NEW HORIZON PUBLIC

SCHOOL & PENGUIN KIDS

PHYSICS INVESTIGATORY PROJECT

To Research the AC/DC Convertor
(Full Wave Rectifier)

Name : Chitranjali Ranjan

Class : XII (Science) Division : A
Roll No. : 1
Academic Year : 2024 – 25
 ACKNOWLEDGEMENT
I wish to express my deep gratitude and sincere thanks to
my Respected Principal Mam, Mrs. Amita Dutta ma’am of
New Horizon Public school, New Panvel for the
encouragement. You always inspire us to do our best for
the students. Thank you, ma’am, for being such a great
and exceptional leader, for managing the entire school.
You are humble and make yourself accessible to all.
I extend my hearty thanks to my subject teacher Mrs.
Poonam Ojha ma’am. I take this opportunity to express
my deep sense of gratitude for her invaluable guidance,
useful suggestions and constant encouragement, which
has sustained my efforts at all stages of this project work.
I can’t forget to offer my sincere thanks to my parents
and friends who helped me to carry out this project work
and thank them for their valuable advice and support,
which I received from time to time.
 CERTIFICATE
This is to certify that Ms. Chitranjali Ranjan of class XII A
have successfully completed the Physics Investigatory
Project on ‘To Research The AC/DC Convertor (Full Wave
Rectifier)’ under the guidance of Mrs. Poonam Ojha
ma’am as prescribed by the CBSE for academic session
2024-2025.

Signature of Signature of
Signature of Subject Teacher Principal
External Examiner
 School Stamp

INDEX
Sr
No.
TOPICS
1. INTRODUCTION
2. AIM & THEORY
3. MATERIALS REQUIRED
4. PROCEDURE
5. OBSERVATION
6. OBSERVATION TABLE
7. CONCLUSION
8. GALLERY
9. PRECAUTIONS
10. BIBILIOGRAPHY
 INTRODUCTION
The AC/DC converter, cornerstone in the realm of
electronics, plays a pivotal role in transforming
alternating current (AC) into direct current (DC),
thereby enabling the operation of a vast array of
devices. This conversion is essential for powering
countless devices, from household appliances to
advanced electronics.
Among the various configurations, the Full Wave
Rectifier stands out as a fundamental
implementation, offering efficient conversion and
consistent power output.
In this brief exploration, we will delve into the
fundamental principles behind AC/DC conversion,
highlighting its importance and application in
modern technology. By understanding the nuances
of AC/DC conversion and the specific advantages
offered by the Full Wave Rectifier, we gain valuable
insights into the foundational elements of electronic
circuitry and power management.
 AIM OF THE PROJECT & THEORY
The aim of this project is to construct and analyses a Full Wave
Rectifier circuit (Bridge Rectifier) to convert alternating current
(AC) to direct current (DC) investigating its operational
principles, efficiency, and performance characteristics under
varying load conditions.

The conversion of AC into DC is called Rectification. Electronic

devices can convert AC power into DC power with high
efficiency. A drawing of Full Wave Bridge Rectifier is given
below.

The bridge is composed of four diodes in a diamond shape.

During the positive half cycle of input voltage vin, the terminal
‘A’ is at positive potential with respect to the terminal ‘B’ and
because if this diodes D1 and D2 are forward biased whereas
diodes D3 and D4 are reversed biased. The current therefore
flows through diodes D1, D2 and load resistor RL.

During the negative half cycle of input voltage waveform, on the

other hand, the diodes D3 and D4 are forward biased whereas
the diodes D1 and D2 are reversed biased. As a consequence,
current flows through diodes D3 and D4. The input and output
voltage waveform may be analytically written as:

And

Where
 MATERIALS REQUIRED

 Diodes

 Transformers

 Resistors

 Capacitors

 Breadboard or PCB

 Power Supply

 Connecting Wires

 Bulb
 PROCEDURE
1. Prepare Components:

-Identify the terminals of the transformer’s center-taped

secondary winding.

-Identify the cathode (marked with a stripe) and anode

terminals of the diodes.

-Choose appropriate diodes, ensuring they can handle the

expected voltage and current.

2. Connect Diodes in Bridge Configuration:

-Place four diodes on the breadboard or PCB in a bridge

configuration
 -Connect the anode of one diode to the cathode of
another diode in a diagonal fashion, forming a bridge.
Repeat this for the other two diodes.

3. Connect Transformer:

-Connect the center tap of the transformer to the ground

rail of the breadboard or PCB.
-Connect one of the secondary windings to one terminal
of the bridge formed by the diodes.
-Connect the other end of the secondary winding to the
remaining terminal of the bridge.

4. Output Connection:

-Connect the capacitor across the output terminal of

the bridge rectifier to smooth out the pulsating DC voltage.
The capacitor’s negative terminal should connect to the
ground rail.

5. Optional Filtering:
-Optionally, you can add resistor in the series with the
capacitor to provide additional filtering and adjust the
output voltage.

6. Testing:

-Apply AC voltage to the primary winding of the

transformer using a power supply.

