Voltage Regulator using LM317 and it’s Application
- 1. Department of Electrical Engineering “Voltage Regulator using LM317 and it’s Application” PBL Presentation on
- 2. 31/07/2025 DIT, Department of Electrical Engineering 2 Flow of Presentation o Introduction o Literature Survey o Proposed System o Block Diagram with Explanation o Circuit Diagram with Explanation o Details of Software and Hardware o Simulation Diagram/Programming/ Both o Details of hardware and Selection of Components o Advantages, Disadvantages and Applications o Conclusion
- 3. Introduction A variable voltage regulator is circuit which varies the output voltage by taking specific range supply at input, and it allows the output voltage to be adjusted manually within specified range it's commonly used in electronic circuits to provide stable voltage to components such as integrated circuits. This circuit has an inbuilt bridge rectifier, so We can directly supply 12V AC supply form 230 -12v step down transformer to the bridge rectifier. The whole circuit converts 230V AC to 0v – 12v DC. We can also monitor the output voltage on the digital voltmeter, connected with the circuit We can use this circuit as a variable DC power supply for different electronics projects and also integrate with other circuits.
- 4. Literature Survey o The LM317 datasheet provided by the manufacturer (usually Texas Instruments) is a primary source of information. It includes details about the operating conditions, electrical characteristics, and typical application circuits. o "The Art of Electronics" by Paul Horowitz and Winfield Hill: This comprehensive book covers a wide range of electronic circuits and components, including voltage regulators. It provides practical insights and design considerations for using components like the LM317. o Websites such as All About Circuits, Electronics Hub, and Electronics Tutorials provide tutorials, articles, and user forums discussing voltage regulators and their applications.
- 5. Proposed System Block Diagram :- Bridge Rectifier Step Down Voltage 230 to 12V AC Input voltage 12v DC Variable Output voltage o Step-down Voltage (230-12V AC): This likely represents a transformer that reduces the incoming voltage from 230V AC to 12V AC. o Bridge Rectifier: This component converts the AC voltage to DC voltage. It essentially rectifies the alternating current into a pulsating direct current. o Input Voltage (12V DC) to Voltage Regulator: The rectified DC voltage (from the bridge rectifier) serves as the input to the voltage regulator. o Voltage Regulator: This regulates the incoming voltage to a stable output voltage. It ensures that the output voltage remains constant despite changes in the input voltage or load. o Variable Output Voltage: This indicates that the voltage regulator is adjustable, allowing you to vary the output voltage as needed within a certain range
- 7. Sr No. Component Name Specification Quantity Cost (Rs.) 1 Single phase Transformer 230/12v AC step down 01 100/- 2 Diodes 1N4007 06 30/- 3 Capacitors 10uF,100 nF 1000uF 35 v 05 25/- 4 Resistor 1k ohm 220 ohm 02 10/- 5 Voltmeter Digital 01 150/- 6 Potentiometer 10k ohm 01 30/- 7 LM317IC 1.5 A , upto 37v 01 30/- 8 LED 5mm,10mm 02 15/- 9 Motor 12V DC, 0.15-0.75A 01 100/- TOTAL 460 Components :-
- 8. Details of Hardware :- Transformer 230-12V AC Potentiometer 10k ohm LM317IC Variable voltage Regulator Input 12v AC Output 0-12V DC
- 9. Advantages :- 1.Adjustability : It allows to adjust the output voltage according to specific requirements (0-12v DC). 2.Stability : Circuit provides stable output voltage despite fluctuations in input voltage and load conditions. 3.Easy to use : Its simple configuration and availability in various package types make it easy to implement in different circuit and application. Disadvantages :- 1. Limited Current Output :The LM317 is not suitable for high-current applications as it has a relatively low maximum output current compared to other voltage regulators. 2. Heat Dissipation: When regulating higher voltage differentials or currents, the LM317 can generate significant heat, requiring adequate heat sinking to prevent overheating and ensure proper operation. 3. Voltage Regulation Accuracy: In projects requiring precise voltage regulation, the LM317's inherent voltage reference inaccuracies might require additional calibration or compensation circuitry, adding complexity to the design.
- 10. Applications :- Battery charging system DC Motor speed controller Electrical Projects Light Intensity Control Electrical appliances Testing
- 11. 31/07/2025 DIT, Department of Electrical Engineering 11 Conclusion o The project successfully demonstrated the design and implementation of a variable voltage regulator using the LM317IC. Through experimentation, we observed the regulator's ability to provide a stable Variable output voltage(0-12V DC) with current capacity 1.5. across a range of input voltages (11-12V) AC , showcasing its versatility and reliability. o Despite encountering some challenges during the design and testing phases, such as component selection and circuit optimization, the project ultimately achieved its objectives. o Furthermore, the practical application of the variable voltage regulator was explored, highlighting its potential use in various electronic devices and systems where stable and adjustable voltage supply is essential., We can use this circuit as a variable DC power supply for different electronics projects & also integrate with other circuits. highlighting its potential in powering electronic devices with different voltage requirements. Overall, the project contributes to a better understanding of voltage regulation principles and practical applications using the LM317IC.
- 12. 31/07/2025 DIT, Department of Electrical Engineering 12 Learnings Teamwork Circuit Design Technical skills Project Manegement Problem Sloving Communication Skills
- 13. 31/07/2025 DIT, Department of Electrical Engineering 13 Any Query
- 14. 31/07/2025 DIT, Department of Electrical Engineering 14 Thank you !