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What is Electrical Engineering? Popular Fields, Major Courses, Scope, Jobs and Salary

Hello friends, I hope you are having a good time. In today's tutorial, I am going to discuss detailed information about what is Electrical Engineering? We will cover the following contents; Electrical Engineering fields, major & minor courses, Scope, Jobs, Salary, famous electrical engineers & their contribution and top universities offer Electrical Engineering degree. Before further discussing our topic, let me ask you a question. Did you ever imagine your life without electricity? We can’t, right? That’s why, I always find electrical engineering the most developed and broad field of engineering, provides thousands of job opportunities in different companies. For example, from smartphones to power generation houses, electrical engineers are required by companies everywhere.  Are you also interested in the development and designing of electrical devices? Then, I’m sure this tutorial is for you. Now, let’s come to the point: what is Electrical Engineering?

What is Electrical Engineering?

• Electrical engineering (the engineering discipline) deals with the production & distribution of electricity as well as designing & developing complex electrical systems.
• Electrical engineering also involves the term electronics engineering, deals with electronic circuits (i.e. transistors, integrated circuits etc.), While the electrical engineers work with high power generation.
• Electrical engineers gets highly paid jobs in renewable energy projects, lighting & transport systems, power production & transmission etc.

Major courses of Electrical Engineering

Every university has a different curriculum but there are some major subjects, common in almost every electrical engineering syllabus. Let's discuss them out:

1. Electrical Machines: This subject is all about AC and DC motors and generators.
2. Power Systems: This subject teaches you about generation & distribution of electricity from Power house.
3. Control System: In this subject, you will learn about how to control, manage and regulate the electrical system and devices using various control loops.
4. Basic Electronics & communication subjects: This course will focus on analog & digital communications and electronic circuit.
5. Network Theory/Signal: This course focuses on teaching you the basic electrical principles.

Some other major subjects are:

• Introduction to Engineering.
• Basic electronics.
• Power Engineering.
• Electrical Machines theory.
• Circuit Theory.
• Computer Architecture.
• Non-conventional energy.
• Electrical installations.
• Electrical machines drawing.
• Power Circuits and Systems.
• Electrical control system.
• Digital Systems.
• Electrical lighting..
• Microprocessor Applications.
• Electric Circuits.
• Microprocessor.
• Principles of Programming.
• Switch gears and protection.
• Electromagnetics.
• Electrical instruments & materials.
• Signals and Systems.
• Microelectronic Circuits.
• Communication Systems.

Minor courses of Electrical Engineering

Minor courses also depend on university or also the choice of students. Let’s discuss some common minor courses choose by electrical engineering students.

Minor Courses of Electrical Engineering
Logic Design	Dynamic System Theory
Signals & Systems	Introduction to Learning from Data
Control Systems	Stochastic Processes
Electronics	Wireless Communication
Analog Electronics	Digital Communication
Machine Learning	Digital Signal Processing
Communication Systems	Introduction to Information Theory
Electrical Energy Systems	Speed Processing
Electromagnetics	Digital Image Processing & Communication
Physics of Semiconductor Devices	Computational Optical Imaging
Deep Learning	Optical Fibers and Waveguides
Optimization Theory and Methods	Introduction to Subsurface Imaging
Sustainable Power Systems	Lasers and Applications
Introduction to Biomedical Optics	Computational Methods (Materials Science)
Optical Spectroscopic Imaging	Solar Energy Systems
Introduction to Photonics	Physics of Semiconductor Materials
Engineering Optics	Semiconductor Devices
Electromagnetic Fundamentals	Electronic Optical & Magnetic Properties of Materials
Fabricating Technology for Integrated Circuits	Analog VLSI (Circuit Design)
Nano & Micro-Electronic Devices Technology	Analog Design Fundamentals

Branches of Electrical Engineering

Let’s find out some popular fields of electrical engineering and briefly discuss them.

1. Power and energy

Let me tell you, this field of electrical engineering, mainly deals with the generation and transmission of electricity on large scale.  Further, this is also working on the manufacturing of electrical generators, electrical motors and transformers. They also focus on the projects under governments such as power grid.

2. Automation and control

This field is actually all about developing, controlling different complex systems as well as controllers, and is responsible for their proper functioning. To design such controllers, they take helps form electrical engineers. The control engineers have all over in the airliners as well as in the modern automobile companies. They also work in designing robotics using control algorithms.

3. Electronics

Electronic engineers are focusing on the designing of integrated electronic circuits & their components, transistors, capacitors, resistors, diodes and many more.

4. Microelectronics and nanoelectronics

They deal with the fabrication and designing of micro size electronic circuits components; such as semiconductor transistors.

5. Signal processing

They are working on the analysis techniques and testing of communication signals. It may be analog signals or digital signals. In the case of analog signals, the signal processing mainly relates to amplification and filtering for telecommunications. Besides, In digital signals, signal processing involves in compression, detection of error & correction of error.

6. Telecommunications

They focus on the communication channels in space through coax cable, optical fiber or free space. Some other popular fields of electrical engineering are:

• Radio-frequency engineering.
• Electronics.
• Systems engineering.
• Computer engineering.
• Photonics.
• Telecommunications.
• Signal processing.
• Power engineering.
• Optics.
• Instrumentation.

Electrical Engineering jobs and salaries

We have already discussed the fields of electrical engineering. According to BLS, mostly electrical engineers getting hired by research & development companies and popular engineering industries. Moreover, the federal government and other manufacturing industries are also interested in young electrical engineers. Electrical engineers generally worked indoors in any company, but the experienced & senior engineers may also get the position of just visiting sites. The manufacturing industries hired electrical engineers are:

• Defense.
• Marine.
• Commercial construction.
• Computers & components.
• Automotive.
• Lighting.
• Aerospace.
• Consumer electronics.
• Telecommunications & traffic control.
• Railroad.

There are also government departments, offer employments to electrical engineers in national laboratories, transportation departments as well as in the military. As you are well aware, each company has its own qualification criteria for job. Some firms need bachelor degree in electrical engineering.  But a master degree will enhance the chance of promotion and salary. Most importantly, most famous companies require the certificate from good institutes such as Institute of Electrical and Electronics Engineers or Institution of Engineering and Technology. Let’s talk about the estimated salary of an electrical engineer. In 2014, the estimate salary range of a bachelor degree holding electrical engineer was $55,570 to $73,908 according to research. The electrical engineers holding master degree with 5-10 years experience were paid with $$74,007 to $108,640. Additionally, a senior engineer with 15 years of experience with a doctorate degree was getting $97,434 to $138,296 salary. This is amazing; isn’t it?

What are the Key Skills of Electrical Engineering?

Common skills gained with an electrical engineering degree include:

• Develop a strong numeracy.
• Provides basic IT skills.
• Technical expertise.
• Self-management (such as planning & meeting deadlines).
• Allow to design and analyze technical diagrams.
• Teach how to do Team work & communication skills.
• Allow the flexibility.
• Make you able to identify and solve problems.
• Budgeting.
• Professional communication, spoken and written.
• Data analysis.
• Deeply understanding about how to deal with high electrical power systems & safety regulations.
• Provide awareness of other stuff; such as business and environmental issues.

Top reasons why you should choose Electrical Engineering?

1. Job opportunities

The famous companies all over the world are hiring young electrical engineers, give then good training with a great salary package. That’s why I think, this is one the most valued profession.

2. Bright job offers from abroad

Getting an electrical engineering degree, means you have a lot of job opportunities all around the world. A lot of technical firms are willing to hire people from other countries. Well! I must say, you will have a bright future ahead.

3. Other specialized fields

It may seem like doing an electrical engineering means you are just going to deal with electricity. But, the truth is, you will definitely have chances to learn about other specialization fields such as;

• Signal Processing.
• Power Engineering.
• Telecommunications.
• Microelectronics.
• Control Systems.
• Radio-Frequency Engineering.

4. Get chance to study top universities

Getting a degree from a well-known university has a strong impact on your future. Many companies also hire stud nets graduates from good universities. There are so many famous universities offering this degree bachelor as well as master throughout the world. These universities not only provide you high level engineering skills but also groom your personality. Let me enlist some top universities of 2021.

• University of Portsmouth; U.K.
• Chalmers University of Technology; Sweden
• University of Birmingham; U.K.
• University of Leeds; U.K.
• University of Colorado Denver; U.S.
• University of Twente (UT); Netherlands
• Massachusetts Institute of Technology.
• University of California; Berkeley.
• California Institute of Technology.
• Georgia Institute of Technology.
• Stanford University.
• University of California; Berkeley.
• California Institute of Technology.
• University of Illinois; Urbana, Champaign.
• Georgia Institute of Technology.
• University of Texas; Austin (Cockrell)
• Carnegie Mellon University.
• University of Michigan; Ann Arbor.
• Tsinghua University; China
• Harbin Institute of Technology; China
• Aalborg University; Denmark
• Nanyang Technological University; Singapore
• Southeast University; China
• National University of Singapore; Singapore
• University of Technology Sydney; Australia
• Zhejiang University; China
• University of Electronic Science and Technology of China; China
• Huazhong University of Science and Technology; China

Popular Electrical Engineers and their Contributions

There are so many great electrical engineers who contributed in this field. Let's discuss a few of them for your better understanding with electrical engineering.

