A PROJECT REPORT

On

SIM CARD BASSED PREPAID ENEGY STORE METER

Submitted in partial fulfilment of the requirements for the award of the degree

of

Bachelor of Technology

In

Department of Electronics & Communication Engineering

Submitted By: - Under the guidance of:-

DEEPAK GUPTA Er.AMRINDRA B. SINGH

DEEPAK SHARMA (H.O.D.)

GOVIL SHARMA Department of E.C.E.

HAPPY ADLAKHA AIET, Alwar

JAGRITI MISHRA

MOHIT BHARDWAJ

1

AL*WAR INSTUTUTE OF ENGINEERING &TECHNOLOGY, MIA

ALWAR-301030 (RAJ.), INDIA

MAY 2014

CERTIFICATE

This is to certify that the project entitled “Sim Card Bassed Prepaid Energy Store Meter” submitted

to Alwar Institute of Engineering & Technology , affiliated to RTU, Kota for the award of the degree of

Bachelor of Technology in Mechanical Engineering is a record of bonafide work carried out by them

under my supervision and guidance during session 2014-2015.

Date:-Place:-Alwar

Amrinder B. Singh Mr. Parul Trivedi

(H.O.D.) (Associate Professor)

Deptt. Of E.C.E. Deptt. of E.C.E

Alwar Institute of Engineering & Technology MIA, Alwar 301030, Rajasthan

2

CANDIDATE’S DECLARATION

We here by declare that the work of project “Aadaptive Head Lights” is being presented in

the partial fullfillment of the requriment for the award of Bachelor of Technology in

Mechanical Engineering to Alwar Institute of Engineering & Technology, Alwar, Affiliated to

Rajasthan Technical University,Kota is an authentic record of our work carried out during VIII

semester under the supervision of our guide Sh.Anil Kumar Mahawar Associate Professor,

Department of Mechnical Engineering, Alwar Institute of Engineering & Technology, Alwar .

The matter embodied in this report has not been submitted by us for the award of any other

degree or diploma.

Date:

1. Deepak Gupta (10EAEEC022 ) ---------------

2. Deepak Sharma (10EAEEC023 ) ---------------

3. Govil Sharma (10EAEEC027 )--------------

4. Happy Adlakha (10EAEEC028)--------------

5. Jagriti Mishra (10EAEEC029)-------------------

6. Mohit Bharadwaj (10EAEEC047)-----------------

3

ACKNOWLEDGEMENT

I wish to express my sincere gratitude to all the members of Department of Electronics &

Communication Engineering for their constant encouragement, supervision, suggestion and

advice through out my Project work .

I acknowledge my gratitude to my family members for their unconditional support and

whole hearted blessings to accomplish this task.

A word of thank is due to my friends who stood by me and always helped me to take the

best foot forward and all the Faculty and staff members of my college. I acknowledge all who

helped me at each and every step, where their support was required.

We want to give special thanks to H.O.D. Sir.

Lastly, I thank almighty God whose constant blessing has given me strength and patience to

bring this work into its present form.

Date: -

Place: -

4

Table of Contents

Subtitle 1

Certificate 2

Candidate Declaration 3

Acknowledgement 4

Abstract 6

1. INTRODUCTION 7

2. CIRCUIT BLOCK 09

3. COMPONANT LIST 10

4. DESIGN PRINCIPAL 11

5. CIRCUIT DESCRIPTION 13

a. Power Supply……………………………………….....13

b. Transformer…………………………………………...14

c. Auto restet……………………………………………...26

d. GSM Modem…………………………………….…...27

e. LCD…………………………………………………...29

g. Relay………………………………………..…….......32

6 .SOFTWARE USE 34

7.WORKING PRINCIPAL 41

8.FEATURES 42

9.FUTURE USE 43

10.CONCLSION 43

5

ABSTRACT

Every month we can see a person standing in front of our house from Electricity board or water

Board whose duty is to read the energy meter/water meter and handover the bills (electric or

water) to the owner of that house . This is nothing but meter reading. According to that reading

we have to pay the bills. The main drawback of this system is that person has to go area by area

and he has to read the meter of every house and handover the bills. The Electricity board and

Water authority has to give privileges for these people to do their duty monthly. The thing is,

Government will not appoint any particular persons for this duty. The people working in these

boards will go on a particular day and do their duty leaving all their pending works. Due to

this, their work will be delayed and this is great loss for government. To overcome this

drawback we have come up with an idea and this idea will help the government and it will save

the time of the employees working in these boards. The aim of the project is to automate the

prepaid billing of energy meter and water meter. In this project the front end is User friendly

and the employees can work on this software with minimum knowledge of Computers.

Employees can read the meter by sitting in the Office.

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INTRODUCTION:

Now-a-days technology has developed to a large extend. At the same time the need for

systems with automation and high security are preferred. So, by using one of the best

technologies available i.e. GSM we are designing an automatic power meter reading system for

commercial and domestic purposes. For paying electricity bills we have to go to e-seva for

paying the bills, this is very time consuming process and in electrical department side there

may be a chance of errors in noting the units and issue of monthly bills. By using this project

we can avoid such problems.

The development of a GSM Automatic Power Meter Reading (GAPMR) system is

presented in this paper. The GAPMR system is consists of GSM digital Power meters installed

in every consumer unit and an electricity ebilling system at the energy provider side. The GSM

Digital Power Meter (GPM) is a single phase digital kWh power meter with embedded GSM

Modem which utilizes the GSM network to send its power usage reading using Short

Messaging System (SMS) back to the energy provider wirelessly. A working prototype of the

GAPMR system was build to demonstrate the effectiveness and efficiency of automatic meter

reading, billing and notification through the use of GSM network.

