PROJECT FILE LED LAMP CERTIFICATE

THIS IS TO CERTIFY THAT Alind Khare (XII A), Pallav Joshi (XIIA), SESSION 2013-14 HAVE COMPLETED THEIR INFORMATICS PRACTICES PROJECT AND HAS GIVEN A SATISFACTORY ACCOUNT OF IT IN THE PROJECT FILE CONTAINING A RECORD OF THE PROJECT WORK.THIS PROJECT HAS BEEN COMPLETED AS PER THE CBSE GUIDELINES.

Teachers Signature

Mr. HEMANT PATIDAR Ms. NIRMALA REDDY

ACKNOWLEDGEMENT

We owe a great many thanks to a great many people who helped and supported me during the project.

Our deepest thanks to teachers, Mr. HEMANT PATIDAR and Ms. NIRMALA REDDY, for guiding and correcting various documents with attention and care. They have taken pain to go through the project and make necessary correction as and when needed.We express our thanks to the Principal Mr. AJAY MISHRA Sir, D.P.S. Bhopal, for extending his support.

Our deep sense of gratitude to the helpful people at D.P.S., and outside for their support.

We would also thank our Institution and our faculty members without whom this project would have been a distant reality. We also extend our heartfelt thanks to our family and well wishers.

CONTENTS

1. INTRODUCTION

2. CIRCUIT DIAGRAM

3. CIRCUIT EXPLANATION

4. DESCRIPTION OF COMPONENTS

5. CONCEPT OF LED LAMP

6. APPLICATIONS

7. CONCLUSION

BIBLIOGRAPHY

INTRODUCTION

AnLED lamp(orLED light bulb) is asolid-state lampthat useslight-emitting diodes(LEDs) as the source of light. LED lamps offer longservice lifeand high energy efficiency, but initial costs are higher than those offluorescentandincandescent lamps.Chemical decompositionof LED chips reduces luminous flux over life cycle as with conventional lamps.

The LEDs involved may be conventionalsemiconductorlight-emitting diodes,organic LEDs(OLED), orpolymer light-emitting diodes(PLED) devices. However, PLED technologies are not commercially available. Diode technology improves steadily.LED lamps can be made interchangeable with other types of lamps. Assemblies of high power light-emitting diodes can be used to replace incandescent or fluorescent lamps. Some LED lamps are made with bases directly interchangeable with those of incandescent bulbs. Since theluminous efficacy(amount of visible light produced per unit of electrical power input) varies widely between LED and incandescent lamps, lamps are usefully marked with theirlumenoutput to allow comparison with other types of lamps. LED lamps are sometimes marked to show the watt rating of an incandescent lamp with approximately the same lumen output, for consumer reference in purchasing a lamp that will provide a similar level of illumination.Light-emitting diodes usedirect current(DC) electrical power. To use them onACpower they are operated with internal or externalrectifiercircuits that provide a regulated current output at low voltage. LEDs are degraded or damaged by operating at high temperatures, so LED lamps typically includeheat dissipationelements such asheat sinksandcooling fins.

CIRCUIT DIAGRAM

Capacitors Resisitors DiodesC1 = 22uF 50V R1 = 470K 1W D1,D2,D3,D4 = IN 4007 MicC2 = 474K 250V R2 = 470R 1W D5,D6,D7,D8 = LED

CIRCUIT EXPLANATION

Capacitor C2along with diodes D1 through D4 forms the AC step down circuit. C2 reduces high voltage AC from mains to a low voltage AC which is rectified by the diodes D1-D4. Capacitor C1 removes ripples from AC so that low voltage DC is available to power the LEDs.

C2 is the X rated AC capacitor that reduces AC voltage throughCapacitive Rectance property.

Resistor R1 is very important to remove the stored voltage from C2 when power is switched off. This prevents lethal shock.

Resistor R2 limits the inrush current. More LEDs can be added by reducing the value of R2.

Shock Hazard : -

Since the circuit is directly connected to mains, take utmost care to avoid shock. No components should be touched when it is connected to mains. Construct this circuit only if you are experienced in handling high voltage AC.

DESCRIPTION OF COMPONENTS

Diode IN 4007 Mic :- This is a simple, very common rectifier diode. Often used for reverse voltage protection, the 1N4007 is a staple for many power, DC to DC step up, and breadboard projects. 1N4007 is rated for up to 1A/1000V.

Diode LED :- Alight-emitting diode(LED) is asemiconductorlight source.LEDs are used as indicator lamps in many devices and are increasingly used for otherlighting.

Capacitor 474K 250V :- C2 is the X rated AC capacitor that reduces AC voltage throughCapacitive Rectance property.

