Physics Project on Full Wave Rectifier Class 12 CBSE

PHYSICS PROJECT ON Full Wave Rectifier 2016-2017

Name – Somrat Dutta Class – XII Sec – A School Roll No – Board Roll No – School – Delhi Public School, Siliguri

INDEX

1. AIM 2. ACKNOWLEDGEMENT 3. CERTIFICATE 4. INTRODUCTION 5. MATERIALS REQUIRED 6. CIRCUIT DIAGRAM 7. WORKING 8. BIBLOGRAPHY

AIM

“To construct a full wave rectifier and show that Alternating Current is rectified into a Direct Current”

Acknowledgement

The project could have never been possible without the support of various sources. It is extremely impossible to thank every individual who has helped me in completing this project. Some people have helped in the basic formularization and there were sources that helped me in giving the ideas a physical form/shape. I am extremely grateful to my mentor, Mr. Shekhar Jha for his invaluable guidance in the project right from the beginning. His vital support helped the project to take a logical and suitable shape. I take this opportunity to thank the School authorities, for extending their full support and cooperation in the project. Last but not the least; I would like to thank everyone who has offered a helping hand when required

CERTIFICATE

This is to certify that Somrat Dutta (Roll_No:…..……) student of Class XII, Delhi Public School, Siliguri has completed the project titled. “Full Wave Rectifier” during the academic year 2016-17 towards partial fulfillment of credit for the Physics Project evaluation of AISSCE 2017, and submitted working model and satisfactory report, as compiled in the following pages, under my supervision.

_________________________

Teacher’s Signature

Introduction A full wave rectifier is a device which is used to rectify all the alternating current components in an alternating supply and make it purely a direct current. The two alternating halves of an alternation current are rectified in a full wave rectifier which is an advantage over a half wave rectifier. Most electronic devices cannot withstand very high voltage or alternating current due to its intense high power. The use of batteries in all devices is not practical as their replacement and durability is a huge problem as the device has to be dismantled each time for such

a replacement. So these rectifiers are used in most of the electronic devices like TV’s, Radios, Chargers, and Lightings etc.

Materials required

1. Connecting wires 2. A plug 3. Single lead wire - 2m 4. 3 nuts & Bolts 2 to 3cm length

5. Circuit board 6. A Transformer 7. A capacitor 8. A Resistor (1 K Ω ) 9. P-N junction diodes 10. A LED 11. Insulation tape, Blades, soldering wax, soldering lead, soldering iron &sand paper

circuit diagram

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 connect ion is connected 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

1st when the A.C. is supplied to the transformer, it steps down the 230V 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 1st half cycle of the A.C. input Diode D1 is forward biased and a current ‘I’ flows in the circuit in the direction S 1D1 ABEOS1. During this time diode D2 is reverse biased. So it does not conduct any electric current. During the next half cycle, the diodeD2 is forward and D1 is reversed. Hence D2 conducts current in the direction S2D2 ABEOS2and 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

 Physics – Textbook for XII (NCERT)  Modern’s ABC of Physics

 Laboratory Manual (Rachna Sagar Pub.)  Encyclopedia