Design And Construction Of A Signal Generator

ABSTRACT

This work is on signal generator. A signal generator is a signal source that has the capability of producing different types of waveforms as its output signal. The most common output waveforms are sine-waves, triangular waves, square waves, and sawtooth waves. The frequencies of such waveforms may be adjusted from a fraction of a hertz to several hundred kHz.

Actually, the signal generators are very versatile instruments as they are capable of producing a wide variety of waveforms and frequencies. In fact, each of the waveforms they generate is particularly suitable for a different group of applications.

 CHAPTER ONE

1.1                                                        INTRODUCTION

Signal generator is an electronic device that generates electronic signals and waveform. These electronic signals are either repeating or non-repeating as per the requirements and field of applications.  Signal generators in all their forms are widely used within test and development systems, being used with other test instruments.

When looking at what a signal generator is, it will be seen that they come in many forms – there are many signal generator types, each one being used to provide a different form of signal. Some provide RF signals, others audio signals, some can provide different shapes of waveform and others may provide just pulses.

Signal generators have been used for many years. Early types were very basic by the standard of today’s different types of signal generator. Performance levels as well as the variety of facilities that are available have increased and improved.

There are different types of signal generators with different level of capability and functionality. All the signal generators have different designs, different dimensions, and parameters. So, the variety of generators serves different purposes and covers a range of applications. The signal generators are used in designing, repairing of electronic devices, and in troubleshooting. Every versatile signal generator can create unlimited number of signals to meet the debug challenges. You can vary the output of the signal generator by setting the amplitude and frequency of the output signal while a simulation is in the process. A signal generator is piece of test equipment that produces an electrical signal in the form of a wave. This is used as a stimulus for the item being tested.

1.2                                    AIM OF THE PROJECT

The main aim of this work is to build a piece of electronic test equipment used to generate different types of electrical waveforms over a wide range of frequencies. Some of the most common waveforms produced by the function generator are the sine wave , square wave, triangular wave and sawtooth shapes. These waveforms can be either repetitive or single-shot (which requires an internal or external trigger source). Integrated circuits IS used to generate waveforms of the signal generator.

1.3                          SIGNIFICANCE OF THE PROJECT

The generation of signal is an important development in the troubleshooting and development of electronic design. The generator is used to provide known test conditions for the performance evaluation of electronic system design and for replacing signals that are missing in systems during repairing work. Most commonly they generate sine waves.

1.4                                              PURPOSE OF THE PROJECT

The purpose of this work is to generate simple repetitive waveforms. Typically this signal generator type will produce waveforms or functions such as sine waves, sawtooth waveforms, square and triangular waveforms. But in this work we are considering a square waveform.

1.5                                          APPLICATION OF THE PROJECT

1. Signal sweeps to get transfer functions of an analog circuit
2. Generate clock signals at various frequencies or with varying degrees of phase modulation to test circuit stability
3. RF signal generators can be mixed together to generate complex signals for testing mixers and similar RF components

1.6                                              PROBLEM OF THE PROJECT

1. The problem notice in signal generator is that when we connect the signal generator to the oscilloscope with a BNC cable and proceed to create a simple signal to measure, the amplitude measured on the oscilloscope does not match what you set on the signal generator.  The sine wave may read 1V peak-to-peak (Vpp) on the signal generator, and yet on the oscilloscope, it says 20Vpp or 2Vpp.
2. It requires time to set the output frequencies.

1.7                       PROJECT WORK ORGANISATION

The various stages involved in the development of this project have been properly put into five chapters to enhance comprehensive and concise reading. In this project thesis, the project is organized sequentially as follows:

Chapter one of this work is on the introduction to this study. In this chapter, the background, significance, objective limitation and problem of this study were discussed.

Chapter two is on literature review of the study. In this chapter, all the literature pertaining to this work was reviewed.

Chapter three is on design methodology. In this chapter all the method involved during the design and construction were discussed.

Chapter four is on testing analysis. All testing that result accurate functionality was analyzed.

Chapter five is on conclusion, recommendation and references.