Resistor 470K 1W :-

Capacitor 22uF 50V :- High temperature electrolytics for use in switch mode power supplies found in TVs, VCRs, etc. 105 C operating temperature satisfies characteristic W of JIS-C-5141 standards. 20% tolerance.

CONCEPT OF LED LAMP

Diode Bridge OR Bridge Rectifier

Adiode bridgeis an arrangement of four (or more)diodesin abridge circuitconfiguration that provides the samepolarityof output for either polarity of input. When used in its most common application, for conversion of analternating current(AC) input into adirect current(DC) output, it is known as abridgerectifier. A bridge rectifier providesfull-wave rectificationfrom a two-wire AC input, resulting in lower cost and weight as compared to a rectifier with a 3-wire input from atransformerwith acenter-tappedsecondary winding.

The essential feature of a diode bridge is that the polarity of the output is the same regardless of the polarity at the input. The diode bridge circuit is also known as theGraetz circuitafter its inventor, physicistLeo Graetz, and the single-phase version, with four diodes, may also be referred to as anH bridge.

In the diagrams below, when the input connected to the left corner of the diamond ispositive, and the input connected to the right corner isnegative, current flows from the upper supply terminal to the right along thered(positive) path to the output, and returns to the lower supply terminal via theblue(negative) path.

When the input connected to theleftcorner is negative, and the input connected to therightcorner is positive, current flows from the lowersupply terminal to the right along thered(positive) path to the output, and returns to theuppersupply terminal via theblue(negative) path.

In each case, the upper right output remains positive and lower right output negative. Since this is true whether the input is AC or DC, this circuit not only produces a DC output from an AC input.

Bridge Rectifiers :- APPLICATIONS

White-light light-emitting diode lamps have longer life expectancy and higher efficiency (the same light for less electricity) than most other lighting. LED sources are compact, which gives flexibility in designing lighting fixtures and good control over the distribution of light with small reflectors or lenses.

The main difference of LED to other light sources is the directed light. Thus illuminating a flat defined area requires less Lumen compared to light sources which would need reflectors or lenses to do the same. For illuminating an 360 orbit, the benefits of LED are much smaller. LED lamps are used for both general and special-purpose lighting. Where colored light is needed, LEDs naturally emitting many colors are available, with no need for filters. This improves the energy efficiency over a white light source that generates all colors of light then discards some of the visible energy in a filter Most LED lamps replace incandescent bulbs rated from 5 to 60 watts. LED Sign modules.

Favorite uses for LED light bulbs1. Lamps:Lamps are a great place to use LED light bulbs. The lamp shade will help deflect the light trumping the directness of LED lights. Plus when the lamp gets knocked over, your bulb will survive the crash.2. Bathroom:Most likely the most used light switch in the house will be the bathroom light switch. Incandescent and CFL light bulbs don't like being turned on and off very often. This is why an LED light bulb is the perfect solution for your bathroom lighting needs. Line up a few bulbs in your vanity and fill the can lights with LED bulbs as well. It will take years before you have to worry about changing out the bulbs again!3. Motion Lights:A lot of homes and business have motion sensors on their outdoor lights. They turn on and off when someone walks by or drives by and even when the wind blows! Not only will a LED light bulb save energy in this situation, it will take the abuse of being turned on and off all the time!4. Always On:This happens mostly in businesses, where there is a safety light on all the time. The fastest way to recoup the cost of a LED light bulb is to have it turned on all the time! This makes LED bulbs the perfect solution for those lighting applications that are turned on all the time!5. Display Cases:LED light bulbs are perfect for display cases for your home or store. They emit hardly any damaging UV light and the cool running bulb won't burn your hand or melt you products!6. Garage Door Openers:Also known as light bulb destroyers, garage door openers are very tough on light bulbs due to their vibrating nature. By using LED light bulbs in your opener you may never have to change the bulbs again! LED's are very good at taking a beating from vibrating sources.

CONCLUSION

LED lights are great all rounders. LED lights are incredibly energy efficient, they illuminate people and things in the best possible light, they help the environment, require less maintenance than traditional bulbs.

L.E.D lights, or Light-Emitting Diodes, have been used industrially for traffic lights, exit signs and home electronics for a long time. Unlike traditional bulbs, L.E.D lights illuminate when the movement of electrons across a semiconductor creates light. This long-lasting, energy-saving technology is now a viable option for home and commercial users.

L.E.D. Lighting Concepts is focused on helping you create a stylish, comfortable and beautifully lit space.

BIBLIOGRAPHY

http://en.wikipedia.org http://www.ledlightingconcepts.com.au http://www.allaboutcircuits.com http://www.datasheetarchive.com http://ledsmagazine.com http://electroskan.wordpress.com