Design And Construction Of An Accurate Room Temperature Controller

ABSTRACT

The accurate room temperature controller is designed with microcontroller is quite useful for conference halls, auditoriums, cinema halls, and other commercial organizations where many people gathered together, and lot of fans are required at these places. Depending up on the weather condition, organizers of the above places are supposed to be control each and every fan, otherwise lot of energy will be wasted. Controlling each and every fan manually is highly impossible; there by this project work is taken up, which controls the fan automatically depending upon the temperature. Here for the demonstration purpose single fan is considered, but in practical all the fans can be connected to this single instrument, so that all the fans rotates equally.

The basic concept of this project work is, depending upon the room temperature to control the fan speed automatically. Since our weather conditions are widely varied, temperature up and downs are common in our country. When the temperature is less then 20 0C fan is not required, there by a facility is provided in the system that the fan will be switched off automatically at less then 20 0C. The system is programmed to run the fan at its maximum speed at 40 0C. There fore the fan speed varies linearly between 20 0C to 40 0C.

TABLE OF CONTENT

COVER PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

TABLE OF CONTENT

CHAPTER ONE

• INTRODUCTION
• BACKGROUND OF THE PROJECT
• OBJECTIVES OF THE PROJECT
• PROBLEMSTATEMENT
• PURPOSE OF THE PROJECT
• SCOPE OF THEPROJECT
• APPLICATION OF THE PROJECT

CHAPTER TWO

LITERATURE REVIEW

2.1      OVERVIEW OF TEMPERATURE CONTROL

2.2      REVIEW OF DIFFERENT TYPES OF TEMPERATURE CONTROLLERS AND THEIR WORKING PRINCIPLE

2.3      DEFINITION OF TEMPERATURE SENSOR

2.4      TYPES OF TEMPERATURE SENSORS

CHAPTER THREE

METHODODLOGY

3.1      SYSTEM BLOCK DIAGRAM

3.2      SYSTEM CIRCUIT DIAGRAM

3.3      SYSTEM CIRCUIT AND WORKING

3.4      COMPONENT’S DESCRIPTION

3.5      DESCRIPTION OF CAPACITOR

3.6      DESCRIPTION OF CAPACITOR

3.7      DESCRIPTION OF LED (LIGHT EMITTING DIODE)

CHAPTER FOUR

CONSTRUCTION PROCEDURE AND TESTING

• CASING AND PACKAGING
• ASSEMBLING OF SECTIONS
• TESTING OF SYSTEM OPERATION
• INSTALLATION OF THE COMPLETED DESIGN
• PROBLEM ENCOUNTERED
• COST ANALYSIS

CHAPTER FIVE

5.1 CONCLUSION

5.2      RECOMMENDATION

5.3      BIBLIOGRAPHY

CHAPTER ONE

1.0                                                        INTRODUCTION

The main purpose of this Digital Temperature Controller is to control the temperature of any device like AC or any other electronic devices whose temperature keeps fluctuating and thus requires a constant watch on the device. The use of this system eliminates constant watching on the device by self controlling the temperature of the system.

Our proposed project consists of digital temperature sensors for more accurate temperature control in various industries. Our system overcomes the disadvantages of thermostat/analog systems in terms of accuracy. This system can be used in any firm or organization where it is very important to maintain precise temperatures. LCD display is used to display the temperature and when the temperature exceeds the set limit, the lamp is switched off in order to control the temperature. The heater is demonstrated with the help of a lamp. After the heater is switched off, the AC is switched ON. Here AC is demonstrated with the help of small fan. After the AC is switched ON, it remains ON until the temperature reaches below the exceed limit. Thus the system keeps on switching ON/OFF the heater or the AC for automatically controlling the temperature of the system. The system uses a digital temperature sensor in order to detect temperature and pass on the data to the microcontroller. The 8051 microcontroller processes data and sends the temperature to be displayed on LCD screen. The display consists of 7 segment display unit to display up to 4 numbers.
It consists of 4 push buttons for setting the high and low temperatures. Pressing set button allows user to increment and decrement high and low temperatures. After that the system detects temperature and switches the load when it goes beyond set limits.

1.2                                         BACKGROUND OF THE PROJECT

Nowadays, the air conditioning is widely used especially in warm countries including Malaysia. Usually the conventional air conditioning is always cooling the room depending on the fixed temperature setting and is not automatically adjusted for the comfort of the users. In the central air conditioning control field, excellent real-time, high reliability, and good intelligence are proposed by many researchers. The traditional PID algorithm is, in fact, still playing a main role in the control process. The air conditioning system has becoming a field to be researched to improve the user convenience by applying intelligent system such as THERMOCOUPLE.

While the enhanced air conditioning system is being designed, the consideration of the type of control system must be included in a modeling design. In particular the controller must be able to avoid the inefficiency of having the air conditioning operate all the time. Several control options were considered at presence sensing circuit, which would turn the air conditioning off when people are not in the room with the air conditioning and a temperature sensor input, which would change the air conditioning operation depending on room temperature [1]. Based on the observation of the using the present conventional air conditioning application, it always working all the time without a systematic control. Therefore, the control of the air conditioning is adjusted through a feedback control system to monitor and maintain a constant temperature based on the data input from the sensor.

1.3                                            OBJECTIVES OF THE PROJECT

The objectives of this project are:

1. To find the mathematical model of an air conditioning
2. To design a controller using temperature sensor.
3. To analyses the performance of the
4. Real-time temperature is displayed on its LCD screen.

1.4                                                                              PROBLEM STATEMENT

The problem happens when the air conditioning is still functioning although in the event of cold weather. The function is uncontrolled and must be manually turned on and off. 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 room temperature control 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.

1.5                                            PURPOSE OF THE PROJECT

The main purpose of this Digital Temperature Controller is to control the temperature of any device like AC or any other electronic devices whose temperature keeps fluctuating and thus requires a constant watch on the device.

1.6                                                 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 compressor of air conditioning

1.7                                          APPLICATION OF THE PROJECT

This device can be used for temperature control electrical appliances such as:

1. Air conditioner
2. Refrigerator

• Fan,

1. furnace etc.