Global system for mobile communication (GSM) is a globally accepted standard for digital

cellular communication system, which has rapidly gained acceptance and market share

worldwide, although it was initially developed in a European context. In addition to digital

transmission, GSM incorporates many advanced services and features, including worldwide

roaming in other GSM networks. The advanced services and architecture of GSM have made it

a model for future third-generation cellular systems.

This project is aimed to develop a system to provide security by intimating the condition in

the form of SMS by making use of GSM technology. This project makes use of a GSM

transceiver to send the messages resembling the condition. According to this system, the

mobile no. of concerned person will be stored in the microcontroller.

7

` The main objective of this project is to design a prepaid energy meter system with the help

of GSM technology. For measuring energy consumed by the user we are going to use one

digital energy meter, at the same time as it uses 1unit the count will be displayed in LCD. In

this project we are using bulbs as a load. Up to end of month no of units consumed and total

amount to be pay will update according to the power consumption and at the end of the month

total amount will transferred to last month due Coloum. And if the customer not paid that

money within the 15 days then we will trip the total power supply connected to load and we

will give intimation to the customer through GSM SMS. We will provide the supply to

customer when only he pays the bill.

This project is based on VTU syllabus. The proposed system is based on ATMEL

89S52 μcontroller which is in our syllabus. For doing this project we use some of the

software like v Embedded C for programming the application software to the

microcontroller. v Protel schematic software is used for designing the circuit diagram

for this project. v Express PCB software is used for designing the PCB for this project.

(Since PCB making is a big process and involves lot of machineries which are

expensive, we aregoing to outsource this to the manufacturer.)

8

BLOCKDIAGARM:

The main aim of this project is to implement an GSM based automatic energy meter reading

system with instant billing.

In this project we have shown the concept of postpaid energy meter which will automatically

sense the energy used in the home and when it reaches to that value which is initially fed in the

hardware it will disconnect the power line.

9

MICRO CONTROLLE

R

POWER SUPPLY

GSM

LCD

MAX232

EEPROM ENERGY METER

REL----AY

HOMEAPPLIANCES

OPTOCOUPLE

R

RTC

BUZZER

Sr. no Equipment Quantity

1 IC 8051 MC 1

2 IC LM324 1

3 Crystal (3.579545mhz) 1

4 VOLTAGE REGULATOR 1

5 2 LINE LCD DISPLAY 1

6 CRYSTAL OSCILLATOR(11.0592mhz) 1

7 DIODE 1

8 PUSH BUTTON 1

9 LEDS 4

10 RESISTER(220Ω,4.7kΩ,10kΩ) BOX

11 CAPACITORS(10uf,1000uf) 5

12 RELAYS 1

13 Bc547 1

14 GSM MODEM 1

15 BULB 1

17 ENERGY METER 1

18 IC2003 2

19 EEPROM 1

20 CONECTTING WIRES

COMPONANT LIST

10

DESIGN PRINCIPLE

Energy meters, the only direct revenue interface between utilities and the consumers, have

undergone several advancements in the last decade. The conventional electro-mechanical

meters are being replaced with electronic meters to improve accuracy in meter reading. Asian

countries are currently looking to introduce prepaid electricity meters across their distribution

network, buoyed up by the success of this novel methodology in South Africa. The existing

inherent problems with the post-paid system and privatization of state held power distribution

companies are the major driving factors for this market in Asia.

Over 40 countries have implemented prepaid meters in

their markets. In United Kingdom the system, has been in

use for well over 70 years with about 3.5 million

consumers. The prepaid program in South Africa was

started in 1992, since then they have installed over 6

million meters. Other African counties such as Sudan,

Madagascar are following the South African success. The

concept has found ground in Argentina and New Zealand

with few thousands of installations.

The prepaid meters in the market today are coming up with smart cards to hold information on

units consumed or equivalent money value. When the card is inserted, the energy meter reads

it, connects the supply to the consumer loads, and debits the value. The meters are equipped

with light emitting diodes (LED) to inform consumers when 75 percent of the credit energy has

been consumed. The consumer then recharges the prepaid card from a sales terminal or

distribution point, and during this process any changes in the tariff can also be loaded in the

smart card. The concept of pre paid is one of the immerging fields for the paid service

providers. The concept becomes so popular because it has so many advantages. The services

like electricity, gas, water telephone etc are now days get privatized. The service provider

company some time incurs heavy losses due to non collection of bills. These service items

cannot be recovered from the user after providing so the concept of pre paid reduce risk and

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increase profitability. Also the bill collection infrastructure is not necessary which intern

increase improve the efficiency of the service providing companies. The concept of pre paid

starts in the manual form by receiving advance deposits but now due to the revolution of IT

and electronics industry the manual recharging process is replaced with automatic and

electronic recharging. The recharging methods can be with wire based like telephone line and

also by using wireless technology like radio and blue tooth communication. The prepaid

system is designed with a smart technology using microcontroller and the recharging process

is by some method of communication.

Benefits of Prepaid Meters

Improved operational efficiencies: The prepaid meters are likely to cut the cost of meter reading as no

meter readers are required. In addition, they eliminate administrative hassles associated with

disconnection and reconnection. Besides, going by South Africa’s experience, prepaid meters could

help control appropriation of electricity in a better way than conventional meters.

