Abstract
This project work focuses on the design and construction of heat detector for use in homes, industries, offices etc. It uses thermistor as the heat sensitive element; which is a type of resistor whose resistance changes significantly according to temperature change. The thermistor was connected as a voltage divider to one input therminal of the comparator (Pin 2) of the 555 timer IC as the resistance of the thermistor increases, the voltage at pin 2 decreases. Thus pin 1 becomes high and biases the N.P.N transistor moleing it to drive the 9V input load which activities the alarm circuit with the design of rate-of-heat detector a temperature increase of the sensor, to output is at 75oC or more per minutes; that is to trigger alarm. The heat sensor can be said to be ideal for environments with high dust or rapaid fire development.
Table of Content
Title Page: ================================= i
Certification: ============================== ii
Table of Content: =========================== iii
Chapter One
1.0 Introduction: ========================= 1
1.1 Background of the Study: ================ 1
1.2 Statement of the Problem: ================ 4
1.3 Objective of the Study: ================ 4
1.4 Significance of the Study: ================= 5
1.5 Scope of the Study: ====================== 6
1.6 Research Question: ====================== 6
Chapter Two
Literature Review: =========================== 8
2.1 Heat (Heat Transfer): ===================== 8
2.2 Sensor: =============================== 11
2.2.1 Heat Sensor: =========================== 15
2.2.2 Electromechanical: ====================== 17
2.2.3 Optomechanical: ======================== 20
2.2.4 Electropneumatic: ====================== 21
2.3 Application of Heat Sensor: =========== 22
2.4 Forms of Heat Sensor: =============== 24
2.4.1 Thermo couples: ==================== 25
2.4.2 Resistant Temperature Devices (RTD): ====== 26
2.4.3 Infrared Sensors: ====================== 27
2.4.4 Bimetallic Devices: ================= ==== 27
2.4.5 Thermometers: ======================== 28
2.4.6 Silicon Diode: ====================== 29
2.4.7 Thermostat: ========================== 29
2.5 Description of Component: =============== 30
2.5.1 Thermistor: ========================== 31
2.5.2 Transistor: =========================== 32
2.5.3 Resistor ============================= 33
2.5.4 Capacitor: =========================== 35
2.5.5 Buzzer: ============================= 36
2.5.6 Veroboard: =========================== 37
2.5.7 Light Emitting Diode: ================= 37
Chapter Three
Materials and Method: ======================= 39
References: ================================ 48
This project work focuses on the design and construction of heat detector for use in homes, industries, offices etc. It uses thermistor as the heat sensitive element; which is a type of resistor whose resistance changes significantly according to temperature change. The thermistor was connected as a voltage divider to one input therminal of the comparator (Pin 2) of the 555 timer IC as the resistance of the thermistor increases, the voltage at pin 2 decreases. Thus pin 1 becomes high and biases the N.P.N transistor moleing it to drive the 9V input load which activities the alarm circuit with the design of rate-of-heat detector a temperature increase of the sensor, to output is at 75oC or more per minutes; that is to trigger alarm. The heat sensor can be said to be ideal for environments with high dust or rapaid fire development.
Table of Content
Title Page: ================================= i
Certification: ============================== ii
Table of Content: =========================== iii
Chapter One
1.0 Introduction: ========================= 1
1.1 Background of the Study: ================ 1
1.2 Statement of the Problem: ================ 4
1.3 Objective of the Study: ================ 4
1.4 Significance of the Study: ================= 5
1.5 Scope of the Study: ====================== 6
1.6 Research Question: ====================== 6
Chapter Two
Literature Review: =========================== 8
2.1 Heat (Heat Transfer): ===================== 8
2.2 Sensor: =============================== 11
2.2.1 Heat Sensor: =========================== 15
2.2.2 Electromechanical: ====================== 17
2.2.3 Optomechanical: ======================== 20
2.2.4 Electropneumatic: ====================== 21
2.3 Application of Heat Sensor: =========== 22
2.4 Forms of Heat Sensor: =============== 24
2.4.1 Thermo couples: ==================== 25
2.4.2 Resistant Temperature Devices (RTD): ====== 26
2.4.3 Infrared Sensors: ====================== 27
2.4.4 Bimetallic Devices: ================= ==== 27
2.4.5 Thermometers: ======================== 28
2.4.6 Silicon Diode: ====================== 29
2.4.7 Thermostat: ========================== 29
2.5 Description of Component: =============== 30
2.5.1 Thermistor: ========================== 31
2.5.2 Transistor: =========================== 32
2.5.3 Resistor ============================= 33
2.5.4 Capacitor: =========================== 35
2.5.5 Buzzer: ============================= 36
2.5.6 Veroboard: =========================== 37
2.5.7 Light Emitting Diode: ================= 37
Chapter Three
Materials and Method: ======================= 39
References: ================================ 48