The document is a project report submitted by four students for their B.Tech degree in Electrical Engineering. It discusses the design of an Arduino-based power inverter using MATLAB. The objective is to design a low-cost inverter compared to commercially available options. The report includes chapters on the history of inverters, components used including Arduino, MOSFETs, transformers and batteries. It also discusses simulations of inverter circuits and the design of the Arduino-based inverter circuit.

1. ARDUINO BASED POWER INVERTER USING MATLAB
PROJECT REPORT
Submitted in partial fulfillment of the requirement for the degree
of B.Tech (Electrical Engineering)
By
Himanshu Sharma (13UEE009)
Rohit Kumar (13UEE013)
Amit Dhiman (13UEE036)
Mayank (14LEE002)
Under the Supervision of
Bhupender Singh
(Asstt. Proff. EE Department)
Baddi University
Of Emerging Sciences & Technology
NH-21A, Vill.Makhnumajra, Baddi, Distt.Solan
Himachal Pradesh-173205

2. ACKNOWLEDGEMENTS
We expressed my sincere gratitude to the Baddi University of Emerging Sciences & Technology,
Baddi for giving me the opportunity to work on the final project report during my final year of
B.tech. The project work is an important aspect in the field of engineering.
We would like to thank, Er. Geena Sharma Head, Department of Electrical Engineering for her
valuable advice and healthy criticism throughout our project which helped us immensely to
complete our work successfully.
We would thankful to Er. Bhupinder, our project supervisor for providing us each and every
facility to excel in our work and encouraging us to give the best.
We would also like to express our thanks to our respected other faculty members of the
department for their valuable comments. We are thankful to all staff of Electrical Engineering
Department for their kind support.
We wish thank my friends who worked a lot in the fields and gave the mending support directly
or indirectly during the complication of project work and making it a great success.
Date :- (Himanshu Sharma)
(Rohit Kumar)
(Amit Dhiman)
(Mayank)

3. DECLARATION
―We hereby declare that this submission is our own work and that, to the best of
our knowledge and belief, it contains no material previously published or written
by another person nor material which has been accepted for the award of any other
degree or diploma of the university or other institute of learning, except where due
acknowledgement has been made in the text.‖
Place: Baddi Signature
Date:
Name:
Himanshu Sharma 13UEE009
Rohit Kumar 13UEE013
Amit Dhiman 13UEE036
Mayank 14LEE002

4. Baddi University
of Emerging Sciences & Technology
NH-21, Vill. Makhnumajra, Baddi, Distt. Solan
Himachal Pradesh.173205
CERTIFICATE
This is to certify that the dissertation entitled ―Ardiuno Based Power Inverter
Using MATLAB‖ submitted to Baddi University, Himachal Pradesh by Himanshu
Sharma, Rohit Kumar, Amit Dhiman, Mayank, BUPIN: 13UEE009, 13UEE013,
13UEE036, 14LEE002 is a partial fulfillment of the requirement for the award of
the B.Tech. Degree in Electrical Engineering. The matter embodied is the actual
work by the students named above and this work has not been submitted earlier in
a part or full for the award of any other degree.
Project Guide
Er.Bhupender
(Asst. Professor, EE Deptt.)

5. OBJECTIVE
The primary objective of designing this Arduino based power
inverter is to design a low cost inverter as compared to the existing
expansive inverter available in the market. Arduino based power inverter
is flexible in operation i.e. frequency can be controlled and changed as
per requirement.

6. Table of Contents
ACKNOWLEDGEMENT I
CERTIFICATE II
DECLARATION III
OBJECTIVE IV
Chapter-1 Introduction
1.1 History 1
1.2 Inverter 1
1.3 Types of Inverter 2
1.3.1 Square Wave Inverter 2-3
1.3.1.1 Application of Square wave Inverter 3
1.3.2 Pure Sine Wave Inverter 3-4
1.3.2.1 Advantages of Pure Sine Wave Inverter 4
1.3.2.2 Application 5
1.3.3 Modified Sine Wave Inverter 5-6
Chapter-2 Introduction of Component Used
2.1 Arduino 7
2.1.1 Introduction 7
2.1.2 Arduino Mega 2560 8
2.1.2.1 Power 9
2.1.2.2 Communication 10
2.1.2.3 Automatic Software (Reset) 10
2.1.2.4 USB Over-Current Protection 10-11
2.1.2.5 Physical Characterstics and Shield Compatibility 11
2.2 Power MOSFET 11
2.2.1 Introduction 11
2.2.2 Types of MOSFET 12
2.2.3 IRF9630 (MOSFET Used) 13
2.3 Heat Sink 13-14
2.4 Opotocoupler 14
2.4.1 4n37 (Opotocoupler Used) 15
2.5 Resistance 15
2.5.1 Working of Resistor 16
2.6 Transformer 17-18
2.6.1 12-0-12/220V Transformer 18
2.7 Battery 18-19
2.7.1 Principle of Operation 19-20

7. Chapter-3 Simulation of Inverter Circuit
3.1 Center tapped inverter 21
3.2 Bridge inverter 22-23
Chapter-4 Designing of Arduino Based Inverter Circuit
4.1 Simulink Model 24
Datasheets of Component Used 26-31
Result 32
References 33

