Device controlling with remote

Description
 In this project a circuit is designed to control any four electrical devices such as fan,light,television etc. with a small remote. The size of the remote is so small such that you can made it look like a key chain.

BLOCK DIAGRAM EXPLANATION

VOLTAGE REGULATOR

            The IC is used as the voltage regulator. It converts the 6V supply into 5V regulated supply

ENCODER

          The IC HT12E is used as the encoder. It converts the input pulse into binary signals and it is given to the transmitter..

ASK TRANSMITTER

            The ASK transmitter is a 433 MHz Radio Frequency signal transmitter. ASK is short for Amplitude Shift Keying. It modulates the binary signals into analogue signal.

ASK RECEIVER

The ASK receiver receives the binary signals transmitted by the transmitter. It demodulates the received analogue signal into binary signal.

DECODER

The IC HT12Dis used as decoder. It decodes the binary signal.

 CIRCUIT  DIAGRAM

remote section

 Receiver section

                                                                                                                        

WORKING

           

This device has two circuits, one for the remote section and other for controlling devices. The basic working of the robot is that, when the switch in remote is pressed then a signal is produced and it is then encoded and then modulated and transmitted to the recever and the receiving section demodulate and decodes the signal and the signal in remote is reproduced in the receiving unit. This signal is applied to the relays

Here we use HT12E and HT12D as the encoder and decoder. They have 8 bit address and 4 bit data. Hence we can transmit 4 signals , using theses 4 signals we can control 4 devices

Now consider the remote section .The main elements in the remote section are an encoder IC, an ASK transmitter and four switches. The encoder IC has 18 pins. The pins one to eight are the address bits. The four pins, pin no.8 to 13 are the data bits or input terminals. These four pins are connected to the four switches. When a switch is closed, that pin is grounded. Thus a signal is produced and the encoder converts it into binary signal and this binary signal is modulated and transmitted by the ASK transmitter.

Now consider the receiver section. The signal is received and demodulated by the ASK receiver and this binary signal is given to the decoder. The decoder converts it into actual signal corresponding to the pin in encoder, the same pin produces a ground signal while the other data pins produces a +VCC as output. The output from the data pins are given to the relays.