Design And Construction Of Automatic Hand Dryer With Temperature Display

 

AUTOMATIC HAND DRYER WITH TEMPERATURE DISPLAY

 

ABSTRACT

This project deals on the design and construction of automatic hand dryer with temperature display facility which is capable of drying a wet hand placed under its vent goes of automatically. It corporate a temperature sensing and displays unit which displays the temperature of the blown out air. This system is designed in top-down methodology using passive and active components sensors (LM35 & LDR) at the input to sense temperature and hands respectively. The control unit is made up of signal conditioning unit, voltage comparator and frequency generator, and decimal counting unit. The output interface comprises transistor, driver, actuator, Electromagnetic relay and a –digit seven segment Display. The sensor are installed at the front of the blower and this device dries with warm air only. When a hand is placed under the vent to block the line of sight of the LASER Diode and LDR, the blower gets actuated and blows warm air. As the hand is removed, the blower stops automatically along side the temperature display. The principle behind the work of this system is that the hands must be opaque enough to block the line of sight of the opto coupler. This removes the stress, time and dangers associated with push button type. The result being automatic hand dryer with temperature display.

 

TABLE OF CONTENT

Title page       -           -           -           -           -           -           -           -           -           i

Certification page    -           -           -           -           -           -           -           -           ii

Approval page          -           -           -           -           -           -           -           -           iii

Dedication     -           -           -           -           -           -           -           -           -           iv

Acknowledgement               -           -           -           -           -           -           -           v

Abstract         -           -           -           -           -           -           -           -           -           vi

Table of content       -           -           -           -           -           -           -           -           vii

List of tables             -           -           -           -           -           -           -           -           -           ix

List of figures           -           -           -           -           -           -           -           -           x

 

 

Chapter One

1.1.           Introduction -           -           -           -           -           -           -           -           1

1.1.1.     Problem statement   -           -           -           -           -           -           -           1

1.1.2.     Aim and objectives              -           -           -           -           -           -           2

1.1.3.     Justification of the study   -            -           -           -           -           -           -           3

1.1.4.     Scope of the project             -           -           -           -           -           -           -           3

1.1.5.     Project report organization-           -           -           -           -           -           3

 

Chapter Two

2.1. Literature review          -           -           -           -           -           -           -           4

2.1.1. Analysis of the existing system      -           -           -           -           -           5

2.1.2. Theories and models relevant to the design -       -           -           -           6

 

Chapter Three

3.1. Automatic hand dryer with temperature display     -           -           -           9

3.1.1. Description of the system building blocks            -           -           -           9

3.1.2. Block diagram development into working circuit            -           -           9

3.1.3 System design specification             -           -           -           -           -           -           10

3.1.4. Power supply unit     -           -           -           -           -           -           -           11

3.1.5 Principle of operation of the system           -           -           -           -           -           12

3.1.6. System design calculation               -           -           -           -           -           13

3.1.7 The control logic circuit        -           -           -           -           -           -           14

3.2   The Ne555 timer                      -           -           -           -           -           -           14

3.3   Other System components     -           -           -           -           -           -           22

 

Chapter Four

4.1. Implementation, testing and result                 -           -           -           -           38       

4.1.2   Testing           -           -           -           -           -           -           -           -           38

4.1.3. Result -           -           -           -           -           -           -           -           -           39

4.1.4 Packaging        -           -           -           -           -           -           -           -           40

4.1.5. Bill of engineering quality   -           -           -           -           -           -           40

 

Chapter Five

5.1. Summary of achievement        -           -           -           -           -           -           42

5.2. Conclusion        -           -           -           -           -           -           -           -           43

            References    -           -           -           -           -           -           -           -           44

           

LIST OF TABLES

3.1 The system components list     -           -           -           -           -           -           -           35

4.1 Bill of engineering quantity -  -           -           -           -           -           -           -           40

LIST OF FIGURES

2.1       Physical layout of seven segment             -           -           -           -           -           -           8

2.2       Schematic diagram of seven segment       -           -           -           -           -           8

3.1       Block diagram of the system         -           -           -           -           -           -           10

3.2       Block diagram of the Regulated    -           -           -           -           -           -           12

3.3       Ne555 timer  -           -           -           -           -           -           -           -           -           14

3.4.      Internal block           -           -           -           -           -           -           -           -           15

3.5.      Pin out diagram -      -           -           -           -           -           -           -           -           15

3.6       Standard Ne555 astable circuit sensor     -           -           -           -           -           17

3.7       The blower    -           -           -           -           -           -           -           -           -           18

3.8       The LM35 integrated circuit sensor -       -           -           -           -           -           19

3.9       The LM35 wired circuit board       -           -           -           -           -           -           20

3.10    Voltmeter      -           -           -           -           -           -           -           -           -           21