8. Chapter-1
Introduction
1.1 History
One of the most significant battles of the 19th century was fought not over land or
resources but to establish the type of electricity that powers our buildings.
At the very end of the 1800s, American electrical pioneer Thomas Edison (1847–1931)
went out of his way to demonstrate that direct current (DC) was a better way to supply electrical
power than alternating current (AC), a system backed by his Serbian-born arch-rival Nikola
Tesla (1856–1943). Edison tried all kinds of devious ways to convince people that AC was too
dangerous, from electrocuting an elephant to (rather cunningly) supporting the use of AC in the
electric chair for administering the death penalty. Even so, Tesla's system won the day and the
world has pretty much run on AC power ever since.
The only trouble is, though many of our appliances are designed to work with AC, small-
scale power generators often produce DC. That means if you want to run something like an AC-
powered gadget from a DC car battery in a mobile home, you need a device that will convert DC
to AC—an inverter, as it's called.
1.2 Inverter
An inverter is an electrical device that converts direct current (DC) to alternating current
(AC), the converted AC can be at any required voltage and frequency with the use of appropriate
transformers, switching, and control circuits. An inverter is essentially the opposite of a rectifier.
Static inverters have no moving parts and are used in a wide range of applications, from small
switching power supplies in computers, to large electric utility high-voltage direct current
applications that transport bulk power. Inverters are commonly used to supply AC power from
DC sources such as solar panels or batteries.
The electrical inverter is a high-power electronic oscillator. It is so named because early
mechanical AC to DC converters was made to work in reverse, and thus was "inverted", to
convert DC to AC.
Direct current (DC) is the unidirectional flow of electric charge. Direct current is
produced by such sources as batteries, thermocouples, solar cells, and commutator type electric
machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can
also be through semiconductors, insulators, or even through a vacuum as in electron or ion
beams. The electric charge flows in a constant direction, distinguishing it from alternating
current (AC). A term formerly used for direct current was galvanic current.

9. 1.3 Types Of Inverter
Most of the Home appliance alternating electrical power is observed. However AC
power is not always available and the need for mobility and simplicity has given in batteries
Thus, for portable AC power, for this purpose inverter is needed. Inverters take a DC voltage
from an input terminal of a battery or a solar panel as input. These inverters are classified by
depending on their output as three types
1. Square Wave Inverter
2. Modified Sine Wave Inverter
3. Pure Sine Wave Inverter
These 3 types of inverters less expensive and it is modified though delivering the same
average voltage to a load, it is not appropriate for delicate electronic devices on the precise
timing. Most of the pure sine wave inverter offer having good accuracy it is very high load
capacity, but they are more complex in design and more expensive.
Pure sine wave inverters will power devices with more accuracy less power loss, and less
heat generation. Pure sine wave inversion process is accomplished by taking a DC voltage source
and switching it across a load using an H-bridge parameter. If this voltage needs to be boosted
from a DC source, it can be accomplished before the AC stage by using a DC-DC boost
converter or after the AC stage by using a boost transformer. The inverted signal itself is
composed of a pulse-width-modulated (PWM) signal the PWM signal is encodes a sine wave.
The duty cycle of the sine wave output signal is changed such that the sine wave power is
transmitted. This output power can be used alternatively.
There are two basic designs for producing household plug-in voltage from a lower-
voltage DC source, the first of which uses a switching boost converter to produce a higher-
voltage DC and then converts to AC. The second method converts DC to AC at battery level and
uses a line frequency transformer to create the output voltage.
1.3.1 Square wave inverter
This is one of the simplest waveforms an inverter design can produce and is best suited to
low-sensitivity applications such as lighting and heating. Square wave output can produce
"humming" when connected to audio equipment and is generally unsuitable for sensitive
electronics.
Fig. 1.1 A Square Waveform

10. The conversion of DC to AC is most commonly done through the use of MOSFET
inverter circuits which can switch the voltage across the load, providing a digital approximation
of the desired AC signal. The simplest variant of this inversion is the production of a square
wave conversion of a sine wave. In the form of square wave, the load voltage must be switched
majorly from high voltage to low Voltage, without using for an intermediate step (0V). In order
to deliver the same power as the sine wave to be approximated, the amplitude value of the square
wave value and sine wave’s RMS value is same.
Therefore, the average voltages, and the power delivered will be the same for the two
waveforms. Square wave inverters are very rarely used in practice, as many devices which utilize
timing circuits that on something close to the sine wave from the power company cannot operate
with such a rough. In addition, a square wave has relatively large 3rd and 5th harmonic
components which burn power and severely cut down on the efficiency of devices using such
inverters as a power source.
1.3.1.1 Applications of square wave inverter
Majorly square wave inverter applications voltage source inverter having many
applications in many low cost AC motor drives, that is like as an uninterrupted power supply and
circuits utilizing electrical resonance between an inductor and capacitor. Some examples of
circuits utilizing like resonance phenomenon are induction heating units and electronic ballasts
for fluorescent lamps.
1.3.2 Pure Sine wave inverter
A power inverter device which produces a multiple step sinusoidal AC waveform is
referred to as a sine wave inverter. To more clearly distinguish the inverters with outputs of
much less distortion than the "modified sine wave" (three step) inverter designs, the
manufacturers often use the phrase pure sine wave inverter. Almost all consumer grade inverters
that are sold as a "pure sine wave inverter" do not produce a smooth sine wave output at all, just
a less choppy output than the square wave (one step) and modified sine wave (three step)
inverters. In this sense, the phrases "Pure sine wave" or "sine wave inverter" are misleading to
the consumer. However, this is not critical for most electronics as they deal with the output quite
well.
Where power inverter devices substitute for standard line power, a sine wave output is
desirable because many electrical products are engineered to work best with a sine wave AC
power source. The standard electric utility power attempts to provide a power source that is a
good approximation of a sine wave.
Sine wave inverters with more than three steps in the wave output are more complex and
have significantly higher cost than a modified sine wave, with only three steps, or square wave
(one step) types of the same power handling. Switch-mode power supply (SMPS) devices, such