Popular Electrical Engineers of all Times
No.	Name	Contributions
1	Otto A. Knopp	He is the founder of standard transformers testing as well as compensation winding.
2	A. K. Erlang	He worked on communication signals and queuing.
3	Alan Blumlein	He was one of the greatest electrical engineer invented telecommunications, radar system, stereo, television and sound recording.
4	Albert H. Taylor	Was the first engineers, demonstrated the radar.
5	Alec Reeves	He was the inventor of pulse coding & modulation.
6	Alfred Rosling Bennett	He discovered the electric lighting & telephones.
7	Alessandro Volta	He invented electrical battery.
8	André Blondel	He worked on oscillography and give electrical machine theory.
9	Andy Bechtolsheim	He has contribution in the invention of sun Microsystems
10	Arnold Orville Beckman	Discovered pH meter, Beckman Instruments and Silicon Valley.
11	Hugo Hirst	He was the co-founder of General Electric Company plc.
12	Bern Dibner	He is the founder of Burndy Co., electrical connectors,

I want to enlist some more famous electrical engineers.

Charles Frederick Burgess	William Duddell
Alan Archibald Campbell-Swinton	Allen B. DuMont
John Renshaw Carson	J. Presper Eckert
James Kilton Clapp	Thomas Edison
Edith Clarke	Cyril Frank Elwell
Lynn Conway	Douglas Engelbart
Seymour Cray	Justus B. Entz
Sidney Darlington	Lloyd Espenschied
Lee de Forest	Federico Faggin
Jack Dennis	Michael Faraday

Popular books of Electrical Engineering

There are a vide variety of books about electrical engineering.  A good book about this field will better help you to understand it. Here are some book, I want to recommended.

• Automation and Robotics.
• Introduction to Electronic Engineering.
• Essential Engineering Mathematics.
• Introduction to Power Electronics.
• Electronic Measurements: Exercises and Assignments.
• Electrical Power.
• Control Engineering Problems with Solutions.
• Concepts in Electric Circuits.
• Nuclear Powered Generation of Electricity.
• Three Phase Electrical Circuit Analysis.
• Essential Electromagnetism: Solutions.
• Electromagnetism for Electronic Engineers.
• Advanced Topics in Electrodynamics.
• Fundamental Engineering Optimization Methods.
• Essential Electromagnetism.
• An Introduction to Nonlinearity in Control Systems.
• CMOS Integrated Circuit Simulation with LTspice.
• Electric Drive Dimensioning and Tuning.
• Essential Electrodynamics: Solutions.
• Introduction to Digital Signal and System Analysis.
• Thermal Modelling of Electric Machines.
• Essential Electrodynamics.

I hope this article helps you to better understand electrical engineering, its scope, fields, popular books and top electrical engineers & their contribution.

Brushless DC Motor

Hello friends, i hope you all are fine and enjoying. Today i am going to share a new tutorial which is Brush-less DC motor. The basics of DC motor have been explained in one of my previous tutorial which was named as Difference Between DC and AC motors in that tutorial i explained in detail the basics of a DC motor, its construction and working.

Now in today's tutorial i am going to share a tutorial on one of the type of DC motor which is Brush-less DC motor. Brush-less DC motor is commonly known as Electronic Commutated motor. It is in fact a synchronous motor. From the word DC, one thing becomes clear that the supply voltage will be DC but as i mentioned in the previous line that it is a synchronous motor then, it will need AC supply to run. So what actually happens is that from source DC voltages appears and after the inverter circuit, we get AC voltages and these AC voltages are actually given to the motor to operate. The rotor of a Brush-less DC motor is actually a permanent magnet rotor. While some winding is done on stator. Brush-less DC motors are also commonly known as stepper motor but there is a very little difference in between both these motors and their operation. Like stepper motor are generally used at that placed where they have to stop again and again and the continuous operation of the motor is not required. There is also another big difference between Brush-less DC motor and stepper motor that the rotor of stepper is placed to work in proper angular direction. Now lets get started with the working and applications of Brush-less DC motor

Brush-less DC motor

Brush-less DC has 2 parts. One is called rotor and the other is called Stator. Here the rotor is a permanent magnet and it rotates inside the fixed armature. This assembly gives us a very big advantage which is, that it reduces the heating losses. Rotor is placed inside the stator and this allows the motor to produce more torque. It is our choice to make a brushless DC motor of different poles. For example we can made a motor having 2,3 or poles and all are DC brushless motors. Brush-less DC motor can be made in 2 different design. In first design, the rotor is placed inside the fixed stator. This configuration is also known as 'inrunner' because the rotor is running inside the stator.

While in the second configuration, we have a fixed stator inside and the permanent magnet rotor rotates around it.  This type of configuration is called 'outrunner'. We can also place the stator windings in 2 different configurations. If we place the stator winding in delta configuration and we are dealing with a 3 pole motor then, all the windings will be connected in series and the power supply from the source is applied to all the windings. The resulting configuration looks like a triangle shape. While on the other hand if we wish to place the stator winding in Wye (Y) then we will common the one terminal of each winding. And to the remaining 3 terminals, we will connect the power supply to all those three points.(Since we are working with 3 phase motor and we will have three wires and all of them will be phase wires).

Both these winding configurations have their own advantages and they are listed below as:

• If you have made the stator winding configuration in Delta, then this motor will have a low starting torque. Which means at slow speeds it will generate a very low torque and at higher speeds its torque will also increase with speed.
• The Star type stator motor possess high starting torque. At starting or at very low speed it generates much high torque but as the motor picks up speed, it torque doesn't builts up as compared to Delta type motor.
• Efficiency also have a greater impact on the operation and reliability of motor operation. If we compare the efficiecies of both these motors then, we will see that motor having Star shaped winding is more efficient as compared to delta shape winding.
• Reason is that the star shape winding motor have high starting torque and it is able to drag heavy loads even at low speeds.

Control circuit of Brush-less DC motor

As i explained earlier that the supply voltages may be DC but this motor requires AC voltages to operate actually. So, we have a control circuit which allows the motor this kind of operation of the motor on such voltages. Since the control circuit has to rotate the rotor so the control circuit needs to know the position of the rotor in rest position. To cope with this thing, we implement HALL EFFECT Sensor in control circuit. If you are using a 4 pole motor then the controller will energize the 2 coils with NORTH polarity and the other 2 coils with South polarity. When the stator coils will be energized then one set of coils will tends to push the rotor away from it and the other set of coils will tend to attract the rotor to itself, in this way the rotor will start to rotate and a torque will be established in it and afterwards it would be able to pick load.

Practical Applications

Brush-less DC motor possess a large no of industrial applications. Although, these types of motors are little costly and also complex to operate because of the control circuit but still we can't ignore the importance of this type of motor. Some of its industrial based applications are listed below as:

• Biggest and most common use is that these motors are used in laptops and computers for cooling purpose.
• An old use of low power and very low speed DC brushless motor was that they were used in gramophones records.
• High rating and bigger size DC brushless motors are used in transport vehicles and also in Hybrid cars.
• These motors may be of small size but have permanent magnet rotor and are able to develop high starting torque.
• In refrigeration and cooling systems, Brushless DC motor is used in all appliances for the condenser cooling purposes. Both large and small air-conditioning systems uses Brushless DC motor.
• When high voltages AC is generated and transmitted, so need a control mechanism for its safe operation and control. Brushless DC motors are also used at those places for proper cooling of micro processors.
• Brushless DC are able to develop high starting torque and gives good speed response. That's why they are widely used in water pumps, fans and variable speed industrial applications.
• These motors are preferred to work in industries because they possess high power density, can give good speed and torque characteristics and also high efficiency.
• Brushless DC motors have good thermal conditions so they are able to operate at variable speed without excessive heating.
• Brushless DC motor have the biggest demand in defense applications. Now a days they are commonly used in helicopter's rotors, because of their favorable power to wight ratio.

Alright friends, that's all from today's tutorial. If you have any questions then, feel free to ask. Till next tutorial Take Care !!! :)

Brushed DC Motor

Hello friends, i hope you people are fine and enjoying. Proceeding to my previous tutorial, in which i explained Brushless DC motor in detail. Now in this tutorial i am going to explain in detail the second type of DC motor which is Brushed DC motor. In this tutorial, we will see what is in fact a Brushed DC motor, how it works and what are the advantages and practical application of this type of motor on some other type of motors.

Brushed DC motors are also known as commutated DC motors. Reason is that these motors contain commutator and carbon brushes for rotor excitation. I will explain all these terminologies in detail, later in tutorial. These are the most important type of motors designed to run directly on DC power supply. These were the very first type of motors, which were designed to operate on DC voltages at industrial levels and as we also know that DC power system had been used in some countries like USA for power transmission and distribution. DC series motors are still in use for industrial applications. Reason is that these motors gives us the ease to vary the speed of motor by simply changing the supply voltages or magnetic field strength. We can also change the speed and torque characteristics of the motor by changing the power supply connections. Brushed DC motors contain carbon brushes, which wear out with time and continuous operation of motor, so where maintenance operation is required, Brushless DC motor is preferred. Now first of all, lets see the operating principle of Brushed DC motor:

Operating principle of Brushed DC Motor

Brushed DC motor rotates on the principle of Fleming's Left Hand Rule. When a current is make to pass through a coil placed in a permanent magnetic field, then a torque acts on the coil which makes it to rotate. The direction of rotation of the coil is given by the Fleming's Left Hand Rule. The process can be elaborated by the image which is shown below as:

The above figure a showing the basic operating principle of Brushed DC motor. I have chosen the example of permanent magnet Brushed DC motor to make it easy to understandable. From the above shown image, you can see that:

• A DC supply has been connected to rotor circuit through carbon brushes and commutator.
• Commutator is made of brass while carbon brushes are made of soft silicon material.
• The reason why carbon brushes are made of silicon is to reduce the friction between carbon brushes and commutator.
• If you use carbon brushes made of brass or copper then, conduction between carbon brushes and commutator will increase but a massive sparking will produce, which can damage our system.
• When the rotor poles are at 90 degrees to the stator poles then zero torque is produced in rotor.
• On the other hand, when rotor poles are at 0 degrees to the stator poles, then maximum torque is produced in rotor circuit.
• So we can conclude that half of the supply cycles would be wasted in this way, that's why we have connected commutator in this system. It automatically change the direction of direction after every half cycle.
• The resultant gives us maximum torque continuously during our operation.

