Automatic Headlight dimmer

1. SEMINAR PRESENTATION
ON
HEADLIGHT DIMMER
PRESENTED BY
ROHIT SHRIVASTAVA
1212221086

2. ABSTRACT
Drivers mostly use high beam during night
which causes discomfort to people coming
from opposite direction
Glare for short time
Glare causes temporary blindness resulting in
road accidents

3. TROXLER EFFECT
1. Temporary blindness
2. 1000 Lumens = Glare
3. Even after source of light is
removed, an after image
persists for some time
creating a BLIND SPOT.
4. Reaction time increases by
1.4 sec.

5. BEAMS OF HEADLIGHT
Low Beam: 700 Lumens, 135°
High Beam:1200 Lumens,15°

6. COMPONENTS OF CIRCUIT
1. LDR(Light Dependent Resistor)
2. Two Resistances to be used as Potential
Divider
3. Transistor(BJT) or MOSFET(for quick
switching)
4. Relay Switch
5. LEDs (to simulate Headlights)
6. Supply Voltage

7. COMPONENT RATING
1. LDR: As intensity of light falling
increases, resistance of LDR
decreases
2. Resistances: 0.25W; 1.6kΩ,30Ω
3. BJT/MOSFET: BC 547/IRF 840
4. Relay: 400Ω coil, 12V, 5 Terminal
Type
5. Supply: 12V from vehicle’s battery box
6. LED bulbs: 0.25W for simulating
headlights

8. CIRCUIT DIAGRAM

9. RELAY WORKING

10. THE IMPLEMENTATION
 It should be kept at a safe place,
protecting from external environment
like rain, and dust.
 The placement of this circuit should be
in line with the eye of the driver, so that
it responds exactly in the same way how
a driver would react to the bright light.
 It should be compact and easy to install.

11. POSITIONING OF CIRCUIT

12. ADVANCED APPROACH

13. REFERENCES
[1] C.Susana Martinez, S.L.Macknik and D.H.Hubel, 1st
Edition, Thomas publications, “The role of fixational eye
movements in visual perception”
[2] Ryota Kanai, Yukiyasu Kamitani and Universiteit
Utrecht, 3rd Edition, Zchingz Publications, “Time-locked
perceptual fading Induced by visual Transients”
[3] S.Aishwarya, Bright Headlights a major cause of
accidents, The Hindu, Online edition, May 02,2006.
[4] C.Guttman, High intensity headlights could cause road
accidents by dazzling oncoming drivers, Eurotimes,
April 2003.
[5] http://seminarprojects.com/Thread-automatic-
headlight-full-report