Velammal New Gen School Physics Project (2024-2025) PDF

VELAMMAL NEW GEN SCHOOL NEDUNGUNDRAM SENIOR SCHOOL CERTIFICATE EXAMINATION PHYSICS (042) PROJECT REPORT ON RECTIFIERS (2024 – 2025) NAME: CLASS: XII REG.NO:  BONAFIDE CERTIFICATE This is to ce...

VELAMMAL NEW GEN SCHOOL NEDUNGUNDRAM SENIOR SCHOOL CERTIFICATE EXAMINATION PHYSICS (042) PROJECT REPORT ON RECTIFIERS (2024 – 2025) NAME: CLASS: XII REG.NO:  BONAFIDE CERTIFICATE This is to certify that this PHYSICS Project on the topic…………………………………………has been successfully completed by… … … … … … … … … … … … … of class XII,Roll.no…………………. at Velammal New-Gen School, Nedungundram for the partial fulfilment of this project as a part of Senior School Certificate Examination-CBSE, New Delhi for the academic Year 2024– 2025. Date: ……………. Signature of Principal Signature of the Guide Submitted for SSCE 2024-2025, PHYSICS Practical examination on …………………….. Signature of the Signature of the Internal Examiner External Examiner  ACKNOWLEDGEMENT Apart from the efforts taken by me, the success of the project depends largely on the encouragement and guidelines of many others. I take this opportunity to express my gratitude to the people who have been instrumental in the successful completion of this project. I express deep sense of gratitude to almighty God for giving me the strength to complete the project successfully. I express my heartfelt gratitude to my parents for the constant encouragement while carrying out this project. I express my deep sense of gratitude to our honorable Principal HILDA MABEL R, who has been continuously motivating and extending a helping hand to us. My sincere thanks to MS.DIVYA a guide, mentor, above all a friend, who critically reviewed my project and guided me during the implementation of the project. The guidance and support received from all the members who contributed, was vital for the success of the project. I am grateful for their constant support and help. NAME: CLASS: XII 4  CONTENTS 1. AIM 2. INTRODUCTION 3. MATERIALS REQUIRED FOR CONSTRUCTION 4. CIRCUIT DIAGRAM 5. CONNECTION DETAILS 6. PROCEDURE 7. WORKING 8. OBSERVATION AND RESULT 9. APPLICATIONS AND USES OF RECTIFIERS 10. CONCLUSION 11. BIBLIOGRAPHY 5  AIM To construct a full wave rectifier and show that the Alternating Current is rectified into a Direct current The Aim is to  Understanding Rectifiers and Rectification  Explain center tapped full wave rectification  Explain bridge full wave rectification. 6  INTRODUCTION A rectifier is an electrical component that converts alternating current (AC) to direct current (DC). A rectifier is analogous to a one-way valve that allows an electrical current to flow in only one direction. The process of converting AC to DC is known as rectification. A rectifier can take several physical forms, such as solid-state diodes, vacuum tube diodes, mercury-arc valves, silicon-controlled rectifiers, and various other silicon-based semiconductor switches. 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 electronic devices like TVs, Radios, Chargers, Lightings, etc 7  MATERIALS REQUIRED IN CONSTRUCTION  Connecting wires  A plug  Single lead wire- 2m  Three nuts and bolts 2-3 cm length  Circuit board  A Transformer (12 V )  A Resistor  p-n junction diode (4 nos )  A LED  Insulation tape, Blades, Soldering wax, Soldering Iron, Soldering Lead, and Sandpaper 8  CIRCUIT DIAGRAM Circuit diagram of a full wave rectifier : 9  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 are 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 the capacitor with the diode connection is connected to the other end of the resistor. Connect 2 leads on both ends of the resistor to measure the output and this is connected to the + ve & -ve terminals of the bulb. 10  HALF WAVE RECTIFIER A half-wave rectifier converts an AC signal to DC by passing either the negative or positive half-cycle of the waveform and blocking the other. Half-wave rectifiers can be easily constructed using only one diode, but are less efficient than full-wave rectifiers. Since diodes only carry current in one direction, they can serve as a simple half-wave rectifier. Only passing half of an AC causes irregularities, so a capacitor is usually used to smooth out the rectified signal before it can be usable. Half-wave rectifier circuit with capacitor filter and a single diode. Application  They are used for rectification applications  They are used for Signal demodulation purposes  They are used for Signal peak applications Advantages  Simple: The circuit design of it is simple and completely 11  straightforward.  Cheap: As it requires and uses a minimal number of components, it is cheaper.  