Reduced financial risks: Since the payment is up-front, it reduces the financial risk by improving the

cash flows and necessitates an improved revenue management system.

Better customer service: The system eliminates billing delay, removes cost involved in

disconnection/reconnection, enables controlled use of energy, and helps customers to save money

through better energy management.

In this project the Prepaid Energy meter can be charged from a remote by using a

mobile. Once the user feel to recharge The prepaid energy meter he can transfer the amount to

the service provider bank account and the service provider will make a call to the system and

log in to that and charge it by entering digits from its key pad. The recharging can be done

from any mobile set but the system access code must be put in to log into the energy meter.

This type of systems are now days getting popular and many popular and well known

companies make products and sale in the market.

Market Drivers

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Power sector reforms: The upcoming competitive and customer focused deregulated power

distribution market will force the market participants to make the existing metering and billing process

more competent. This is likely to drive the prepaid market.

Increasing non-technical losses: Metering errors, tampering with meters leading to low registration

and calibration related frauds are some of the key components of non-technical losses. India reports

greater than 10 percent of non-technical losses. It has been reported that prepaid meters control non-

technical losses better than conventional ones.

Opportunities in the emerging electrifying markets: Most of the Asian countries do not have 100

percent electrification; hence new markets are being created by the increasing generating capacity.

Prepaid systems can be more easily introduced in such new markets rather than the existing ones.

The Prepaid Energy meter is designed by using a 8 bit microcontroller. The Microcontroller

receive the pulse by interfacing optical pickups from a traditional electromagnetic energy

meter. The electrical Induction energy meter works with the principle as follows,

CIRCUIT DESCRIPTION

a) POWER SUPPLY :-( +ve)

Circuit connection: - In this we are using Transformer (0-12) v, 1Amp, IC 7805 & 7812,

diodes IN 4007, LED & resistors.

Here 230V, 50 Hz ac signal is given as input to the primary of the transformer and the

secondary of the transformer is given to the bridge rectification diode. The o/p of the diode is

13

LED

LED

1k

- +

IN4007 * 4

GND

9-0-9Vac/1Amp

1000uF/35V

7812

POWER SUPPLY

+5V

+12V230VAC

50Hz 2.2k

7805

given as i/p to the IC regulator (7805 &7812) through capacitor (1000mf/35v). The o/p of the

IC regulator is given to the LED through resistors.

The microcontroller and other devices get power supply from AC to Dc adapter through

voltage regulator. The adapter output voltage will be 12V DC non regulated. The 7805 voltage

regulators are used to convert 12 V to 5VDC.

Vital role of power supply in ‘‘Remote billing of energy meter/water meter using gsm modem’

The adapter output voltage will be 12V DC non regulated. The 7805/7812 voltage regulators

are used to convert 12 V to 5V/12V DC.

TRANSFORMER: transformer is a device that transfers electrical energy from one circuit to another through

inductively coupled conductors —the transformer's coils or "windings". Except for air-core

transformers, the conductors are commonly wound around a single iron-rich core, or around

separate but magnetically-coupled cores. A varying current in the first or "primary" winding

creates a varying magnetic field in the core (or cores) of the transformer. This varying

magnetic field induces a varying electromotive force (EMF) or "voltage" in the "secondary"

winding. This effect is called mutual induction.

If a load is connected to the secondary circuit, electric charge will flow in the secondary

winding of the transformer and transfer energy from the primary circuit to the load connected

in the secondary circuit. The secondary induced voltage VS, of an ideal transformer, is scaled

14

from the primary VP by a factor equal to the ratio of the number of turns of wire in their

respective windings:

By appropriate selection of the numbers of turns, a transformer thus allows an alternating

voltage to be stepped up — by making NS more than NP — or stepped down, by making it

BASIC PARTS OF A TRANSFORMER

In its most basic form a transformer consists of:

A primary coil or winding.

A secondary coil or winding.

A core that supports the coils or windings.

Refer to the transformer circuit in figure as you read the following explanation: The primary

winding is connected to a 60-hertz ac voltage source. The magnetic field (flux) builds up

(expands) and collapses (contracts) about the primary winding. The expanding and contracting

magnetic field around the primary winding cuts the secondary winding and induces a

alternating voltage into the winding. This voltage causes alternating current to flow through the

load. The voltage may be stepped up or down depending on the design of the primary and

secondary windings.

THE COMPONENTS OF A TRANSFORMER

Two coils of wire (called windings) are wound on some type of core material. In some cases

the coils of wire are wound on a cylindrical or rectangular cardboard form. In effect, the core

15

material is air and the transformer is called an AIR-CORE TRANSFORMER. Transformers

used at low frequencies, such as 60 hertz and 400 hertz, require a core of low-reluctance

magnetic material, usually iron. This type of transformer is called an IRON-CORE

TRANSFORMER. Most power transformers are of the iron-core type. The principle parts of a

transformer and their functions are:

The CORE, which provides a path for the magnetic lines of flux.

The PRIMARY WINDING, which receives energy from the ac source.

The SECONDARY WINDING, which receives energy from the primary winding and

delivers it to the load.

The ENCLOSURE, which protects the above components from dirt, moisture, and

mechanical damage.

