This document describes a physics investigatory project to construct a full wave bridge rectifier. The aim is to show that alternating current (AC) can be rectified into direct current (DC). The project includes an introduction to rectifiers, materials required like diodes and a transformer, a circuit diagram, procedures to construct the circuit, an explanation of how the circuit works to rectify AC to DC, observations from testing the circuit, and conclusions. Safety precautions and uses of rectifiers are also discussed.

1. PHYSICS INVESTIGATORY
PROJECT
By
CHIRAG V PATEL
XII
KENDRIYA VIDYALAYA NO. 2, KRIBHCO NAGAR, SURAT

2. AIM
To construct a Full Wave Bridge
rectifier and show that the
alternating current (AC) is rectified
into a direct current (DC).

3. INDEX
1. CERTIFICATE
2. ACKNOWLEDGEMENT
3. INTRODUCTION
4. AIM
5. MATERIALS REQUIRED
6. CIRCUIT DIAGRAM
7. PROCEDURE
8. WORKING
9. BIBLIOGRAPHY

4. KENDRIYA VIDYALAYA NO.2,SURAT
DEPARTMENT OF PHYSICS
CERTIFICATE
This is to certify that CHIRAG V PATEL, a student to class
XII has successfully completed the project titled “FULL
WAVE RECTIFIER” Under the guidance of MR. PAWAN
KUMAR (Subject Teacher) during the academic year 2015-
16 in partial fulfillment of physics practical examination.
Signatureof external examiner Signatureof physicsteacher
Signatureof principal

5. ACKNOWLEDGEMENT
In the accomplishment of this project successfully, many
People have best owned upon me their blessing send the
heart pledged support, this time to thank all the people
who have been concerned with project.
Primarily I would thank god for being able to complete
this project with success. Then I would like to thank my
principal Mrs. KAMALA NIKHURPA and physics teacher
Mr. PAWAN KUMAR, whose valuable guidance has been the
ones that helped me patch this project and make it full
proof success his suggestions and his instructions hasserved as
the major contributor towards the completion of the
project.
Then I would like to thank my parents and friends who
have helped me with their valuable suggestions and
guidance has been helpful in various phases of the
completion of the project.

6. INTRODUCTION
A rectifier is an electrical device that converts
alternating current (AC), which periodically reverses
direction, to direct current (DC), which flows in only one
direction. The process is known as rectification.
Rectification produces a type of DC that encompasses
active voltages and currents, which are then adjusted into
a type of constant voltage DC, although this varies
depending on the current's end-use. The current is allowed
to flow uninterrupted in one direction, and no current is
allowed to flow in the opposite direction.
Physically, rectifiers take a number of forms, including
vacuum tube diodes, mercury-arc valves, copper and
selenium oxide rectifiers, semiconductor diodes, silicon-
controlled rectifiers and other silicon-based semiconductor
switches.
Rectifier circuits may be single-phase or multi-phase.
Most low power rectifiers for domestic equipment are
single-phase, but three-phase rectification is very
important for industrial applications and for the
transmission of energy as DC.

7. MATERIALS REQUIRED
1. Connecting Wires
2. A plug
3. Single Lead Wire- 2m
4. Three Nuts & Bolts 2-3cm length
5. Circuit Board
6. A Transformer (12V)
7. A Resistor
8. P-N Junction Diodes (4nos)
9. A LED
10. Insulation Tape, Blades, Soldering
Wax, Soldering Lead, Soldering Iron &
Sand Paper

9. CIRCUITDIAGRAM
A
B
D
C
PROCEDURE
Take the transformer and attach it to one end of the circuit
board. Attach the plug with the wire of desired length and connect
it to the transformer AC In now, take four diodes and connect the
4 diodes into a loop. Connect the anode of diode D1 to the anode
of D2.
Connect the cathode of D2 to anode of D3. Connect the cathode
of D3 to anode of D4 and connect the anode of D4 to cathode
of D1. The output of transformers should be connected to A and
C. Now, take two capacitor and connect its –ve terminal to –ve
and +ve terminal to +ve and connect both the capacitors to B
and D. Connect a resistor and a LED to the capacitor. Attach
wire from the capacitor and connect it to the output device.

10. WORKING
When the AC is supplied to the transformer, it step down the
240V
Main supply to 12V.It has a capability of delivering 700mA. The
12 volts AC appearing across the secondary is the RMS value. The
four diodes labeled D1 to D4 are arranged in “series pairs” with
only two diodes conducting current during each half cycle. The
four diodes labeled D1 to D4 are arranged in “series pairs” with
only two diodes conducting current during each half cycle. During
the positive half cycle of the supply, diodes D1 and D2 conduct in
series while diodes D3 and D4 are reverse biased and the current
flows through the load as shown below.
The Positive Half-cycle
During the negative half cycle of the supply, diodes D3 and D4
conduct in series, but diodes D1 and D2 switch “OFF” as they are

11. now reverse biased. The current flowing through the load is the
same as before.
The Negative Half-cycle
In subsequent Half cycles of the AC Current the above process are
repeated. In both the half cycle sit is clear that current flows
through the resistor in only one direction. Even though the
voltage across load is unidirectional it will still contain safe AC
components. This is filtered and made smooth using a capacitor,
which filters 99% of the AC current. A resistor is then used to
adjust the output voltage. Capacitor also nearly filters all AC
components from supply and resistance is adjusted for the required
output. As this is as simple circuit, two capacitors and one
resistor are being used. The output Direct Current and voltage
light up the LED and other source connected with it.

12. OBSERVATION & CONCLUSION
On connecting in galvanometer to the output of bridge
circuit 12V current is coming.

13. PRECAUTIONS
1. Keep safe yourself from high voltage.
2. Solder the wire safely.
3. While soldering don’t touch the soldering tip.
4. Solder under adult supervision.

14. USES
Most electronic device cannot with stand very high voltage or
alternating current due to its intense high power. The use of
batteries in all devices is not practical as the replacement and
durability is a huge problem as the devise has to be dismantled each
time for such replacement. So these rectifiers are used in most of
the electronic devices like TV, Radios, Chargers and Lighting sets.
The common uses of rectifiers are to supply polarized voltage for
welding, detection of amplitude modulated radio signals.
BIBLIOGRAPHY
1. HELP FROM TEACHERS 2.HELP FROM INTERNET
3.NCERT TEXTBOOK
WEBSITES
www.google.com
www.scribd.com
www.wikipedia.com

15. THANK YOU