2. CONTENTS
• INTRODUCTION
• WORKING
• MAIN COMPONENTS
• ABOUT THE COMPONENTS
• CIRCUIT ANALYSIS
• ADVANTAGES
• APPLICATIONS
• CONCLUSION
• REFERENCE
3. INTRODUCTION
WHY AUTOMATE STREET LIGHTS?
Our main concern is to make lights more
interactive with the physical world. These
lights can be also be implemented with the
IOT making it a sustainable infrastructure
for future advancement.
And these are the advantages at present
• reduced human efforts
• reduced wastage of power
• economical
6. • BROADLY IT CAN BE EXPLAINED AS A LIGHT WHICH
AUTOMATICALLY GETS TURNED ON AT SUNSET AND GETS
TURNED OFF AFTER SUNRISE.
• IT MAINLY REQUIRES A LIGHT DEPENDENT RESISTOR (LDR)
AND VOLTAGE COMPARATOR (OP AMP).
• LDR RESISTANCE DECREASES WITH INCREASE IN INTENSITY
OF LIGHT AND INCREASES IN ABSENCE OF LIGHT WHICH
PROVIDES A SIGNAL TO OP AMP.
• OP AMP CONSISTS OF BJTs WHICH ARE CONNECTED AND
DESIGNED IN SUCH A WAY THAT IT CAN BE USED TO
COMPARE THE REFERENCE VOLTAGE SIGNAL AND THE
INCOMING VOLTAGE SIGNAL FROM THE LDR.
WORKING
7. MAIN COMPONENTS
• PRINTED CIRCUIT BOARD (PCB)
• RESISTOR
• POTENTIOMETER
• OPERATIONAL AMPLIFIER (IC LM358)
• OP AMP BASE
• POWER SUPPLY
• LIGHT DEPENDENT RESISTOR (LDR)
• LED
• CONNECTING WIRES
8. PCB
A printed circuit board, is a non-conductive
material with conductive lines etched.
Electronic components are mounted on the
board and the traces connect the components
together to form a working circuit.
POTENTIOMETER
A potentiometer is a three-terminal resistor with a sliding or rotating
contact that forms an adjustable voltage divider. If only two terminals are
used, one end and the wiper, it acts as a variable resistor or rheostat.
9. RESISTORS
LEDS
A resistor is a passive two-terminal electrical
component that implements the flow of current
in the circuit.
Two types :
• Fixed Resistor
• Variable Resistor
A light-emitting diode (LED) is a
semiconductor light source that emits light
when current flows through it.
The LED emits light when it is forward
biased and it emits no light when it is reverse
biased.
12. WORKING OF LDR
WORKING PRINCIPLE
IS
PHOTOCONDUCTIVIT
Y.
IT IS AN OPTICAL
PHENOMENON IN WHICH
WHEN LIGHT SHINES ON
IT RELEASE ELECTRONS
FROM VALENCE TO
CONDUCTION BAND
WHICH INCREASE THE
NUMBER OF ELECTRONS
TO CARRY THE
CURRENT.THUS AS THE
LIGHT INCREASES
14. ADVANTAGES
• Lower chances of over heating
• Risk of accidents are minimized
• Energy efficient
• Low cost of operation
• Enhanced safety and security
• BUT Slightly higher cost of installation!