11. as personal computers or DVD players, function on quality modified sine wave power. AC
motors directly operated on non-sinusoidal power may produce extra heat, may have different
speed-torque characteristics, or may produce more audible noise than when running on
sinusoidal power.
Fig. 1.2 Sine wave
Most of the power source for most applications is a 60Hz, 230v AC sine wave, Identical
to the 120V Vrms Source available. It is majorly available from some developed companies.
Most of the low power electronic household plug-in devices are designed to work with this
source (high power devices such as cooking ovens use a 240V source). These
electronic equipment will be Most likely to work properly and most efficiently on such a voltage
and current sources. The full sine wave source is produced Most easily for high power
applications through rotating electrical machinery such as naval gas-turbine machineries,
homemade applications of diesel or gasoline backup generators or other types of generators
employed by power companies that employs a shaft torque to create an AC current.
These power sources provides a relatively clean, pure sine waves (lacking significant
harmonics and high frequency noise) thanks to their analog rotational things. Such as rotating
machinery can be an appropriate for low-power backup supply usage due to their high cost, huge
size and required maintenance. There are mainly useful for pure sine wave applications.
The Non sinusoidal waveform generated is also called as a relaxation oscillator. The op
amp relaxation oscillator is also called as a square wave generator. The frequency of the
oscillator is f=1/T. Here T is also known as a Time and f is a frequency of the oscillator. In this
op amp generator both Z1and Z2. The unsymmetrical square wave can be had by different square
waves.
1.3.2.1 Advantages of the Pure Sine Wave Inverter
Office buildings considering a backup power inverter, a true sine wave model will allow
proper function of all electronic office equipment and fluorescent tube lighting. And some of
electronic equipments like a Toyostove, battery chargers, electric drills, digital clock radios or
other sensitive electronics should consider a true sine wave inverter to ensure proper functioning
of all household appliances.

12. 1.3.2.2 Applications
1. It can applicable many power applications like electric tube light, kitchen appliances,
power tools, TVs, radios, computers and many more electronics gadgets we are using.
2. Various inverters may have different features making them better suited for different
specific applications. Very small inverters are available that connect to a car cigarette
lighter, with a single three-prong AC outlet as the output. Large inverters are generally
designed to be hardwired into a building electrical system. Some inverters offer 240 volts
output. The right inverter for any specific use can be found with the help of an
experienced inverter dealer.
3. It will be useful in all electronic applications, when using pure sine wave power. True
sine wave inverters will produce AC power as well as a better than utility power,
Ensuring that even the most sensitive equipment will run properly. While sine wave
inverters are more expensive than modifying sine wave models, The quality of their
waveform can be a definite advantage.
1.3.3 Modified sine wave inverter
A "modified sine wave" inverter has a non-square waveform that is a useful rough
approximation of a sine wave for power translation purposes. Most inexpensive consumer power
inverters produce a modified sine wave rather than a pure sine wave.
The waveform in commercially available modified-sine-wave inverters is a square wave
with a pause before the polarity reversal, which only needs to cycle back and forth through a
three-position switch that outputs forward, off, and reverse output at the pre-determined
frequency. Switching states are developed for positive, negative and zero voltages as per the
patterns given in the switching Table. The peak voltage to RMS voltage ratio does not maintain
the same relationship as for a sine wave. The DC bus voltage may be actively regulated, or the
"on" and "off" times can be modified to maintain the same RMS value output up to the DC bus
voltage to compensate for DC bus voltage variations.
The ratio of on to off time can be adjusted to vary the RMS voltage while maintaining a
constant frequency with a technique called Pulse Width Modulation (PWM). The generated gate
pulses are given to each switch in accordance with the developed pattern to obtain the desired
output. Harmonic spectrum in the output depends on the width of the pulses and the modulation
frequency. When operating induction motors, voltage harmonics are usually not of concern;
however, harmonic distortion in the current waveform introduces additional heating and can
produce pulsating torques.
Numerous items of electric equipment will
operate quite well on modified sine wave power inverter
devices, especially loads that are resistive in nature such
as traditional incandescent light bulbs. Fig. 1.3 Modified Square wave

13. However, the load may operate less efficiently owing to the harmonics associated with a
modified sine wave and produce a humming noise during operation. This also affects the
efficiency of the system as a whole, since the manufacturer's nominal conversion efficiency does
not account for harmonics. Therefore, pure sine wave inverters may provide significantly higher
efficiency than modified sine wave inverters.
Most AC motors will run on MSW inverters with an efficiency reduction of about 20%
owing to the harmonic content. However, they may be quite noisy. A series LC filter tuned to the
fundamental frequency may help. A common modified sine wave inverter topology found in
consumer power inverters is as follows:
An on board microcontroller rapidly switches on and off power MOSFETs at high
frequency like ~50 kHz. The MOSFETs directly pull from a low voltage DC source (such as a
battery). This signal then goes through step-up transformers (generally many smaller
transformers are placed in parallel to reduce the overall size of the inverter) to produce a higher
voltage signal. The output of the step-up transformers then gets filtered by capacitors to produce
a high voltage DC supply. Finally, this DC supply is pulsed with additional power MOSFETs by
the microcontroller to produce the final modified sine wave signal.

