Design And Construction Of A 12V Variable Battery Charger

ABSTRACT

This project is on a 12v variable automatic battery charger. This work is aimed at building a 12v variable automatic battery charger that can be used to charge batteries with different battery voltages.

Method: The device was first built on a breadboard which is later transfer to vero board and soldered.

Result: The device was completely built and coupled, the result during the test shows that the charger was able to respond to its operation when a 6, 12 and 24volts battery was connected it. The variable charging voltage was achieved by tuning the potentiometer.

Conclusion and Recommendation: At the end of this project – battery charger, this device was built and tested. This type of device is important because there are many rechargeable devices that use 12v battery. I recommend that device should be used for any other device lower or higher than 12v rating.

COVER PAGE

1. CERTIFICATION

III. DEDICATION

1. ACKNOWLEDGEMENT
2. ABSTRACT:

CHAPTER ONE

INTRODUCTION

• BACKGROUND OF THE STUDY
• PROBLEM STATEMENT
• AIM AND OBJECTIVE OF STUDY
• LIMITATIONS OF STUDY
• SIGNIFICANCE OF STUDY
• APPLICATION OF STUDY
• DEFINITIONS OF TERMS

CHAPTER TWO

LITERATURE REVIEW

2.1    HISTORICAL BACKGROUND OF BATTERY CHARGER

2.2    REVIEW OF BATTERY CHARGER

2.3    REVIEW OF RECHARGEABLE BATTERY

2.4    REVIEW OF RELATED WORKS

2.5    REVIEW OF DIFFERENT TYPES OF BATTERY CHARGERS

CHAPTER THREE

DESIGN METHODOLOGY

3.1    SYSTEM BLOCK DIAGRAM

3.2    CIRCUITS DIAGRAM

3.3    CIRCUIT DESCRIPTION

3.4      CIRCUIT OPERATION

3.5      CALCULATE THE LM317 OUTPUT VOLTAGE

3.6      DESCRIPTION OF COMPONENTS USED

CHAPTER FOUR

RESULTS/ANALYSIS

4.1    CONSTRUCTION PROCEDURE AND TESTING ANALYSIS

4.2    CASING AND PACKAGING

4.3    ASSEMBLING OF SECTIONS

4.4      TESTING OF SYSTEM OPERATION

4.5      INSTALLATION OF THE COMPLETED DESIGN

CHAPTER FIVE

5.1    CONCLUSION

5.2    SUGGESTION FOR FURTHER IMPROVEMENT

REFERENCES

CHAPTER ONE

1.0                                                        INTRODUCTION

1.1                                           BACKGROUND OF THE STUDY

Battery charger is an electronics device used in charging and recharging batteries when used up by the instrument connected to it. This electronics device has the ability to charger battery of 3v to 12 or more when they are used up.

The 12-volt battery charger uses household current to put an electric charge into a discharged battery. The charger’s circuits convert 240-volt household alternating current (AC) to the 12-volt direct current (DC) that the battery needs.

A 12-volt battery charger is roughly the size of a car battery. It has a thick cable ending in two heavy-duty copper alligator clips, a black clip for the battery’s negative terminal and a red one for positive. The charger has an on-off switch and a meter to indicate charging power.

All battery chargers have a power input, which receives energy from the energy source, and a power output that delivers energy to the load. In most battery charger, the power input and output consist of electrical connectors or hardwired circuit connections, though some power supplies employ wireless energy transfer in lieu of galvanic connections for the power input or output. A battery charger can be regulated are variable.

Variable battery charger is an electronic circuit that is designed to provide a variable dc voltage value across load terminals when the adjuster is turn.

The power supply output is given as input to the voltage regulating device that provides the final output. The voltage output of the power supply remains constant irrespective of large variations in the input AC voltage or output load current.

Variable 12v battery charger circuit using a variable regulator as a regulating device. The input AC voltage (230 Voltas Vrms), is supplied to a transformer. The output will be a stepped down ac output appropriate for the desired dc output. This ac voltage is then given to a bridge rectifier to produce a full-wave rectified output. This is then given to a pi-filter circuit to produce a dc voltage. The filter output may have some ac voltage variations and ripples. This is further filtered using a regulating circuit whose output will be a variable dc voltage. This variable dc voltage is then given to a voltage divider, which supplies the different dc voltages that may be needed for different electronic circuits. This work is at building a variable 12v battery charger.

