Prepaid Energy Meter Review And Assesment

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Prepaid Energy Meter
Student’s Name
Institutional Affiliation
Date

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Abstract
Since the distribution of electrical energy began, the conventional billing method has been to
send a company representative to read the energy meters (for water or electrical energy) and
provide the information to the customer to make the necessary payments. This approach is
inefficient and time wasting since the individual has to travel from area to area going from
house to house to take readings. This represents a significant amount of time and resources
wasted since the board or energy authority has to send its employees who also have other
duties to perform. To overcome this problem and improve the effectiveness and efficiency of
service delivery, this project investigated the automation of the energy billing system for
water and electricity to eliminate the need for individual meter reading. The project was
designed to be user friendly and easy to operate to enable customers and employees to use the
system without specialized training. Java was used for the front end design.
Table of Contents
Table of figures...................................................................................................... 2
Abstract................................................................................................................. 2
Introduction........................................................................................................... 3
Working.............................................................................................................. 3
Circuit diagram................................................................................................... 4
Description of the circuit.................................................................................... 4
Circuit explanation............................................................................................. 5
Block diagram..................................................................................................... 6
System advantages............................................................................................ 6
Description of the components.............................................................................. 7
Conclusion........................................................................................................... 12
Bibliography......................................................................................................... 13
Table of figures
Figure 1: Complete circuit diagram.......................................................................4
Figure 2: Circuit breakdown................................................................................... 5
Figure 3: System block diagram............................................................................ 6
Figure 4: AT89S52 microcontroller........................................................................8
Figure 5: EEPROM AT24C02................................................................................... 9
Figure 6: DSM modem......................................................................................... 10
Figure 7: ADC0808 chip....................................................................................... 11
Figure 8: LCD display........................................................................................... 11
Figure 9: BC546 transistor pinout........................................................................12

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Introduction
The objective of this project is to minimize the long queues normally witnessed in
billing centers. The designed system is also required to cut-off the power supply to the
customer automatically if the bill is not settled. Additionally, the project aims to minimize
power loss and power theft which leads to loss of revenue for the government. To fully
implement this project, GSM technology is incorporated to enable communication between
the service provider and the consumer in terms of energy consumption in units. If the number
of units gets too low, the sytstem is designed to alert the user to recharge. This technology
can be adopted by all power distribution companies, self-contained housing projects, and
private communities. The adoption of this strategy will yield better energy management,
minimize losses, save time and minimize customer overcharging due to incorrect meter
reading. This system enables real time tracking of consumption which leaves little room for
billing errors.
Working
The primary controller in this system is the AT89S52 microcontroller. One of its functions is
to gather data from the consumption meter and the smart card. Switches are used here to
replace the IC. The smart card which acts as the switch provides information regarding the
limit of the available units. The microcontroller compares the reading on the energy meter
with the information on the smart card. The microcontroller then triggers a buzzer if the card
credit is low. If the credit falls below a certain threshold, the microcontroller activates a relay
whose function is to cut-off and restore power. A parallel port connection is used to interface
the microcontroller with the LCD screen. This microcontroller-based system continuously
monitors the readings, greatly increasing the efficiency and accuracy in computation of bills
and reducing human intervention. The system can notify the consumer about the balance of
the credit via the GSM module which is connected serially with the microcontroller. The
programming utilizes the GSM’s messaging features via the AT command. The GSM utilizes
its own communication network. Low credit triggers the relay which shuts down power to be
restored only when the meter is recharged. Java Basics software is the main software used as
a platform to develop the application for sending or receiving SMS via the modem,
processing and storing data. The software is meant to perform two major tasks,
i) To maintain the database
ii) To interact with the modem and to read the COM port
This project explores the interface of a microcontroller and a GSM module with an energy
meter in each house. Each house has an energy meter with a unique identity provided by the
service provider. The microcontroller and GSM module are incorporated into the energy
meter. The energy consumption data is stored in the form of SMS in the microcontroller. This
SMS can then be sent to the specific number assigned by the provider. The transmitted
message is received by the modem on the other end as a command which directs the
microcontroller to compute the readings. The controller then sends the results to the modem
which transmits the information back to the provider control center where the Java software
calculates the total consumption. This process is very fast and saves time and illegal power
consumption.

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Circuit diagram
Figure 1: Complete circuit diagram
Description of the circuit
A transformer with a voltage rating of 12 V on the secondary side was used. A bridge
rectifier converts the AC supply to the required DC voltage. A filter consisting of a capacitor
and a resistor provides clean power without ripples. Integrated circuits are very sensitive and
require a very stable DC supply. For steady voltage, an LM7805 voltage regulator is
employed to provide a stable DC voltage of 5 V.