8/9/2019 Compact Fluorescent Light Bulb

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Compact Fluorescent Light Bulb

 A compact fluorescent lamp (CFL), also called compact fluorescent light, energy-saving light,

and compact fluorescent tube, is a fluorescent lamp designed to replace an incandescent lamp;

some types fit into light fixtures formerly used for incandescent lamps !he lamps use a tube "hich is

curved or folded to fit into the space of an incandescent bulb, and a compact electronic ballast in the

base of the lamp

Compared to general-service incandescent lamps giving the same amount of visible light, CFLs use

one-fifth to one-third the electric po"er, and last eight to fifteen times longer A CFL has a higher

purchase price than an incandescent lamp, but can save over five times its purchase price in

electricity costs over the lamp#s lifetime  Li$e all fluorescent lamps, CFLs contain

toxic mercury "hich complicates their disposal %n many countries, governments have established

recycling schemes for CFLs and glass generally

!he principle of operation in a CFL bulb remains the same as in other fluorescent lighting& electrons

that are bound to mercury atoms are excited to states "here they "ill radiate ultraviolet l ight as they

return to a lo"er energy level; this emitted ultraviolet light is converted into visible light as it stri$es

the fluorescent coating on the bulb (as "ell as into heat "hen absorbed by other materials such as

glass)

CFLs radiate a spectral po"er distribution that is different from that of incandescent lamps

%mproved phosphor  formulations have improved the perceived color of the light emitted by CFLs,

such that some sources rate the best 'soft "hite' CFLs as subectively similar in color to standard

incandescent lamps

CFLs typically have a rated service life of ,***+,*** hours, "hereas standard incandescent

lamps have a service life of .* or ,*** hours  /o"ever, the actual lifetime of any lamp depends

on many factors, including operating voltage, manufacturing defects, exposure to voltage spi$es,

mechanical shoc$, fre0uency of cycling on and off, lamp orientation, and ambient operating

temperature, among other factors

!he life of a CFL is significantly shorter if it is turned on and off fre0uently %n the case of a -minute

on1off cycle the lifespan of some CFLs may be reduced to that of incandescent light bulbs !he

23 4nergy 3tar  program suggests that fluorescent lamps be left on "hen leaving a room for less

than minutes to mitigate this problem CFLs produce less light later in their lives than "hen they

are ne" !he light output decay is exponential, "ith the fastest losses being soon after the lamp is

first used 5y the end of their lives, CFLs can be expected to produce .*+6*7 of their original light

output !he response of the human eye to light is logarithmic !hat is, "hile the human eye is highly

sensitive to changes in the intensity of faint light sources, it is less sensitive to changes in the

intensity of brighter light sources since the pupils compensate by dilating or constricting 3o,

presuming the illumination provided by the lamp "as ample at the beginning of its life, and the light

output of a bulb gradually decreases by 87, vie"ers "ill perceive a much smaller change in light

intensity

http://en.wikipedia.org/wiki/Fluorescent_lamphttp://en.wikipedia.org/wiki/Incandescent_light_bulbhttp://en.wikipedia.org/wiki/Light_fixturehttp://en.wikipedia.org/wiki/Electronic_ballasthttp://en.wikipedia.org/wiki/Luminous_fluxhttp://en.wikipedia.org/wiki/Mercury_(element)http://en.wikipedia.org/wiki/Fluorescent_lamp#Principles_of_operationhttp://en.wikipedia.org/wiki/Color_temperature#Spectral_power_distributionhttp://en.wikipedia.org/wiki/Phosphorhttp://en.wikipedia.org/wiki/Service_lifehttp://en.wikipedia.org/wiki/Incandescent_light_bulb#Voltage.2C_light_output.2C_and_lifetimehttp://en.wikipedia.org/wiki/Incandescent_light_bulb#Voltage.2C_light_output.2C_and_lifetimehttp://en.wikipedia.org/wiki/Voltage_spikehttp://en.wikipedia.org/wiki/Shock_(mechanics)http://en.wikipedia.org/wiki/Operating_temperaturehttp://en.wikipedia.org/wiki/Operating_temperaturehttp://en.wikipedia.org/wiki/Energy_Starhttp://en.wikipedia.org/wiki/Exponential_decayhttp://en.wikipedia.org/wiki/Logarithmic_scalehttp://en.wikipedia.org/wiki/Incandescent_light_bulbhttp://en.wikipedia.org/wiki/Light_fixturehttp://en.wikipedia.org/wiki/Electronic_ballasthttp://en.wikipedia.org/wiki/Luminous_fluxhttp://en.wikipedia.org/wiki/Mercury_(element)http://en.wikipedia.org/wiki/Fluorescent_lamp#Principles_of_operationhttp://en.wikipedia.org/wiki/Color_temperature#Spectral_power_distributionhttp://en.wikipedia.org/wiki/Phosphorhttp://en.wikipedia.org/wiki/Service_lifehttp://en.wikipedia.org/wiki/Incandescent_light_bulb#Voltage.2C_light_output.2C_and_lifetimehttp://en.wikipedia.org/wiki/Incandescent_light_bulb#Voltage.2C_light_output.2C_and_lifetimehttp://en.wikipedia.org/wiki/Voltage_spikehttp://en.wikipedia.org/wiki/Shock_(mechanics)http://en.wikipedia.org/wiki/Operating_temperaturehttp://en.wikipedia.org/wiki/Operating_temperaturehttp://en.wikipedia.org/wiki/Energy_Starhttp://en.wikipedia.org/wiki/Exponential_decayhttp://en.wikipedia.org/wiki/Logarithmic_scalehttp://en.wikipedia.org/wiki/Fluorescent_lamp

8/9/2019 Compact Fluorescent Light Bulb

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