CFL and LED lamps.pdf

compact fluorescent light, energy-saving light, and compact
fluorescent tube.
The CFL was initially designed to replace the incandescent lamp
in terms of its compactness as well as energy efficiency.
The basic construction of a CFL consists a tube which is
curved/spiraled to fit into the space of an incandescent bulb,
and a compact electronic ballast in the base of the lamp
compact fluorescent light, energy-saving light, and compact
fluorescent tube.
• The CFL was initially designed to replace the incandescent lamp
in terms of its compactness as well as energy efficiency.
• The basic construction of a CFL consists a tube which is
curved/spiraled to fit into the space of an incandescent bulb,
and a compact electronic ballast in the base of the lamp

1. CFL & LED lamps

2. Compact Fluorescent Lamp (CFL)
•compact fluorescent light, energy-saving light, and compact
fluorescent tube.
•The CFL was initially designed to replace the incandescent lamp
in terms of its compactness as well as energy efficiency.
•The basic construction of a CFL consists a tube which is
curved/spiraled to fit into the space of an incandescent bulb,
and a compact electronic ballast in the base of the lamp.

4. How Compact Fluorescent Lamp (CFL)
works –Working Principle
•ACFLusesvacuumpipewhichisprinciplewisesametothestrip
lamps(commonlyknownasTubelight).
•Tubehastwoelectrodesonbothendswhichistreatedwith
Barium.
•Cathodeishavingatemperatureofabout900ºCandgenerates
abeamofelectronswhichisfurtheracceleratedbypotential
differencebetweenelectrodes.

5. •TheseacceleratedelectronsstrikeMercuryandArgonatomswhichin
turnresultsintheariseofalowtemperatureplasma
•ThisprocessinitiatestheradiationofMercuryinUltravioletform.
•Tube’sinsidefacecontains‘Luminophore’whosefunctionisto
convertUltravioletlightintovisiblelight.
•ThistubeisfedwithACpowersupplywhichfacilitatethechanging
functionalityofAnodeandCathode.
•TheCFLalsoconsistsaswitchedmodeconverter.Itfunctionsona
veryhighfrequencyandactsasareplacementofballast(choke)and
starterassembly.

6. Circuit Explanation ofCFL
•The CFL PCB is quite compact and fits in the holder base.
•Though being compact, it efficiently performs the requirements
as a choke.
•KeycomponentsofPCBofCFL
ThePCBofaCFLcontainsthefollowingkeycomponents:
•Bridgerectifiermadeupofdiode1N-4007
•Suppressorforsuppressinginterference
•Filtercapacitor
•Fusepoint
•Supplypoint

8. Phase wise Circuit Explanation of CFL
•The working of a CFL can be divided into two broad phases: –
•Starting Phase
•Normal Phase
•Starting Phase
•The starter segment comprise of a Diac, C2, D1 and R6. The
components D3, R3, D2 and R1 work as a protection circuit and
the rest as normal operation circuit.
•D refers for diode
•R refers for Resistor
•C refers for Capacitor, and
•Q stands for Transistor
•

9. •TheDiac,C2andR2sendavoltagepulsetoQ2Transistor’sbasewhich
causesittogetitsthresholdvalueanditstartsoperating.
•Assoonastheoperationstarts,theD1diodeblocksthewholesection.
•CapacitorC2isalsodischarged(afterchargedtoitsfullvalue)eachtime
thetransistorQ2operates.
•Thereforeafteritsfirststart,Thereisnotenoughenergyleftforreopening
ofDiac.
•Further,thetransistorsareexcitedwiththehelpofTR1transformer.
•Asthevoltageisraisedfromresonantcircuit(L1,TR1,C3andC6),the
tubelightsupassoonasresonantvoltageisspecifiedbycapacitorC3
(whichfeedsFilaments).
•AtthismomentthevoltageC3isover600V.

10. •Normal Phase
•Justaftertheionisationofgaspresentinthevacuum-pipe,the
practicalshortingofcapacitorC3iscarriedout.
•Thisresultsinsteppingdownofthevoltage.AfterthatC6starts
drivingthechanger.Averysmallvoltageisgeneratedbythis
change,yetitissufficienttorunthelampin‘ON’condition.
•Underregularrunningcondition,ifthetransistorcomesin
OPENstate,ThecurrentbeingfedtoTR1keepsincreasingtill
thecoreoftransformersaturates,andthusthefeedtobase
dropsdownresultingittoclosethetransistor.
•Immediatelyafterthisprocess,thesecondtransistorisexcited
byreversewindingofTR1andsotheprocessgoeson.

