CHAPTER ONE

INTRODUCTION

1.1  BACKGROUND STUDY OF THE PROJECT

    A stepper motor is a “digital” version of the electric motor. The rotor moves in discrete steps as commanded, rather than rotating continuously like a conventional motor. When stopped but energized, a stepper (short for stepper motor) holds its load steady with a holding torque. Wide spread acceptance of the stepper motor within the last two decades was driven by the ascendancy of digital electronics. Modern solid state driver electronics was a key to its success. And, microprocessors readily interface to stepper motor driver circuits (Acarneley, 2002).

Going down the memory lane since the inception of mankind, man is insatiable. They always yearn for a better comfort if not for the best. They are ever ready to risk even their lives to acquire a comfort and convenient zone. Therefore, the primary aim of any man is to actualize a comfortable, safe, convenient home. However, the scientist cum engineers are not left out in this trend, as they are always on top of their gears working towards enhancement of standard of living via science and technology.

In line with the aforementioned quest of man to improve on the quality of lives they live, Stepper motor came into foreplay. Stepper motor is used to control the position and speed of devices such rechargeable fans, antenna, elevator and so on. Stepper motors with microcontrollers are used in numerous applications when there is need of controlling the motion. This is due to the robust structure of stepper motor, absence of brushes and better control capacity when they are used with microcontrollers. These motors have excellent response to starting, stopping with reversing.

    The microcontroller is used for sending control pulses to the stepper motor drive. The microcontroller is used both to control the speed as well as position of stepper motor. The speed of stepper motor is directly proportional to the frequency of drive input pulses which is controllable with the help of microcontrollers and the rotation is proportional to the number of output pulses.

1.2  OBJECTIVE OF STUDY

The primary objective of this project is to present a study on applications of stepper motors.

1.3  SIGNIFICANCE OF THE STUDY

The application stepper motors in modern day control of electrical motors is an advantageous one with distinct function like providing a wide range of rotational speeds can be utilized, Precise open-loop positional control without any feedback mechanism, Possible very low speed rotation, the life of a stepper motor is determined by the life of the stepper motor bearing, very good at starting, stopping, and reversing direction, provides precise positioning and repeatability of movement, maintains full torque at standstill position when energized. These special features and functions made this project quite significant.

Also, the use of microcontrollers to be send control pulses to stepper motor with the programmable property may not be sufficient enough to drive the motor. Hence, stepper motor drives are implemented. This has good feature over semiconductor switches that requires a firing circuit which is not easy and losses are more as compared to the drivers.

Furthermore, the old electric motor cannot be used in some small electronic devices (such as Printers, Scanners, DVD player etc) that require smaller size of DC motor. Hence, the used of the advanced technology of stepper motors provides a means of achieving these functions.

1.4  LIMITATIONS OF THE STUDY

In achieving a task of this kind, you must find out that it quite challenging, time and money consuming. It was easy carrying out the project construction at the same time coping with other school learning and assessment as both of them were conflicting despite the short period we had.

Searching of relevant components to build the circuit was also quite challenging as some were not readily available in the market. We had to travel far and near in search of it.

Lastly, there were no enough funds necessary to achieving the project construction this also stood as a stumbling block considering the financial and economic meltdown we experience in our country today. The problem of packaging, coupled with stress and time factor also limited the success of the project.

1.5  ORGANISATION OF THESIS

The work carried out has been summarized in six chapters.

Chapter 1 highlights the brief introduction.  

Chapter 2 highlights the brief introduction summary of work carried out by various researchers.

Chapter 3 highlights the methodology and design concepts. However, it illustrates the breakdown of the stages which the device constructed in this project undergoes in operation.

Chapter 4 highlights the major components used in the construction of this project.

Chapter 5 highlights the specifications and the components used.

Chapter 6 highlights he advantages, challenges and prospects for future students.