BRIDGE RECTIFIER

A bridge rectifier makes use of four diodes in a bridge arrangement to achieve full-wave

rectification. This is a widely used configuration, both with individual diodes wired as shown

and with single component bridges where the diode bridge is wired internally. Basic operation

According to the conventional model of current flow originally established by Benjamin

Franklin and still followed by most engineers today, current is assumed to flow through

electrical conductors from the positive to the negative pole. In actuality, free electrons in a

conductor nearly always flow from the negative to the positive pole. In the vast majority of

applications, however, the actual direction of current flow is irrelevant. Therefore, in the

discussion below the conventional model is retained.

In the diagrams below, when the input connected to the left corner of the diamond is positive,

and the input connected to the right corner is negative, current flows from the upper supply

terminal to the right along the red (positive) path to the output, and returns to the lower supply

terminal via the blue (negative) path.

16

When the

input connected to the left corner is negative, and the input connected to the right corner is

positive, current flows from the lower supply terminal to the right along the red path to the

output, and returns to the upper supply terminal via the blue path.

In each case, the upper right output remains positive and lower right output negative. Since this

is true whether the input is AC or DC, this circuit not only produces a DC output from an A

input, it can also provide what is sometimes called "reverse polarity protection". That is, it

permits normal functioning of DC-powered equipment when batteries have been installed

backwards, or when the leads (wires) from a DC power source have been reversed, and

protects the equipment from potential damage caused by reverse polarity.

Prior to availability of integrated electronics, such a bridge rectifier was always constructed

from discrete components. Since about 1950, a single four-terminal component containing the

four diodes connected in the bridge configuration became a standard commercial component

and is now available with various voltage and current ratings.

17

OUTPUT SMOOTHING

For many applications, especially with single phase AC where the full-wave bridge serves to

convert an AC input into a DC output, the addition of a capacitor may be desired because the

bridge alone supplies an output of fixed polarity but continuously varying or "pulsating"

magnitude (see diagram above). The function of this capacitor, known as a reservoir capacitor

(or smoothing capacitor) is to lessen the variation in (or 'smooth') the rectified AC output

voltage waveform from the bridge. One explanation of 'smoothing' is that the capacitor

provides a low impedance path to the AC component of the output, reducing the AC voltage

across, and AC current through, the resistive load. In less technical terms, any drop in the

output voltage and current of the bridge tends to be canceled by loss of charge in the capacitor.

This charge flows out as additional current through the load. Thus the change of load current

and voltage is reduced relative to what would occur without the capacitor. Increases of voltage

correspondingly store excess charge in the capacitor, thus moderating the change in output

voltage / current. The simplified circuit shown has a well-deserved reputation for being

dangerous, because, in some applications, the capacitor can retain a lethal charge after the AC

power source is removed. If supplying a dangerous voltage, a practical circuit should include a

reliable way to safely discharge the capacitor. If the normal load cannot be guaranteed to

perform this function, perhaps because it can be disconnected, the circuit should include a

bleeder resistor connected as close as practical across the capacitor. This resistor should

consume a current large enough to discharge the capacitor in a reasonable time, but small

enough to minimize unnecessary power waste.

18

Because a bleeder sets a minimum current drain, the regulation of the circuit, defined as

percentage voltage change from minimum to maximum load, is improved. However in many

cases the improvement is of insignificant magnitude.

The capacitor and the load resistance have a typical time constant τ = RC where C and R are

the capacitance and load resistance respectively. As long as the load resistor is large enough so

that this time constant is much longer than the time of one ripple cycle, the above

configuration will produce a smoothed DC voltage across the load.

In some designs, a series resistor at the load side of the capacitor is added. The smoothing can

then be improved by adding additional stages of capacitor–resistor pairs, often done only for

sub-supplies to critical high-gain circuits that tend to be sensitive to supply voltage noise.

The idealized waveforms shown above are seen for both voltage and current when the load on

the bridge is resistive. When the load includes a smoothing capacitor, both the voltage and the

current waveforms will be greatly changed. While the voltage is smoothed, as described above,

current will flow through the bridge only during the time when the input voltage is greater than

the capacitor voltage. For example, if the load draws an average current of n Amps, and the

diodes conduct for 10% of the time, the average diode current during conduction must be 10n

Amps. This non-sinusoidal current leads to harmonic distortion and a poor power factor in the

AC supply. In a practical circuit, when a capacitor is directly connected to the output of a

bridge, the bridge diodes must be sized to withstand the current surge that occurs when the

power is turned on at the peak of the AC voltage and the capacitor is fully discharged.

Sometimes a small series resistor is included before the capacitor to limit this current, though

in most applications the power supply transformer's resistance is already sufficient.

Output can also be smoothed using a choke and second capacitor. The choke tends to keep the

current (rather than the voltage) more constant. Due to the relatively high cost of an effective

choke compared to a resistor and capacitor this is not employed in modern equipment.

Some early console radios created the speaker's constant field with the current from the high

voltage ("B +") power supply, which was then routed to the consuming circuits, (permanent

magnets were then too weak for good performance) to create the speaker's constant magnetic

field. The speaker field coil thus performed 2 jobs in one: it acted as a choke, filtering the

power supply, and it produced the magnetic field to operate the sp

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REGULATOR IC (78XX)

It is a three pin IC used as a voltage regulator. It converts unregulated DC current into

regulated DC current.