TYPES of Brushed DC Motor

Based on the types of connections between Rotor and Stator windings, DC Brushed motors have been divided into 5 major types. All these types are given below as:

Series Type DC Motor

• In these type of motors, the rotor winding is in series with rotor winding.
• These type of motors have High Starting Torque.
• The beauty of these type of motors is that, their speed varies automatically with the applied load. If load increases or suddenly vanishes then, this motor has the ability to maintain it's speed.
• These motors are used at those places where the motor has to supply heavy load. For example in Electric trains DC series motors are used.

Shunt Type DC Motor

• In these type of motors, rotor winding is in parallel with stator winding.
• These motors have low starting torque as compared to Dc series motor.
• These motors have constant speed and their speed doesn't varies with load.

Compound Type DC Motor

• You can judge the properties of this motor by its name. In this type of DC motor, both series and compound windings are embedded together.
• This type of motor have much dominating features than any other type of DC motor.
• These motors have high starting torque, which is in fact a property of DC series motor.
• While on the other hand, this motor is capable to run on constant speed and it speed doesn't vary as much with load, which is in fact a property of DC shunt motor.

Permanent Magnet Type DC Motor

• It can be seen from the name of these type of motors that they contain a permanent magnet stator instead of a wound electromagnet stator.
• No need of external energizing field current.
• More efficient design.
• This design is only possible for small size but much efficient motors.

Separately Excited Type DC Motor

• In these type of motors, some heavy excitation system is required for the excitation of rotor circuit.
• High field is drawn by these type of motors.
• This motor has the ability to draw much heavy loads even at a very low speed.
• The reason these motors are able to bear much heavy loads is that they draw much field current and much armature voltages.

Features and Practical Applications

Brushed DC motors possess a large no of features and practical applications. Some of them are listed below as:

1. These motors have a very simple design and it is very cost effective to built them on large scale.
2. Their operation is very simple and it doesn't requires any control mechanism.
3. DC motors are used in both domestic and industrial applications, because of their simpler design and advanced features.
4. They are commonly used in car power windows and seats.
5. Car's wind wiper motor is also a DC motor. And it has variable speed and high starting torque.
6. DC motors are enclosed in a solid frame and they don't have any environmental impact on their operation. They are capable to work under any severe condition.

Alright friends, this ends my today's tutorial here. If you have questions regarding my today's tutorial, feel free to ask. Till next tutorial Take Care!!! :)

Introduction to Buck Converter

Hey Guys! Hope you all are doing great and having fun. Today, I am going to discuss the details on the Introduction to Buck Converter. It is a power converter which is mainly used to stepping down the voltage from its input to the output load. It mainly consists of two semiconductors and one energy storing components which can be either capacitor or inductor. It works best in the circuits where electrical isolation is not required.

Introduction to Buck Converter

• Buck converters are power converters which are mainly used for converting high voltage to the low voltage. These converters are highly efficient, showing almost 90% of efficiency.
• They are useful for performing a special task like converting the huge supply voltage of 12 V in the computer to 1.8 V for making it useful for operating small components like USB, CPU, and DRAM.
• Transistor used in buck converter act as a switching device. Obtaining a continuous output is the main purpose of buck converter which can be achieved by using the energy stored in the capacitor.
• Transistor switches between on and off at high frequency. Energy stored in the capacitor is mainly used in the buck converter during the off condition of the transistor, making it useful for obtaining a continuous output.
• Circuit diagram of a buck converter is given below:

   

• Buck converter is mainly called as a DC to DC converter. Source input can either be obtained directly from DC source or from rectified AC source.
• After getting DC source, it is passed through a switching transistor which converts it AC source. Eventually, the AC source is converted to DC source at the output voltage.

1. Buck Converter Working Principle

• Buck converter consists of switching transistor, diode, and energy storing elements such as capacitor or inductor. Transistor switches between on and off continuously. When the transistor switch is turned on, it is denoted by T(on) and when it is turned off, it is denoted by T(off). Duty cycle can be obtained by the dividing the time when switch is turned on with the total time of the cycle

D = T(on)/T

• Inductors works in both ways i.e. it opposes the current from changing its direction and also as an energy storing element. Energy is stored in the inductor which prevents the output from getting too high and that energy is released when the transistor is switched to off condition.

If Transistor is Switched ON

• When transistor is switched on, current will flow from the inductor L. Current flowing through the load is being restricted by the inductor and a surplus amount of energy will be stored in the inductor. Circuit diagram of a buck converter is shown in the figure given below when the transistor is switched on.

• The diode which is reverse biased won't take part in the operation of the buck converter as there is large positive voltage appear to the cathode part of the diode. When the switch is closed the voltage across inductor will be

V(Inductor) = V(in) - V(out)

• The capacitor using in this circuit diagram will continuously charge up to the maximum value and releases its energy when the transistor switches to off condition.

If Transistor is Switched OFF

When transistor switches to off condition, the diode available in the buck converter turns to forward biased, making its cathode negative and anode side positive. Circuit diagram of the buck converter is shown in the figure given below when transistor is switched off.

• When transistor is switched off, the inductor will automatically change its polarity with respect to the polarity given in transistor on condition. Now, the voltage across the inductor is also called back emf and it will give its energy back to the circuit during off condition. Here V(inductor) = - V(out)
• Sometimes we need minimum output at the output voltage, in this case, current flowing through the inductor becomes zero. When it falls below zero, it results in automatically discharing the capacitor energy which is stored when the transistor is operated in on condition. When capacitor is completely discharged, it automatically erupts the high switching losses. Pulse frequency modulation is used to avoid such losses.
• The average value of energy stored in inductor will always remain same at the end of the cycle.
• When output begins to fall, the only source of energy will be the energy from the capacitor, causing the current to flow through load and also preventing it from going too high.
• We get the output in the ripple form, instead of getting in square form. And can be defined as

V(out) = V(in) * T(on)/ T

Here T(on) is a time duration of the cycle when the transistor is on and T is the total time of the cycle.

• • Ripple formed in buck converter shows that voltage goes high at the on state and drops down at off state.

2. Examining the current waveform during overall cycle

Let us examine the current wave form of diode current, inductor current and input current during overall cycle. This diagram clearly shows that inductor current is equal to the sum of diode and input/switch current.

• During whole cycle input current will be much less than the output current, resulting in stepping down the voltage at the output. Notice that, assuming the ideal conditions, the overall power of the cycle will remain constant. i.e. V(in)*I(in) = V(out)*I(out)
• However, getting perfect circuit is not possible in reality due to some energy losses. Maximum efficiency that practical buck converters exhibit is about 85%.

3. Applications of Buck Converters

Buck converters exhibit a wide range of application depending on its efficiency and durability. Some of its main applications are given below.

USB ON-the-GO

USB On-the-GO is mainly used for connecting the mouse, keyboard and other useful devices to the smartphone. The main purpose of buck converter using in USB is to draw power from the USB and delivers it to the smartphone. Hence, it is the main source of regulating the power in both directions.

• When smartphone is plugged into charging, the buck converter is used to charge the lithium battery inside the smartphone,
• When some mice or keyboard is connected to the smartphone, buck converter works in a reverse order and draws power from the lithium battery and delivers it to the keyboard or mouse connected to the smartphone.

POL (Point of Load) converter for Laptops

• POL, also known as a voltage regulator, is a converter that is widely used in laptops and desktop computers. It is very useful in operating the motherboard at low voltage.
• Compressors are very delicate devices fixed in the laptops and even a fraction of the increase in voltage can damage its overall performace and quality. So, buck converter in the laptops does its job very nicely by maintaining the voltage in the processor as low as 1.8V.

Solar Chargers

• Buck converters are widely used in solar chargers. They often come with a built-in microcontroller which allows the buck converter to draw maximum power and helps in charging the battery in limited time possible.

Quad-copters

• Quad-copters come with a highly efficient buck converter for dropping down the input voltage. Quad-copter mostly uses DC power supply such as small batteries which are placed in a series. Normally 5 to 6 batteries are used to make quad-copter fully operational. These batteries provide voltage that ranges between 6 to 25 V.
• Buck converter in the batteries converts that voltage to 3.3 V for making it useful for flight controller which is a backbone of quad-copter.

This is the brief overview of buck converter, its working principle, and applications. I have tried my best to cover as many aspects as possible. However, if you still think some of your questions went unanswered, you can connect me in the comment section below. I will try my best to resolve all of your queries relating to buck converters. Will see you all in the next article. Stay Tuned!

Introduction to Transformer

Hey Fellas! I warmly welcome you to be here. Today I'm going to discuss the Introduction to Transformer. I'll unlock the complete details of its working principle, construction, types, and applications. It is widely used for the transformation of electrical energy. The inception of transformation has revolutionized the electrical field and made our life easy more than ever before. Because of its extensive advantages, it works as a core for electrical engineering. In today's tutorial, I have explained in detail all about Transformer but still if you got trouble anywhere, then you can ask in comments and I will try my best to resolve them. So, now let's get started with Introduction to Transformer:

1. Introduction to Transformer

• Transformer is a simple static device that helps in transferring the electrical power between two circuits.
• Transformer works on the Faraday’s Law of Electromagnetic Induction.

