ABSTRACT
Now a days, everyone wants to control their appliance wirelessly (i.e. remote control). Here is a simple tested and inexpensive remote control switch utilizing reading available components. The project is designed to operate electrical loads using a TV remote. The remote transmits coded infrared data which is then received by a sensor interfaced to the control unit. The system operates electrical loads depending on the data transmitted from the TV remote. Operating conventional wall switches is difficult for elderly or physically handicapped people. This proposed system solves the problem by integrating house hold appliances to a control unit that can be operated by a TV remote.
Circuit Description of infrared (IR) remote control switch
As in all wireless systems Infrared (IR) remote control switch also comprise two major section i.e. transmitter and receiver section.
Transmitter Section: – The logic of this section is simple and is build around most versatile IC NE555 (IC1), configured as astable multivibrator to produce frequency about 38 KHz. This is so, because IR module receiver used here works in range of 38 KHz frequency. Timing component of infrared remote control switch is resistor R1 and R2 and capacitor C2, determine the range of oscillating. Where, formula of generated frequency (F) from transmitter section IR remote is given by
F = 1.443 / (R1 + 2R2) C2
The output frequency from pin 3 of IC1 is fed to base of transistor T1 through resistor R4 and is configured as Darlington pair with transistor T2 in order to drive IR LED and resistor R5 works as current limiter.
Receiver Section: – Transmitted signal from transmitter is received by infrared (IR) receiver module (TSOP 1738) and is fed to base of PNP transistor T3 through resistor R6 for amplification. Amplified signal is fed to pin 2 of IC2 through coupling capacitor C6. IC2 is configured as monostable multivibrator which is triggered when low pulse from