In this project we will control the devices using powerline transmission medium. We will send controlling data through powerline from transmitter. On receiver end we will control the devices.
Data commmuniction using power line is important project according to today’s increasing rush of power line and data lines. In this project we will transmit data using earth wire. Earthing very important for this project. It will also help to control the the various devices with power supply circuit. In this project we will transmit data using DTMF encoder IC 91214 . IC 91214 is frequency generators . actually we will send particular frequency to decode it at reciver. We wll amplify the signal after DTMF technology play the key role .In amplifiers first of all we will use voltage amplifier and then power amplifier . there will be IC741 as voltage amplifier circuit. And then transistorized power amplifier circuit. In receiver side there will be amplifiers then there will be DTMF decoder driver IC 8870. we will reamplify the signal because of the week signal detected at receiver. Ic 8870 has pin no2, 3 as input pins . output of decoder will be Binary coded decimal. There will be four outputs will be input to Microcontroller IC 89c051 . output of IC will be on LCD display. In this way we will transmit data . DTMF frequency lie with in voice frequency range.
DTMF is Dual tone Multi frequency. Dtmf frequency wave is very equal to sine wave like
In spite of sending pulses we will send DTMF signal. This technology is use in telephones. That’s why its very important and reliable in Data communication. Morever its frequency range lie with in voice frequency range.