Faraday’s Law of Electromagnetic Induction:

• It is a process by which primary coil induces a voltage into the secondary coil with the help of magnetic induction. The coil windings are electrically isolated and magnetically connected around a common circuit called core.

• If we apply varying current in one coil, it results in creating a magnetic field and automatically induces the varying voltage in the secondary coil.
• Hence power is transmitted from one coil to another through the magnetic field.
• A slight change in current in transformers helps in increasing and decreasing the AC voltage in many electrical power applications.

Transformers are available in different sizes weighing from cubic centimeters to hundreds of tons. Without transformers it would be very difficult to transfer the power generated at the grid station to the area around the city. The high voltage and current produced at grid station can be reduced to low level which in turn helps in operating the electrical appliances at home.

2. Construction of Transformer

• A simple static transformer is a linear device that consists of coils that are mutually inductive and steel core.
• The windings in the coil are insulated from each other and from the steel core.
• The whole assembly of windings and steel core are encased in a device called tank.
• The major purpose of the tank is to insulate the core assembly from the coil windings.

• In order to take out the terminals of transformer specific bushings made up of capacitor are used.
• Added amount of oil conservator is also used in the tank which provides cooling and reduces friction.

Almost all types of transformers come with a core that is made up of laminated sheets of steel. In order to achieve continuous magnetic path, air gap between the sheets must be kept minimum. Laminated sheets of steel, with the added amount of silicon, are heat treated in order to provide low hysteresis losses and low eddy current and high permeability.

3. Mathematical Formulas for Transformer

Till now, we have seen the basic introduction and construction of Transformers, but when it comes to designing, then we have to make some mathematical derivations. In this section of this tutorial, I am gonna focus on some basic concepts of Transformers and will also share their mathematical formulas.

Turn Ratio

• Transformer has a turn ratio which dictates the operation of transformer and the value of output voltage applied to the secondary windings.
• Turn ratio is defined as a number of turns of the primary coils divided by the number of turns of secondary coil.

TR = Np /Ns

If Ns > Np then it is called step up transformer

If Np > Ns then it is called step down transformer

Transformation Ratio

• Transformation Ratio is defined as the secondary voltage divided by the primary voltage. And it is denoted by K.

K = Vs / Vp or Ns/Np

Transformer EMF Equation

• If we apply electrical source on the primary side of transformer, it will produce the magnetizing flux across the core of transformer.
• It must be a rate of change of flux that is connected to both, primary and secondary coils.
• According to Faraday’s Law of Electromagnetic Induction, changing flux in the coil must induce EMF in it.

• Suppose the flux created forms a sinusoidal function. As it is a rate of change of flux so it must be derivative of sine function which is a cosine function.
• We can easily get the rms value of the induced EMF if we get the rms value of cosine wave and multiply it with the number of turns of coils.

• Now let's have a look at the Faraday's Law of Electromagnetic Induction:

4. Types of Transformers

There are many types of transformers available in market but we can't cover them all in this tutorial. So, I am gonna just focus on those, which are used most commonly. Transformer can be differentiated into following types:

Step Up Transformer

Transformer is known as step up transformer if the number of turns of coil in secondary coil is greater than the number of turns of coil in primary coil. In other words, when transformer is used to increase the voltage on the secondary coil it is called step up transformer.

Step Down Transformer

Similarly, a transformer is known as step down transformer if the number of turns of coil in primary coil is greater than the number of turns of coil in the primary coil. Or if transformer is used to decrease the voltage on the secondary coil, it is called step down transformer.

Impedance Transformer

A transformer is called impedance transformer if it is used to deliver the same voltage to the secondary windings as applied to the primary windings. Hence output remains constant with respect to the input. This type of transformer is used for the isolation of electrical circuits or impedance matching.

Core Type Transformer

Core type transformer comes with a cylindrical coils that are form-wound. In this transformer, windings are encircled around some part of core. The cylindrical coils are insulated from each other with the help of paper or cloth and encompass high mechanical strength. Low voltage windings are arranged in a specific way to provide quick insulation with the laminated core of steel. A core type transformer is shown in the figure given below. L.V and H.V are described as Low voltage windings and High voltage windings respectively.

Shell Type Transformer

Shell type transformer comes with a steel core that covers some part of the coil windings. The coils in this transformer are also form-wound and are arranged in different layers that are insulated from each other. Such type of transformer comes in two shapes i.e. rectangular type or distributed type. It is like a disc arranged with insulated spaces, providing a horizontal cooling. Both, rectangular and distributed types of shell transformer are given in the figures below. In order to provide compact look and minimum movement, this transformer comes with a rigid bracing that combines the whole transformer at one place. Main purpose of bracing is to control vibration and provide minimum noise during operation. Both, shell type and core type transformers, encompass same characteristics but they are different with respect to cost. Shell type transformer is high in demand due to high voltage and the construction of its design. Things that are taken into consideration before buying the transformer include, heat distribution, cooling process, weight, voltage rating and kilo-watt ampere rating. Transformer comes with a tank, brushes, and oil. The oil used in the transformer provides cooling and provides insulation between steel core and coil windings. Sometimes, it happens, the tank used in the transformer doesn’t provide the required cooling effect. This is due to the quality of oil used in the tank. In order to provide accurate cooling and quick insulation, oil must be free from sulfur or alkalies. If we leave alkalies and sulfur in the oil, it causes the oil to moist, hence damaging the quality of oil quite significantly. Even the small amount of this moisture is enough to effect the quality of the oil. If operational tank doesn’t provide required cooling, then we use radiators on the sides of tank. This provides proper cooling and helps in maintaining the temperature of transformer to the required level. In order to make oil free from any moisture, tank must be sealed air-tight. This is easy to apply on the small transformers. In case of huge transformer, providing an air-tight sealing is difficult to implement, hence big chambers are used to maintain the temperature of transformers. These chambers refrain the moisture from adding in the oil. Oil decomposes quickly when it encounters with oxygen during the heating process, leaving a dark material on the transformer, which eventually, can damage the cooling process.

5. Energy Losses in Transformers

Transformers are used for the transformation of electrical energy. The coils used in the transformer are entitled to many energy losses. Some of them are given below:

Heat Loss

Heat loss is a common factor in transformer. Some form of energy is used to reduce the resistance in the transformer in order to provide steady flow of electrical energy from one coil to another. When it escapes from coils of the transformer, this energy is converted into heat which erupts the energy loss. Heat loss can be minimized by using the good conducting material in the coil or by using wires of high cross sectional area. Eddy current also pertains to heat loss. When primary coil is connected to the electrical power, it induces the alternating magnetic field in the primary coil. Same magnetic field also passes through the steel core, helps in inducing the small current in the same core which erupts heat losses. In order to overcome heat loss, steel core must be laminated perfectly. This can be achieved by placing an insulating strips in the strips of the core material. Without effecting magnetic field, these insulating strips results in reducing the eddy current.

Hysteresis Loss

Hysteresis Loss also occurs due to magnetic field passing through the core material. When magnetic field passes through the core, the core becomes real magnet with separate north and South Pole. As the magnetic field changes its direction it also allows to magnetize the core material in another direction. Energy loss happens when core is magnetized in one direction and resists the core to magnetize in another direction. Surplus energy is required to magnetize the core material in other direction. Only way to minimize the hysteresis loss is to use the core material that is made up of good magnetizing material such as iron, which can be re-magnetized easily than other materials.

6. Applications of Transformer:

After reading the whole article, you have got the clear idea what is the basic purpose of electrical transformer. It can be used in our homes, apartments, buildings and electrical appliances i.e. where electrical power is required according to our needs and requirements. Following are the some applications of transformer:

• It can be used to alternate the amount of voltage and current. When current increases, voltage decrease and when voltage increases, then current decreases i.e. P = V * I
• Value of reluctance, capacitance and resistance can be controlled by the help of transformer.
• It finds many applications when it prohibits the flow of DC current from one circuit to another.
• Transformer is also used as an impedance device where same amount of voltage is required to the output as implied to the input. Hence, it also allows the two circuit be electrically isolated.

So, that was all about Transformers. I hope you have all enjoyed it. If you have any problem then ask in comments. Will meet you guys in the next tutorial. Till then take care and have fun !!! :)                          

Stepper Motor Projects

Hello everyone! I hope you all will be absolutely fine and having fun. Today, I am going to share a list of Stepper Motor Projects using different software e.g. Arduino, Matlab and NI LabVIEW. I have already shared these projects but they are posted randomly. So, today I thought that I should combine all those projects into a single one. So I am going to share the links of all of those tutorials in this tutorial so that it may be helpful for engineering students or anyone who wants to visit. This tutorial will help you to visit all of my Stepper Motor Projects. You should also have a look at this Stepper Motor Simulation in Proteus. The links of all the tutorials will be given and you will be able to download the desired project code or simulation from the corresponding link. I will make separate sections for each software to control stepper motor. In each section all the possible controls of stepper motor will be given in detail. If you have any sort of problem, you can ask in comments. I will try my level best to solve your issues. So, let's get started with Stepper Motor Projects. first of all, I will post projects i which I have done direction control of stepper motor:

Stepper Motor Projects

In this section of Stepper Motor Projects, I will provide you the list of the tutorials in which I have already controlled the direction of the stepper motor using three different software e.g. Arduino, Matlab and NI LabVIEW. I have used the same hardware and Arduino source code in all of these tutorials. In case of Matlab and NI LabVIEW I have sent commands through the serial monitor towards Arduino and hence the whole system works.

