Design And Construction Of A Rectified Power Supply With Multiple Output Of 6V, 12V And 15V

ABSTRACT

Rectification in power supply system involves using one or more than one diodes that converts the alternating current (AC) into direct current (DC). The primary functional elements are diodes, which only let current pass one way. By suitable layout of the diodes AC in a single or three-phase circuit is converted to a rippling, but single direction, current. Capacitors may be used to smooth the resulting current. This work is aimed building a rectified power supply with multiple output of 6v, 12v and 15v. The device was built around a transformer, rectifying diodes, regulators and capacitor.  This device was built and tested; the device was seen producing output of 6, 12 and 15v.

TABLE OF CONTENTS

 TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

TABLE OF CONTENT

CHAPTER ONE

• INTRODUCTION
• BACKGROUND OF THE PROJECT
• STATEMENT OF PPROBLEM
• AIM/OBJECTIVE OF THE PROJECT
• SCOPE OF THE PROJECT
• RESEARCH QUESTION
• APPLICATION OF THE PROJECT

CHAPTER TWO

LITERATURE REVIEW

2.1    REVIEW OF RECTIFIER DEVICES

2.2    RECTIFIER CIRCUITS

2.3    REVIEW OF REGULATED POWER SUPPLY

2.4    REVIEW OF POWER SUPPLY CHARACTERISTICS

2.5     REVIEW OF GENERAL APPLICATION OF POWER SUPPLY APPLICATIONS

2.6    REVIEW OF TYPES OF POWER SUPPLY

CHAPTER THREE

3.0      METHODOLOGY

3.1      SYSTEM BLOCK DIAGRAM

3.2      SYSTEM CIRCUIT DIAGRAM

3.3      CIRCUIT OPERATION

3.3      CIRCUIT PARTS

CHAPTER FOUR

4.0       RESULT ANALYSIS

4.1      CONSTRUCTION PROCEDURE AND TESTING

4.2      ASSEMBLING OF SECTIONS

4.3      CONSRUCTION OF THE CASING

4.4      TESTING OF SYSTEM OPERATION

4.5      OBSERVATIONS

CHAPTER FIVE

• CONCLUSIONS

5.2     REFERENCES

CHAPTER ONE

1.0                                                        INTRODUCTION

1.1                                           BACKGROUND OF THE STUDY

A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction.

A Rectifier converts AC (alternating current) to DC (direct current) The rectifier circuit takes alternating current (AC)and converts it into a positive direct current (DC) output. Many power supplies, such as standard electrical output, produce AC voltage. Many handheld tools and other devices use DC. The rectifier is to provide desired DC power for the application.

Physically, rectifiers take a number of forms, including vacuum tube diodes, wet chemical cells, mercury-arc valves, stacks of copper and selenium oxide plates, semiconductor diodes, silicon-controlled rectifiers and other silicon-based semiconductor switches. Historically, even synchronous electromechanical switches and motor-generator sets have been used. Early radio receivers, called crystal radios, used a “cat’s whisker” of fine wire pressing on a crystal of galena (lead sulfide) to serve as a point-contact rectifier or “crystal detector”.

Rectifiers have many uses, but are often found serving as components of DC power supplies and high-voltage direct current power transmission systems. Rectification may serve in roles other than to generate direct current for use as a source of power. As noted, detectors of radio signals serve as rectifiers. In gas heating systems flame rectification is used to detect presence of a flame.

Depending on the type of alternating current supply and the arrangement of the rectifier circuit, the output voltage may require additional smoothing to produce a uniform steady voltage. Many applications of rectifiers, such as power supplies for radio, television and computer equipment, require a steady constant DC voltage.

To obtain a complete circuit for this work, the circuit is mainly composed of the:

Input transformer: The input transformer is used to transform the incoming line voltage down to the required level for the power supply. Typically the input transformer provides a step down function. It also isolates the output circuit from the line supply.

Rectifier: The power supply rectifier converts the incoming signal from an AC format into raw DC. Either half wave or more commonly full wave rectifiers may be used as they make use of both halves of the incoming AC signal.

Smoothing: The raw DC from the rectifier is far from constant falling to zero when the AC waveform crossed the zero axis, and then rising to its peak. The addition of a reservoir capacitor here fills in the troughs in the waveform, enabling the next stage of the power supply to operate. Large value capacitors are normally used within this stage.

Regulator: This stage of the power supply takes the smoothed voltage and uses a regulator circuit to provide a constant output virtually regardless of the output current and any minor fluctuations in the input level. In these applications the output of the rectifier is smoothed by an electronic filter, which is capacitor, followed by a voltage regulators to produce a steady voltages of 6, 12 and 15v, which is the main aim of this work.

1.2                                                  PROBLEM STATEMENT

In many electronics projects, we see that there is a requirement of fixed-voltage power supply, fixed means no fluctuation in voltage. The output of any circuit fully depends on input voltage supply and it should be constant. Any sensitive circuit is more essential to operate on regulated power than any normal circuit. If I use RF operation in any circuit then its frequency must be constant because there is a small bit of voltage and current fluctuation make more variation of the output signal. We use the voltage regulator to regulate the voltage supply which maintains constant supply. 220 ac to 15v/12v/6v DC Regulated Power DC converter Bridge Rectifier as required.

1.3                                    AIM AND OBJECTIVES OF THE STUDY

The main aim of this work is to build a rectified power supply of multiple outputs of 6, 12 and 15v. The objectives are:

1. To build the prototype of the system
2. To have a power supply with multiple outputs of 6, 12 and 15v

• To have a wider knowledge of rectifier used for power supply application.

1. To use the voltage regulator to regulate the voltage supply which maintains constant supply.220/230v ac to 15v/12v/6v DC Regulated Power DC converter Bridge Rectifier as required.

1.4                                                   SCOPE OF THE STUDY

A rectifier circuit converts the Alternating Current (AC) input power into a Direct Current (DC) output power. The scope of this study covers building a rectified power supply of multiple out which was built around a step down transformer, a filter (capacitor), three different rating regulator (6, 12, and 15v). The complete work was built to generate a voltage of 6, 12 and 15v.

1.5                                                  RESEARCH QUESTIONS

At the end of the day, answers to the following questions shall be provided:

1. What is a rectifier and its types?
2. What is a rectifier used for?

• What is rectifier and its principle?

1. Why rectifier is used in power supply?
2. Which rectifier is generally used in DC power supply?

1.6                                            APPLICATION OF RECTIFIERS

The primary application of rectifiers is to derive DC power from an AC supply (AC to DC converter). Rectifiers are used inside the power supplies of virtually all electronic equipment. AC/DC power supplies may be broadly divided into linear power supplies and switched-mode power supplies. In such power supplies, the rectifier will be in series following the transformer, and be followed by a smoothing filter and possibly a voltage regulator.

Rectifiers are also used for detection of amplitude modulated radio signals. The signal may be amplified before detection. If not, a very low voltage drop diode or a diode biased with a fixed voltage must be used. When using a rectifier for demodulation the capacitor and load resistance must be carefully matched: too low a capacitance makes the high frequency carrier pass to the output, and too high makes the capacitor just charge and stay charged.