Physics

Investigatory Project

Full Wave Rectifier

Submitted by: Prabhat Singh Tomar

DEPARTMENT OF PHYSICS CERTIFICATE

This is to certify that Prabhat Singh Tomar, a student of class XII-C, has successfully completed the project titled “ FULL WAVE RECTIFIER” under the guidance of Mrs. Darakhshan Gupta (Subject Teacher) during the academic year 2015-16 . Mrs. Darakhshan Gupta Dept. of Physics Cambridge School

ACKNOWLEDGEMENT

In the accomplishment of this project successfully, many people have bestowed upon me their blessings and the heart pledged support, this time I am utilizing 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 physics teacher Mrs.Darakhshan Gupta, whose valuable guidance has been the one that helped me patch this project and make it foolproof success. Her instructions has served 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.

INDEX

1.INTRODUCTION 2.AIM

3. MATERIALS REQUIRED 4. CIRCUIT DIAGRAM

5. PROCEDURE 6. WORKING

7. BIBLIOGRAPHY

INTRODUCTION A rectifier is an electrical device that converts alternating current (AC), which periodically changes 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.

AIM

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

MATERIALS REQUIRED

1. Connecting Wires 2. A plug

3. Single Lead Wire- 2m 4. Cardboard 5. Capacitor

6. A Transformer (6V) 7. A Resistor

8. P-N Junction Diode 9. A LED

10. Insulation Tape, Blades, Soldering Wax, Soldering Lead, Soldering Iron &

Sand Paper

Connection Details:

  Connections are done as in the circuit. The A.C. supply is given to both the input wires of the transformer and the two ends of the secondary coil is given to the P side of the two diodes and the N side of the diodes are twined and then connected to one end of the capacitor and the other end to the center tap lead and to the resistor. Further, the other end of capacitor with the diode connection isconnected to the other end of the resistor. Connect 2 leads on both the ends of the resistor to measure the output and this is connected to the +ve & -ve terminals of the bulb.   

WORKING

First when the A.C. is supplied to the transformer, it steps down the 220V main supply to 6 volts. It has a capability of delivering a current of 500mA. The 6 volts A.C. appearing across the secondary is the RMS value and the peak value is 8.4 volts. During the first half cycle of the A.C. input Diode D1 is forward biased and a current ‘I’ flows in the circuit in the direction S1D1ABEOS1. During this time diode D2 is reverse biased. So it does not conduct any electric current. During the next half cycle the diode D2 is forward and D1 is reversed. Hence D2 conducts current in the direction S2D2ABEOS2 and D1 does not conduct any current. In subsequent half cycles of the A.C current the above processes are repeated. In both the half cycles it is clear that current flows through the resistor in only one direction ABE. Even though the voltage across RL is unidirectional it will still contain a few A.C components. This is filtered and made

smooth using a capacitor, which filters 99% of the A.C current. A resistor is then used to adjust the output voltage. Capacitor also nearly filters all A.C components from the supply and resistance is adjusted for the required output. As this is a simple circuit, only one capacitor and a resistance are being used. But there will be slight factor of A.C.current still left in the output but it is negligible. The output Direct Current and voltage light up the LED.

 

BIBLIOGRAPHY 1. www.google.com 2. www.wikipedia.com 3. School Library 4. www.physicstoday.com 5. www.scribd.com