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TOPIC 5 - LAMPS & LIGHT FITTINGS - Coggle Diagram
TOPIC 5 - LAMPS & LIGHT FITTINGS
DISCHARGE LAMP
Gas is either mercury or sodium vapour
Gas in the glass tube may be at low or high pressure
Low Pressure Mercury Lamp (Fluorescent Lamp)
Efficacy 65-105 lm/W
Life 8,000 to 20,000 hours
Requires starter and ballast.
For most indoor areas especially low bay lighting (i.e. mounting height of maximum 6m)
Available in tubes, circular, compact sizes
Produces large proportion of UV
Phosphor used to convert UV to visible light
Colour depends on type of phosphors used
Warm white (3000K), daylight (6500K)
Compact Fluorescent Lamps
Commonly referred to as energy saving lamps
High Pressure Mercury Lamp
They are either clear glass or phosphor coated
Efficacy about 60 lm/W
Lamp life about 16,000 hrs
Metal Halide Lamp
Metal halide is a compound between metal and halogen.
Lamp life is shorter – 10,000 hrs
Used in sports stadium, lower power lamps are used in shop display lighting.
Low Pressure Sodium (SOX) Lamp
produces a distinctively yellow light that is
monochromatic
Have a high
luminous efficacy
Traditionally used for street lights and garden lightings
High Pressure Sodium (SON) Lamp
Has a better colour rending that is more acceptable than low pressure sodium lamp
Used in modern street lighting
INCANDESCENT LAMP
The filament is heated to a very high temperature by an electric current & light is produced
The higher the temperature the more light is produced & the whiter the light.
Halogen Lamp
Low voltage (12V)
Longer life (2000 hours)
Higher efficacy (17-22 lm/W)
Better colour
For display lighting in sales application, task lighting
GLS
Suitable for social areas and domestic application
Light is seen as warm
The filament is surrounded by an inert gas
The inert gas suppresses the evaporation of the filament
The lamp produces a continuous spectrum that is deficient in blue
LED LAMP
Luminaires (light fitting)
It is the light fitting that holds or contains a lamp.
It controls the distribution of light, usually absorbing & directing light
Mounting Position
recessed into the ceiling (recessed)
fixed on the ceiling (surface mounted)
suspended from the ceiling (pendant)
They produce light by a process of electroluminescence when semiconductor crystals are electrically excited
Efficacies are improving over the years
Now it is the most efficient type of lamp
Life: more than 50,000 hrs
Most suitable in areas where lighting have to be left on for long hours
Also used in corridor lightings of HDB estates