11. •Advantages ofCompact Fluorescent Lamp (CFL)
•TheadvantagesofCFLareasfollows:–
•Itisenergyefficiency
•Ithasahigherlifespan(nearlyfivetofifteentimes)comparedtotheold
filamentbulbs.
•Ithaslesserpowerrating(almost80percent)comparedtotheoldfilament
bulbs.
•Itislowlifecyclecost.Though,ithasahigherpurchasepricethanan
incandescentlamp,itcansaveoverfivetimesitspurchasepricein
electricitycostsoverthelamp’slifetime.
•Disadvantages of Compact Fluorescent Lamp (CFL)
•Ittakesmoretimetostart
•TheinitialPurchasecostishigh.
•Itdoesnotcomesindarkshadestoo.
•Likeallotherfluorescentlamps,CFLscontainmercury,whichcomplicates
theirdisposal.

12. How is performance affected by ambient
temperature?
•Performance characteristics of compact fluorescent lamps will be
affected by lamp base position and by operation in cold or hot
environments.
•Temperature impacts both short-term and long-term performance. In
the short-term, temperature impacts CFL light output, electricpower,
and luminousefficacy, with most lamps operating at their peak in an
ambient temperature of about 77°F (25°C).
•Over long periods of time, elevated temperatures may shorten ballast
life and consequently reduce lamp life in self-ballasted CFLs.

13. Figure 9. Impact of ambient temperature on power, light output, and efficacy of many
fluorescent lamps
Short-term thermal effects
Operating fluorescent lamps in cold or hot environments will lead to
reduced light output, reduced power, and reduced efficacy, as shown in
Figure

14. •Some manufacturers of CFLs report information about light output at a
range of temperatures
•If this information is not available, users can generalize from other curves
showing fluorescent output forminimum bulb wall temperatureor
ambient temperature, such as Figure

15. Figure 10. Impact of ambient temperature on
light output of amalgam and nonamalgam
fluorescent lamps
AsshowninFigurereductioninlightoutput
canbeminimizedwiththeuseofa
mercuryamalgam
UseofmercuryamalgamwithCFLsisoftennot
reportedinlampcataloginformation.
However,userscanrequestthisinformation
fromthelampmanufacturer.

16. LED lamp
•An LED lamp or LED light bulb is an electric light for use in light
fixtures that produces light using one or more light-emitting diodes
(LEDs).
•LED lamps have a lifespan many times longer than equivalent
incandescent lamps, and are significantly more efficient than most
fluorescent lamps, with some LED chips able to emit up to 303
lumens per watt (as claimed by Cree and some other LED
manufacturers).
•However, LED lamps require an electronic LED driver circuit when
operated from mains power lines, and losses from this circuit means
that the efficiency of the lamp is lower than the efficiency of the LED
chips it uses.

17. •The most efficient commercially available LED lamps have efficiencies
of 200 lumens per watt (Lm/W).
•The LED lamp market is projected to grow by more than twelve-fold
over the next decade, from $2 billion in the beginning of 2014 to $25
billion in 2023, a compound annual growth rate (CAGR) of 25%.
•As of 2016, many LEDs use only about 10% of the energy an
incandescent lamp requires.

18. •Similar to incandescent lamps (and unlike most fluorescent lamps), LEDs
come to full brightness immediately with no warm-up delay.
•Frequent switching on and off does not reduce life expectancy as with
fluorescent lighting
•Light output decreases gradually over the lifetime of the LED (see Efficiency
droop section).
•Some LED lamps are made to be a directly compatible drop-in replacement
for incandescent or fluorescent lamps.
•LED lamp packaging may show the light output in lumens, the power
consumption in watts, the color temperature in Kelvin or a colour
description such as "warm white", "cool white" or "daylight", the operating
temperature range, and sometimes the equivalent wattage of an
incandescent lamp delivering the same output in lumens.

19. •The directional emission characteristics of LEDs affect the design of
lamps.
•While a single power LED may produce as much light output as an
incandescent lamp using several times as much power, in most
general lighting applications multiple LEDs are used.
•This can form a lamp with improved cost, light distribution, heat
dissipation and possibly also color-rendering characteristics.
•LEDs run on direct current (DC), whereas mains current is alternating
current (AC) and usually at much higher voltage than the LED can
accept.

20. •LED lamps can contain a circuit for converting the mains AC into DC at
the correct voltage.
•These circuits contain rectifiers, capacitors, and may have other active
electronic components, which may also permit the lamp to be
dimmed.
•In an LED filament lamp, the driving circuit is simplified because many
LED junctions in series have approximately the same operating
voltage as the AC supply.
•LEDs require a power supply system (driver) to interface them with
the electric network. Generally the current waveform contains some
amount of distortion, depending on the luminaries’ technology.[11]

22. •LED lamps are often made with arrays ofsurface mount LED
modules(SMD modules) that replace incandescent or compact
fluorescent lamps, mostly replacing incandescent lamps rated from 5
to 200 watts.
•A significant difference from other light sources is that the light is
more directional, i.e., emitted as a narrower beam

23. What is Li-Fi Technology –How it Works, Applications & Advantages
•Li-Fi is a new way ofwirelesscommunicationwhich uses LED lights to
transmit data wirelessly.
•The data flow speed of this wireless data communication technology is quite
high and has low cost installation.
It is well accepted that transmission of data is one of the most important day to
day activities in today’s fast changing world. Some problems that is normally
faced are:
•Slow connection to the Internet when multiple devices are connected
•Unavailability of fixed bandwidth due to overcrowding does not allow high
data transfer rates.
•This technology can be a solution to all these problems. Researches are going
on to develop this technology on a broad scope.

