I used Mutual Inductance principle in which the two coils of wire are brought into close proximity with each other so the magnetic field from one links with the other, a voltage will be generated in the second coil as a result magnetically-induced voltage only happens when the magnetic field flux is present.

1. Components Required :-
 Resistor
 Capacitor
 Transistor
 PCB board
 Winding Coil
 Soldering Rod
 Soldering Wire ( Lead )
 Power Supply

2. Capacitor: -
A capacitor (originally known as a condenser) is a
passive two-terminal electrical component used to
store electrical energy temporarily in an electric
field. The forms of practical capacitors vary widely,
but all contain at least two electrical conductors
(plates) separated by a dielectric (i.e. an insulator
that can store energy by becoming polarized). The
conductors can be thin films, foils or sintered beads
of metal or conductive electrolyte, etc. The non -
conducting dielectric acts to increase the
capacitor's charge capacity. A dielectric can be
glass, ceramic, plastic film, air, vacuum, paper, mica, oxide layer etc. Capacitors
are widely used as parts of electrical circuits in many common electrical devices.
Unlike a resistor, an ideal capacitor does not dissipate energy. Instead, a
capacitor stores energy in the form of an electrostatic field between its plates.
Transistor: -
A transistor is a semiconductor device used
to amplify and switch electronic signals and electrical
power. It is composed of semiconductor material with
at least three terminals for connection to an external
circuit. A voltage or current applied to one pair of the
transistor's terminals changes the current through
another pair of terminals. Because the controlled
(output) power can be higher than the controlling
(input) power, a transistor can amplify a signal.

3. Resistor: -
A resistor is a passive two-terminal electrical
component that implements electrical resistance as a circuit
element. Resistors act to reduce current flow, and, at the
same time, act to lower voltage levels within circuits. In
electronic circuits, resistors are used to limit current flow, to
adjust signal levels, bias active elements, and
terminate transmission lines among other uses. High-power
resistors that can dissipate many watts of electrical power
as heat may be used as part of motor controls, in power
distribution systems, or as test loads for generators. Fixed
resistors have resistances that only change slightly with
temperature, time or operating voltage. Variable resistors can be used to adjust circuit
elements (such as a volume control or a lamp dimmer), or as sensing devices for heat,
light, humidity, force, or chemical activity.
Printed Circuit Board: -
A printed circuit board (PCB) mechanically supports and
electrically connects electronic
components using conductive tracks, pads and other
features etched from copper sheets laminated onto a non-
conductive substrate. PCBs can be single sided (one
copper layer), double sided (two copper layers) or multi-
layer (outer and inner layers). Multi-layer PCBs allow for
much higher component density. Conductors on different
layers are connected with plated-through holes called vias.
Advanced PCBs may contain components - capacitors,
resistors or active devices - embedded in the substrate.

4. Mutual Inductance: -
If two coils of wire are brought into close proximity with each other so the magnetic field
from one links with the other, a voltage will be generated in the second coil as a result.
This is called mutual inductance: when voltage impressed upon one coil induces a
voltage in another.
A device specifically designed to produce the effect of mutual inductance between two
or more coils is called a transformer.
It is actually intended as a precision standard unit for mutual inductance, but for the
purposes of illustrating what the essence of a transformer is, it will suffice. The two wire
coils can be distinguished from each other by color: the bulk of the tube’s length is
wrapped in green-insulated wire (the first coil) while the second coil (wire with bronze-
colored insulation) stands in the middle of the tube’s length. The wire ends run down to
connection terminals at the bottom of the unit. Most transformer units are not built with
their wire coils exposed like this.
Because magnetically-induced voltage only happens when the magnetic field flux is
changing in strength relative to the wire, mutual inductance between two coils can only
happen with alternating (changing—AC) voltage, and not with direct (steady—DC)
voltage. The only applications for mutual inductance in a DC system is where some
means is available to switch power on and off to the coil (thus creating a pulsing DC
voltage), the induced voltage peaking at every pulse.
A very useful property of transformers is the ability to transform voltage and current
levels according to a simple ratio, determined by the ratio of input and output coil turns.
If the energized coil of a transformer is energized by an AC voltage, the amount of AC
voltage induced in the unpowered coil will be equal to the input voltage multiplied by the
ratio of output to input wire turns in the coils. Conversely, the current through the
windings of the output coil compared to the input coil will follow the opposite ratio: if the
voltage is increased from input coil to output coil, the current will be decreased by the
same proportion. This action of the transformer is analogous to that of mechanical gear,
belt sheave, or chain sprocket ratios:

5. A transformer designed to output more voltage than it takes in across the input coil is
called a “step-up” transformer, while one designed to do the opposite is called a “step-
down,” in reference to the transformation of voltage that takes place. The current
through each respective coil, of course, follows the exact opposite proportion.

6. Conclusion: -
In this project I used Mutual Inductance principle in which the two
coils of wire are brought into close proximity with each other so the magnetic field from
one links with the other, a voltage will be generated in the second coil as a result
magnetically-induced voltage only happens when the magnetic field flux is present.