Design And Construction Of An Automatic Emergency Light Circuit

This low cost automatic emergency lighting circuit turns on a lamp during power failures. It is powered by a NiCad battery that is being charged by the main power line when there is no blackout. The circuit design is very simple and can be made by almost anyone. The voltage from the step down transformer is rectified by diode D1 and filtered by C1. The NiCad battery gets charged with about 100 mA via the diode D2 and resistor R1. The battery must have a capacity of at least 2 Ah to tolerate the charging rate.

When the main power supply fails during a blackout, the charging current is interrupted and a current flows from the base of T1 via resistor R2 which triggers the transistor to conduct and the two emergency lamps light up. When the main power returns, the charging current flows again through D2 and the transistor turns the lamps off.

TABLE OF CONTENTS

COVER PAGE

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWELDGEMENT

ABSTRACT

CHAPTER ONE

1.0      INTRODUCTION

1.1      BACKGROUND OF THE PROJECT

• PURPOSE OF THE PROJECT
• AIM OF THE PROJECT
• OBJECTIVE OF THE PROJECT
• PURPOSE OF THE PROJECT
• LIMITATION OF THE PROJECT
• ADVANTAGES OF THE PROJECT
• PROBLEM OF THE PROJECT
• APPLICATION OF THE PROJECT
• RESEARCH QUESTION
• PROJECT ORGANISATION

CHAPTER TWO

LITERATURE REVIEW

• OVERVIEW OF THE STUDY
• REVIEW OF THE RELATED STUDY

CHAPTER THREE

3.0     CONSTRUCTION METHODOLOGY

3.1      BASIC OF THE SYSTEM

3.2     BLOCK DIAGRAM OF THE SYSTEM

3.3      SYSTEM OPERATION

3.4      CIRCUIT DIAGRAM

3.5      CIRCUIT DESCRIPTION

3.6     DESCRIPTION OF COMPONENTS USED

3.7      POWER SUPPLY UNIT

CHAPTER FOUR

4.0      TESTING AND RESULTS

• CONSTRUCTION PROCEDURE AND TESTING
• INSTALLATION OF THE COMPLET DESIGN
• ASSEMBLING OF SECTIONS
• TESTING OF SYSTEM OPERATION
• COST ANALYSIS

CHAPTER FIVE

• CONCLUSION
• RECOMMENDATION
• REFERENCES

KEYWORD: automatic emergency light circuit, automatic led emergency light project pdf, emergency light circuit board, emergency light circuit diagram free, construction of emergency light, led emergency light circuit diagram without transformer, led emergency light circuit with battery overcharge protection, emergency photo lamp, emergency light project pdf.

How does the automatic emergency light works

The voltage from the step down transformer is rectified by diode D1 and filtered by C1. The NiCad battery gets charged with about 100 mA via the diode D2 and resistor R1. The battery must have a capacity of at least 2 Ah to tolerate the charging rate.

When the main power supply fails during a blackout, the charging current is interrupted and a current flows from the base of T1 via resistor R2 which triggers the transistor to conduct and the two emergency lamps light up. When the main power returns, the charging current flows again through D2 and the transistor turns the lamps off.

The “TEST” button S1 is used to check the function of the circuit. If the secondary coil of the transformer delivers a higher voltage level, replace R1 with a higher value resistor to avoid exceeding the maximum charging current allowed for the NiCad battery being used.

Emergency light parts

• 220V to 4.5V / 2A Transformer
• D1 = 1N4004
• D2 = 1N4001
• R1 = 33Ω/1W
• R2 = 470Ω
• C1 = 470µF/16V
• T1 = 2SB242
• La1, La2 = 2.5V bulbs
• Battery = 2.5V / 2Ah Nicad

Automatic Emergency Lighting Circuit Diagram