24. Fig. 1 –Introduction to Li-Fi
Technology

25. What is Li-Fi Technology
•The term Li-Fi (Light and Fidelity) refers to Visible Light
Communication (VLC) technology. This technology uses a part of the
electromagnetic spectrum that is still not utilized generally i.e. the
Visible Spectrum.
•In simple terms, LiFiis a light-based Wi-Fi. This technology has a
much broader spectrum for transmission compared to conventional
methods ofwirelesscommunication which uses radio waves.
•The basic ideology of this technology is transference of data using
LED light of varying intensities.
•It uses transceivers fitted with LED lamps that can transmit and
receive information.
•This results in adding new and unutilized bandwidth of visible light
and may offer additional frequency band than those bands which are
available for RF communication.

26. Fig. 2 –Uses of Electromagnetic
Spectrum

27. •Since LiFiuses the visible spectrum, concerns of adverse effects of
electromagnetic waves (associated with Wi-Fi technology) gets
alleviated.
•Security concerns are also reduced as data or information on the
Internet cannot be accessed in the absence of light.
•How Does a Li-Fi Work
•Li-Fi is a Visible Light Communications (VLC) system and such a
system has two qualifying components:
•One device with a Photo-diode able to receive light signals.
•A light source coupled with a Signal Processing Unit.
•The VLC system signals work by switching bulbs on and off within
nanoseconds such that human eyes are unable to notice it.
•High brightness white LED acts as a light source i.e. as transmission
source.
•A silicon photo-diode with good response to visible light is the
receiving element.

28. Fig. 3 –How Does the Li-Fi Technology
Work

29. •LEDs are switched on and off to generate digital strings of
combination of 1s and 0s.
•To generate a new data stream, data is encoded in the light by
changing the flickering rate of the LED, which is used as the
source.
•The LED output appears constant to the human eye by the fast
flickering rate of the LED.
•VLC data rate is increased by parallel data transmission using an
array of LEDs where each LED transmits a different data stream.

30. •Applications of Li-Fi Technology
•This technology has a wide range of applications such as:
•Public Internet access using existing LED lighting.
•Auto-piloted cars that communicate through their LED based
headlights.
•Connecting with specialists across the globe from the operation
theater.
•Since it uses just the light, it can be used safely in locations or areas
where the presence of radio waves raises concerns of security.

31. •Advantages of Li-Fi technology are:
•Efficiency: Efficient use of energy consumption due to the use of LED
illumination which are already in use for lighting purpose. Hence the
transmission of data will require negligible additional power/ energy.
•High speed: The technology uses bandwidth that is not is use currently.
Hence, low interference, wider bandwidths and high-intensity output are
its key data features.
•Availability: As the light source is available everywhere, availability is not
an issue. Hence, wherever there is a light source, there will be Internet.

32. •Cost Efficient: This technology requires few components for its
working. The technology also uses negligible additional power for
data transmission. Overall, utilization of this technology becomes cost
efficient.
•Security: within a confined area. This internet cannot be intercepted
and misused outsideAslight cannot pass through opaque structures,
LiFiinternet is available only to those the area under operation.
•Futuristic: This technology has a great scope in future due to the
extensive growth in the use of LEDs. Overall, it is considered a
sustainable model for Internet access as it incurs lower cost and offers
higher efficiency.

33. •Limitations of Li-Fi
•Some of the major limitations of Li-Fi are:
•Access of internet is limited by the presence of a light source.
•Data transmission speed can get lowered because of interference of
natural light (sunlight) and normal electric light.
•Since light cannot pass through opaque objects, obstacles on
pathways can affect data transmission.
•It has a much shorter range than Wi-Fi.
•Not yet developed for mass scale adoption.

34. Fig. 5 –Strength and Weakness of Li-Fi
Technology

35. •
Li-Fi Wi-Fi
Spectrum UsedVisual Light Radio Frequency
Range
Depends on light
intensity, can be lower
than Wi-Fi
Less than 200 meters
Cost
High installation cost,
low regular usage cost
Low cost
Security High Less (compared to Li-Fi)
Data transfer
speed
Higher (compared to
Wi-Fi, can be up to 100
times faster)
High
Availability
Yet to be available for
commercial use
Widely available
What is the difference between Wi-Fi and Li-Fi Technology
Wi-Fi offers highest speed access to internet among the current technology. However, if we compare Li-Fi with Wi-Fi, we find the
following key differences:
Due to the speed and security offered by Li-Fi
technology compared to Wi-Fi, Li-Fi is here to
stay and likely to be used widely.