Normally we get fixed output by connecting the voltage regulator at the output of the filtered

DC (see in above diagram). It can also be used in circuits to get a low DC voltage from a high

DC voltage (for example we use 7805 to get 5V from 12V). There are two types of voltage

regulators 1. fixed voltage regulators (78xx, 79xx) 2. variable voltage regulators(LM317) In

fixed voltage regulators there is another classification 1. +ve voltage regulators 2. -ve voltage

regulators POSITIVE VOLTAGE REGULATORS This include 78xx voltage regulators. The

most commonly used ones are 7805 and 7812. 7805 gives fixed 5V DC voltage if input voltage

is in (7.5V, 20V).

The Capacitor Filter

The simple capacitor filter is the most basic type of power supply filter. The application of the

simple capacitor filter is very limited. It is sometimes used on extremely high-voltage, low-

current power supplies for cathode-ray and similar electron tubes, which require very little load

current from the supply. The capacitor filter is also used where the power-supply ripple

frequency is not critical; this frequency can be relatively high. The capacitor (C1) shown in

figure 4-15 is a simple filter connected across the output of the rectifier in parallel with the

load. Full-wave rectifier with a capacitor filter.

When this filter is used, the RC charge time of the filter capacitor (C1) must be short and the

RC discharge time must be long to eliminate ripple action. In other words, the capacitor must

charge up fast, preferably with no discharge at all. Better filtering also results when the input

20

frequency is high; therefore, the full-wave rectifier output is easier to filter than that of the half-

wave rectifier because of its higher frequency.

For you to have a better understanding of the effect that filtering has on Eavg, a comparison of

a rectifier circuit with a filter and one without a filter is illustrated in views A and B of figure

4-16. The output waveforms in figure 4-16 represent the unfiltered and filtered outputs of the

half-wave rectifier circuit. Current pulses flow through the load resistance (RL) each time a

diode conducts. The dashed line indicates the average value of output voltage. For the half-

wave rectifier, Eavg is less than h approximately 0.318) of the peak output voltage. This value

is still much less than that of the applied voltage. With no capacitor connected across the

output of the rectifier circuit, the waveform in view A has a large pulsating component (ripple)

compared with the average or dc component. When a capacitor is connected across the output

(view B), the average value of output voltage (Eavg) is increased due to the filtering action of

capacitor C1.

UNFILTERED

Half-wave rectifier with and without filtering.

21

FILTERED

The value of the capacitor is fairly large (several microfarads), thus it presents a relatively low

reactance to the pulsating current and it stores a substantial charge.

The rate of charge for the capacitor is limited only by the resistance of the conducting diode,

which is relatively low. Therefore, the RC charge time of the circuit is relatively short. As a

result, when the pulsating voltage is first applied to the circuit, the capacitor charges rapidly

and almost reaches the peak value of the rectified voltage within the first few cycles. The

capacitor attempts to charge to the peak value of the rectified voltage anytime a diode is

conducting, and tends to retain its charge when the rectifier output falls to zero. (The capacitor

cannot discharge immediately.) The capacitor slowly discharges through the load resistance

(RL) during the time the rectifier is non-conducting.

The rate of discharge of the capacitor is determined by the value of capacitance and the value

of the load resistance. If the capacitance and load-resistance values are large, the RC discharge

time for the circuit is relatively long.

A comparison of the waveforms shown in figure 4-16 (view A and view B) illustrates that the

addition of C1 to the circuit results in an increase in the average of the output voltage (Eavg)

and a reduction in the amplitude of the ripple component (Er) which is normally present across

the load resistance.

Now, let's consider a complete cycle of operation using a half-wave rectifier, a capacitive filter

(C1), and a load resistor (RL). As shown in view A of figure 4-17, the capacitive filter (C1) is

assumed to be large enough to ensure a small reactance to the pulsating rectified current. The

resistance of RL is assumed to be much greater than the reactance of C1 at the input frequency.

When the circuit is energized, the diode conducts on the positive half cycle and current flows

22

through the circuit, allowing C1 to charge. C1 will charge to approximately the peak value of

the input voltage. (The charge is less than the peak value because of the voltage drop across the

diode (D1)). In view A of the figure, the charge on C1 is indicated by the heavy solid line on

the waveform. As illustrated in view B, the diode cannot conduct on the negative half cycle

because the anode of D1 is negative with respect to the cathode. During this interval, C1

discharges through the load resistor (RL). The discharge of C1 produces the downward slope

as indicated by the solid line on the waveform in view B. In contrast to the abrupt fall of the

applied ac voltage from peak value to zero, the voltage across C1 (and thus across RL) during

the discharge period gradually decreases until the time of the next half cycle of rectifier

operation. Keep in mind that for good filtering, the filter capacitor should charge up as fast as

possible and discharge as little as possible.

Figure 4-17A. - Capacitor filter circuit (positive and negative half cycles). POSITIVE HALF-

CYCLE.

23

Figure 4-17B. - Capacitor filter circuit (positive and negative half cycles). NEGATIVE HALF-

CYCLE

Since practical values of C1 and RL ensure a more or less gradual decrease of the discharge

voltage, a substantial charge remains on the capacitor at the time of the next half cycle of

operation. As a result, no current can flow through the diode until the rising ac input voltage at

the anode of the diode exceeds the voltage on the charge remaining on C1. The charge on C1 is

the cathode potential of the diode. When the potential on the anode exceeds the potential on the

cathode (the charge on C1), the diode again conducts, and C1 begins to charge to

approximately the peak value of the applied voltage.

After the capacitor has charged to its peak value, the diode will cut off and the capacitor will

start to discharge. Since the fall of the ac input voltage on the anode is considerably more rapid

than the decrease on the capacitor voltage, the cathode quickly become more positive than the

anode, and the diode ceases to conduct.