1.2                                          STATEMENT OF THE PROBLEM

Conventional 12v battery charger is only limited to charging 12v battery which makes it difficult in charging other batteries with higher or lower voltages when the need arises. A variable 12v battery charger was invented to solve this problem by providing a variable output voltage to charge batteries with higher or lower rated charging voltages.

1.3                                  AIM AND OBJECTIVES OF THE PROJECT

The aim of this work is to build a 12v variable battery charger. The study seeks

1. To build the system prototype
2. To provide a variable required voltage and current to the battery using an AC supply at the input.

• To provide a variable output voltage from a battery charger using a potentiometer.

1.4                                           LIMITATION OF THE PROJECT

This device is limited at producing from 3v – 24 v output using a 30 volts center tap transformer.

1.5                                         SIGNIFICANCE OF THE PROJECT

This work makes it possible for someone to use one battery charger to charge different battery of higher or lower voltage rating without considering buying a new or different battery charger.

1.6                                          APPLICATION OF THE PROJECT

A 12v variable battery charger is a charger that electricians and electrical project hobbyists use to charge batteries used for power supply. The power supply is used as a gauge to make sure the piece of work the person has completed is able to withstand certain amounts of voltage and current load. Tests are generally conducted by applying different amounts of voltage to the piece of completed work a little at a time to ensure the stability of the circuit the individual has created. These types of power supplies also are used by hobbyists to power small electronics requiring variable voltage and by tattoo artists to power tattooing guns.

By using such a 12v variable battery charger, the individual is able to spot any temperaments or inconsistencies in the circuit he’s created in a manner that allows for adjustment to be made without having to scrap the entire project. A 12v variable battery charger is a useful tool for anyone who has a background with electrical circuitry and components. It also has many uses other than just testing.

In addition to being used to test circuits, this type of power supply may be used by miniature hobbyists as well. For example, such tools are commonly used by those who work with miniature electronic train sets. The battery charger can be adjusted to either speed up or slow down the train as it is pushed around the track by the power of the completed circuit.

1.7            Definitions of terms

Below are terms that are frequently used in this work and their definitions:

Battery: a container consisting of one or more cells, in which chemical energy is converted into electricity and used as a source of power.

Charger: a device for charging a battery or battery-powered equipment.

Capacitor – a charge storage device made up of two metallic plates separated by a dielectric, with equal but opposite charges. The AC impedance of a Capacitor is (1 / jWL) and acts as an open circuit in DC applications.

Circuit – a complete path that allows electrical current from one terminal of a voltage source to the other terminal.

Alternating (AC) Current – currents that have a harmonic time dependence.

Ampere (A) – the unit of measurement for electrical current in coulombs per second.

CHAPTER FIVE

5.1                                                           CONCLUSION

Having carefully selected the entire component that are required for the construction of the charger and built according to the circuit diagram we were able to design and construct a workable battery charger.

This charger is not designed for 3- 12V batteries; otherwise the charge output voltage will not be sufficient to carry out any meaniful charging operation.

As with any charger it must be housed in a clean environment and operations should be by will trained individual.

Protective materials should be worn while charging batteries to avoid danger to health as a result of the gassing from the battery as the gas are highly inflammable.

CONCLUSION/SUGGESTION FOR FURTHER IMPROVEMENT

In this report we explained the methodology to charge any battery ranging from 3 to 24V. Using this system when the battery is charged fully it will shut off automatically. The circuit consists of very less components and simple in design. Think of the many ways that we can use an auto turn-off battery charger in our life. Whether we have marine batteries, motorcycle batteries, car batteries or other sources of electricity that need to be charged up, we can count on quality auto turn-off battery charges to add many years of life through the cycling cycles.

In the implementation of this project what has proved most difficulties is the selection of the right value of components some were using two diode (the maraine value), in order to have a perfect full wave rectification, we made use of four diodes and the and a functional portable battery is been designed and constructed.

The charger is very simple to use, ever to a Longman all he needs is just a little instruction and it will be accustomed to its method of working.

There is still further improvement demanded from use, mostly in the area of building a work complex and functions charger that could charge battery of higher voltage that might ranges to 48 volts and be able to charge move that two or three battery at the sometimes having more than one terminal.

No doubt, the design and construction of this portable charger.  Gas thrilled us in order to make things works.  In fact, this actually performed us to take even challenges to this kind of coincidence and commitment.

Due to the possibility of this, it has surely put smiles on the face of most people like some motorist who has long been finding it difficult charging there own batteries at their homes and at their convenient time.