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PRE PAID ENERGY METER.

 

In this project we show that how we interface the digital energy meter to the easy recharge unit and convert this meter into prepaid  energy meter. By using this technique we show that how we convert all meter with the prepaid logic. When any  concept is prepaid then there is a security of misuse of electricity  uses. Normally in every postpaid connection bill is much higher then the prepaid. When there is postpaid, no body want t take care of the  wastage, but at the end  of month  when bill is present then bill is paid by the house inchrage,  small workers in the office, employees in the school, in all the private and govt office no body want to take care of the wastage. So we add some innovative idea to avoid and save this valuable energy for every one.

 

In this project we use one lcd screen. LCD screen display  the balance amount every time, LCD screen not only show the balance amount but at the same time  lcd display the unit consumption.  When the balance is zero then output is off.

 Now  for  continue the voltage we must need  to recharge the unit from the mobile phone.

 

Circuit working:

 

Our project is to be divided into 6 parts.

 

1.    5 VOLT REGULATED POER SUPPLY

2.     MOBILE SIGNAL DECODER

3.    BCD TO DECIMAL DECODER.

4.    MICROCONTROLLER INTERFACE.

5.    LCD INTERFACE .

6.    RELAY INTERFACE CIRCUIT

 

 

 

 

 

 

 

 

Componets used in this project.

 

LCD  FOR DISPLAY PURPOSE DISPLAY THE BALANCE AMOUNT AND UNIT CONSUME ( 2 LINE AND 16 CHARACTER)

 

MICROCONTROLLER. 89C51, 40 PIN CONTROLLER, 128 BYTE RAM, 4 K BYTE RAM. USED HERE FOR LCD DISPLAY AND START STOP FUNCTION. CHECK THE BALANCE AND CONTROL THE LOAD AS PER THE BALANCE.

 

IC 8870 , DTMF DECODER IC.

 

IC 8870 PROVIDE A GSM INTERFACE WITH THIS CIRCUIT. DUE TO THIS  IC WE DECODE THE CALL THE PROVIDE A BALANCE IN THE ENERGY METER AUTOMATICALLY.

 

IC 74154 IS A BCD TO DECIMAL DECODER ATTACH WITH THE MICROCONTROLLER TO INTERFACE WITH THE DTMF DECODER

 

5 VOLT REGULATED POWER SUPPLY TO PROVIDE A  REGULATED VOLTAGE TO THE MICROCONTROLLER UNIT.

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In  this project we will connect LCD at port 0.  Which will show Units  consumption and balance available. In GSM interface circuit we will use nokia mobile to interface with GSM detecting circuit. GSM interface circuit will be DTMF decoder IC. DTMF circuit will get input at pin2 of microcontroller.

 

 

 

 

 

 

 

 

 

 

5 VOLT REGULATED POWER SUPPLY CIRCUIT.

 

In this project firstly we use one step down transformer. Step down transformer step down the voltage from 220 volt Ac to  12 volt Ac. This Ac voltage is further converted into DC with the help of rectifier circuit. In rectifier circuit we use four diode. All the diodes  are arranges as a bridge rectifier circuit. Output of this rectifier is pulsating Dc. To convert this pulsating DC into smooth dc we use one capacitor as a filter components. Capacitor converts the pulsating Dc into smooth DC with the help of its charging and discharging effect.

Output of the rectifier is now regulated with the help of  IC regulator circuit. In this project we use positive voltage regulator circuit. Here we use three pin regulator. Output of this regulator is regulated voltage. If we use 7805 regulator then its means its is 5 volt regulator and if we use 7808 regulator then its means that it is 8 volt regulator circuit. In this project we use 5 volt dc regulated power supply for the complete circuit. Separate 9 volt dc power supply is used for the relay coil

 

 

 

 

 

 

DTMF DECODER

 In the  DTMF decoder circuit  we use one DTMF decoder circuit to interface the  mobile unit with this project. We  dial the number of the phone connected to the energy meter then phone is automatic on and  no we press a button 1 or button 2 to enter a value of 50 to 100 Rs in the meter. For this purpose we must need a mobile interface circuit with out project.  . In this interface circuit we use one main ic 8870. This ic 8870 decode the dtmf pulses into bcd pulse . This bcd pulses is further converted into decimal unit with the help of bcd to decimal decoder circuit.. For the bcd to decimal decoder circuit we use ic 74154 to decode the bcd signal to decimal signal.