3.11    Diagram of transistor           -           -           -           -           -           -           -           22

3.12.   Diagram IC linear voltage regulator 75xxICs      -           -           -           -           23

3.13    Photo-resistor -         -           -           -           -           -           -           -           -           24

3.14    The symbol for a photo resistor -  -           -           -           -           -           -           25

3.15    Voltage comparator ICs      -           -           -           -           -           -           -           27       

3.16    A typical Resistor    -           -           -           -           -           -           -           -           29

3.17    Resistor connected in parallel       -           -           -           -           -           -           31

3.18    Resistor in series      -           -           -           -           -           -           -           -           31

3.19    A typical electrolytic capacity -    -           -           -           -           -           -           32

3.20    A transformer           -           -           -           -           -           -           -           -           33
3.21    A typical PN junction Diode          -           -           -           -           -           -           34

3.22    The system circuit diagram                        -           -           -           -           -           -           37

 

CHAPTER ONE

1.1.         INTRODUCTION

Automatic Hand Dryer with Temperature Display Overview

Engineering is concerned with goal-oriented projects.  Projects that can eliminate problems like time lapse, stream and energy spent, cost and environmental dangers/hazards.  In the old days, there were no choices, if you wanted a hand dryer (or hand drier, depending on where you live), you got a push button, cast iron dryer, and it did the job. In 1980’s, hand dryers began appearing in automatic version, with infra-red sensors that detected the presence of hands under the dryer’s nozzle.

The advantages of automatic dryers are obvious. The first is hygienic hand dryer, reducing the possible spread of germs that could be left on the dryer. The second is energy savings. You only use the dryer for as long as you need it. Many timers are set for 30 seconds. But the user may choose to leave after only 10 seconds of drying, wasting energy used for the rest of the cycle. On the order hand, another user may dry his hands for 35 seconds, wasting almost an entire second’s push of the button.

This project work on the design and implementation of an automatic hand-dryer with temperature display is built to eliminate the dangers and problems associated with the manual process of hand-dryer and to display the temperature of the air used in drying the object.  This project is realized with passive and active components.  And it is pure hardwired in that it does not use micro-program control.

 

1.1.1.     Problem Statement

In a third world country like Nigeria there is poor growth in industrialization as such bars and restaurant all over the places resort to hand towels in cleaning of hands. This has brought about a problem of contracting diseases through the use of same hand towels by many people.

The recent Ebola virus outbreak caused a very big wrath such tat researches should be carried out in better techniques of hand drying in public places like bars, restaurants conveniences and sensor centre (Eateries).

A technique that should have a feature such that no two persons can use the some towel to clean hands is necessary and should be adopted.

This quest resulted to a research on the design and implementation of automatic hand-drier that dries a wet hand without having andy contact with the system.

This proposed system will reduce/prevent contracting of deadly diseases through the use of contact-method of hand cleaning in public places.

 

1.1.2.     Aims and Objectives

The aim of this project is to design and implement an automatic hand dryer with temperature displays facility while is capable of drying a wet hand placed under its vent and displays the temperature of the blown out air in degree centigrade.

1.      To develop an opto-coupler that can sense and opaque object like hand using laser diode and light dependent Resistor (LDR).

2.      T o develop a system that can sense the temperature of warm air using LM 35 Ic temperature sensor.

3.      To develop a system that can switch a handheld blower using electromagnetic relay.

4.      To develop a 2-digit decimal counting unit that will display the temperature in seven segment format.

5.      To develop a regulated power supply synthesized from NEPA (MAINS) that can power the overall system.

 

1.1.3.     Justification of the study

            This project design and implementation of automatic hand-dryer with temperature display justifies a lot in automation and control.  It means a lot in CEE, EEE and Physics and Electronic.  This project is a marketable product for homes and restaurants.  A project of this type if properly modified, can function as a temperature control system for server room, kiln and ovens.

 

1.1.4.     Scope of the Project

            This project work focuses on the design and implementation of automatic hand-dryer with temperature display.  It covers the following; IC Liner Temperature Sensor (LM 35), Opto-coupler using LDR and laser diodes, decimal counting unit and Quad-comparator (LM 339).  It covers other passive and active components used in the design.  The project also x-rays the mode of calculation of the basic circuit parameters used in the design.  This report does not cover the design of the motor used in hand-dryer.(it was market purchased).

 

1.1.5.     Project Report Organization

            This project report is presented in five chapters to appropriately illustrate the steps involved in its implementation.  Chapter one covers the introduction and objectives of the system while chapter two is basically the literature review and theories relevant to the project.  Chapter three focuses on the system design and analysis while chapter four is the system implementation, testing and result.  The fifth and last chapter covers the summary and conclusion.