14. Chapter-2
Introduction of Component Used
2.1 Arduino
2.1.1 Introduction
Arduino is an open-source electronics platform based on easy-to-use hardware and
software. Arduino boards are able to read inputs - light on a sensor, a finger on a button, or a
Twitter message - and turn it into an output - activating a motor, turning on an LED, publishing
something online. You can tell your board what to do by sending a set of instructions to the
microcontroller on the board. To do so you use the Arduino programming language (based on
Wiring), and the Arduino Software (IDE), based on Processing.
Arduino was born at the Ivrea Interaction Design Institute as an easy tool for fast
prototyping, aimed at students without a background in electronics and programming. As soon as
it reached a wider community, the Arduino board started changing to adapt to new needs and
challenges, differentiating its offer from simple 8-bit boards to products for IT applications,
wearable, 3D printing, and embedded environments. All Arduino boards are completely open-
source, empowering users to build them independently and eventually adapt them to their
particular needs. The software, too, is open-source, and it is growing through the contributions of
users worldwide.
Arduino also simplifies the process of working with microcontrollers, but it offers some
advantage for teachers, students, and interested amateurs over other systems:
Inexpensive- Arduino boards are relatively inexpensive compared to other
microcontroller platforms. The least expensive version of the Arduino module can be assembled
by hand, and even the pre-assembled Arduino modules cost less than $50
Cross-platform- The Arduino Software (IDE) runs on Windows, Macintosh OSX, and
Linux operating systems. Most microcontroller systems are limited to Windows.
Simple, clear programming environment- The Arduino Software (IDE) is easy-to-use
for beginners, yet flexible enough for advanced users to take advantage of as well. For teachers,
it's conveniently based on the Processing programming environment, so students learning to
program in that environment will be familiar with how the Arduino IDE works.
Open source and extensible software - The Arduino software is published as open
source tools, available for extension by experienced programmers. The language can be
expanded through C++ libraries, and people wanting to understand the technical details can

15. make the leap from Arduino to the AVR C programming language on which it's based. Similarly,
you can add AVR-C code directly into your Arduino programs if you want to.
Open source and extensible hardware - The plans of the Arduino boards are published
under a Creative Commons license, so experienced circuit designers can make their own version
of the module, extending it and improving it. Even relatively inexperienced users can build the
breadboard version of the module in order to understand how it works and save money.
2.1.2 Arduino Mega 2560
The Mega 2560 is a microcontroller board based on the ATmega2560. It has 54 digital
input/output pins (of which 15 can be used as PWM outputs), 16 analog inputs, 4 UARTs
(hardware serial ports), a 16 MHz crystal oscillator, a USB connection, a power jack, an ICSP
header, and a reset button. It contains everything needed to support the microcontroller; simply
connect it to a computer with a USB cable or power it with an AC-to-DC adapter or battery to
get started. The Mega 2560 board is compatible with most shields designed for the Uno and the
former boards Duemilanove or Diecimila. The Mega 2560 is an update to the Arduino Mega,
which it replaces.
Summary
Microcontroller ATmega2560
Operating Voltage 5V
Input Voltage (recommended) 7-12V
Input Voltage (limits) 6-20V
Digital I/O Pins 54 (of which 14 provide PWM 54 (of which 14 provide PWM output)
Analog Input Pins 16
VDC Current per I/O Pin 40 mA
DC Current for 3.3V Pin 50 mA
Flash Memory 256 KB of which 8 KB used by bootloader
SRAM 8 KB
EEPROM 4 KB
Clock Speed 16 MHz
Table 2.1 Specification of Arduino Mega 2560
Fig. 2.1 Arduino Mega 2560

