Upload
debasis-das
View
220
Download
0
Embed Size (px)
Citation preview
8/7/2019 AUTOMATIC HEADLIGHT2, rajib
http://slidepdf.com/reader/full/automatic-headlight2-rajib 1/17
AUTOMATIC HEAD LIGHTAUTOMATIC HEAD LIGHT
PRESENTED BY :
RAJIB KUMAR PANDA
ROLL NO. 25226REG NO. 0601105091
19-Feb-11 EE/IGIT
GUIDED BY:
MRS. A .ROUT
Electrical Engineering Department
Indira Gandhi Institute of Technology
Sarang-759146, Dhenkanal, Orissa
1
8/7/2019 AUTOMATIC HEADLIGHT2, rajib
http://slidepdf.com/reader/full/automatic-headlight2-rajib 2/17
OUTLINESOUTLINES
INTRODUCTION
LIGHT SOURCE
CONSTRUCTION
TWO FILAMENT BULBS
HEAD LIGHT DAZZLES
AUTOMATIC DIPPER
WORKING OF AUTOMATIC DIPPERCONCLUSION
19-Feb-11 EE/IGIT 2
8/7/2019 AUTOMATIC HEADLIGHT2, rajib
http://slidepdf.com/reader/full/automatic-headlight2-rajib 3/17
INTRODUCTIONINTRODUCTION
The number of vehicles on our roads is increasing dayby day. An automatic dipper is a unit, which canautomatically judge when the headlight beam needs to
be lowered, and which dip the headlamp from whichbeam to a dipped beam.
As the dipper unit is well connected to the lightingsystem of the vehicle, we have to look into the typeand construction of a head light before discussing the
wiring diagram or the construction of Automaticdippers.
19-Feb-11 EE/IGIT 3
8/7/2019 AUTOMATIC HEADLIGHT2, rajib
http://slidepdf.com/reader/full/automatic-headlight2-rajib 4/17
LIGHT SOURCELIGHT SOURCE
There are two kinds of light sources
One that emits light.
Other that reflects lights.
The headlight is composed of three elements:
The light filament that gives off light when a currentflows through it.
The parabolic reflector that reflect the light infront.
The lens that refracts of distorts the light beaminto an illuminating pattern.
19-Feb-11 EE/IGIT 4
8/7/2019 AUTOMATIC HEADLIGHT2, rajib
http://slidepdf.com/reader/full/automatic-headlight2-rajib 5/17
CONSTRUCTIONCONSTRUCTION
Earlier the bulb was placed at the focus of a
parabolic silvered reflector in order to give a
parallel beam of light.
The following figure shows a parabolicreflector with bulb, the lines showing light rays
emitted from the filament of the bulb in all
directions.
This type of headlight given a parallel lightbeam.
19-Feb-11 EE/IGIT 5
8/7/2019 AUTOMATIC HEADLIGHT2, rajib
http://slidepdf.com/reader/full/automatic-headlight2-rajib 6/17
The parabolic reflector showing light
rays emitted from the filament of the bulb
19-Feb-11 EE/IGIT 6
8/7/2019 AUTOMATIC HEADLIGHT2, rajib
http://slidepdf.com/reader/full/automatic-headlight2-rajib 7/17
The effect of changing the position of
filament on the nature of the light beam
19-Feb-11 EE/IGIT 7
8/7/2019 AUTOMATIC HEADLIGHT2, rajib
http://slidepdf.com/reader/full/automatic-headlight2-rajib 8/17
TWO FILAMENT BULBSTWO FILAMENT BULBS
In two filaments headlights there uses atwo-filament bulb with a fixed reflector.In this case, one filament is meant for the
dipping beam and the other main beam The main beam filament is located at the
focus of the reflector.
The dip beam filament is located behindthe focus.
19-Feb-11 8
8/7/2019 AUTOMATIC HEADLIGHT2, rajib
http://slidepdf.com/reader/full/automatic-headlight2-rajib 9/17
A double ± filament lamp
19-Feb-11 EE/IGIT 9
8/7/2019 AUTOMATIC HEADLIGHT2, rajib
http://slidepdf.com/reader/full/automatic-headlight2-rajib 10/17
HEADLIGHT DAZZLESHEADLIGHT DAZZLES
The dazzle effect is one of the major problems
faced by a driver in night driving
Automatic Dipper is one such mechanism,
which is employed for safety night drivingwithout the intense dazzling effects
The dazzling effect can be prevented by
Reducing the brightness of the headlights of the
vehicles.
Stopping high intensity light from entering the
vehicles of on-coming drivers or road users.
19-Feb-11 EE/IGIT 10
8/7/2019 AUTOMATIC HEADLIGHT2, rajib
http://slidepdf.com/reader/full/automatic-headlight2-rajib 11/17
8/7/2019 AUTOMATIC HEADLIGHT2, rajib
http://slidepdf.com/reader/full/automatic-headlight2-rajib 12/17
MAIN COMPONENTSMAIN COMPONENTS
Light sensitive photocell
High-low beam relay
Sensitivity control
Amplifier.
19-Feb-11 EE/IGIT 12
8/7/2019 AUTOMATIC HEADLIGHT2, rajib
http://slidepdf.com/reader/full/automatic-headlight2-rajib 13/17
WORKINGWORKING
The photoelectric cell senses the intensity of light fromthe oncoming vehicles.
The sensitivity control sets the intensity level at which
the photocell amplifier will energize.
When the light from the oncoming strikes the lightsensitive plate provided in it, an electric current is
released.
When the oncoming vehicle is nearing, its strong light
sets the amplifier unit(thyraton) into operation. The thyraton greatly amplifies the current provided by
the phototube.
It becomes strong enough to put the power relay unit
into operation.19-Feb-11 EE/IGIT 13
8/7/2019 AUTOMATIC HEADLIGHT2, rajib
http://slidepdf.com/reader/full/automatic-headlight2-rajib 14/17
SINGLE POLE DOUBLESINGLE POLE DOUBLE
THROW RELAYTHROW RELAYy Current will flow between the movable contact and
one fixed contact when the coil is DEenergized and
between the movable contact and the alternate fixed
contact when the relay coil is energized.
19-Feb-11 EE/IGIT 14
8/7/2019 AUTOMATIC HEADLIGHT2, rajib
http://slidepdf.com/reader/full/automatic-headlight2-rajib 15/17
WORKING OF AUTO DIPPERWORKING OF AUTO DIPPER
19-Feb-11 EE/IGIT 15
8/7/2019 AUTOMATIC HEADLIGHT2, rajib
http://slidepdf.com/reader/full/automatic-headlight2-rajib 16/17
CONCLUSIONCONCLUSION
Auto dippers are devices, which will attain
more and more importance in the
forthcoming years.
When we are driving on busy street, it is
a great problem to change the light from
head to dipper or vise versa.
So, this mechanism can give the solutionfor the above problems.
19-Feb-11 EE/IGIT 16
8/7/2019 AUTOMATIC HEADLIGHT2, rajib
http://slidepdf.com/reader/full/automatic-headlight2-rajib 17/17
THANK YOU
19-Feb-11 EE/IGIT 17