ABSTRACT

The purpose of this project is to design and construction of a central wireless switch for electrical and electronic appliances. A central wireless switch for electrical and electronic appliance is a GSM based online power control switch system that controls the entire appliance in the EEE general office using GSM network. It will act as an embedded system which would monitor and control appliances and other devices locally using built-in input and output peripherals. This device can control the inflow of electricity power supply in a building or turn off the equipments when there is emergency using a GSM cell phone. The device consists of a special arrangement of GSM signal amplifier, PICl2f629 micro controller (the peripherals interface control), capacitors, resistors, diode, regulators and electromagnetic relay to effect power switching. After successful design of the system various sub sections of it were tested for efficiency and proper functioning. The results confirm that the system is ok.

CHAPTER ONE

INTRODUCTION

1.1 Background of Study

Due to the stress and risk of controlling electrical appliance in the school 
building at night, we are motivated to design and build a central wireless 
remote switch for the electrical and electronic department. A central wireless switch for electrical and electronic appliance is an electronic device specially designed to use GSM mobile cell phone to shut down electrical power supply to the entire appliance in the EEE general office where there are ugly power situations such as fire outbreak, lightning strikes, switching surges, transients, neutral failure and other abnormal conditions or malfunctions that can destroy lives and properties. Ndubuisi (2011).

The system implements the emerging applications of the GSM technology 
which enable the users to carry out some task from anywhere in the world via a GSM network. The system is made up of a GSM amplifier unit, PIC12f629 micro controller, power control and a power supply unit. These sub circuits are designed using passive and active electronic components like capacitors, resistors, diode, regulators, transistors, electromagnetic relay, microcontroller and battery.

 New age of technology has redefined communication; Most people nowadays have access to mobile phones and thus the world indeed has become a global village. At any given moment, any particular individual can be contacted with the mobile phone. But the application of mobile phone cannot just be restricted to sending SMS or starting conversations. New innovations and ideas can be generated from it that can further enhance its capabilities. Technologies such as Infra-red, Bluetooth, etc which has developed in recent years goes to show the very fact that improvements are in fact possible and these improvements have eased our life and the way we live. Remote management of several homes, offices and the school appliances is a subject of growing interest and in recent years, we have seen many systems providing such controls. Appliances of a certain location 
are eliminated with the use of this system. These days, apart from supporting voice calls a mobile phone can be used to send text messages as well as multimedia messages (that may contain pictures, graphics, animations, etc).

Sending written text messages is very popular among mobile phone users. Instant messaging, as it is also known, allows quick transmission of short messages that allow an individual to share ideas, opinions and other relevant information. We have used the very concept to design a system that acts as a platform to receivemessages which in fact are commands sent to control different appliances and devices connected to the platform. We have designed a control system which is based on the GSM technology that effectively allows control from a remote area to the desired location. The application of our suggested system is immense in the ever changing technological world. It allows a greater degree of freedom to an individual whether it is controlling their appliances or office equipments. Shizhuang (2007)

There is no need to be physically present in order to control. I have implored the use of both hardware and software to bring about the entire project. The hardware components are solely coordinated by the micro controller chip while the c programming language is used to program the chip.

1.2 Statement of Problem

Surge may occur in power line which may damaged a lot of 
sensitive electrical and electronic appliances in various homes and offices. When the occurrence is not being solved or controlled it may lead to sudden explosion and fire outbreaks. And in most cases the users of the electrical appliance are busy and may not be close to switch-off the appliances when surge occurs. Also, it is also stressful to do the monitoring and switching off the load. Hence, the need for using a remotely controlled device for electrical appliances so as to be able to control the appliances for safety.

1.3 Aim and Objectives

This project focuses on design and construction of a central wireless switch that controls the entire appliances for electrical and electronic engineering general office. Therefore, the specific objectives are as follows;

1. To design a device that controls electrical and electronic appliances.

2. To provide a wireless system that can switch off and on electrical and electronic appliances

3. To design and construct a system that uses GSM network for control of the entire appliances for electrical and electronic engineering general office

1.4 Scopes of Work

The central wireless switch for electrical and electronic appliances project uses GSM network to cover a wide area of operation but it is limited to network failure and airtime subscription.

1.5 Major Constraints

Along the course of project completion we encountered various problems 
and obstacles. Not everything that we had planned went smoothly during the project development span. Also we had a limited amount of time for its 
completion so we were under a certain amount of pressure as well. We had to start from the research phase at the beginning and needed to gain knowledge on all the devices and components that we had intended to use for our project. Other phases of the project included coding, debugging, testing, documentation and implementation and it needed certain time for completion so we really had to manage the limited time available to us and work accordingly to finish the project within the schedule. One of the major constraints of this project is the funding and sourcing of some components like the signal transistors and microcontroller chip used.

1.6 Constraints Considerations

The following is a list of constraint Considerations

o                   The controlled appliances will need an electrical control interface. This system is only capable of controlling electrical devices.

o                   The control module will need to be shielded against electrostatic discharges. This will increase the reliability of the system.

o                   Battery backup for controlling unit can be implemented in case of power disruption.

·       Technology Considerations: The considerations for this system will include a choice of networks, communication protocols and interfaces.

·       Cellular Networks: The widely available networks are based on GSM. This network provides wide area coverage and can be utilized more cost-effectively for this project.

·       Communication Protocols: The available communication protocol that we have used is SMS. The SMS is the most efficient because this project requires a cellular communication and limited data to be sent.

·       I/O interfaces between microcontroller and devices: Serial I/O is considered as options for connection between the GSM receiver and the micro controller. Using the micro controller, a control circuit will be implemented to control the electrical appliances.

1.7 Significance of the Project

This project when realized will;

1.                 Help to save electricity bill and protects your electrical appliances 
simply by remote controlling of the appliance any day any time.

2.                 Reduce the stress that is preventing people from going to switch off their appliances when not in used.

3.                 Give a fast turning off of appliances during power surge or any electrical faults in the building.

4.                 Serves as a lasting solution to the electricity problems that 
usually occur when people forget to put off their appliances. It gives a fast response to power control.

1.8 Limitation of the project.

The project has certain limitations and a list of such is mentioned below: -

A.   The receiver must reside in a location where a signal with sufficient.Strength can be received from a cellular phone network.

B.   Only devices with electrical controlling input ports will be possible targets for control.

C.   Operation of the controlling unit is only possible through a cell phone with SMS messaging and calls capabilities.

D.   The Controlling unit must be able to receive and decode SMS messages or calls.

1.9 Report Organization

The remaining parts of this project report are organized as follows: In 
Chapter two, the past and current research on the systems is briefly overviewed. This is done in order to justify the topic of this project, and to 
show that a research gap exists. Chapter three presents the system design 
module by module. Here, the structure of the device is discussed in detail. 
Chapter four describes the integration and testing of the project

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