Operation of the simple capacitor filter using a full-wave rectifier is basically the same as that

discussed for the half-wave rectifier. Referring to figure 4-18, you should notice that because

one of the diodes is always conducting on. either alternation, the filter capacitor charges and

discharges during each half cycle. (Note that each diode conducts only for that portion of time

when the peak secondary voltage is greater than the charge across the capacitor.)

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Another thing to keep in mind is that the ripple component (E r) of the output voltage is an ac

voltage and the average output voltage (Eavg) is the dc component of the output. Since the

filter capacitor offers a relatively low impedance to ac, the majority of the ac component flows

through the filter capacitor. The ac component is therefore bypassed (shunted) around the load

resistance, and the entire dc component (or Eavg) flows through the load resistance. This

statement can be clarified by using the formula for XC in a half-wave and full-wave rectifier.

First, you must establish some values for the cir

Micro controller-AT89S52

The AT89S52 is a low-power, high-performance CMOS 8-bit microcontroller with 8K bytes of

insystem programmable Flash memory. The device is manufactured using Atmel’s high-

density nonvolatile memory technology and is compatible with the industry- standard 80C51

instruction set and pin out..

Features:

v 8K Bytes of In-System Programmable (ISP) Flash Memory

v Endurance: 1000 Write/Erase Cycles

v 4.0V to 5.5V Operating Range

v 256 x 8-bit Internal RAM

v 32 Programmable I/O Lines

v Full Duplex UART Serial Channel

v Fully Static Operation: 0 Hz to 33 MHz

Vital role of Micro controller-AT89S52 in ‘Remote billing of energy meter/water meter using

GSM modem’ is as follows.

v It will transmit the consumption amount to MODEM

v It will acts a master to communicate with memory

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v Whenever command is sent to reset the memory ,controller resets the memory

v Controller takes the pulses from the energy meter and increments the Unit which depends

upon 5/16/2014 Prepaid Energy Meter using GSM | ENGINEERING PROJECTS- Electronics

http://finalyearenggprojects.wordpress.com/prepaid-energy-meter-using-gsm/ 4/22

v Controller takes the pulses from the energy meter and increments the Unit which depends

upon the calculations and stores in memory.

v Microcontroller also switches off the energy meter whenever the command is sent from the

server.

Auto reset Circuit :

The auto reset circuit is a RC network as shown in the mother board circuit diagram. A

capacitor of 1-10mfd is connected in series with a 8k2 resister the R-C junction is connected to

the micro controller pin –9 which is reset pin. The reset pin is one when ever kept high( logic

1) the programme counter (PC) content resets to 0000h so the processor starts executing the

programme. from that location. When ever the system is switched ON the mother board gets

power and the capacitor acts as short circuit and the entire voltage appears across the resistor,

so the reset pin get a logic 1 and the system get reset, whenever it is being switched ON.

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GSM modem (900/1800 MHz);

Semen’s GSM/GPRS Smart Modem is a multi-functional, ready to use, rugged unit that can be

embedded or plugged into any application. The Smart Modem can be controlled and

customized to various levels by using the standard AT commands. The modem is fully type-

approved, it can speed up the operational time with full range of Voice, Data, Fax and Short

Messages (Point to Point and Cell Broadcast), the modem also supports GPRS (Class 2*)

spontaneous data transfer.

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GSM (Global System for Mobile communications) is the technology that underpins most of the

world's mobile phone networks. The GSM platform is a hugely successful wireless technology

and an unprecedented story of global achievement and cooperation. GSM has become the

world's fastest growing communications technology of all time and the leading global mobile

standard, spanning 218 countries. GSM is an open, digital cellular technology used for

transmitting mobile voice and data services. GSM operates in the 900MHz and 1.8GHz bands

GSM supports data transfer speeds of up to 9.6 kbps, allowing the transmission of basic data

services such as SMS.

Crystal Oscillator

The 8051 family microcontroller contains an inbuilt crystal oscillator, but the crystal has to be

connected externally. This family of microcontroller can support 0 to 24MHz crystal and two

numbers of decoupling capacitors are connected as shown in the figure. These capacitors are

decouples the charges developed on the crystal surface due to piezoelectric effect. These

decoupling capacitors are normally between 20pf to 30pf. The clock generator section is

designed as follows,

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The Microcontroller design consist of two parts

1) Hardware.

2) Software.

The controller operates on +5 V dc, so the regulated + 5v is supplied to pin no. 40 and

ground at pin no. 20. The controller is used here need not required to handle high frequency

signals, so as 4 MHz crystal is used for operating the processor. The pin no. 9 is supplied with

a +5V dc through a push switch. To reset the processor .As prepare codes are store in the

internal flash memory the pin no. 31 is connected to + Vcc

c) LCD DISPLAY

In this section, we will explain everything ranging from the properties of liquid crystal

molecules to the basic principle of display technology by using TN type liquid crystals as an

example.

The parallel arrangement of liquid crystal molecules along grooves

When coming into contact with grooved surface in a fixed direction, liquid crystal molecules

line up parallelly along the grooves.

Natural state

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When liquid crystals are sandwiched

between upper and lower plates, they line-

up with grooves pointing in directions 'a'

and 'b,' respectively

The molecules along the upper plate point in direction 'a'

and those along the lower plate in direction 'b,' thus forcing

the liquid crystals into a twisted structural arrangement./

(figure shows a 90-degree twist) (TN type liquid crystal)

Light travels through the spacing of the molecular arrangement

The light also "twists" as it passes through the twisted liquid crystals

Light passes through liquid crystals, following the direction in

which the molecules are arranged. When the molecule

arrangement is twisted 90 degrees as shown in the figure, the

light also twists 90 degrees as it passes through the liquid

crystals.