-Use an oscilloscope to observe the waveform at the input

and output of the rectifier. You should see a full wave
rectified waveform at the output.

7. Adjustment:

-If necessary, adjust the components values or

connections to optimize the performance of the rectifier.

8. Finalization:
-Once satisfied with the performance, finalize the
connection and secure the component on the breadboard
or PCB.

OBSERVATIONS
a. Rectification of AC to DC.

 The output voltage across the capacitor will

show rectification of the input AC voltage.
Instead of a sinusoidal waveform, you will
observe a waveform that consist of only positive
half cycle.

b.Reduce the Ripple:

 Compare to the raw rectified output of a half-

wave rectifier, the ripple voltage (the AC
component superimposed on the DC output)
 will be reduced due to the full wave
rectification.

c. Higher Efficiency:

 The full wave rectifier configuration allows for

better utilization of the transforms secondary
winding, resulting in higher efficiency compared
to half wave rectification.

d.Smoothing Effect of Capacitor:

 The capacitor connected across the output

terminals smooth out the pulsating DC voltage
by storing charge during peaks and discharging
during troughs, resulting in a more stable output
voltage.

e. Improved Output Voltage:

  The output voltage will be higher than that of a
half-wave rectifier for the same transformer and
the load condition since it utilizes both half of
the input AC waveform.

f. Waveform Observation:
 When observed on an oscilloscope, the output
waveform will show a series of positive half
cycles each followed by a brief period of zero
voltage before the next half cycle begins.

g. Voltage Drop Across Diodes:

 There will be a voltage drop across the diodes

(typically around 0.7 volts for the silicon diodes),
which will affect the overall output voltage.

h.Load Effect:

 Applying different load to the output of the

rectifier will affect the output voltage and ripple.
 Higher load may cause a voltage drop, while
lower loads may result in a higher ripple.

OBSERVATION TABLE

OBSERVATIO DESCRIPTION
N
Input Voltage AC voltage applied to the transformer
primary winding
Output Voltage DC voltage measured across the
capacitor
Ripple Voltage AC component superimposed on the
DC output voltage, measured peak-to-
peak or RMS
Diode Voltage Voltage drops across each diode in
Drop the bridge rectifier, typically around
0.7 volts for silicon diodes
Waveform Shape of the output waveform
 observed on the oscilloscope
Efficient Comparison of output power to input
power, indicating how effectively the
rectifier converts AC to DC
Load Effect Changes in the output voltage and
ripple when different loads are
applied to the output of the rectifier
Stability Stability of the output voltage and
ripple under varying load conditions

CONCLUSION
Effective AC to DC Conversion: The experiment
demonstrates the efficacy of the Full Wave Rectifier in
converting alternating current (AC) to direct current (DC)
with improved efficiency compared to half-wave
rectification.

Reduced Ripple: By utilizing both halves of the input AC

waveform, the Full Wave Rectifier produces a smoother DC
output with reduced ripple voltage compared to half-wave
rectification, resulting in a more stable power supply.
Higher Output Voltage: The Full Wave Rectifier
configuration results in a higher output voltage compared to
half-wave rectification for the same input AC voltage and
load conditions, making it suitable for applications requiring
higher DC voltage levels.

Improved Efficiency: Due to the utilization of both positive

and negative half-cycles of the input AC waveform, the Full
Wave Rectifier offers higher efficiency and better utilization
of the transformer’s secondary winding, leading to more
effective power conversion.

Voltage Drop Across Diodes: The experiment highlights the

presence of a voltage drop across the diodes in the bridge
rectifier configuration, typically around 0.7 volts for silicon
diodes, which affects the overall output voltage.

Load Dependence: The output voltage and ripple

characteristics of the Full Wave Rectifier are influenced by
the applied load, with higher loads potentially causing a
voltage drop and changes in ripple magnitude.
Stability and Reliability: The Full Wave Rectifier
demonstrates stability and reliability under varying load
conditions, providing a consistent DC output suitable for
powering electronic devices and circuits.

Applicability: The experiment underscores the practical

utility of the Full Wave Rectifier in a wide range of
applications, including power supplies for electronic
equipment, battery charging circuits, and motor control
systems.

GALLERY
-> Transformer -> Capacitor

-> Diodes -> Resistor & Bulb

-> Full Wave Rectifier

PRECAUTIONS

1. Electrical Safety
a. Always ensure proper electrical
isolation.
b. Use appropriate insulated tools.
c.Never touch components while the circuit
is powered.
 d. Wear rubber-soled shoes when working.

2. Component Protection
a. Use heat sinks for diodes to prevent
thermal damage.
b. Install proper fuses or circuit breaker
c.Ensure adequate ventilation for heat
dissipation.
d.Check voltage ratings of all components
before use.

BIBILOGRAPHY
 NCERT PHYSICS CLASS 12

 ARIHANT PUBLISHERS ALL-IN-ONE PHYSICS

CLASS 12

 CATALYST NEW PATTERN PHYSICS

 CONCEPTS OF PHYSICS H.C. VERMA

 www.google.com