The document discusses different types of headlights used in vehicles. It describes standard incandescent headlights, sealed-beam halogen headlights, high-intensity discharge (HID) headlights using xenon gas, and LED headlights. For each type, it provides details on the light source technology, brightness levels, lifespan, advantages and disadvantages compared to other types. Halogen headlights are cheaper but less bright than HID xenon headlights. LED headlights have very high efficiency and lifespan though they are not as bright as HID currently. The document compares the key differences between the headlight types through diagrams and images.

1. HEADLIGHTS
VIBHAVARI GHADGE
ADAM, PUNE
20 FEB 2019
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2. Head lights
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• Headlights are mounted on the
front of a vehicle to light the road
ahead during darkness or other
times when normal visibility is
poor.
• These are necessary to illuminate
the road sufficiently to permit
safe night driving.
• These are usually provided with
two or more beams, one of which
provides maximum illumination
for night driving, and the other is
so designed as to permit
deflection to the ground to the
side of the road to minimize glare
when passing other cars on the
road. When a third beam is used,
it is usually of low intensity for
city driving.
Fig.1 Headlights
Source:http://www.mattcastruccikia.com/b
log/what-are-the-different-types-of-
headlights/

3. Types of Headlights
a. Standard Headlights(Filament bulb)
b. Sealed-Beam Headlight(Halogen bulb )
c. HID (High Intensity Discharge)
Headlamps i.e. Xenon bulbs
d. LED headlights
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Fig.2 Headlights
Source: http://www.mattcastruccikia.com/blog/what-are-the-different-
types-of-headlights/

4. A. Standard Headlights
• Standard headlights feature a
forward facing bulb in a
reflective box or case.
• These bulbs were incandescent,
featuring similar build to home
light bulbs.
• These incandescent bulbs wore
hot, didn’t last long and cast a
sticky, muted light which wasn’t
especially useful.
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Fig.3 Incandescent bulb
Source: https://www.eurocarparts.com/ecp/p/car-
parts/car-electrics

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B. Sealed-Beam Headlight
• It is a two-beam headlamp system.
• Both these beams produce-
• a straight-ahead (upper or “country” driving beam) and
• a deflected (lower or “traffic” beam) in which the light from both
beams is deflected to the right side of the road and slightly
downward to minimize glare.
• The maximum intensity of country beam is specified at 75,000cp.
• The maximum intensity of traffic beam is specified at 50,000cp.
• Country beam is used only when there is no traffic.
• Example : Halogen type headlight

6. Halogen gases
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• A halogen is a monovalent element on the Periodic Table, which easily forms negative ions.
• There are 5 such halogens - but only iodine and bromine are used in lamps.
• A halogen lamp's typical rated life is about 2,000 hours, which is about 2 times longer than
that of standard incandescent lights.
• Halogen lights produce the most heat of almost any other light source.
Fig.4 Halogen lamp construction
Source :http://www.cobotex.com/lamps-26-led/halogen.pdf

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Advantages of halogen headlights
1. They are inexpensive. A major reason most manufacturers use reflector-type
headlamps is their low cost of production.
2. They are smaller than projector units.
3. Halogen bulbs offer sufficiently bright light. Hence, in most conditions, there's
sufficient illumination without spending a lot of money.
Fig.5 Halogen bulb
Source : https://mycarneedsthis.com/best-halogen-headlight-bulbs-to-buy/

8. C. HID Headlamps
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• Xenon is a noble gas used in HID lamp
and it's odorless and colorless.
• It produces a bright-white light when
stimulated by electricity.
• Xenon is a more expensive material than
any of the halogens.
• A xenon light's typical rated life is around
10,000 hours.
• It takes less energy to achieve the same
lumen output.
Fig.6 HID gas discharge lamp
Source: https://www.bulbs.com/learning/hid.aspx

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• HID or Xenon headlights are
electronically controlled.
• The Xenon gas in these headlights,
prevents the beam from flickering
when they are switched on.
• Xenon bulbs are much brighter than
halogen, which helps to see further
and better during night time driving.
• They can also produce higher colour
temperatures than halogen.
Fig.7 Xenon Headlight
Source : https://m.dailyhunt.in/news/india

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Advantages of Xenon headlights :
1. Improved brightness
2. Better visibility in poorly lit conditions
• Instead of using filament, an electrical arc is
created between two electrodes that excites
a gas inside the headlamp which vaporizes
metallic salts that sustain the arc and emit
light.
• Xenon gas discharge.mp4
• More than 15,000volts are used to jump the
gap between the electrodes.
Fig.8 Xenon bulb
Source : https://google/images/PbcRnB

11. D.LED Headlight
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Fig.9 LED Headlight
Source : https://m.dailyhunt.in/news/india
• LEDs are not only efficient and effective
but also add to the aesthetics.
• While LEDs aren't as bright as Xenon
HIDs, they reach their peak brightness
level many times faster.
• Also, they have a much higher life than
other headlights.
• They have a lifespan of 15,000 hours.
• They have very high efficiency levels as
they convert most of their power intake
into light energy. Hence, they don't heat
up.

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Advantages of LED headlights
1. LEDs produce a much more penetrating, illuminating white light.
2. LEDs are resistant to shock and vibration.
3. LED headlamps reduce oncoming driver perception of glare.
4. LEDs are mercury free, making them environmentally friendly unlike some
HID/xenon systems.
Disadvantages of LED headlights
1. They do create a small amount of heat at the emitter This creates a chance
for other parts be damaged.
2. LED headlights require cooling like fans and heat sinks to keep from
melting which is in not-so-cool area.
3. They Can be incredibly expensive.

13. Comparision
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Fig.10 Comparision between types of headlamps
Source: http://www.mattcastruccikia.com/blog/what-are-the-different-types-of-
headlights/

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Fig.11 Difference between intensities of types of headlamps
Source: http://www.mattcastruccikia.com/blog/what-are-the-different-types-of-
headlights/

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Practical difference between light intensities
Fig.12 Practical difference between light intensities
Source : www.youtube.com

16. THANK YOU
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