The document is a project report on a solar energy based automatic street light controller submitted by Amar Gupta, Manisha Bagani, and Varun Shah. It describes the controller's use of a 555 timer IC wired as a monostable multivibrator to automatically turn street lights on at dusk when detected by an LDR light sensor, and off at dawn. When dark, the LDR increases resistance to trigger the 555 IC and relay to power the lights from the solar panel energy storage. It saves around 40% of electricity costs compared to regular street lights.

1. A PROJECT REPORT ON
SOLAR ENERGY BASED
AUTOMATIC STREET LIGHT
CONTROLLER
SUBMITTED
BY
AMAR GUPTA
MANISHA BAGANI
VARUN SHAH

2. Solar energy based automatic street light controller
CHAMELI DEVI INSTITUTE OF TECHNOLOGY
AND MANAGEMENT
DECLARATION
We here by declare that the information provided in this report is
on the basis of keen study and hence the information is correct to
the best of our knowledge. We shall be accountable for any
misleading information in any part of this report.
` AMAR GUPTA
MANISHA BAGANI
VARUN SHAH
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3. Solar energy based automatic street light controller
CONTENTS
1. Introduction
2. IC 555
3. Circuit Diagram
4. Schematic Plan
5. Working
6. Components Required
7. Applications
8. Conclusion
9. Bibliography
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4. Solar energy based automatic street light controller
INTRODUCTION
Solar powered automatic street light controller is an very efficient device which
regulated the street light working. It automatically turns on when there is dark at
the dusk time and turns off at the dawn when the sun is out.
Solar powered automatic street light controller is one of the applications of
electronics to increase the facilities of life. The use of new electronic theories has
been put down by expertise to increase the facilities given by the existing
appliance. Here the facility of ordinary street light is increased by the making it
controlled automatically.
In Solar powered automatic street light controller there is a provision in which
the energy required to run the street light is provided by the solar energy.. In this
NE 555 IC is wired as Monostable multivibrator. For regulating the input AC
supply there is a regulator Section consisting of IC 7812. For detecting the light
the LDR is used as the sensor.
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5. Solar energy based automatic street light controller
555 Timer IC
The 555 Timer IC is an integrated circuit (chip) implementing a
variety of timer and multivibrator applications. The IC was designed
and invented by Hans R. Camenzind. It was designed in 1970 and
introduced in 1971 by Signetics (later acquired by Philips). The
original name was the SE555/NE555 and was called "The IC Time
Machine". The 555 gets its name from the three 5-kohm resistors used
in typical early implementations. It is still in wide use, thanks to its
ease of use, low price and good stability. As of 2003, 1 billion units
are manufactured every year.
Depending on the manufacturer, it includes over 20 transistors, 2
diodes and 15 resistors on a silicon chip installed in an 8-pin mini
dual-in-line package (DIP-8).
The 556 is a 14-pin DIP that combines two 555s on a single chip.
The 558 is a 16-pin DIP that combines four slightly modified 555s on
a single chip (DIS & THR are connected internally, TR is falling edge
sensitive instead of level sensitive).
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6. Solar energy based automatic street light controller
Also available are ultra-low power versions of the 555 such as the
7555 and TLC555. The 7555 requires slightly different wiring using
fewer external components and less power.
The 555 has three operating modes:
• Monostable mode: - In this mode, the 555 functions as a "one-shot".
Applications include timers; missing pulse detection, bounce free
switches, touch switches, Frequency Divider, Capacitance
Measurement, Pulse Width Modulation (PWM) etc.
• Astable Mode :- Also called as Free Running mode. The 555 can
operate as an oscillator. Uses include LED and lamp flashers, pulse
generation, logic clocks, tone generation, security alarms, pulse
position modulation, etc.
• Bistable mode or Schmitt trigger: - The 555 can operate as a flip-
flop, if the DIS pin is not connected and no capacitor is used. Uses
include bouncefree latched switches, etc.
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7. Solar energy based automatic street light controller
Internal Schematic of 555 Timers IC
Schematic Symbol of 555 Timers IC
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8. Solar energy based automatic street light controller
SCHEMATIC PLAN
Light dependent resistor LDR is used as the light sensor. Its resistance increases
in absence of light while it decreases in present of light. NE 555 IC is wired as
monostable multivibrator. The trigger to this is signals from potential across 100k
resistor.
The 230 V AC is stepped down to 12 V by transformer (12V-0-12V). This 12V is
regulated by IC 7812 regulator to provide 12V. This 12V is supplied to the whole
circuit.
IC 7812 is used as the regulator IC which regulates the current and voltage to the
IC 555 and the rest of the circuit The output of IC 555 is used to drive a transistor
When the transistor conducts it operates the relay and controls the turn on and off
of the street light.
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9. Solar energy based automatic street light controller
WORKING
The 230 V from AC mains is stepped down to 12V and Regulated by IC 7812.
This 12V is used for providing supply to the entire circuit. During the day time
condition, the presence of light decreases the resistance of the LDR So the
potential drop across the 100Kohm resistor increases so the voltage across the
trigger becomes greater than 1/3 of Vcc that is 4 volt so the output becomes zero
so the relay remains at off state so the light doesn’t turns off. In dark condition
like at night the resistance of the LDR increases so the potential drop across the
100k ohm resistor becomes less than 1/3 Vcc so the IC 555 is triggered and the
relay operates to turn on the street light . The solar panel of 12V provides a
potential of 12 volts to the circuit which operates upon the IC 555 and ultimately
controls the relay to regulate the street lights .This NE 555, which is wired as
Monostable multivibrator, is used to trigger the relay.
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10. Solar energy based automatic street light controller
COMPONENTS REQUIRED
1. IC 7812
2. IC 555
3. Carbon film resistors
4. Electrolytic capacitors
5. Ceramic capacitors
6. 230 VOLT AC bulb
7. Diodes
8. Transistor- BC548
9. Solar panel
11. Centre tapped transformer
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11. Solar energy based automatic street light controller
APPLICATION
This system is designed for outdoor application in un-electrified remote rural
areas. This system is an ideal application for campus and village street lighting.
Street light gives bright light over a semi circular radius of 30 feet. The system is
provided with battery storage backup sufficient to operate the light for 10-11
hours daily. The system is provided with automatic ON/OFF time switch for
dusk to down operation and overcharge / deep discharge prevention cut-off with
LED indicators.
Solar Street Lighting System is an ideal lighting system for Roads, Yards,
Residential Colonies, Townships, Corporate Offices, Hospitals , Educational
Institutions and Rural Electrification.
So, in all, installation of this circuit brings luxury to the daily life.
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12. Solar energy based automatic street light controller
CONCLUSION
With the knowledge of new techniques in “Electronics”, we are able to make our
life more comfortable. One such application of electronics is “Solar energy
based automatic street light controller”.
Solar powered automatic street light controller is one of the applications of
electronics to increase the facilities of life. The use of new electronic theories has
been put down by expertise to increase the facilities given by the existing
appliance. Here the facility of ordinary street light is increased by the making it
controlled automatically
This circuit is simple to use and efficient. It can be assembled with ease. It is
cheap and hence very economic. It is small in size and can be fixing inside the
street light.
It saves around 40% of electricity from per street light. So throughout the world if
we use this concept then it will eliminate the energy crisis to a larger extent.
It is ecofriendly and utilizes the renewable source of energy very well.
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13. Solar energy based automatic street light controller
BIBLIOGRAPHY
• Wikipedia.com
• Solargadgets.com
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