Dark Sensor using LDR on Breadboard

It spreads light in the dark and remains off in the light.

SUBMITTED BY:

SAQIB IQBAL (14-CS-07)

FAWAZ ALI (14-CS-09)

SUBMITTED TO:

Mr. JIBRAN

DATE OF SUBMISSION:

March 16, 2015

ABSTRACT

The circuit presented here is a project of a DARK SENSOR using LDR (Light Dependent Resistor) on BREADBOARD.

LDRs are a particularly convenient electronics component to use. They provide large change in resistance for changes in light level.

In view of their low cost, ease of manufacture, and ease of use LDRs have been used in a variety of different applications. At one time LDRs were used in photographic light meters, and even now they are still used in a variety of applications where it is necessary to detect light levels.

We can use dark or light sensors in street light and we the light sensor can give the robot vision and make it easier for it to operate autonomously.

TABLE OF CONTENTS

1. Introduction……………………………………………………………………………………………………………………………….......................4

2. BreadBoard………………………………………………………………..…………………………………………………………………………………...5

3. Project…..………………………………………………………………………………………………………………………………………...................6

4. Components…………………………………………………………………………………………………………………………………………………….7

4.1. Transisitor……………….…………………….………………………………………….…………………………………..………………………..7

4.2. LED.…………………………………...…………….………………………….………………………………………………..………………………..7

4.3. LDR.……………….………………………………………………………..……………………………….…………………..…………………………8

4.4. Resistors……….……….……………………………………………….……………………………………………………………………………….8

4.5. Battery…………………………………………………………………………………………………………………………………………………....9

4.6. Buzzer………………………………………………………………………………………………………………………………………….………....9

5. Steps Of Construction And Working….…………………………………………………………………………………………………………….10

6. Circuit Diagram.…………………………………………….…………………………………………………….....................………………….....13

7. Schematic Diagram…………………………………………………………………………………………………………………………………………13

8. Acknowledgement ………………………………….……………………………………………………………………………………………………..14

9. Biblography…………………………………………….……………………………………………………………………………………………………..14

INTRODUCTION

Lighting can account for 10-38% of the total energy bill in typical cities worldwide. The main consideration in the present field technologies are Automation, Power consumption and cost effectiveness. Automation is intended to reduce man power with the help of intelligent systems. Power saving is the main consideration forever as the sources of the power are getting diminished due to various reasons.

The main aim of this project is to saving system with LDR this is to save the power. We want to save power automatically instead of doing manual. So it’s easy to cost effectiveness. This saved power can be used in some other cases. So in villages, towns etc. we can design intelligent systems for the usage of light or we can also use this to reduce the electricity bill of our home. This project can also be used for security of the houses, banks, etc.

WHAT IS BREADBOARD

A breadboard is a device for testing temporary electronics projects. Components used to test a circuit can be reused for other projects. None of the components are damaged.

Almost all people start to learn electronics using breadboard because it is the simplest way of making circuit. The photograph shows a typical small breadboard which is suitable for beginners building simple circuits with one or two ICs (chips).

Connections on Breadboard

Breadboard has many tiny sockets or holes arranged on a 0.1’’ grid. The leads or terminals of most of the components like resistors, diodes, transistors, etc. can be pushed straight into the holes.

A breadboard has 4 rows of holes at the top and 4 rows at the bottom and there are several columns of holes in the middle.

There are two groups of vertical columns in the middle part, as you see in the picture below it has been separated by a blue rectangular block.

None of the rows and columns are linked to one another.

The holes in rows are linked horizontally and column holes are linked vertically.

Converting a circuit diagram to a breadboard layout is not straight forward because the arrangement of components on breadboard looks quite different from the circuit diagram. When putting parts on breadboard you must concentrate on their connections, not their positions on the circuit diagram.

OUR PROJECT

COMPONENTS

1) 2 NPN Transistors (Code no: BC547)A BC547 transistor is a negative-positive-negative (NPN) transistor that is used for many purposes. Together with other electronic components, such as resistors, coils, and capacitors, it can be used as the active component for switches and amplifiers.

2) 1 LEDA semiconductor diode that emits light when conducting current and is used in electronic equipment

3) 1 LDR (Light Dependent Resistor)

Light Dependent Resistor or Photoresistor, which is a passive electronic component, basically a

resistor which has a resistance that varies depending of the light intensity. A photoresistor is

made of a high resistance semiconductor that absorbs photons and based on the quantity and

frequency of the absorbed photons the semiconductor material give bound electrons enough

energy to jump into the conduction band. The resulting free electrons conduct electricity

resulting in lowering resistance of the photoresistor. The number of electrons is dependent of

the photons frequency.

4) 4 Resistors (330 ohms, 470 ohms, 1k ohms, 4.7k ohms)A resistor is an electrical component that limits or regulates the flow of electrical current in an electronic circuit. Resistors can also be used to provide a specific voltage for an active device such as a transistor.

5) 9 volts batteryA battery is an electrochemical cell (or enclosed and protected material) that can be charged electrically to provide a static potential for power or released electrical charge when needed.

6) Buzzer

An electrical device, similar to a bell that makes a buzzing noise and is used for signaling.

STEPS OF CONSTRUCTION AND WORKING

Step 1: Put first transistor Q1-BC547 on breadboard as shown in the picture.

Step 2: Put another transistor Q2- BC547 on breadboard as in step 1.

Step 3: Put wires across emitter pin of both transistors and -ve terminal of battery(lowest/ bottom row of breadboard.)

Step 4: Put a wire across Collector pin of transistor Q1 and Base pin of transistor Q2.

Step 5: Put a resistor 1K across positive terminal of battery (topmost row of breadboard) and Collector pin of transistor Q1.

Step 6: Insert Light dependent resistor (LDR) across positive terminal of battery (topmost row of breadboard) and base terminal of transistor Q1.

Step 7: Put a resistor- 330 Ohm across base pin of transistor Q1 and negative terminal of battery (lowest bottom row of breadboard).

Step 8: Put a resistor 330R across positive terminal of battery (topmost row of breadboard) and anode terminal of LED (Light emitting diode) & Connect the cathode terminal of LED to Collector pin of transistor Q2. Do same to attach the buzzer

The circuit is ready for testing. Connect battery terminals and see the output. As you block light falling on LDR (Light dependent resistor), the LED glows and buzzer produces a sound.

Circuit Diagram :

Schematic Diagram

Acknowledgement

We wish to thank all our respected teachers and friends for their excellent contribution and support for the completion of this project. Especially we are very much thankful to our class fellow Syed Muhammad Taha (D-14-CS-03) for his guidance as well as for providing necessary information regarding the project & also for his support in completing the project.

BIBLOGRAPHY

1) http://www.buildcircuit.com/dark-sensor-on-breadboard/ 2) http://mjkcircuits.blogspot.com/2014/07/dark-sensor-using-ldr-on-breadboard.html 3) http://www.instructables.com/id/Dark-Sensor-with-LDR-transistor-and-a-LED/