The design and construction of an Automatic Alarm System to monitor the water level is an electronic device which attempt to monitor the flood level/water level and to alert the user to put it off. Being an electronic device, it is Automatic and highly sensitive to water. The system is a network comprising of a Sensor Unit which is a plastic container fitted with Two Probes made of Copper Conductor; Solid State Switch which is a direct coupling of Amplifier using Complimentary Circuits of two Transistors, NPN and PNP. It consists of Oscillator Unit is an Electronic Circuit that use AC output signal without requiring any external applied input; and then the Audio power amplifier which consists of a Darlington Pair in which the Emitter of one is connected to the base of the other directly. It’s a rugged device and can be used under diverse conditions. With the low power consumption of the device, it can function for a very long time before it calls for a battery replacement. This is due to the fact that the Oscillator is in a standby mode when Flood or spillage due to over-drainage does not occur. It can withstand Mechanical Vibrations when moving it from one place to another as well as adverse condition of water (Non-distilled) be it rain, river or pond.

The Switching unit is responsible for switching ON/OFF of the buzzer when actuated; the Sensor unit normally senses the water level, indicating and sensing the water level from the designated point and Buzzer unit which is responsible for activating an Audio sound (Alarm) when the water level fills up the tank.

With the low power consumption of the device, it can be used under any condition and it can function for a very long time before the need will arise for battery replacement.

This project comprised of five chapters; Chapter One deals strictly with the Introduction which includes: Statement of the problem; Significance of the Study; Background of the Study; Scope of the Study; and Limitations of the Study.

Chapter Two contains the review of related literature; and the theory of components. Chapter Three has the Design Analysis and Block diagram. Chapter Four accounts for the construction stages, Materials used and Bill of Engineering Measurement and Evaluation. Chapter Five contains the Summary, Conclusion and Recommendation.

TABLE OF CONTENT Page â„"

ABSTRACT-------------------------------------------------------------------------- vi.

TABLE OF CONTENT------------------------------------------------------------- vii.

CHAPTER ONE

INTRODUCTION------------------------------------------------------------ 1 - 7

THE BASIC FEATURES--------------------------------------------------- 7 - 8

STATEMENT OF THE PROBLEM--------------------------------------- 8

SIGNIFICANCE OF THE STUDY---------------------------------------- 8 - 9

BACKGROUND OF THE STUDY---------------------------------------- 9

SCOPE OF THE STUDY---------------------------------------------------- 9

LIMITATION OF THE STUDY------------------------------------------- 10

DEFINITION OF TERMS-------------------------------------------------- 10 - 11

CHAPTER TWO

2.0. REVIEW OF RELATED LITERATURE-------------------------------- 12 - 13

2.1. THEORY OF COMPONENTS-------------------------------------------- 13 - 31

CHAPTER THREE

3.0. DESIGN AND ANALYSIS------------------------------------------------- 32

3.1. BLOCK DIAGRAM---------------------------------------------------------- 32

3.2. CIRCUIT DIAGRAM-------------------------------------------------------- 33

3.3. PRINCIPLES OF OPERATION-------------------------------------------- 34 - 35

CHAPTER FOUR

4.0. CONSTRUCTION TECHNIQUES/DESCRIPTION-------------------- 36

4.1. SOLDERING TECHNIQUES------------------------------------------------ 36 - 43

4.2. STEPS IN SOLDERING------------------------------------------------------ 43 - 47

4.3. TOOLS USED IN CONSTRUCTION-------------------------------------- 47 - 48

4.4. MATERIALS USED----------------------------------------------------------- 48

4.5. BILL OF ENGINEERING MEASUREMENT AND EVALUATION-- 49

4.6. TESTING------------------------------------------------------------------------- 50 - 51

CHAPTER FIVE:

5.0. SUMMARY AND CONCLUSION----------------------------------------- 52

5.1. RECOMMENDATION-------------------------------------------------------- 52 - 53 REFERENCES------------------------------------------------------------------ 54 - 55