 

 

 

 

 

7           8           9

 

 

PIN DESCRIPTION

 

 

IC 8870 is a DTMF (dual tone multiple frequency) decoder .It converts dtmf pulse into the equivalent BCD signal. Pin no. 18 and 10 of this IC are connected to the positive supply. This positive supply is from the 5 volt regulator circuit. Pin no. 9,5,6 are connected to the negative supply. Signal from the telephone line is in the form of dtmf pulse is applied to pin no. 2 of this IC through 2.2k ohm resistor and .1mfd capacitor. This signal is also connected to pin no. 3 through 100k ohm resistor. Pin no. 7 and 8 are connected to a crystal of frequency 3.7945 mh. Pin no. 16 and 17 of this IC is reset pin. Pin no. 11,12,13,14 are the BCD output of this IC.

 

Substitute ICs:  9170, 3170

 

 

 

 

 

Block Diagram of receiver

 

 

 

ADVANTAGES

        Low cost

        Reliable

        Portable

        Flexible  due to microcontroller

        Easy to use- system is very easy to understand

Features-

        Wireless system

        LCD display

        Prepaid recharge

        Unit on LCD

        Balance On LCD

        Automatic cut after balance finish

        GSM technology

Hardware required-

        8051 programmer universal kit

        CRO 20 Mhz

        Digital multimeter

Software required:

        Keil software- Microvision 2

        ORCAD for PCB design 10.5

        Proteus for simulation 7.4 version

 

 

 

 

 

 

 

 

 

Work division:

 

Circuit and theory- Abinav Pathak- 15 sept 2010

 

Component collection- Gaurav- 30 sept 2010

 

Programming- Himanshu -15 Oct 2010

 

PCB designing- Abinav- 30 Oct 2010

 

Final Testing and rework- Abinav ,Himanshu,Gaurav- 10 Nov2010

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Component List

 

 COST

 

 

S.No.

Item

Quantity

Rate/Unit

 

 

1

MCU 89C051

0

80

 

 

 

 

 

 

 

 

 

Mobile

 1

 35

 

 

 

74154

 

 

 

 

 

IC91214

1

25

 

 

3

IC4049

0

25

 

 

4

IC8870

1

40

 

 

5

IC555

0

10

 

 

6

IC817

1

15

 

 

7

IC3021

0

15

 

 

 

Push to On Sw

3

12

 

 

8

SOLDERING WIRE

1

25

 

 

9

SOLDERING IRON

1

120

 

 

10

FLUX

1

10

 

 

11

CONNECTING WIRE

1

50

 

 

12

TR548

2

2

 

 

13

TR558

0

2

 

 

14

RESISTENCES

20

0.5

 

 

15

CAPACITORS

 

 

 

 

 

1000f

2

10

 

 

 

100f

1

5

 

 

 

470f

4

5

 

 

16

DIODES

8

1

 

 

17

LED

8

1

 

 

 

Crystal 12MHz

2

25

 

 

18

IC BASE

3

5

 

 

 

IF set

120

1

 

 

19

IC 7805 Volt. Reg

2

15

 

 

20

TRANSFORMER 9 V

1

30

 

 

21

SOCKETS

3

10

 

 

22

RELAY 9V

3

25

 

 

23

MILER CAP

5

3

 

 

24

CRYSTAL 3.579545

2

20

 

 

25

IC136

2

15

 

 

26

HOLDER

2

10

 

 

27

PLY BOARD

1

100

 

 

28

TAPE ROLL

1

10

 

 

29

Copper Clad Board

1

100

 

 

30

FeCl3

1

100

 

 

31

ZENER

0

3

 

 

 

Screws/bolt

2

2

 

 

 

Betteies

1

15

 

 

 

TOTAL COST

 

 

 

 

 

 

 

Bibliography:

 

www.atmel.com

 

www.projectsidea.com

 

www.8052.com

 

 

Ali Mazidi