16. 2.1.2.1 Power: The Arduino Mega2560 can be powered via the USB connection or with an
external power supply. The power source is selected automatically. External (non-USB) power
can come either from an AC-to-DC adapter (wall-wart) or battery. The adapter can be connected
by plugging a 2.1mm center-positive plug into the board's power jack. Leads from a battery can
be inserted in the GND and Vin pin headers of the POWER connector.
The board can operate on an external supply of 6 to 20 volts. If supplied with less than
7V, however, the 5V pin may supply less than five volts and the board may be unstable. If using
more than 12V, the voltage regulator may overheat and damage the board. The recommended
range is 7 to 12 volts.
The Mega2560 differs from all preceding boards in that it does not use the FTDI USB-to-
serial driver chip. Instead, it features the Atmega8U2 programmed as a USB-to-serial converter.
The power pins are as follows:
VIN: The input voltage to the Arduino board when it's using an external power source (as
opposed to 5 volts from the USB connection or other regulated power source). You can supply
voltage through this pin, or, if supplying voltage via the power jack, access it through this pin.
5V: The regulated power supply used to power the microcontroller and other components on the
board. This can come either from VIN via an on-board regulator, or be supplied by USB or
another regulated 5V supply.
3.3V: A 3.3 volt supply generated by the on-board regulator. Maximum current draw is 50 mA.
GND: Ground pins.
Input and Output: Each of the 54 digital pins on the Mega can be used as an input or output,
using pinMode(), digitalWrite(), and digitalRead() functions. They operate at 5 volts. Each pin
can provide or receive a maximum of 40 mA and has an internal pull-up resistor (disconnected
by default) of 20-50 kΩ. In addition, some pins have specialized functions:
Serial: 0 (RX) and 1 (TX); Serial 1: 19 (RX) and 18 (TX); Serial 2: 17 (RX) and 16 (TX); Serial
3: 15 (RX) and14 (TX). Used to receive (RX) and transmit (TX) TTL serial data. Pins 0 and 1
are also connected to the corresponding pins of the ATmega8U2 USB-to-TTL Serial chip .
External Interrupts: 2 (interrupt 0), 3 (interrupt 1), 18 (interrupt 5), 19 (interrupt 4), 20
(interrupt 3), and 21 (interrupt 2).These pins can be configured to trigger an interrupt on a low
value, a rising or falling edge, or a change in value. See the attachInterrupt() function for details.
PWM: 0 to 13. Provide 8-bit PWM output with the analogWrite() function.
LED: 13.There is a built-in LED connected to digital pin 13. When the pin is HIGH value, the
LED is on.

17. Analog Pin: The Mega2560 has 16 analog inputs, each of which provide 10 bits of resolution
(i.e. 1024 different values). By default they measure from ground to 5 volts, though is it possible
to change the upper end of their range using the AREF pin andanalogReference() function. There
are a couple of other pins on the board.
AREF: Reference voltage for the analog inputs. Used with analogReference().
Reset: Bring this line LOW to reset the microcontroller. Typically used to add a reset button to
shields which block the one on the board.
2.1.2.2 Communication: The Arduino Mega2560 has a number of facilities for communicating
with a computer, another Arduino, or other microcontrollers. The ATmega2560 provides four
hardware UARTs for TTL (5V) serial communication.
An ATmega8U2 on the board s one of these over USB and provides a virtual com port to
software on the computer (Windows machines will need a .inf file, but OSX and Linux machines
will recognize the board as a COM port automatically. The Arduino software includes a serial
monitor which allows simple textual data to be sent to and from the board. The RX and TX
LEDs on the board will flash when data is being transmitted via the ATmega8U2 chip and USB
connection to the computer (but not for serial communication on pins 0 and 1).
2.1.2.3 Automatic Software (reset): The auto-reset. Rather than requiring a physical press of
the reset button before an upload, the Arduino Mega2560 is designed in a way that allows it to be
reset by software running on a connected computer. One of the hardware flow control lines
(DTR) of the ATmega8U2 is connected to the reset line of the ATmega2560 via a 100 nF
capacitor. When this line is asserted (taken low), the reset line drops long enough to reset the
chip. The Arduino software uses this capability to allow you to upload code by simply pressing
the upload button in the Arduino environment. This means that the boot loader can have a shorter
timeout, as the lowering of DTR can be well-coordinated with the start of the upload.
This setup has other implications. When the Mega2560 is connected to either a computer
running Mac OS X or Linux, it resets each time a connection is made to it from software (via
USB). For the following half-second or so, the bootloader is running on the Mega2560. While it
is programmed to ignore malformed data (i.e. anything besides an upload of new code), it will
intercept the first few bytes of data sent to the board after a connection is opened. If a sketch
running on the board receives one-time configuration or other data when it first starts, make sure
that the software with which it communicates waits a second after opening the connection and
before sending this data. The Mega contains a trace that can be cut to disable
2.1.2.4 USB Over-current Protection: Overload is removed. The Arduino Mega has a
resettable poly fuse that protects your computer's USB ports from shorts and over-current.

18. Although most computers provide their own internal protection, the fuse provides an extra layer
of protection. If more than 500 mA is applied to the USB port, the fuse will automatically break
the connection until the short
2.1.2.5 Physical Characteristics and Shield Compatibility: The maximum length and width of
the Mega PCB are 4 and 2.1 inches respectively, with the USB connector and power jack
extending beyond the former dimension. Three screw holes allow the board to be attached to a
surface or case. Note that the distance between digital pins 7 and 8 is 160 mil (0.16"), not an
even multiple of the 100 mil spacing of the other pins.
The Mega is designed to be compatible with most shields designed for the Diecimila or
Duemilanove. Digital pins 0 to 13 (and the adjacent AREF and GND pins), analog inputs 0 to 5,
the power header, and ICSP header are all in equivalent locations. Further the main UART
(serial port) is located on the same pins (0 and 1), as are external interrupts 0 and 1 (pins 2 and 3
respectively). SPI is available through the ICSP header on both the Mega and Duemilanove /
Diecimila.
2.2 Power MOSFETs
2.2.1 Introduction
The metal–oxide–semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS
FET) is a type of field-effect transistor (FET). It has an insulated gate, whose voltage determines
the conductivity of the device. This ability to change conductivity with the amount of applied
voltage can be used for amplifying or switching electronic signals. Although FET is sometimes
used when referring to MOSFET devices, other types of field-effect transistors also exist.
Although the MOSFET is a four-terminal device with source (S), gate (G), drain (D), and
body (B) terminals, the body (or substrate) of the MOSFET is often connected to the source
terminal, making it a three-terminal device like other field-effect transistors. Because these two
terminals are normally connected to each other (short-circuited) internally, only three terminals
appear in electrical diagrams.
Fig. 2.2 MOSFET Terminals

