Design And Construction Of An Automatic Fan Speed Control System Using 16F877A Microcontroller

ABSTRACT

Automatic controls play an ever-increasing role in a human way of life. Automatic control is vast technological area whose central aim is to develop control strategies that improve performance when they applied to a system. The distinct characteristic of automatic control is that it reduces the human operator. One such gadget is the fan. The fans are generally available with speed control; depending on the requirement the speed is set. Usually, when the temperature is high the fan set at high speed and at lower temperatures the fan is operated with lower speed. This is done manually using human. In this paper, an automatic control solution is suggested to control the fan speed. A circuit with LM35DZ temperature sensor, PIC16F877A microcontroller, brush less DC motor and few of electronic components is designed and implemented to control the fan speed automatically. As an additional feature LCD is used to present the temperature and the fan speed. Finally, the designed system circuit is tested in many times and performed very well.

TABLE OF CONTENTS

COVER PAGE

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWELDGEMENT

ABSTRACT

CHAPTER ONE

INTRODUCTION

1.1      BACKGROUND OF THE PROJECT

• AIM OF THE PROJECT
• OBJECTIVE OF THE PROJECT
• PURPOSE OF THE PROJECT
• LIMITATION OF THE PROJECT
• SCOPE OF THE PROJECT
• APPLICATION OF THE PROJECT
• PROJECT WORK ORGANISATION

CHAPTER TWO

LITERATURE REVIEW

• OVERVIEW OF THE STUDY
• OVERVIEW OF DC MOTOR
• REVIEW OF DIFFERENT TYPES DC MOTOR
• REVIEW OF THE PREVIOUS STUDY

CHAPTER THREE

SYSTEM DESIGN

• SYSTEM COMPONENTS DESCRIPTION
• SYSTEM BLOCK DESCRIPTION
• FAN SPEED CONTROL SYSTEM CIRCUIT DESIGN
• SYSTEM CIRCUIT DESCRIPTION

CHAPTER FOUR

TESTING AND RESULTS

• RESULT AND DISCUSSION

CHAPTER FIVE

• CONCLUSION
• REFERENCES

CHAPTER ONE

1.0                                                        INTRODUCTION

The electric fan is one of the most essential electric devices of all time due to its benefits like cost effectiveness, low power consumption, etc. The electrical fan is a basic building block of several advanced technologies. These are essential devices in computers, large LED lights, the space station, lasers, petrol and electric automobiles; countless other things. The fan is used in HVAC systems which let human beings to build huge or underground constructions. It would be tough to visualize a world without the electric fan!

Nowadays, the humankind is moving towards the new technologies by replacing the manual operations to automatic controlled devices. One of the basic requirements of the people during hot weather is a cooling fan. But, the speed of the fan can be controlled by manual operation using a manual switch namely fan regulator or dimmer. By turning the dimmer, the fan speed can be altered. It can be watch in some places like where the temperature is high during the morning though the temperature falls down radically at night time. The users do not understand the difference in temperature. So to overcome the speed of the fan here is a solution to vary according to temperature. This concept is particularly applicable for the areas like where temperature changes radically during day and night time. This project will convert the manual fan into automatic fans. The automatic fans will change its speed according to the temperature in the room.

Many researches focusing on automatic temperature control system application in different fields will gain  the benefits. For examples, an automatic temperature controller for multi element array hyperthermia systems [2], multi-loop automatic temperature control system design for fluid dynamics [3], design of automatic temperature- control circuit module in tunnel microwave heating system [4], the automatic temperature system with Fuzzy self-adaptive Proportional- Integral-Derivative (PID) control in semiconductor laser [5].

This paper will show how PIC16F877A microcontrollers can be used and applied in a real-world application. One practical use is to integrate a microcontroller in a temperature control system that can be used for automatically controlling a room temperature.

1.1                                              OBJECTIVE OF THE STUDY

The main objective of this study is to discusses about temperature controlled fan block diagram, working of each block and properties. At the end of this work student involved shall also be able to:

• To control the speed of a dc fan.
• To design a controller using temperature sensor.
• To analyses the performance of the

1.2                                                   AIM OF THE PROJECT

The main aim of the project is to automatically control the speed of your fan according to the temperature using pic 16f877a microcontroller.

1.3                                               PROBLEM STATEMENT

The problem happens when the ac fan is still functioning although in the event of cold weather. The function is uncontrolled and must be manually turned on and off or reduced the speed of the fan. Sometimes it can lead to high usage of electricity which in turn raises the electricity bill when the user forgot to switch it off. The system also does not have the capacity to adjust the room temperature regardless of the ambient temperature. To address the problem, the automatic temperature control ac fan that can control the temperature automatically is proposed. The advantages of such a system are less energy usage, and provides more convenient to the consumers.

1.4                                            PURPOSE OF THE PROJECT

The main purpose of this device is to control the speed of a fan can be linearly controlled automatically, depending on the room temperature.

1.5                                                 SCOPE OF THE PROJECT

Below are the scopes of the project:

1. In this work, used a K-type thermocouple for direct measurements of up to 1000ºC temperature. In K-type thermocouple, the two materials used to form the junction are Chromel (Ni-Cr) and Alumel (Ni-Al). K-type is a low-cost and one of the most popular general-purpose thermocouples
2. Inside and outside room temperature are used in the controller

• The analysis controller performance in terms of automatic temperature control based on the speed of the ac fan.

1. temperature controlled ac fan regulator include a diac, triac, 220 power supply and a sensor for sensing the temperature of the environment or device, and a control unit being configured to collect data during the operation of the circuits. The control unit is also configured to execute a predetermined program and calculate a cut-off temperature based on the data and a predetermined target temperature. The control unit is further configured to control the speed of the fan provided to the controlled appliances through a relay, when the temperature of the sensor is equal to or greater than the calculated cut-off temperature.

1.6                                          APPLICATION OF THE PROJECT

Apart from using this device in ac fan regulator, this device can also be used in temperature controlling of electrical appliances such as:

1. Air conditioner
2. Refrigerator

• Fan,

1. furnace etc.

1.7                                           LIMITATION OF THE PROJECT

Though temperature controlled ac fan regulator is designed to controlled 220vac fan, but when the sensor is directly exposed to liquid (water) can damaged the sensor thereby causing the sensor to malfunctioning.

The circuit don’t offer isolation from the HV line and present more of a safety issue.

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 this study. In this chapter, the background, significance, aim, purpose, objective limitation and problem of this work was discussed.

Chapter two is on literature review of the study. In this chapter, all the literature pertaining to this work was reviewed.

Chapter three is on methodology. In this chapter all the method involved were discussed.

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

Chapter five is on conclusion, recommendation and references.