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