Stepper Motor Direction Control using Arduino

In the tutorial Stepper Motor Direction Control using Arduino, I have interfaced a stepper motor with Arduino UNO board to control its clockwise and counter clockwise direction. I have used a motor controller named as H-Bdridge to control the direction of stepper motor. It can control only one stepper motor at a time.. The algorithm was very simple. Commands for clockwise and counter clockwise rotation are sent through the serial monitor of Arduino softwrare. These commands are then passed to the motor controller and then it decides the direction of rotation of stepper motor after manipulating the Arduino commands. Direction of stepper motor can be reversed by simply changing the polarity so L298 controls the direction of the stepper motor by continuously making its pins low, high and vice versa.

• You can download the complete simulation there.
• Download .rar file, extract it and enjoy the complete simulation:

Stepper Motor Direction Control Using Arduino

Stepper Motor Direction Control using Matlab

In the tutorial Stepper Motor Direction Control in Matlab, I have created a simple Graphical User interface (GUI) in Matlab having three different buttons for controlling the clockwise, counter clockwise direction of the stepper motor and to stop the stepper motor as well. Two more buttons are also there on the GUI for opening and closing the serial port. As we press any of the buttons, corresponding command is sent through the serial port from Matlab to Arduino and then Arduino transfers those commands to the H Bridge and hence the entire process gets completed. Pressing the Open Serial Port button, serial port will be opened and we will be able to communicate with the Arduino using serial communication and at the end we must close the serial port in order to avoid the exchange of unnecessary commands being sent through the serial port.

• You can download the complete simulation here.
• Download .rar file, extract it and start playing with the simulation.

Stepper Motor Direction Control Using MATLAB

Stepper Motor Direction Control using NI LabVIEW

In the tutorial Stepper Motor Direction is Controlled in NI LabVIEW, I have controlled the clockwise and counter clockwise direction of the stepper motor using serial communication between NI LabVIEW and Arduino. Commands like C, S and A are sent through NI LabVIEW towards Arduino for clockwise rotation of the stepper motor, stop the stepper motor and anti clockwise rotation of the same stepper motor respectively. There are three different buttons on the front panel of NI LabVIEW. These buttons are used to send commands C, S and A from NI LabVIEW to Arduino using Serial communication.

• You can download the complete simulation here.
• Download .rar file, extract it and start playing with the simulation.

Stepper Motor Direction Control in LabVIEW

Stepper Motor Direction Control using PIC Microcontroller

First of all I have made Stepper Motor Drive Circuit in Proteus ISIS and I have controlled the speed angle as well as the direction of the stepper motor using PIC micro controller. I have made a pretty simple logic. I have placed a serial terminal in my Proteus simulation. You have to sent the commands through that serial terminal. The stepper motor will change its direction as well the speed after manipulating those commands.

• You can download the complete simulation here.
• Download .rar file, extract it and start playing with the simulation.

Stepper Motor Direction Control using PIC Microcontroller

Stepper Motor Speed Control

In this section of Stepper Motor Projects, I will provide you the list of the tutorials in which I have already controlled the speed of the stepper motor using three different software e.g. Arduino, Matlab and NI LabVIEW. I have used the same hardware and Arduino source code in all of these tutorials. In case of MATLAB and NI LabVIEW I have sent commands through the serial monitor towards Arduino and hence the whole system works.

Stepper Motor Speed Control using Arduino

In Stepper Motor Speed Control using Arduino, I have actually used the builtin command myStepper.step to control the speed for the stepper motor. For this purpose, I have not used PWM pins of L298 motor controller instead I only used input pins of it, to control the speed of the stepper motor. By assigning higher values to the myStepper.step motor can be rotated at higher speed. Similarly motor will rotate slowly if the value of myStepper.step is lower. All the executed commands are printed on the serial monitor and I have also printed those executed commands on LCD as well for this project.

• You can download the complete Arduino Source code here.
• Download .rar file, extract it and start playing with the simulation.

Stepper Motor Speed Control using Arduino

Stepper Motor Speed Control in Matlab

In Stepper Motor Speed Control in Matlab, I have created a  Graphical User Interface (GUI) in Matlab having two extra buttons as compared to the GUI of Stepper Motor Direction Control in Matlab. One for continuously accelerating the speed of the stepper motor and the other for continuously deaccelerating the speed of the same stepper motor. As we press any button, corresponding command will be sent through the serial port from Matlab to Arduino using serial communication. The logic created is pretty simple, the speed of the motor will accelerate continuously as many time we press the button and if the maximum speed is reached, motor maintains the same speed even we continue to enhance its speed. Same procedure will be followed to reduce the speed of the stepper motor.

• You can download the complete simulation here.
• Download .rar file, extract it and start playing with the simulation.

Stepper Motor Speed Control using MATLAB

Stepper Motor Speed Control using NI LabVIEW

This one is the last one among Stepper Motor Projects, named as Stepper Motor Speed Control in NI LabVIEW, I have have placed five different buttons on the front panel to control the direction as well as the speed of the DC motor. By pressing the Accelerate button again and again speed of the stepper motor will increase in proportion to the number of times the buttons is pressed. Similarly, by pressing Deaccelerate button again and again the speed of the stepper motor will decrease in proportion to the number of times the button is pressed. First of all you need to press the Start button in order to start the serial communication between NI LabVIEW and Arduino. After pressing it you will be able to send the commands serially from NI LabVIEW towards Arduino.

• You can download the complete simulation here.
• Download .rar file, extract it and start playing with the simulation.

Stepper Motor Speed Control using LabVIEW These are all Stepper Motor Projects posted yet on our blog. I hope you all enjoyed this tutorial. If you face any sort of problem you can ask me anytime without even feeling any kind of hesitation. I will try my level best to solve your issue in a better way, if possible. I will explore Arduino, Matlab and NI LabVIEW further in my later tutorials. Till then, Take care :)

DC Motor Projects

Hello everyone! I hope you all will be absolutely fine and having fun. Today, I am going to share a list of tutorials on DC Motor Projects using different software e.g. Arduino, Matlab and NI LabVIEW. I have already shared these tutorials but they are posted randomly. So, today I thought that I should combine all those tutorials into a single one. So I am going to share the links of all of those tutorials in this tutorial so that it may be helpful for engineering students or anyone who wants to visit. This tutorial will help you to visit all of my tutorials related to DC motor control. The links of all the tutorials will be given and you will be able to download the desired tutorial from the corresponding link. I will make separate sections for each software to control DC motor. In each section all the possible controls of DC motor will be given in detail. If you have any sort of problem, you can ask in comments. I will try my level best to solve your issues. In today's tutorial, I have simply combined all the DC Motor Projects posted on our blog. I will update this list in future. So, let's get started with DC Motor Projects:

DC Motor Direction Control - DC Motor Projects

In this section of DC Motor Projects, I will provide you the list of the tutorials in which I have already controlled the direction of the DC motor using three different software e.g. Arduino, Matlab and NI LabVIEW. I have used the same hardware and Arduino source code in all of these tutorials. In case of Matlab and NI LabVIEW I have sent commands through the serial monitor towards Arduino and hence the whole system works. So, let's get started with these DC Motor Projects:

1- DC Motor Direction Control using Arduino

In the tutorial DC Motor Direction Control using Arduino, I have interfaced a DC motor with Arduino UNO board to control its clockwise and counter clockwise direction. I have used a motor controller named as H-Bridge to control the direction of DC motor. It can simultaneously control two DC motors. The algorithm was very simple. Commands for clockwise and counter clockwise rotation are sent through the serial monitor of Arduino software. Its one of the basic DC Motor Projects. These commands are then passed to the motor controller and then it decides the direction of rotation of DC motor after manipulating the Arduino commands. Direction of DC motor can be reversed by simply changing the polarity so L298 controls the direction of the DC motor by continuously making its pins low, high and vice versa.

• I have posted a detailed tutorial on DC Motor Direction Control using Arduino.
• You can read that tutorial and download the complete simulation & code by clicking the below button:

Download DC Motor Direction Control Arduino Source Code

2- DC Motor Direction Control using Matlab

In this DC Motor Project, I have done the DC Motor Direction Control in Matlab, I have created a simple Graphical User interface (GUI) in Matlab having three different buttons for controlling the clockwise, counter clockwise direction of the Dc motor and to stop the DC motor as well. Two more buttons are also there on the GUI for opening and closing the serial port. As we press any of the buttons, corresponding command is sent through the serial port from Matlab to Arduino and then Arduino transfers those commands to the H Bridge and hence the entire process gets completed. Pressing the Open Serial Port button, serial port will be opened and we will be able to communicate with the Arduino using serial communication and at the end we must close the serial port in order to avoid the exchange of unnecessary commands being sent through the serial port.

• You can download the complete simulation here.
• Download .rar file, extract it and start playing with the simulation. I hope you have enjoyed this DC Motor Project.

Download DC Motor Direction Control Matlab Simulation

3- DC Motor Direction Control using NI LabVIEW

In the tutorial DC Motor Direction Control in NI LabVIEW, I have controlled the clockwise and counter clockwise direction of the DC motor using serial communication between NI LabVIEW and Arduino. Commands like C, S and A are sent through NI LabVIEW towards Arduino for clockwise rotation of the DC motor, stop the DC motor and anti clockwise rotation of the same DC motor respectively. There are three different buttons on the front panel of NI LabVIEW. These buttons are used to send commands C, S and A from NI LabVIEW to Arduino using Serial communication.

• You can download the complete simulation here.
• Download .rar file, extract it and start playing with the simulation.