Easy to use: As the construction is easy, the device is easy to use. Disadvantages:  Power Loss: As they only allow the half cycle of AC signal, and another half cycle is wasted, this leads to power loss. Working of Half Wave Rectifier: The half-wave rectifier has both positive and negative cycles. During the positive half of the input, the current will flow from positive to negative, which will generate only a positive half cycle of the AC supply. When the AC supply is applied to the transformer, the voltage will decrease at the secondary winding of the diode. All the variations in the AC supply will be reduced, and we will get the pulsating DC voltage to the load resistor. Efficiency of a half-wave rectifier Since only half of the input waveform is passed, the efficiency of a half- wave rectifier is lower than that of a full-wave rectifier. The maximum efficiency of a half-wave rectifier is about 40.5%, and the maximum efficiency of a full-wave rectifier is twice that. 12  FULL WAVE RECTIFIER A full wave rectifier is defined as a rectifier that converts the complete cycle of alternating current into pulsating DC. Unlike halfwave rectifiers that utilize only the halfwave of the input AC cycle, full-wave rectifiers utilize the full cycle. The lower efficiency of the half-wave rectifier can be overcome by the full-wave rectifier. Application:  They are used for identifying the amplitude of modulating radio signal  Full wave bridge rectifiers are used in a power supply circuit for different applications.  They are used to provide power supply to devices that require DC voltage similar to LED and motor.  They are used in mobile phones, laptops, and charger circuits.  They are used in UPS to convert AC into DC. 13   They are used in welding.  Advantages  They have higher efficiency than half-wave rectifiers. i.e. they convert AC into DC more efficiently.  There is no loss in output power since they utilize both half cycles and no voltage signal is wasted in the rectification process.  They have less ripple factor. i.e. output voltage of full wave rectifier has lower ripples than half wave rectifier. Disadvantages  They need more circuit elements than half-wave rectifiers which makes them complex and tends to occupy a lot of space.  They are more expensive than half-wave rectifiers. Working of Full Wave Rectifier: When the AC is supplied to the transformer, it steps down the 240 V main supply to 12 V. It has the capability of delivering 700mA. The 12-volt 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. During a 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. 14  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 now reverse-biased. The current flowing through the load is in the same direction as before. 15  THE NEGATIVE HALF CYCLE In subsequent half cycles of the AC, the above process is repeated. In both the half cycles, it is clear that current flows through the resistor in only one direction. Even though the voltage across the load is unidirectional, it will still contain a few AC components. This is filtered and made smooth using a capacitor, which filters 99 % of the AC. A resistor is then used to adjust the output voltage. The capacitor also nearly filters all AC components from supply and resistance is adjusted for the required output. As this is a simple circuit, two capacitors and one resistor are being used. The output Direct Current and voltage light up the LED and other sources connected with 16 17  OBSERVATION AND RESULT On connecting a voltmeter to the output of the bridge circuit 12 V current is flowing. 18  APPLICATIONS AND USES OF RECTIFIERS The primary application of the rectifier is to derive DC power from AC power. Rectifiers are used inside the power supplies of almost all electronic equipment. In power supplies, the rectifier is normally placed in series following the transformer, a smoothing filter, and possibly a voltage regulator. USES: A rectifier is used for powering appliances: As we know, all electrical appliances use a DC power supply to function. Using a rectifier in the power supply helps in converting AC to DC power supply. Bridge rectifiers are widely used for large appliances, which can convert high AC voltage to low DC voltage. These are used with transformers: Using a half-wave rectifier can help us achieve the desired DC voltage by using step-down or step-up transformers. Full-wave rectifiers are even used for powering up the motor and LED, which works on DC voltage. Uses of rectifier while soldering: A half-wave rectifier is used in soldering iron types of circuits and is also used in mosquito repellent to drive the lead for the fumes. In electric welding, bridge rectifier circuits are used to supply steady and polarized DC voltage. It is also used in AM radio: 19 A half-wave rectifier is used in AM radio as a detector because the output consists of an audio signal. Due to the lower intensity of the current, it is of very little use to the more complex rectifier. Uses of Rectifiers in Circuits: A half-wave rectifier is used in firing circuits and pulse-generating circuits. It is used for modulation: A half-wave rectifier is used to demodulate the amplitude of a modulated signal. In a radio signal, a full-wave bridge rectifier is used to detect the amplitude of a modulating signal. It is used in the voltage multiplier: For the voltage multiplier, a half-wave rectifier is used. 20  CONCLUSION Rectifiers are found in all power supplies that operate from an AC voltage source. Also, the rectifier is used as a power supply unit. The rectifier converts the AC input voltage to a pulsating DC voltage. The filter eliminates the fluctuations in the rectified voltage and produces a relatively smooth DC voltage. The regulator is a circuit that maintains a constant voltage for variations in the input line voltage or the load. 21  BIBLIOGRAPHY  PHYSICS NCERT BOOK GRADE 12  wikipedia.org  geeksforgeeks.org  byjus.com  www.olabs.edu.in 22