19. 2.2.2 Type Of MOSFETs
It comes in N-channel and P-channel two configuration. The N-channel and P-channel
are further categories into Depletion and Enhancement type:
Fig.2.3 Types Of MOSFETs
 Depletion Type – the transistor requires the Gate-Source voltage, (VGS) to switch the
device ―OFF‖. The depletion mode MOSFET is equivalent to a ―Normally Closed‖ switch.
 Enhancement Type – the transistor requires a Gate-Source voltage, (VGS) to switch the
device ―ON‖. The enhancement mode MOSFET is equivalent to a ―Normally Open‖
switch.

20. 2.2.3 IRF9630 (MOSFETs Used)
These are P- enhancement mode silicon gate power field effect transistors. They are
advanced power MOSFETs designed, tested, and guaranteed to withstand a specified level of
energy in the breakdown avalanche mode of operation. All of these power MOSFETs are
designed for applications such as switching regulators, switching converters, motor drivers, relay
drivers and drivers for other high-power switching devices. The high input impedance allows
these types to be operated directly from integrated circuits.
Features
• 6.5A, 200V.
• rDS(ON )= 0.800Ω.
• Single Pulse Avalanche Energy Rated.
• Nanosecond Switching Speeds.
• Linear Transfer Characteristics.
• High Input Impedance.
For more information Datasheet is attached to Page no. 26-27.
2.3 Heat Sink
A heat sink (also commonly spelled heat sink) is a passive heat exchanger that transfers
the heat generated by an electronic or a mechanical device to a fluid medium, often air or a liquid
coolant, where it is dissipated away from the device, thereby allowing regulation of the device's
temperature at optimal levels. In computers, heat sinks are used to cool central processing
units or graphics processors. Heat sinks are used with high-power semiconductor devices such as
power transistors and optoelectronics such as lasers and light emitting diodes (LEDs), where the
heat dissipation ability of the component itself is insufficient to moderate its temperature.
Fig. 2.4 IRF 9630 (MOSFET)

21. A heat sink is designed to maximize its surface area in contact with the cooling medium
surrounding it, such as the air. Air velocity, choice of material, protrusion design and surface
treatment are factors that affect the performance of a heat sink. Heat sink attachment methods
and thermal interface materials also affect
the die temperature of the integrated circuit. Thermal
adhesive or thermal grease improve the heat sink's
performance by filling air gaps between the heat sink and
the heat spreader on the device. A heat sink is usually made
out of copper and/or aluminium. Copper is used because it
has many desirable properties for thermally efficient and
durable heat exchangers. First and foremost, copper is an
excellent conductor of heat. This means that copper's high
thermal conductivity allows heat to pass through it quickly.
Aluminum is used in applications where weight is a big
concern.
2.4 Optocoupler
In electronics, an opto-isolator, also called an optocoupler, photocoupler,
or optical isolator, is a component that transfers electrical signals between two isolated circuits
by using light. Opto-isolators prevent high voltages from affecting the system receiving the
signal. Commercially available opto-isolators withstand input-to-output voltages up to 10 kV and
voltage transients with speeds up to 10 kV/μs.
A common type of opto-isolator consists of an LED and a phototransistor in the same opaque
package. Other types of source-sensor combinations include LED-photodiode, LED-LASCR,
and lamp-photoresistor pairs. Usually opto-isolators transfer digital (on-off) signals, but some
techniques allow them to be used with analog signals.
Fig. 2.6 Optocoupler Basic Pin-Diagram
Fig.2.5 Heat Sink

22. 2.4.1 4n37 (Optocoupler used)
a) b)
Fig. 2.7 a) 4n37 Optocoupler IC b) Pin Diagram
FEATURES
• Isolation test voltage 5000 VRMS
• Interfaces with common logic families
• Input-output coupling capacitance < 0.5 pF
• Industry standard dual-in-line 6 pin package
APPLICATIONS
• AC mains detection
• Reed relay driving
• Switch mode power supply feedback
• Telephone ring detection
• Logic ground isolation
• Logic coupling with high frequency noise rejection
For More Information Datasheet attached to Page No. 28-30.
2.5 Resistance
The ratio of the voltage applied across a
resistor's terminals to the intensity of current in the
circuit is called its resistance, and this can be
assumed to be a constant (independent of the
voltage) for ordinary resistors working within their
ratings.
Fig. 2.8 Resistor