Download DC Motor Direction Control LabVIEW Simulation

4- DC Motor Direction Control with Arduino in Proteus

In the tutorial, DC Motor Direction Control with Arduino in Proteus, I have designed a complete simulation in Proteus, which will help you in understanding the controlling of DC motor. I have designed DC Motor Drive Circuit in Proteus ISIS. for the DC Motor Direction Control. I have provided the complete simulation and the source code for DC Motor Direction Control in Proteus but I would recommend you to design it on your own, it would be better for you. So, when you send the character C on serial terminal then the motor will rotate in clockwise direction and when the character sent through the serial terminal is A, the motor will rotate in counter clockwise direction and will stop when the character S is sent.

• You can download the complete simulation here.
• Download .rar file, extract it and start playing with the simulation.

Download DC Motor Direction Control Proteus Simulation

DC Motor Speed Control - DC Motor Projects

In this section of DC Motor Projects, I will provide you the list of the tutorials in which I have already controlled the speed of the DC motor using three different software e.g. Arduino, Matlab and NI LabVIEW. I have used the same hardware and Arduino source code in all of these tutorials. In case of Matlab and NI LabVIEW I have sent commands through the serial monitor towards Arduino and hence the whole system works. So, let's get started with these DC Motor Projects:

1- DC Motor Speed Control using Arduino

In DC Motor Speed Control using Arduino, I have actually used the concept of Pulse Width Modulation (PWM). For this purpose, I have used PWM pins EnA and EnB of L298 motor control to control the speed of the DC motor. PWM basically control the electronic pulse duration. When the state of the PWM pins of L298 motor controller is high, the output power will be supplied. I have controlled the speed of the DC motor by turning applied voltage on and off. Duty cycle is the main factor while controlling the speed of the DC motor. When the duty cycle is long i.e signal is power is supplied for a long time, Dc motor will rotate at fast speed and vice versa. Usually the PWM duty cycle is less than 90%. I have also printed the executed commands on LCD for this project.

• You can download the complete simulation here.
• Download .rar file, extract it and start playing with the simulation.

Download DC Motor Speed Control Arduino Source Code

Note:

• You should also have a look at Arduino Library for Proteus, if you wanna use it in Proteus software.
• Here's another LCD Library for Proteus, which will give a stylish look to your simulation.

2- DC Motor Speed Control in Matlab

In DC Motor Speed Control in Matlab, I have also created a GUI in Matlab having two extra buttons as compared to the GUI of DCMotor Direction Control in Matlab. One for continuously accelerating the speed of the DC motor and the other for continuously deaccelerating the speed of the same motor. As we press any button, corresponding command will be sent through the serial port from Matlab to Arduino using serial communication. The logic created is pretty simple, the speed of the motor will accelerate continuously as many time we press the button and if the maximum speed is reached, motor maintains the same speed even we continue to enhance its speed. Same procedure will be followed to reduce the speed of the DC motor.

• You can download the complete simulation here.
• Download .rar file, extract it and start playing with the simulation.

Download DC Motor Speed Control Matlab Simulation

3- DC Motor Speed Control using NI LabVIEW

In DC Motor Speed Control in NI LabVIEW, I have have placed five different buttons on the front panel to control the direction as well as the speed of the DC motor. By pressing the Accelerate button again and again speed of the DC motor will increase in proportion to the number of times the buttons is pressed. Similarly, by pressing Deaccelerate button again and again the speed of the DC motor will decrease in proportion to the number of times the button is pressed. First of all you need to press the Start button in order to start the serial communication between NI LabVIEW and Arduino. After pressing it you will be able to send the commands serially from NI LabVIEW towards Arduino.

• You can download the complete simulation here.
• Download .rar file, extract it and start playing with the simulation.

Download DC Motor Speed Control LabVIEW Simulation

4- DC Motor Speed Control with Arduino in Proteus

In the tutorial DC Motor Speed Control using Arduino in Proteus, I have controlled both the direction as well as the speed of the DC motor. For the direction control of DC motor the functionality remains the same as it was in DC Motor Direction Control with Arduino in Proteus but for the speed control, I have placed an Light Dependent Resistor (LDR) sensor in the simulation and depending on the value of the LDR sensor the speed DC motor will either increase or decrease.

• You can download the complete simulation here.
• Download .rar file, extract it and start playing with the simulation.

Download DC Motor Speed Control Proteus Simultation

This is all from the tutorial DC Motor Projects. I hope you all enjoyed this tutorial. If you face any sort of problem you can ask me anytime without even feeling any kind of hesitation. I will try my level best to solve your issue in a better way, if possible. I will explore Arduino, Matlab and NI LabVIEW further in my later tutorials. Till then, Take care :)

Introduction to Multilevel Inverters

Hello friends, today's tutorial is about Introduction to multilevel inverters, which is quite a wide field so I am not gonna discuss everything here. I will post more about it in my coming tutorials. Today, I am going to through some light on the multilevel inverter, i.e. how they operate and will also discuss their types in detail. So, let's start it.

An inverter, also named a power inverter, is an electrical power device that is used to convert direct current (DC) into alternating current (AC). Using a few control circuits and switches, one can get AC at any required voltage and frequency. Inverter plays exactly the opposite role of rectifiers as rectifiers are used for converting alternating current (AC) into direct current (DC). There are different types of inverters available these days. You should also have a look at Pure Sine wave Inverter Design with code and Modified Sine Wave Inverter Design with code. I think you are gonna like that one. Few most commonly used inverter types are:

• Square wave inverters
• Modified sine wave inverters
• Multilevel inverters
• Pure sine wave inverters
• Resonant inverters
• Grid-tie inverters
• Synchronous inverters
• Stand-alone inverters
• Solar inverters

We have designed a 3 level Diode Clamped Multilevel Inverter in Simulink MATLAB, which you can buy by clicking on the lower button. As it's mostly used by the engineering students that's why we have placed a very small price of $10 so that they can buy it easily and we also get rewarded for our efforts. Buy MATLAB Simulink Simulation

Introduction to Multilevel Inverter

• A multilevel inverter is a power electronic device that is capable of providing desired alternating voltage level at the output using multiple lower-level DC voltages as an input.
• Mostly a two-level inverter is used in order to generate the AC voltage from DC voltage.

Now the question arises what’s the need of using a multilevel inverter when we have a two-level inverter. In order to answer this question, first, we need to look at the concept of the multilevel inverter.

Concept of Multilevel Inverter

First, take the case of a two-level inverter. A two-level Inverter creates two different voltages for the load i.e. suppose we are providing Vdc as an input to a two-level inverter then it will provide + Vdc/2 and – Vdc/2 on output. In order to build an AC voltage, these two newly generated voltages are usually switched. For switching mostly PWM is used as shown in Figure 2.1, reference wave is shown in the dashed blue line. Although this method of creating AC is effective but it has few drawbacks as it creates harmonic distortions in the output voltage and also has a high dv/dt as compared to that of a multilevel inverter. Normally this method works but in few applications, it creates problems particularly those where low distortion in the output voltage is required.

PWM voltage output of a two-level inverter

The concept of multilevel Inverter (MLI) is a kind of modification of a two-level inverter. In multilevel inverters we don’t deal with the two-level voltage instead in order to create a smoother stepped output waveform, more than two voltage levels are combined together and the output waveform obtained in this case has lower dv/dt and also lower harmonic distortions. The smoothness of the waveform is proportional to the voltage levels, as we increase the voltage level the waveform becomes smoother but the complexity of the controller circuit and components also increases along with the increased levels. The waveform for the three, five and seven level inverters are shown in the below figure, where we clearly see that as the levels are increasing, the waveform becoming smoother.

A three-level waveform, a _ve-level waveform and a seven-level multilevel waveform, switched at fundamental frequency

Multilevel Inverter Topologies

There are several topologies of multilevel inverters available. The difference lies in the mechanism of switching and the source of input voltage to the multilevel inverters. Three most commonly used multilevel inverter topologies are:

• Cascaded H-bridge multilevel inverters.
• Diode Clamped multilevel inverters.
• Flying Capacitor multilevel inverters.

1. Cascaded H-bridge Multilevel Inverters

This inverter uses several H-bridge inverters connected in series to provide a sinusoidal output voltage. Each cell contains one H-bridge and the output voltage generated by this multilevel inverter is actually the sum of all the voltages generated by each cell i.e. if there are k cells in an H-bridge multilevel inverter then a number of output voltage levels will be 2k+1. This type of inverter has an advantage over the other two as it requires fewer components as compared to the other two types of inverters and so its overall weight and price are also less. Below Figure shows a k level cascaded H-bridge inverter.

One phase of a cascaded H-bridge multilevel inverter

In a single-phase inverter, each phase is connected to a single dc source. Each level generates three voltages which are positive, negative and zero. This can be obtained by connecting the AC source with the DC output and then using different combinations of the four switches. The inverter will remain ON when two switches with opposite positions will remain ON. It will turn OFF when all the inverters switch ON or OFF. To minimize the total harmonic distortion, switching angles are defined and implemented. The calculations for the measurement of switching angle will remain the same. This inventor can be categorized further into the following types:

• 5 levels cascaded H Bridge Multilevel Inverter
• 9 levels cascaded H Bridge Multilevel Inverter

In 5 level cascaded H Bridge Multilevel Inverters, Two H Bridge Inverters are cascaded. It has 5 levels of output and uses 8 switching devices to control whereas in 9 level cascaded H Bridge Multilevel Inverters, Four H Bridge Invertors are cascaded. It has 9 output levels and use and use 16 switching devices.

