Illumination

Individual projectCourse code : EEE 5212

Name : Yik Wei Kian ID : I11008341

Presentation will covered the topic of:

Explain what is illumination. Explain the principle of producing artificial

light.Law of illumination.lighting schemesExplain what is floodlighting .Working principle of types of lamps(watch

videos).Comparison of different light source

What is illumination?

Illumination is the phenomenon when the material was heated up above a certain temperature, the material will start radiating the energy in the form of light.

The principle of producing artificial lightIncrease the temperature of body or gas

above average room temperature (23 Celsius).

begins to radiate energy in the surrounding medium in the form of electromagnetic waves of various wavelengths

A typical human eye will respond to wavelengths from about 390 to 700 nm

electromagnetic waves of various wavelengths

The radiant energy depends on the temperature of the hot body.

when the temperature is low, the radiated energy is in the form of heat waves only (feel hot only)

After certain temperature is reached, the radiated energy is in the form of heat waves and light wave (feel hot and bright)

As the temperature is increased, the wavelength of visible radiation goes on becoming shorter.

The light wave travel with the velocity approximately to 3x10 ^8m/sec.

Red radiation wavelength = 390  nm Violet radiation wavelength = 700 nm For expressing wavelength of light, another

unit called Angstrom Unit 1 A.U. = 10-8 cm= 10-10 cm

Hence red = 3900 x 10-10 cm

Violet = 700 x 10-10 cm

Law of illuminationThere are two laws of Illuminations :a. Law of intensityb. Law of Inverse Squaresc. Lambert’s Cosine Law

Law of illuminationa. Illumination

(E) is directly proportional to intensity (I)

b. Law of Inverse Squares-Illumination(E) inversely proportional to square of distance (D2)

Law of illuminationc. Lambert’s Cosine

Law :illumination(E) measured will vary with respect to the cosine of the angle between the optical axis of the source and the normal to the detector.

lighting schemesDirect lightningIndirect lightingSemi- direct lightingSemi – indirect lightingGeneral diffusing system

1) Direct lightning

•Mean the light from the source fall directly to the object or surface that illuminated.•With the help of shade , globe and reflector •Emit the light downward or upward but not to side•Mostly use for suspended illumination such as table or floor lamp

•The illumination will decrease due to dirty of bulb or reflector.• efficient but glare of lamp cause harsh shadow.

2) Indirect lighting

•Lighting provided by reflection usually from wall or ceiling surfaces.•The lamp either placed behind or in suspension non transparent bowl •The light thrown upward of ceiling and which the light is distributed all over the room by reflection diffusion

•Indirect lighting provide shadow less illumination suitable used in drawing office and workshop

3) Semi- direct lighting

•The system send most of light directly downward to working plane and considerable amount reach upward ceiling wall.

•The division about 30 % upward and 45 % downward.

•The system suitable for the room with high ceiling room.•The shadows produced by semi direct lighting are diffused and do not cause discomfort for glare of light.

4)Semi – indirect lighting

•The system send most of light directly upward to ceiling wall for diffuse reflection and the rest reach downward directly to working plane.

5) General diffusing system

•When the light is completely enclosed or concealed with the help of globe and ceiling panel.•The light is diffused since pass through the glass or plastic.

•The light distribution are equally

what is floodlighting ?•Floodlighting is a broad-beamed, high-intensity artificial lights of powerful projector used to illuminate large surface area.•Used in football court, concert, stadium and other places where the large surface area need to illuminated.•The purpose is to enhance the beauty of building, advertising purpose, industrial and commercial purpose

Working principle of types of lamps(watch videos)

•Incandescence lamp (3 minutes)Discharge lamp :•Fluorescent lamps (1.22 minutes)•Sodium Vapour lamp (2 minutes)•mercury vapour lamp(3 minutes)

Comparison of different light source1. Incandescent lamp :

- take short time to start, light up instantaneously and off momentarily if cut off supply.

- light color is near to naturally. - low installation cost but high operating

cost. - Able to used in DC or AC supply

- switching frequency does not effect the life span of lamp.

2. Discharge lamp (Fluorescent lamps) Need a little time to start (take I sec or

more).When supply is restored lamp go off and

restart(blinking).The color of fluorescent is produced by

various phosphor coatings.Initial installation cost is high but operating

cost is low.Frequency switching will effect lifespan of

lamp.

3. Sodium Vapour lampTake long time to start about 5 to 6 minutes.The lamp turn off and cannot restart until

recovery the supply voltage fall to its normal value.

The color of light is yellowish and produce color distortion.

Initial installation cost is high, operating cost lesser than filament lamp but higher than fluorescent lamp.

Usually use at open space such as high way, road side.

4. mercury vapour lampTake long time to start about 5 -6 minutes. The lamp turn off and cannot restart until

recovery the supply voltage fall to its normal value.

Initial installation cost is high , but operating cost lesser than fluorescent lamp.

Stroboscopic effect(flashes of light) occur in the light .

Usually use at open space such as high way, car park.

References:1. Laws Of Illumination Help for Electrical Energy – Trans tutors .

2015. Laws Of Illumination Help for Electrical Energy – Trans tutors . [ONLINE] Available at: http://www.transtutors.com/homework-help/electrical-engineering/electrical-energy-utilization/laws-of-illumination.aspx. [Accessed 26 October 2015].

2. Types Of Lighting Schemes Help for Electrical Energy - Transtutors . 2015. Types Of Lighting Schemes Help for Electrical Energy - Transtutors . [ONLINE] Available at: http://www.transtutors.com/homework-help/electrical-engineering/electrical-energy-utilization/types-of-lighting-schemes.aspx. [Accessed 26 October 2015].

3. Floodlights | Lighting | Screwfix.com. 2015. Floodlights | Lighting | Screwfix.com. [ONLINE] Available at: http://www.screwfix.com/c/electrical-lighting/floodlights/cat840908. [Accessed 26 October 2015].

4. Incandescent Lamps . 2015. Incandescent Lamps . [ONLINE] Available at: http://homepages.inf.ed.ac.uk/rbf/CVonline/LOCAL_COPIES/RUSK/IncLamps.html. [Accessed 26 October 2015].

5. How Fluorescent Lamps Work - HowStuffWorks. 2015. How Fluorescent Lamps Work - HowStuffWorks. [ONLINE] Available at: http://home.howstuffworks.com/fluorescent-lamp.htm . [Accessed 26 October 2015].

6. High-pressure sodium vapor lamps for open and enclosed luminaires | OSRAM. 2015. High-pressure sodium vapor lamps for open and enclosed luminaires | OSRAM. [ONLINE] Available at: http://www.osram.com/osram_com/products/lamps/high-intensity-discharge-lamps/high-pressure-sodium-vapor-lamps-for-open-and-enclosed-luminaires/index.jsp. [Accessed 26 October 2015].

7. The Mercury Vapor Lamp - How it works & history. 2015. The Mercury Vapor Lamp - How it works & history. [ONLINE] Available at: http://www.edisontechcenter.org/MercuryVaporLamps.html . [Accessed 26 October 2015].

Thank you