23. 2.5.1 WORKING OF RESISTOR
Working of a resistor can be explained with the similarity of water flowing through a
pipe. Consider a pipe through which water is allowed to flow. If the diameter of the pipe is
reduced, the water flow will be reduced. If the force of the water is increased by increasing the
pressure, then the energy will be dissipated as heat. There will also be an enormous difference in
pressure in the head and tail ends of the pipe. In this example, the force applied to the water is
similar to the current flowing through the resistance. The pressure applied can be resembled to
the voltage.
RESISTOR COLOUR CODING
Fig. 2.9 Colour Band on Resistor
To distinguish left from right there is a gap between the C and D bands.
 Band A is first significant figure of component value (left side)
 Band B is the second significant figure (Some precision resistors have a third significant
figure, and thus five bands.)
 Band C is the decimal multiplier
 Band D if present, indicates tolerance of value in percent (no band means 20%)
Resistors manufactured for military use may also include a fifth band which indicates
component failure rate (reliability); refer to MIL-HDBK-199 for further details.
Color
Significant
figures
Multiplier Tolerance
Temp. Coefficient
(ppm/K)
Black 0 ×100
– 250
Brown 1 ×101
±1% 100
Red 2 ×102
±2% 50
Orange 3 ×103
– 15
Yellow 4 ×104
(±5%) 25

24. 2.6 Transformer
A transformer can be defined as a static device which helps in the transformation
of electric power in one circuit to electric power of the same frequency in another circuit. The
voltage can be raised or lowered in a circuit, but with a proportional increase or decrease in the
current ratings.
The main principle of operation of a transformer is mutual inductance between two circuits
which is linked by a common magnetic flux. A basic transformer consists of two coils that are
electrically separate and inductive, but are magnetically linked through a path of reluctance. The
working principle of the transformer can be understood from the figure below.
Table 2.10 Single Phase Transformer
Green 5 ×105
±0.5% 20
Blue 6 ×106
±0.25% 10
Violet 7 ×107
±0.1% 5
Gray 8 ×108 ±0.05%
(±10%)
1
White 9 ×109
– –
Gold – ×10-1
±5% –
Silver – ×10-2
±10% –
None – – ±20% –
Table 2.2 Resistor Colour Code

25. In short, a transformer carries the operations shown below:
1. Transfer of electric power from one circuit to another.
2. Transfer of electric power without any change in frequency.
3. Transfer with the principle of electromagnetic induction.
4. The two electrical circuits are linked by mutual induction.
2.6.1 12-0-12/220V transformer
In our project we use step-up transformer which step-up the 12V to 220V. The current
carrying capacity of this transformer is 2Amp.
Fig. 2.11 12-0-12/220V, 2Amp Transformer
Our transformer specifications are
Input voltage (V1) = 12V
Output voltage (V2) = 200V
Turn ratio = V1/V2 = 12/200 = 1/16.667
2.7 Battery
An electric battery is a device consisting of one or more electrochemical cells with external
connections provided to power electrical devices such as flashlights, smart phones, and electric
cars. When a battery is supplying electric power, its positive terminal is the cathode and its
negative terminal is the anode. The terminal marked negative is the source of electrons that when
connected to an external circuit will flow and deliver energy to an external device. When a
battery is connected to an external circuit, electrolytes are able to move as ions within, allowing
the chemical reactions to be completed at the separate terminals and so deliver energy to the
external circuit. It is the movement of those ions within the battery which allows current to flow
out of the battery to perform work. Historically the term "battery" specifically referred to a
device composed of multiple cells, however the usage has evolved to additionally include
devices composed of a single cell.
Primary (single-use or "disposable") batteries are used once and discarded;
the electrode materials are irreversibly changed during discharge. Common examples are

26. the alkaline battery used for flashlights and a multitude of portable electronic devices. Secondary
(rechargeable) batteries can be discharged and recharged multiple times using mains power from
a wall socket; the original composition of the electrodes can be restored by reverse current.
Examples include the lead-acid batteries used in vehicles and lithium-ion batteries used for
portable electronics such as laptops and smart phones.
Batteries come in many shapes and sizes, from miniature cells used to power hearing aids and
wristwatches to small, thin cells used in Smartphone’s, to large lead acid batteries used in cars
and trucks, and at the largest extreme, huge battery banks the size of rooms that provide standby
or emergency power for telephone exchanges and computer data centers.
Fig. 2.12 12V, 1.3Ah battery
2.7.1 Principle of Operation
Batteries convert chemical energy directly to electrical energy. A battery consists of some
number of voltaic cells. Each cell consists of two half-cells connected in series by a conductive
electrolyte containing anions and cations. One half-cell includes electrolyte and the negative
electrode, the electrode to which anions (negatively charged ions) migrate; the other half-cell
includes electrolyte and the positive electrode to which cations (positively charged ions)
migrate. Redox reactions power the battery. Cations are reduced (electrons are added) at the
cathode during charging, while anions are oxidized (electrons are removed) at the anode during
charging. During discharge, the process is reversed. The electrodes do not touch each other, but
are electrically connected by the electrolyte. Some cells use different electrolytes for each half-
cell. A separator allows ions to flow between half-cells, but prevents mixing of the electrolytes.
Each half-cell has an electromotive force (or emf), determined by its ability to drive electric
current from the interior to the exterior of the cell. The net emf of the cell is the difference
between the emfs of its half-cells. Thus, if the electrodes have emfs and, then the net emf is; in
other words, the net emf is the difference between the reduction potentials of the half-reactions.
The electrical driving force or across the terminals of a cell is known as the terminal voltage
(difference) and is measured in volts. The terminal voltage of a cell that is neither charging nor
discharging is called the open-circuit voltage and equals the emf of the cell. Because of internal
resistance, the terminal voltage of a cell that is discharging is smaller in magnitude than the
open-circuit voltage and the terminal voltage of a cell that is charging exceeds the open-circuit

