonic distortion in Push-pull
amplifier is minimized such that all the even harmonics are eliminated.
7/3/2020 Amit Kumer Podder 18
Circuit Operation
19. Advantages
The advantages of class A Push-pull amplifier are as follows
•High a.c. output is obtained.
•The output is free from even harmonics.
•The effect of ripple voltages are balanced out. These are present in
the power supply due to inadequate filtering.
Disadvantages
The disadvantages of class A Push-pull amplifier are as follows
•The transistors are to be identical, to produce equal amplification.
•Center-tapping is required for the transformers.
•The transformers are bulky and costly.
Transformer-Coupled Push–Pull Circuits
7/3/2020 Amit Kumer Podder 19
20. Maximum Efficiency for Class B Power Amplifier
We have already seen in our previous article about class B power amplifier that a
push-pull circuit uses two transistors working in class B operation .
For class B operation, the Q – point is located at cut-off on both d.c. and a.c. load lines .
For maximum signal operation, the two transistors in class B amplifier are alternately
driven from cut-off to saturation . This is shown in fig.1 .
7/3/2020 Amit Kumer Podder 20
21. 7/3/2020 Amit Kumer Podder 21
Maximum Efficiency for Class B Power Amplifier
24. Tuned amplifiers are the amplifiers that are employed for the purpose
of tuning. Tuning means selecting. Among a set of frequencies available, if
there occurs a need to select a particular frequency, while rejecting all other
frequencies, such a process is called Selection. This selection is done by using
a circuit called as Tuned circuit.
When an amplifier circuit has its load
replaced by a tuned circuit, such an amplifier
can be called as a Tuned amplifier circuit.
The basic tuned amplifier circuit looks as
shown below.
7/3/2020 Amit Kumer Podder 24
Tuned Amplifier
25. The tuner circuit is nothing but a LC circuit which is also called
as resonant or tank circuit. It selects the frequency. A tuned circuit is
capable of amplifying a signal over a narrow band of frequencies that are
centered at resonant frequency.
When the reactance of the inductor balances the reactance of the capacitor,
in the tuned circuit at some frequency, such a frequency can be called
as resonant frequency. It is denoted by fr.
The formula for resonance is
There are two main types of tuned amplifiers. They are −
Single tuned amplifier
Double tuned amplifier
7/3/2020 Amit Kumer Podder 25
Tuned Amplifier
26. The process of injecting a fraction of output energy of some device back to the
input is known as Feedback. It has been found that feedback is very useful in
reducing noise and making the amplifier operation stable.
Depending upon whether the feedback signal aids or opposes the input signal,
there are two types of feedbacks used.
Positive Feedback
The feedback in which the feedback energy i.e., either voltage or current is in phase with
the input signal and thus aids it is called as Positive feedback.
7/3/2020 Amit Kumer Podder 26
Feedback Amplifier
27. Both the input signal and feedback signal introduces a phase shift of 180o thus
making a 360o resultant phase shift around the loop, to be finally in phase with
the input signal.
Though the positive feedback increases the gain of the amplifier, it has the
disadvantages such as
1. Increasing distortion
2. Instability
It is because of these disadvantages the positive feedback is not recommended
for the amplifiers.
7/3/2020 Amit Kumer Podder 27
Feedback Amplifier
28. Negative Feedback
The feedback in which the feedback energy i.e., either voltage or current is out of
phase with the input and thus opposes it, is called as negative feedback.
In negative feedback, the amplifier introduces a phase shift of 180o into the circuit while the
feedback network is so designed that it produces no phase shift or zero phase shift. Thus the
resultant feedback voltage Vf is 180o out of phase with the input signal Vin.
7/3/2020 Amit Kumer Podder 28
Feedback Amplifier
29. Though the gain of negative feedback amplifier is reduced,
there are many advantages of negative feedback such as
Stability of gain is improved
Reduction in distortion
Reduction in noise
Increase in input impedance
Decrease in output impedance
Increase in the range of uniform application
It is because of these advantages negative feedback is
frequently employed in amplifiers.
7/3/2020 Amit Kumer Podder 29
Feedback Amplifier
30. The Output of the amplifier must be
the avtual input multiplied by the gain
of the amplifier
7/3/2020 Amit Kumer Podder 30
Gain of Negative Voltage Feedback Amplifier