Mr.Kantoli S.B. BMP

PPT ON TYPES OF LAMPS

AT B.M.POLYTECHNICBELATI, SOLAPUR.

By - Mr. KANTOLI S.B. Subject: IEN (17639)

Electrical Engineering Dept. Date: 06-01-2016

Mr.Kantoli S.B. BMP

Construction, working and Applications of

Following Lamps:

- Incandescent Lamps.- Low Pressure Mercury Vapour. Vapor (U.S spelling) or Vapour (British spelling)

Lamps (Fluorescent Tube).- Halogen Lamps.- Sodium Vapour Lamps. - High Pressure Mercury Vapour Lamps.- Compact Fluorescent Lamps (C.F.L.)- Metal Halide Lamps.- LED Lamps.- Neon Signs.

Mr.Kantoli S.B. BMP

Gas Discharge Lamps

Mr.Kantoli S.B. BMP1. Incandescent Lamp. (Filament lamp) :

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.

Filament lamps must have,

1. It should have high melting point (3500º C).

2. It should have high resistivity.

3. It should have low temperature co-efficient.

4. It should have low vapor pressure.

5. Mechanically Strong, ductile.

Material used for filament is Carbon, Osmium tantalum and Tungsten.

Gas used inside the lamp ( Nitrogen or Argon )

Life: 1000 Hrs working hrs. Lamp efficiency: 10 - 30 lumens/watt

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Working:

Lamp work on the principal of Incandescence

( i.e. when a hot body is heated, radiant energy is emitted in waveform).

◘ An incandescent bulb generates light through heat.(95% Heat,5% Light)

◘ When electrical current passes through the tungsten filament, it heats to the point where it glows and gives off a yellow-red light.

◘ To keep the filament from burning up immediately, it's housed in a vacuum. Even so, the intense heat of the filament ensures a comparatively short and expensive life span.(Working avi)

Applications: Domestic, Commercial and Industrial. Etc…

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2. Fluorescent Tube:

Construction:

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A fluorescent lamp tube is filled with a gas containing low pressure mercury vapor and argon, xenon, neon, or krypton.

The pressure inside the lamp is around 0.3% of atmospheric pressure.

The inner surface of the lamp is coated with a fluorescent (and often slightly phosphorescent) coating made of varying blends of metallic and rare-earth phosphor salts. The lamp's electrodes are typically made of coiled tungsten and usually referred to as cathodes because of their prime function of emitting electrons. For this, they are coated with a mixture of barium, strontium and calcium oxides chosen to have a low thermionic emission temperature.

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Working: (Working Avi.)

Mr.Kantoli S.B. BMPWorking:

Cathode filament emitting electrons after getting heated due to supply of current .

These electrons while accelerating collide with Argon and Mercury vapour

atoms.

The excited atoms of Mercury give a radiation

Mr.Kantoli S.B. BMP

Applications:

1.In US residences, fluorescent lamps are mostly found in kitchens,

basements, and garages.

2. In countries, like India…

i) Residential.

ii) Commercial.

iii) Small scale industries ….Etc.

3. Halogen Lamps.

Wattage: 20/50 w 12 V

300w, 500w, 1000w 230 V.

Some of them only works

Horizontal and Vertical

Efficiency- 23 to 25

lumen/watt

Argon &Nitrogen

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Mr.Kantoli S.B. BMP

500 W Tungsten Halogen Lamp :

Types of Halogen Lamps:

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Working avi.

1. Indoor lighting.

2. Outdoor lighting.

3. Flood lighting.

4. For vehicle head lights.

5. TV studios

Applications:

6. Photo film.

7. Signaling.

8.Large gardens.

9.Fountains.

10. Airport runways.

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4. Sodium Vapour Lamps. Small Tx is used for heating the Cathode.

Operating Temp.r 300ºC.

Efficiency: 110 lumens/watt.

Containing Sodium Gas And Inert gas either Neon or Argon

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Function of Ignitor:T0 provide a strong/hot enough arc to light (strike) the lamp by overcoming the resistance of the gas in the lamp.Function of Capacitor:

To improve the power factor.

Lamp Working Avi.

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Applications:

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5. High Pressure Mercury Vapour Lamp.

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This lamp start with a small arc between the starting electrode and the main electrode.

This arc goes through argon gas which easily strikes, even in cold weather.

This little arc heats the tube, and over several minutes the tube gets hot enough to vaporize the solid mercury stuck to the sides.

The mercury vaporized creates a strong light between the two main electrodes.

Mr.Kantoli S.B. BMP

◘ The mercury vapor lamp is a negative resistance device.

◘ This means its resistance decreases as the current through

the tube increases.

◘ So if the lamp is connected directly to a constant-voltage

source like the power lines, the current through it will

increase until it destroys itself.

◘ Therefore it requires a ballast to limit the current through

it. (Working avi)

Mr.Kantoli S.B. BMP6. Metal Halide Lamps.Assembly of a quartz or ceramic tube and electrodes is commonly called the arc tube.

Arc tube contains argon or xenon starting gas, mercury and metal halide salts.

Metal halide arc tubes operates at temperatures of 900-1100º C.

Average life= 8000 – 10,000 Hrs Wattage : 35 w – 1500 watt.Efficiency : 65 – 110 lumens/watt

Mr.Kantoli S.B. BMPWorking of Metal Halide Lamps.

Applications:

1) Flood lighting.2) Indoor lighting.3) Landscape lighting4) Shopping malls5) Showrooms6) Super markets. etc

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7.Compact Fluorescent Lamp (CFL)

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COMPARISION WITH INCANDESCENT LAMPS:

Incandescent CFL

1) Life Span: 1000 Hrs 6000-15,000 Hrs

2) Energy consumption: More Less

3) Cost : Less More

4) Starting time: Immediately Take time to give

full illumination.

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8. LED ( Light Emitting Diode) Lamps:

LEDs are semiconductor devices that produces light when an electrical current applied to them.

Latest Lighting Technology.

Invented in 1962.

Lower energy consumption.

Longer life : 50,000 – 100,000 Hrs.

Smaller size , Faster switching.

Dimming.

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Efficiency: 130 lumens/watt.

RGB-Method mixing the proper

amount of light from red, green,

blue

LED yield white light.

Working of LED avi.

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Application:

1) Signs and Traffic signals.

2) Displays.

3) Exit signs.

4) Indicators and Flash lights.

5) Under counters. Etc.

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9. Neon Signs.

Avi on Neon.

And also called cold cathode discharge lamps.

These lamps Operates at a very low temperature (200º C)

The electrodes are housed at the two ends of the tube.

Tube contains neon gas.

Neon gas discharge gives a characteristic red light.

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Applications:

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Mr.Kantoli S.B. BMP

THANK YOU