Light bends 90 degrees as it follows the twist of the molecules

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Molecules rearrange themselves when voltage is applied

When voltage is applied to the liquid crystal structure, the twisted light passes straight through.

The molecules in liquid crystals are easily rearranged by applying voltage or another external

force. When voltage is applied, molecules rearrange themselves vertically (along with the

electric field) and light passes straight through along the arrangement of molecules.

Blocking light with two polarizing filters

When voltage is applied to a combination of two polarizing filters and twisted liquid crystal, it

becomes a LCD display.

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Light passes when two polarizing filters are arranged with polarizing axes as shown above,

left.

Light is blocked when two polarizing filters are arranged with polarizing axes as shown above,

right.

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P0.2

C

LED+R/W

VCC=+5V

P0.1

L

LED-

P0.0

DB7

10k

P0.5

DB2

1k

LIQUID CRYSTAL DISPLAY

10E

EN

P0.6

DB3

P0.7

BC557

P2.2

GND

P2.1

Vcc

MICROCONTROLLER

D

DB4

DB5

P2.0

DB1

DB0

CON.

DB6

P0.4

VCC=+5V

RS

P0.3

RELAY

The relay takes advantage of the fact that when electricity flows through a coil, it becomes an

electromagnet. The

electromagnetic coil attracts a steel plate, which is attached to a switch. So the switch's motion

(ON and OFF) is controlled by the current flowing to the coil, or not, respectively. A very

useful feature of a relay is that it can be used to electrically isolate different parts of a circuit.

It will allow a low voltage circuit (e.g. 5VDC) to switch the power in a high voltage circuit

(e.g. 100 VAC or more).

The relay operates mechanically, so it can not operate at high speed.

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Internal circuit of Relay

34

There are many kind of relays. You can select one according to your needs. The various things

to consider when selecting a relay are its size, voltage and current capacity of the contact

points, drive voltage, impedance, number of contacts, resistance of the contacts, etc. The

resistance voltage of the contacts is the maximum voltage that can be conducted at the point of

contact in the switch. When the maximum is exceeded, the contacts will spark and melt,

sometimes fusing together. The relay will fail. The value is printed on the relay.

μVISION

The μ Vision IDE is, for most developers, the easiest way to create embedded system

programs. This chapter describes commonly used μ Vision features and explains how to use

them.

Before we start to describe how to use μVision, some general remarks, common to many

screens1 and to the behavior of the development tool, are presented. In our continuous effort

to deliver best-in-class development tools, supporting you in your daily work, μVision has

been built to resemble the look-and-feel of widespread applications. This approach decreases

your learning curve, such that

you may start to work with μ Vision right away. Based on the concept of windows: μ Vision

windows can be re arranged, tiled, and attached to other screen areas or windows respectively

It is possible to drag and drop windows, objects, and variables

A Context Menu, invoked through the right mouse button, is provided for most objects. You

can use keyboard shortcuts and define your own shortcuts. You can use the abundant features

of a modern editor. Menu items and Toolbar buttons are greyed out when not available in the

Current context. Graphical symbols are used to resemble options, to mark unsaved changes, or

reveal objects not included into the project. Status Bars display context-driven information.

You can associate μVision to third-party tools

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36

The Project Windows area is that part of the screen in which, by default, the Project Window,

Functions Window, Books Window, and Registers Window are displayed. Within the Editor

Windows area, you are able to change the source code, view performance and analysis

information, and check the disassembly code. The Output Windows area provides information

related to debugging, memory, symbols, call stack, local variables,

commands, browse information, and find in files results.

If, for any reason, you do not see a particular window and have tried displaying/hiding it

several times, please invoke the default layout of μVision through the Window – Reset

Current Layout Menu.

Positioning Windows The μVision windows may be placed onto any area of the screen, even

outside of the μVision frame, or to another physical screen.

Click and hold the Title Bar1 of a window with the left mouse button

Drag the window to the preferred area, or onto the preferred control, and release the mouse

button

Please note, source code files cannot be moved outside of the Editor Windows2.\ Invoke the

Context Menu of the window’s Title Bar to change the docking attribute of a window object.

In some cases, you must perform this action before you can drag and drop the window.

μVision displays docking helper controls3, emphasizing the area where the window will be

attached. The new docking area is represented by the section highlighted in blue. Snap the

window to the Multiple Document Interface (MDI) or to a Windows area by moving the

mouse over the preferred control.

Keil software converts the C-codes into the Intel Hex code.

