SynopsisOn

RF Energy meter

Introduciton

In this project we show that how we interface the digital energy meter to the easy recharge unit and convert this meter into RF feedback ELECTRICITY 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. We will use RF system to give alert for less balance.

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 SUPPLY2. 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..

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.

18 17 16 15 14 13 12 11 10

1 2 3 4 5 6 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

CM8870PI

1

1

COMPONENTS USED:

STEP DWON TRANSFORMER. 220 TO 9 VOLT AC 1 PCDIODE IN 4007 2 PCCAPACITOR 1000mfd 1PC

10 MFD, 1 PC 22 PF 2 PC .1 ( 104) MFD 2PC

IC.8870 DTMF DECODER.74154 BCD TO DECIMAL DECODER.89C51 MICROCONTROLLER.LCD 2 BY 16

TRANSISTOR:BC 548 NPNBC 558 PNP

RELAY12 VOLT DC SINGLE POLE SINGLE THROW

REGULATOR7805.

P.C.B COPPER CLAD BOARD ( GENERAL)

LED (3)

CRYSTAL.3.58 Mhz12 MHz

References:

8051 microcontroller book- Ali and mazidi

www.8051projectseasy.com

www.ludhianaprojects.com

www.atmel.com