Design And Construction Of An Electronics Letter Box

ABSTRACT

This work is on design and construction of an electronic letter box .This   project is developed for the users to find out whether any letter is inside the letter box and also to display the number of letters inside the letter box.

An IR Transmitter and Receiver are connected at the opening of the letter box.  In normal operation, the rays transmitted from the transmitter falls on the receiver.  When anyone puts letter inside the letter box, the letter hides the rays and thereby receives no signal at the particular instance.  Thus it senses that there is a letter inside.

The I.C connected with the sensor counts that there is one letter inside.  When the next letter is put inside the letter box, the sensor senses the letter and the microcontroller counts two.  The same way it counts all the letters inside.

An indicator or buzzer is connected inside the house.  The owner of the house can identify the number of letters inside the letter box. When the letter box is opened, the IC resets and the count goes to zero.

TABLE OF CONTENTS

TABLE OF CONTENT

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

TABLE OF CONTENT

CHAPTER ONE

• INTRODUCTION
  • BACKGROUND OF THE PROJECT
  • PROBLEM STSTEMENT
  • SIGNIFICANCE OF THE PROJECT
  • OBJECTIVE OF THE PROJECT
  • SIGNIFICANCE OF THE PROJECT
  • SCOPE OF THE PROJECT
  • LIMITATION OF THE PROJECT
  • APPLICATION OF THE PROJECT
  • ORGANISATION OF THE PROJECT

CHAPTER TWO

2.0 LITERATURE REVIEW

2.1 HISTORITICAL BACKGROUND OF THE PROJECT

2.2 STYLES AND USAGE

2.3 FUNCTION OF MAJOR COMPONENTS USED

CHAPTER THREE

3.0 CONSTRUCTION

3.1 BLOCK DIAGRAM

3.2 CIRCUIT DIAGRAM

3.3 SYSTEM OPERATION

3.4 CIRCUIT DESCRIPTION

3.5 CIRCUIT PARTS

3.6 DESCRIPTION OF COMPONENTS USE

CHAPTER FOUR

4.0 RESULT ANALYSIS

4.1 CONSTRUCTION PROCEDURE AND TESTING

4.2 CASING AND PACKAGING

4.3 ASSEMBLING OF SECTIONS

4.4 TESTING OF SYSTEM OPERATION

4.5 INSTALLATION OF THE COMPLETED DESIGN

4.6 COST ANALYSIS

CHAPTER FIVE

5.0 CONCLUSION

5.1 RECOMMENDATION

5.2 BIBLIOGRAPHY

CHAPTER ONE

1.1                                                        INTRODUCTION

1.2                                         BACKGROUND OF THE PROJECT

A letter box, letterbox, letter plate, letter hole, deed, mail slot, or mailbox is a receptacle for receiving incoming mail at a private residence or business. For the opposite purpose of collating outgoing mail, a post box is generally used instead. Letterboxes or mailboxes consist of four primary designs:

• A slot in a wall or door through which mail is delivered (through-door delivery)
• A box attached directly to the house (door-to-door delivery)
• A box mounted at or near the street (curbside delivery)
• A centralised mail delivery station consisting of individual mailboxes for an entire building
• A centralised mail delivery station consisting of individual mailboxes for multiple recipients at multiple addresses in a particular neighborhood or community
• An electronics circuit

The electronic letter box is a very useful gadget for homes and offices the circuit. The main advantage of the letter box is we can find out the presence and absence of letter inside the box without opening the box.

In this system, When letter drop by someone into the letter box then the LED attached at the output stops blinking which indicates that there is a letter in your letter box. To identify the presence of a letter in the box we have connected a LDR as well as source of light. LDR is a special kind of resistor whose action based on the intensity of light declining on it. In the time of total darkness LDR resistance is approx 1 mega ohm while at the time of bright light its resistance is 2-5 ohm. In this circuit the light source is adjusted with the LDR in such a way that the light will directly drop on the LDR so that when any letter comes inside the letter box it will chunk the light beam and LDR will be beneath darkness.

1.2                                                  PROBLEM STATEMENT

Traditionally, when letter arrive in an occupant house he or she have to the gate to pick up the letter and sometimes when the occupant is expecting letter he have to go several times to check if the letter have arrived, and this imposes labour and consumes occupant’s time. Thus this circuit solves the problem of going again and again to the gate of the house to check-up whether a letter is there in the box or not.

1.3                                           SIGNIFICANCE OF THE STUDY

This project is very useful in institutions; house etc to identify the letters inside the letter box. Advantage of the letter box is we can find out the presence and absence of letter inside the box without opening the box. Here light depending resistor (LDR) is used as a sensor to detect the presence of letter.

1.4                                             OBJECTIVE OF THE PROJECT

The objective of the project is to design a device that gives beep when a letter is placed in the letter box and intimates the arrival of Mail. The circuit is too simple and uses an LDR as dark sensor and White LED as illuminator.

1.5                                                 SCOPE OF THE PROJECT

This device detect the present of letter, we have used LDR and a source of light. The L.D.R, most important part of this circuit, is a special type of resistance whose value depends on the brightness of the light which is falling on it.
It has a resistance of about 1 mega ohms when in total darkness, but a resistance of only about 2-5 k ohms when brightly illuminated.

The resistance of L.D.R. is minimum when the light falling on is maximum and vice versa when the light falling is minimum. The source of light and LDR is so adjusted in the letter box, that the light will directly fall on the LDR. When a letter is kept inside, it will block the beam of light and LDR will be under darkness.

•                            LIMITATION OF THE PROJECT

1. This device can experience false triggering whenever any other opaque material is drop inside the box.
2. It will stop working whenever mains supply fails.

1.7                                            APPLICTION OF THE PROJECT

This device can be used in the following places:

1. Homes
2. Churches/mosque
3. Garage
4. Offices, or any other public place

1.8                          PROJECT WORK ORGANISATION

The various stages involved in the development of this project have been properly put into five chapters to enhance comprehensive and concise reading. In this project thesis, the project is organized sequentially as follows:

Chapter one of this work is on the introduction to electronic letter box with indicator. In this chapter, the background, significance, objective limitation and problem of electronic letter box were discussed.

Chapter two is on literature review of electronic letter box with indicator. In this chapter, all the literature pertaining to this work was reviewed.

Chapter three is on design methodology. In this chapter all the method involved during the design and construction were discussed.

Chapter four is on testing analysis. All testing that result accurate functionality was analyzed.

Chapter five is on conclusion, recommendation and references.