A view of Keil uVision 3

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38

BUZZER DRIVER

This section interfaces one audible piezo electric buzzer with the controller. The controller

activates the buzzer whenever there is any fault appears in any of the channel. This buzzer

driver section is also one darling ton pair integrated circuit. A single transistor BC547 is used

for this purpose

PIEZO ELECRTIC BUZZER:

It is a device that converts electrical signal to an audible signal (sound signal).The

Microcontroller cannot drive directly to the buzzer, because the Microcontroller cannot give

sufficient current to drive the buzzer for that we need a driver transistor (BC547), which will

give sufficient current to the buzzer. Whenever a signal received to the base of the transistor

through a base resistance (1.5k) is high, the transistor comes to saturation condition i.e. ON

condition thus the buzzer comes to on condition with a audible sound. Similarly, whenever the

signal is not received to the base of the transistor, thus the transistor is in cut-off state i.e. is in

OFF state thus the buzzer does not gets activated

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P3.6

VCC=+12V

1.5k

BUZZER & RELAY DRIVER

P3.7

BC5471.5k

VCC=+12V

RELAY

BC547

Description of the interfaces:

The modem comprises several interfaces:

- LED Function including operating Status

- External antenna ( via SMA)

- Serial and control link

- Power Supply ( Via 2 pin Phoenix tm contact )

- SIM card holder

- LED Status Indicator

The LED will indicate different status of the modem:

- OFF Modem Switched off

- ON Modem is connecting to the network

- Flashing Slowly Modem is in idle mode

- Flashing rapidly Modem is in transmission/communication (GSM only)

Vital role of GSM modem in ‘Remote billing of energy meter/water meter using GSM modem’ Is as follows:

v User GSM modem will transmit the consumption amount to office MODEM.

v Office MODEM will receive the data sent by the user MODEM.

v Instead of IR we are using GSM because in IR lots of disturbance will be there when distance

is more.

v GSM is less costly when compared to IR.

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External EEPROM memory (2/4/8/32/64 Kbytes):

These memory devices are used to store the data for off line process. The AT24C02A / 04A/

08A/ 32/64 provides 2048/4096/8192/32,768/65,536 bits of serial electrically erasable and

programmable read only memory (EEPROM) organized as 56/512/1024/4096/8192 words of 8

bits each. The device is optimized for use in many industrial and commercial applications

where low power and low voltage operation are essential. The AT24C02A/04A/08A is

available in space saving 8-pin PDIP.

Features:

Internally Organized 256 x 8 (2K), 512 x 8 (4K) or 1024 x 8 (8K)

2-Wire Serial Interface (I2C protocol)

High Reliability

– Endurance: 1 Million Write Cycles

– Data Retention: 100 Years

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– ESD Protection: >3000V

Vital role of External EEPROM memory in ‘Remote billing of energy meter/water meter using GSM modem’ is as follows

v Used to store the amount of unit the user consumed.

v We can store the data in microcontroller also but the main drawback when compared to

memory is that, when there is no power the data is lost which is stored in microcontroller. Due

to this memory is used to store the units.

Real Time Clock (RTC – DS1307):

This is used to maintain the current time in off line processing. The DS1307 Serial Real-Time

Clock is a low power; full binary-coded decimal (BCD) clock/calendar plus 56 bytes of NV

SRAM. Address and data are transferred serially via a 2-wire, bi-directional bus. The

clock/calendar provides seconds, minutes, hours, day, date, month, and year information. The

end of the month date is automatically adjusted for months with fewer than 31 days, including

corrections for leap year. The clock operates in either the 24-hour or 12-hour format with

AM/PM indicator. The DS1307 has a built-in power sense circuit that detects power failures

and automatically switches to the battery supply.

WORKING PRINCIPLE:

This project is useful for billing purpose in Electricity board and in water authority. Instead of

going to every house & taking the readings, in this project by just sending an SMS we can

receive the readings of the house and we can recharge the electric bill. This system uses Java

Basics software, which is designed as the application platform to send or receive SMS using

the Modem, then process and stores the data. Java software has two main functions 1) to

interact with Modem and read the COM port 2) maintain the database.

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In this project the micro controller & the GSM unit is interfaced with the Energy meter/water

meter of each house. Every house has a separate number, which is given by the corresponding

authority. The GSM unit is fixed in the energy meter/water meter. The amount of consumption

is stored in memory authority as SMS. Using this software we can send the SMS through

Modem to that particular number which is assigned by these authorities and wait for the

response. On other end the modem will receive the data in the form of a command and informs

the controller to do the readings. After the readings the controller will send data to the modem.

Modem, in turn sends data to the other end. In the office the GSM unit will receive the data and

the Java software will calculate the total consumption. The number assigned by the authorities

isUnique. Using GSM we can get the response very fast due to which time is saved. After

completion of the pulse the power will cut again consumer wants to send an SMS for recharge.

This is due to reduce illegal power using with out paying the money.

Features:

It uses I2C protocol

_ Real-time clock (RTC) counts seconds, minutes, hours, date of the month, month, and day of

the week, and year with leap-year compensation valid up to 2100.

_Two-wire serial interface Consumes less than 500nA in battery backup mode with oscillator

running Vital role of Real-time clock in ‘Remote billing of energy meter/water meter using

GSM modem’is Used to get the real time and date

.

APPLICATION OF REMOTE BILLING OF ENERGYMETER/WATERMETER USING

GSM MODEM:

Used in Homes.

FUTURE ENHANCEMENT:

We are sending bills through post, instead of this, we can add a printer in every house and if we

give print command from the server, it will print the bill and the user can get the bill over there

only.

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FUTURE EXPANSION:

This project can be expanded in the following directions.

1. The electromagnetic induction meter can be replaced with a Electronic meter.

2. Remote recharging can be implemented through telephone line or wireless network.

3. The protection against the power theft and energy meter tampering can incorporate

in this project.

4. A mini printer can be interfaced to get a printed bill or details of billing.

5. Software can be modified to view the balance on request.

CONCLUSION

This project is performing satisfactory function in laboratory condition. The device designed is

used in conjunction with an Induction Energy meter. With minor modification in the software

and hardware this system can be used for field application.

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