The document discusses interfacing a transformer with a laptop using an Arduino. It first describes how a transformer works by mutual induction to transform electrical energy from one circuit to another at different voltage levels while maintaining frequency. It then explains that an Arduino is an open-source electronics platform that can read inputs and turn them into outputs by sending instructions to its microcontroller. Finally, it details how the project provides PWM pulses from an Arduino Uno to a MOSFET, which switches the input to the transformer, allowing the output voltage from the transformer to be controlled by varying the PWM frequency.

1. 1 | S y e d A b u z a r
Interfacing of Transformer with Laptop &
Frequency Control Using Aurduino:
Transformer:
“Device which transforms electrical energy from one circuit to
another by process of mutual induction between two windings.”
It transforms power from one circuit to another without changing its frequency but
in different voltage levels.
Working Principle of Transformer:
The working principle of transformer is very simple. It depends
upon Faraday's law of electromagnetic induction. Actually, mutual induction
between two or more winding is responsible for transformation action in an
electrical transformer.
There are two windings of a Transformer.
1) Primary Winding
2) Secondary Winding.
The winding which takes electrical power from the source, is generally known as
primary winding of transformer. Here in our above example it is first winding.

2. 2 | S y e d A b u z a r
The winding which gives the desired output voltage due to mutual induction in the
transformer, is commonly known as secondary winding of transformer.
The rate of change of flux linkage depends upon the amount of linked flux with the
second winding. So, it is desired to be linked to almost all flux of primary winding
to the secondary winding. This is effectively and efficiently done by placing one
low reluctance path common to both of the winding.

3. 3 | S y e d A b u z a r
Aurduino:
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.

4. 4 | S y e d A b u z a r
PWM:
Pulse Width Modulation, or PWM, is a technique for getting analog results with
digital means.
Digital control is used to create a square wave, a signal switched between on and
off. This on-off pattern can simulate voltages in between full on (5 Volts) and off
(0 Volts) by changing the portion of the time the signal spends on versus the time
that the signal spends off.
The duration of "on time" is called the pulse width. To get varying analog values,
you change, or modulate, that pulse width. If you repeat this on-off pattern fast
enough with an LED for example, the result is as if the signal is a steady voltage
between 0 and 5v controlling the brightness of the LED.

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Working Of Project:
As all major parts are discussed above. The main component used in the project is
Aurduino which provides pulses (PWM). As we know that Transformer works on
alternating input given to it. So for producing alternating input I used Aurduino
Uno for triggering the pulses on gate of Mosfet (z44n).
The MOSFET (Metal Oxide Semiconductor Field Effect Transistor) transistor is a
semiconductor device which is widely used for switching. When there is no
voltage on the gate the device does not conduct. More is the voltage on the gate,
the better the device can conduct.
When MOSFET receives the triggered pulses from aurduino, it gives output when
it receives the +5V and remains off for 0V.
Now this input is given to the Transformer and it works as alternating input which
is amplified by the transformer at output. If I increase the frequency of PWM ,
output of the Transformer is also increased because rate of change of flux increases
and similarly for decreasing the frequency, output will be reduced.
The rated frequency for transformer is 50Hz. I used 12-0-12 to 220V Transformer.

6. 6 | S y e d A b u z a r
Circuit Diagram :