DESIGN AND CONSTRUCTION OF AUTOMATIC STREET LIGHT

CHAPTER ONE

1.0. INTRODUCTION

1.1. GENERAL DESCRIPTION OF THE PROJECT

Industrial electronics has turned the whole world into a global village. One of the most indispensable aspects of these phenomena is automation, which forms the nucleus of the present day electronics technology. Considering the milestone, it was desired to make the choice of the project research on the design and implementation of an automatic fence light controller.

This electronics system is realized with a cadmium – sulphide photo-conductive cell which serves as the light sensor. The output of the light dependent resistor is fed into a delay circuit configured using an n RC- network. The output of the RC-network bases a Darlington pair transistor which drives an electromagnetic are interfaced. The overall circuit is powered by a 12 v d.c. unregulated power supply unit that properly filtered.

1.2. STATEMENT OF THE PROBLEM

This project work signifies a lot in industrial automation, telecom, computer electronics and ICT at large. It seeks to eliminate the stress, time and inconvenience associated with manual switching of security lights. It has a wide range of real-life applications basically in automation and can be used in surveillance system if properly modified. It can be used to illuminate farm settlement automate irrigation pumps in the farm usually in the night to scare away thieves and rodents to increase yield.

1.3. OBJECTIVES OF THE PROJECT

1)To study the existing street light control systems.

2)To design energy efficient street light control system.

3)To develop the hardware of control unit.

4)To test and validate the designed system.

1.4. SCOPE OF THE PROJECT

This project is focused on designing and constructing of an automatic light system using photo-sensitive switch. That is, to illuminate the case study in response to change in weather. The system comes on at twilight through the night and goes off at dawn all through the day. The project research work covers the following photosensitive devices like light dependent Resistor (L.D.R) which serves as the sensor. It x-rays the design calculations of the basic circuit parameter and other areas of applications of this system. It also lays great emphasis on passive and active components like Diode Resistors, capacitors Darlington pair transistors, electromagnetic relays, lamps and transformers.

1.5. OVERVIEW OF THE PROJECT

The high rate of technological advancement in industrial automation, security and control motivated me to embark on a project research work on design and implementation of automatic light system using photosensitive switch. This electronics system is designs in five different modules all combined to form one functional unit. The first module is the sensor (light-dependent-resistor). Its output is conditioned by an RC-network (delay circuit) that forms the second module. The third module is the driver realized with Darlington pair transistor. The fourth module is the electromagnetic relay where the fifth and final module –load are interfaced. The result being a rugged, robost and easy – to – maintain system.