Home Appliances Control Systems Using Phones and RF Remotes

Home Appliances Control Systems Using Phones and RF Remotes

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Introduction

Control of home appliances system is designed to secure appliances from any other unauthorized approach.

Like if any unauthorized user enters into the house , the security alarm will produce and house can be secured.

It allows to control the appliances of the home. If we want to change the status of appliances from outside , it will off or on the appliances and if some security is needed for safety and fire, it will be immediately provides that.


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Types of Home Appliances Control Systems

Controlling home appliances using land line

Controlling home appliances using RF remote

Controlling home appliances using smart phone







Controlling home appliances using land line

The basic principle involves Dual Tone Multiple Frequency.

It involves the generation of sine wave with high frequencies and low frequencies, for each number pressed on the keypad of the phone.

The frequencies in the column side are the high frequencies whereas the frequencies in the row side are the low frequencies.

Thus for each digit pressed, a sine wave signal with dual frequency is generated.

This BCD signal is again decoded using a Demultiplexer and obtained signal is inverted and then latched to drive the corresponding relay.







Block Diagram







Working of the system

The whole system works on the fact that dialing the number 0 connects the telephone line to the appliance mode.

When 0 is dialed, the corresponding signal is decoded by the DTMF decoder into the corresponding BCD code.

This BCD code is further demultiplexed to obtain high level voltage at the corresponding output of the Demultiplexer.

The high signal output from the Flip Flop accordingly energizes a relay.







This relay consists of two change over contacts. As the first CO is connected to NO contact, current flows through a resistor, which disconnects the telephone line from the main connection.

A second timer is used to generate a 3KHz tone to give an indication of the telephone working in appliance mode.

The relay connected to the corresponding Flip Flop gets energized and thus drives the connected load to the on condition.







Controlling home appliances using RF remote

The basic principle involves transmitting the appropriate signals by pressing the required push button and then receiving these signals to operate the load accordingly.

The communication technique used here is RF or radio frequency communication.


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Block Diagram for Transmitter







Block Diagram for Receiver







The whole system is divided into two parts

The transmitter unit – The input commands from the push buttons are given to the Microcontroller which accordingly converts the commands into binary data and this data is encoded and transmitted via the RF module.

The receiver unit- The commands are received and decoded and given to the microcontroller to accordingly control the switching of the loads.

The system involves controlling 4 loads. At the transmitter side, there are four push buttons corresponding to each load.

When one of the push button is pressed, the microcontroller on receiving a high pulse from the button converts this number to a binary data. This parallel binary data is then given to the encoder.







The encoder converts this parallel data to serial form. This serial encoded data is now modulated and transmitted using RF module.

At the receiving end, the RF module demodulates the received signal and feeds it to the decoder. The decoder decodes this signal to get the original binary data.

The microcontroller is programmed to convert this binary data to the decimal number.

The opto isolator connected to the corresponding load receives a low logic signal from the microcontroller and triggers the TRIAC.

The TRIAC now allows the AC supply to the load and the load gets switched on.







Controlling home appliances using smart phone

A smart phone with touch screen panel can be used to control the switching of loads.

The smart phone is used to communicate with a Bluetooth device and accordingly the control unit on receiving the commands can control the switching of loads.







Home appliances control using smart phone







The whole system consists of two parts- the transmitter and the receiver.

The transmitter is a smart phone with Android software. Bluetooth based application software can be free loaded on the phone with characters which can communicate with a Bluetooth device.

The application is a touch screen based graphical user interface where buttons are designed to control the switching on and off of each load as well as all loads together.

At the receiver, the Bluetooth device is interfaced to the microcontroller such that the data received by the device is send to the microcontroller.

Based on the data received, the microcontroller accordingly supplies signal to the relay driver and the corresponding relay is switched on to switch on the load in turn.













Applications

This system can be used in industrial applications

This system reduces human efforts and makes life a bit easy without compromising on the efficiency of appliances.

Using this system one can also save time.







Advantages

Portable and easy to use.

Simple in construction.

Easy to maintain and repair.

Efficient and low cost design.

Low power consumption.







Conclusion

This document presents a user- friendly approach to the available home automation system. This system can easily be implemented because of its wireless communication standards.

Till now, we have researched the literatures for all the topics that include RF remote automation system . Then we have to built the main control program, hardware and the warning systems.


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Engineering

Home Appliances Control Systems Using Phones and RF Remotes