Applications of Cascaded H-bridge Multilevel Inverters

Cascaded H Bridge Multilevel Inverters are mostly used for static var applications i.e., in renewable resources’ of energy and battery based applications. Cascaded H Bridge Multilevel Inverters can be applied as a delta or wye form. This can be understood by looking at the work done by Peng where he used an electrical system parallel with a Cascade H Bridge. Here inverter is being controlled by regulating the power factor. Best application is when we used as photovoltaic cell or fuel cell. This is the example of Parallel connectivity of the H Bridge Multilevel Inverter.

Example of 3 phase Wye Connection

 H Bridge can also be used in car batteries to run the electrical components of the car. Also, this can be used in the electrical braking systems of the vehicles.

Scientists and engineers have also proposed the multiplicative factor on Cascade H Bridge Multilevel. It means that rather than using a dc voltage with the difference in levels, it uses a multiplying factor between different levels of the multilevel i.e., every level is a multiplying factor of the previous one.

Advantages of Cascade H Bridge Multilevel Inverters

1. Output voltages levels are doubled the number of sources
2. Manufacturing can be done easily and quickly
3. Packaging and Layout are modularized.
4. Easily controllable with a transformer as shown in the Fig 2.5
5. Cheap

 Cascaded Inverter with transformer

Disadvantages of Cascade H Bridge Multilevel Inverters

• Every H Bridge needs a separate dc source.
• Limited applications due to a large number of sources.

2. Diode Clamped Multilevel Inverters

Diode clamped multilevel inverters use clamping diodes in order to limit the voltage stress of power devices. It was first proposed in 1981 by Nabae, Takashi and Akagi and it is also known as a neutral point converter. A k level diode clamped inverter needs (2k – 2) switching devices, (k – 1) input voltage source and (k – 1) (k – 2) diodes in order to operate. Vdc is the voltage present across each diode and the switch. Single-phase diode clamped multilevel inverter is shown in the figure below:

One phase of a diode clamped inverter

The concept of diode clamped inverter can better be understood by looking into a three-phase six-level diode clamped inverter. Here the common dc bus is shared by all the phases, use five capacitors and six levels. Each capacitor has a voltage of Vdc and same is the voltage limit of switching devices. One important fact should be noted while considering the diode clamped inverter is that five switches will remain ON at any time. Six level, three-phase dc clamped multilevel inverter is shown in the figure below.

Six level three phase inverter

Outputs of each phase can be understood by the following table. Here reference voltage is the negative Vo. Condition 0 means switch is OFF and vice versa. Output waveforms of six level dc clamped inverter is shown below:

Waveform of Six Level Inverter

 Vab is the voltage due to the phase lag b and a voltage.

Applications of Diode Clamped Multilevel Inverters

The most common application of diode clamped multilevel inverter is when a high voltage Dc and Ac transmission lines are interfaced. This can also be used in variable speed control of high power drives. Static variable compensation is also an application of diode clamped multilevel inverters.

Advantages of Diode Clamped Multilevel Inverters

• The capacitance of the capacitors used is low.
• Back-to-back inverters can be used.
• Capacitors are precharged.
• At fundamental frequency, efficiency is high.

Disadvantages of Diode Clamped Multilevel Inverters

• Clamping diodes are increased with the increase of each level.
• The DC level will discharge when control and monitoring are not precise.

3. Flying Capacitor Multilevel Inverters

The configuration of this inverter topology is quite similar to previous one except the difference that here flying capacitors is used in order to limit the voltage instead of diodes. The input DC voltages are divided by the capacitors here. The voltage over each capacitor and each switch is Vdc. A k level flying capacitor inverter with (2k – 2) switches will use (k – 1) number of capacitors in order to operate. The figure below shows a five-level flying capacitor multilevel inverter.

A Flying Capacitor Multilevel Inverter with five voltage levels

If we compare above figures, it shows that the number of switches, main diodes and DC-bus capacitors are same in both the cases. The only difference between the two topologies is that the previous one uses clamping diodes in order to limit the voltage while this topology uses flying capacitors for this purpose, and as capacitors are incapable of blocking the reverse voltage, which diodes do, the number of switches also increases. Voltage on each capacitor is differing from the next as it has a ladder structure. Voltage difference between two back to back capacitors determines the voltage in the output frame.

Advantages of Flying Capacitor Multilevel Inverters

Static var generation is the best application of Capacitor Clamped Multilevel Inverters.

• For balancing capacitors’ voltage levels, phase redundancies are available.
• We can control reactive and real power flow.

Disadvantages of Flying Capacitor Multilevel Inverters

• Voltage control is difficult for all capacitors.
• Complex startup.
• Switching efficiency is poor.
• Capacitors are expensive than diodes.

So, that was all about Multilevel Inverters and their topologies. I hope you guys have understood this concept in detail. Please let me know if you have any questions. Till next tutorial, take care and have fun !!! :)

Pure Sine Wave Inverter Design With Code

Hello guys, in the last post I have explained the Basics of Inverters along with its types and also the inverters topology in other words working of inverters, then we discussed the Major Components of Inverters. Now in this post I am gonna explain the pure sine wave inverter and how to create it. I have used AVR microcontroller int his project. The reason I am using random microcontrollers is that so you guys get a taste of each one. Before starting on sine wave inverter read this article again and again as I have also mentioned the problem i got while making it. You should also read the Modified Sine Wave Design with Code.

I have divided this tutorial into four parts which are shown below. This is a step by step guide to design and build an inverter and I hope at the end of this tutorial you guys will be able to design your own inverter. I tried my best to keep it simple but still if you guys got stuck at any point ask in comments and I will remove your query. This project is designed by our team and they put real effort in getting this done so that's why we have placed a small fee on its complete description. You can buy the detailed description of this project along with the complete code and circuit diagram, by clicking on the below button:

Buy This Project Note:

• I have also posted a Pure SineWave Inverter Simulation in Proteus, which will be quite helpful if you are designing a pure sine wave inverter.

Pure Sine-Wave Inverter

• Pure Sine wave inverter consist of a microcontroller unit which generates a switching signal of 15 KHz, an H-bridge circuit to convert the signal into AC, a low pass LC filter circuit to block the high frequency components and the transformer unit to step-up the voltages.
• Block diagram of sine wave circuit is given below:

FIGURE 1 : Block diagram of pure sine wave inverter

AVR Micro-Controller Unit

• Microcontroller unit is a multi-purpose control unit which can handle multiple tasks simultaneously.
• We have used it just to generate a switching signal of 15 KHz.
• I am using AVR micro-controller unit for this pure sine wave inverter.

Explanation for PWM in AVR

• AVR is acting as the brain of Pure Sine Wave Inverter.
• Below is the program for atmega16 microcontroller with a clock frequency of 8 MHz (Fcpu = 8MHz). We have worked on a compiler named AVR GCC.
• Initially we included AVR libraries,then we initialized sine table in which the values of a complete sine wave are stored (we generated a sin table in range 0-359 degrees whereas, zero of sine wave is set at decimal 128(0x80 in Hex).

• Then in the next chunk of the code, we used timer0 (8-bit) which starts from 0 and peaks to 255 (it gives a saw tooth output).
• The constant float step = (2*180)/256 = 1.40625 For i=0; s = sin (0*1.40625) = 0 For i = 255 s = sin (255*1.40625) = 358.5937 = 359deg approx.
• This is how the sine wave is generated from 0-359deg.
• When timer reaches 255 then interrupt over flow is generated (Refer the sine wave code, at the end).
• The next part of the code shows that we have used the clock select bits as pre-scalar.
• TIMSK| = (1<<TOIE0) means we are enabling timer overflow interrupt enable 0.
• The last part of the code is the most important part of pure sine wave generator.
• OCR0 is output compare register for timer 0 and it continuously compares timer0 values i.e. 0, 1, 2.......255, and for each value of timer the value from sine wave table is computed then sample++increases the pointer of sine wave table to the next i.e. the value at the second index of sine table and that is computed for the output until samples equals to 255.
• Then we used the command sample = 0 the cycle is repeated again and again.
• Here's the programming code for Pure Sine Wave Inverter:

    #include <stdlib.h>

    #include <avr/io.h>

    #include <util/delay.h>

    #include <avr/interrupt.h>

    #include <avr/sleep.h>

    #include <math.h>

    #include <stdio.h>

    0x80, 0x83, 0x86, 0x89, 0x8C, 0x90, 0x93, 0x96,

    0x99, 0x9C, 0x9F, 0xA2, 0xA5, 0xA8, 0xAB, 0xAE,

    0xB1, 0xB3, 0xB6, 0xB9, 0xBC, 0xBF, 0xC1, 0xC4,

    0xC7, 0xC9, 0xCC, 0xCE, 0xD1, 0xD3, 0xD5, 0xD8,

    0xDA, 0xDC, 0xDE, 0xE0, 0xE2, 0xE4, 0xE6, 0xE8,

    0xEA, 0xEB, 0xED, 0xEF, 0xF0, 0xF1, 0xF3, 0xF4,

    0xF5, 0xF6, 0xF8, 0xF9, 0xFA, 0xFA, 0xFB, 0xFC,

    0xFD, 0xFD, 0xFE, 0xFE, 0xFE, 0xFF, 0xFF, 0xFF,

    0xFF, 0xFF, 0xFF, 0xFF, 0xFE, 0xFE, 0xFE, 0xFD,

    0xFD, 0xFC, 0xFB, 0xFA, 0xFA, 0xF9, 0xF8, 0xF6,

    0xF5, 0xF4, 0xF3, 0xF1, 0xF0, 0xEF, 0xED, 0xEB,

    0xEA, 0xE8, 0xE6, 0xE4, 0xE2, 0xE0, 0xDE, 0xDC,

    0xDA, 0xD8, 0xD5, 0xD3, 0xD1, 0xCE, 0xCC, 0xC9,

    0xC7, 0xC4, 0xC1, 0xBF, 0xBC, 0xB9, 0xB6, 0xB3,

    0xB1, 0xAE, 0xAB, 0xA8, 0xA5, 0xA2, 0x9F, 0x9C,

    0x99, 0x96, 0x93, 0x90, 0x8C, 0x89, 0x86, 0x83,

    0x80, 0x7D, 0x7A, 0x77, 0x74, 0x70, 0x6D, 0x6A,

    0x67, 0x64, 0x61, 0x5E, 0x5B, 0x58, 0x55, 0x52,

    0x4F, 0x4D, 0x4A, 0x47, 0x44, 0x41, 0x3F, 0x3C,

    0x39, 0x37, 0x34, 0x32, 0x2F, 0x2D, 0x2B, 0x28,

    0x26, 0x24, 0x22, 0x20, 0x1E, 0x1C, 0x1A, 0x18,

    0x16, 0x15, 0x13, 0x11, 0x10, 0x0F, 0x0D, 0x0C,

    0x0B, 0x0A, 0x08, 0x07, 0x06, 0x06, 0x05, 0x04,

    0x03, 0x03, 0x02, 0x02, 0x02, 0x01, 0x01, 0x01,

    0x01, 0x01, 0x01, 0x01, 0x02, 0x02, 0x02, 0x03,

    0x03, 0x04, 0x05, 0x06, 0x06, 0x07, 0x08, 0x0A,

    0x0B, 0x0C, 0x0D, 0x0F, 0x10, 0x11, 0x13, 0x15,

    0x16, 0x18, 0x1A, 0x1C, 0x1E, 0x20, 0x22, 0x24,

    0x26, 0x28, 0x2B, 0x2D, 0x2F, 0x32, 0x34, 0x37,

    0x39, 0x3C, 0x3F, 0x41, 0x44, 0x47, 0x4A, 0x4D,

    0x4F, 0x52, 0x55, 0x58, 0x5B, 0x5E, 0x61, 0x64,

    0x67, 0x6A, 0x6D, 0x70, 0x74, 0x77, 0x7A, 0x7D

    void InitSinTable()

    {

    Page | 42

    //sin period is 2*Pi

    const float step = (2*M_PI)/(float)256;

    float s;

    float zero = 128.0;

    //in radians

    for(int i=0;i<256;i++)

    {

    s = sin( i * step );

    //calculate OCR value (in range 0-255, timer0 is 8 bit)

    wave[i] = (uint8_t) round(zero + (s*127.0));

    }

    }

    void InitPWM()

    {

    /*

    TCCR0 - Timer Counter Control Register (TIMER0)

    -----------------------------------------------

    BITS DESCRIPTION

    NO: NAME DESCRIPTION

    --------------------------

    BIT 7 : FOC0 Force Output Compare

    BIT 6: WGM00 Wave form generartion mode [SET to 1]

    BIT 5: COM01 Compare Output Mode [SET to 1]

    BIT 4: COM00 Compare Output Mode [SET to 0]

    BIT 3: WGM01 Wave form generation mode [SET to 1]

    BIT 2: CS02 Clock Select [SET to 0]

    BIT 1: CS01 Clock Select [SET to 0]

    BIT 0: CS00 Clock Select [SET to 1]

    Timer Clock = CPU Clock (No Pre-scaling)

    Mode = Fast PWM

    PWM Output = Non Inverted

    */

    TCCR0|=(1<<WGM00)|(1<<WGM01)|(1<<COM01)|(1<<CS00);

    TIMSK|=(1<<TOIE0);

    //Set OC0 PIN as output. It is PB3 on ATmega16 ATmega32

    DDRB|=(1<<PB3);

    }

    ISR(TIMER0_OVF_vect)

    {

    OCR0 = wave[sample];

    sample++;

    if( sample >= 255 )

    sample = 0;

    }

 

H-Bridge Circuit

• H-Bridge Circuit is acting as the main core of Pure sine Wave Inverter.
• H-bridge circuit is basically enables a voltage to be applied across a load in either direction.
• In inverters, it is used to amplify the input square wave coming from the micro-controller.
• We are giving modulated square wave at the input of the H-bridge because if we give sine wave to the MOSFET or any other switching device like the BJT or IGBT, very high switching losses occur. This is because when we give sinusoidal waveform to any of these devices, they start operating in the linear region, and power loss occurs in devices operating in linear region.
• When we give a square waveform to them, they operate on either saturation or cut-off regions thus having minimum power loss.
• We used IRF5305 and IRFP150 MOSFETs. These are high power MOSFETs with maximum current rating of 31 Amp and 42 Amp respectively.
• IFR5305 is a Pchannel MOSFET whereas IRFP150 is an N-channel MOSFET.
• The circuit configuration of H-bridge is given below:

FIGURE 2 : H-Bridge Circuit

Working

• Working of an H-bridge for pure sine wave inverter can be divided into two modes.
• In Mode1, the input signal at the gate of M1 is high and at the gate of M4 it is low.This causes conduction from M1-M4 and we achieve a +12V signal at the output.
• In Mode2, the input signal at the gate of M3 is high and at the gate of M2 it is low.This causes conduction from M3-M2 and we achieve a -12V signal at the output.
• And thus we obtain a 24Vpeak-peak signal at the output.
• The working of H-Bridge in both conduction modes can be easily understood by the following figure:

FIGURE 3 : H-Bridge Conduction Modes (A) FIGURE 3 : H-Bridge Conduction Modes (B)  

• Due to the conduction of half part of the bridge at +ve half cycle and the other half part of the bridge at –ve half cycle, we obtain a square waveform of 24 Vpeak-peak at the output.
• In figure below is the Proteus simulation showing the waveform output of bridge circuit during each conduction cycle.

FIGURE 4 : Wave-forms of H-bridge conduction cycle

Observations

• In the H-bridge circuit we have observed that input signal"s frequency does not change at the output that means the frequency remains un-altered.
• Only the power of the signal increase in terms of current.

Problems

• Initially we used all the MOSFETs of same type (i-e. n-channel MOSFETs). This caused the shorting of the MOSFETs during the conduction mode. This phenomenon is known as shooting over of the MOSFET.
• Despite the duration of this shooting over was quite small, it caused loading on the MOSFETs.
• The MOSFETs started heating up due to this, and eventually they burned out.
• Another problem occurred while using the MOSFETs of same channel was that the upper MOSFETs (M1 and M3) did not turn on properly.
• After studying, we learned that they required 18V to turn on thus; we needed a MOSFET driver that was IR2110.
• We worked on it but it did not working properly too, because according to the formula for bootstrap capacitor given in datasheet, the driver must have given 18V output but it was not working so we had to search for an alternate.
• Then after extended study we came to know that replacing the upper two n channel MOSFETs with p channel MOSFET is the solution. We applied this technique and it worked.
• Using this technique also solved the problem of MOSFET shooting over by inducing a dead time/delay in the MOSFET switching.

LC Filter

• We have determined inductance of the inductor using LC resonant band stop filter as LC meters were not available in the lab.

FIGURE 5 : LC filter

Working

• Understanding the working of H-Bridge is very essential, if you want to work on Pure sine Wave Inverter.
• The method to determine L or C is simple. Suppose we are required to determine the inductance, then by above circuit,

• V1 signal from function generator is set to 1Vrms using multi-meter.
• At resonance frequency the LC combination will have very low impedance so it will short out the signal and will drop across resistor R1 and prevents the signal to reach the load.
• Using this principle we have varied signal frequency from function generator and we are detecting output voltage at load using multi-meter.
• At resonance frequency multi-meter will show ideally zero volts.
• So by using formula we have :

Problems

• First we designed an RC circuit but we observed that the Resistance R in the circuit acts as a load and dissipates power.
• After studying, we decided to use an LC filter.
• The main problem with the LC filter was the designing of the inductor as the inductor of desired value was not available in the market, thus we had to make it by hand.
• LC meter was not available also thus we had to repeatedly calculate the inductance value mathematically.

Working of Pure Sine Wave Inverter

• Let's have a look at the working of Pure Sine Wave Inverter.
• A 50Hz sin wave is generated with the help of a lookup table within the AVR microcontroller and is modulated over a switching frequency signal of 15KHz.
• As this signal has very weak current, so it is amplified by a BC 547 transistor.
• The amplified signal is given at the gates of M1 and M2 MOSFETs.
• The output of the microcontroller is given to another BC 547 which is working as an inverting amplifier.
• By this, the signal from the microcontroller gets inverted as well as amplified.
• This signal is given at the gates of M3 and M4 MOSFETs.
• Now what happens is that, when the input signal at the gate of M1 of the H-bridge is high and at the gate of M4 of the H-bridge is low, conduction from M1-M4 occurs and we achieve a +12V signal.
• When the input signal at the gate of M3 goes high and at the gate of M2 goes low, conduction from M3-M2 occurs and we achieve a -12V signal.
• Thus at the output we receive a waveform of 12Vpeak or 24Vpeak-peak.
• The output of the H-bridge is then fed into a low pass LC filter which filters the high frequency components of 15 KHz and gives the 50 Hz sine output.
• This output is then fed into a transformer which steps up this 12 Volts AC waveform into 220Volts AC.

So, that's all for today. I hope you guys have enjoyed this Pure Sine Wave Inverter Project. You should also look at Proteus simulation of Pure sine wave and Introduction to Multilevel Inverters, because simulations help a lot in designing hardware projects. So, take care and have fun !!! :)