27. voltage. An ideal cell has negligible internal resistance, so it would maintain a constant terminal
voltage of until exhausted, then dropping to zero. If such a cell maintained 1.5 volts and stored a
charge of one coulomb then on complete discharge it would perform 1.5 joules of work. In actual
cells, the internal resistance increases under discharge and the open circuit voltage also decreases
under discharge. If the voltage and resistance are plotted
against time, the resulting graphs typically are a curve;
the shape of the curve varies according to the chemistry
and internal arrangement employed.
The voltage developed across a cell's terminals depends
on the energy release of the chemical reactions of its
electrodes and electrolyte. Alkaline and zinc–
carbon cells have different chemistries, but
approximately the same emf of 1.5 volts;
likewise NiCd and NiMH cells have different
chemistries, but approximately the same emf of 1.2
volts. The high electrochemical potential changes in the
reactions of lithium compounds give lithium cells emfs
of 3 volts or more. Fig. 2.13 A voltaic cell for demonstration
purposes.

28. Chapter – 3
Simulation of Inverter Circuit
We have simulated our inverter circuitry on Proteus Software. The types of the inverter
circuit are
 Center tapped inverter circuit
 Bridge inverter circuit
3.1 Center tapped inverter
The simulink model is shown in the figure below. This model contain the two MOSFETs
and a transfomer. The gate of the both mosfet are triggered at 180 degree phase shift signal
generated by the Arduino. But in this simulink model we use the pulse generator. The 180 degree
phase angle is generated by the NOT gate known as inverter. The output wave of the pulse
generator is shown in the secong figure by Osclloscope attached to the circuit. The pulse
generater wave is at terminal B in the Osclloscope and the iverted wave in terminal C of the
Oscllosope. The output waveform generated by the inverter circuit is shown the terminal A on
the oscllosope. The output wave form is not pure sine wave. The output waveform is square sine
waveform.
Fig. 3.1 Centre- tapped Inverter Circuit

29. Fig. 3.2 Input and Output waveform of centre-tapped inverter circuit
3.2 Bridge Inverter
The bridge inverter is also known as the H-Bridge inverter. In this type of inverter the
MOSFETs are connected in the bridge form. The four MOSFETs in the circuit are Q1, Q2, Q3 &
Fig. 3.3 Bridge type Inverter Circuit

30. Q4. First MOSFETs Q1& Q3 are triggered at the same time. The current is start flowing Q1
drain terminal to source terminal of the Q3 MOSFET. After that the MOSFETs Q2&Q4 are
triggered at the same time the current in start flowing in another direction. By continues
switching of the MOSFETs we are generating the AC waveform.
The H-bridge arrangement is generally used to reverse the polarity/direction of the motor,
but can also be used to 'brake' the motor, where the motor comes to a sudden stop, as the motor's
terminals are shorted, or to let the motor 'free run' to a stop, as the motor is effectively
disconnected from the circuit.
Fig. 3.4 Input and Output waveform of bridge type inverter circuit

31. Chapter-4
Designing of Arduino Based Inverter Circuit
4.1 Simulink Model
In this project, we have used MATLAB Simulink model for generation of pulses. The pulses
generated are used to trigger the gate terminal of the Mosfets in order to turn them on. The Pulse
Generator block generates a series of scalar, vector, or matrix pulses at regular intervals. The
block's Amplitude, Period, Duty cycle, and Start time parameters determines the characteristics
of the output signal. We can use the Pulse Generator block for continuous systems.
NOT gate is used to generate the inverted waveform simultaneously at the
other Mosfet. Output waveform can be visualize using scope. Output of Simulink model is given
to Arduino at 8 and 9 pins
Fig. 4.1 Simulink Model
To get 50 Hz frequency from the pulse generator following settings can be used which are shown
in fig. 4.2

32. Fig. 4.2 Source Block Parameters of Pulse Generator
Output of MATLAB Simulink model is shown in Fig. 4.3
Fig. 4.3 Output of Simulink Model

34. Datasheets of Components Used
IRF9630

36. 4n37 Optocoupler

39. RESULT
We have successfully designed and implemented Arduino based Inverter circuit. Both center-
tapped inverter circuit and Full bridge type inverter circuit are working properly and we are
getting output in the range of 170-230V AC. We have successfully operated resistive load i.e.
incandescent lamp of 40W. It is being supplied with 220V AC and it is working properly and
drawing a current of 0.2Amp approximately.
Likewise it can also be used to operate Inductive, Capacitive and RLC loads like single
phase induction motors, various household appliances like induction heater, JMG etc.

40. References
www.birstolwatch.com
A Course in Power Electronics By Dr. P.S. Bimbhra
www.wikipedia.com
www.youtube.com/electroboom