14-06-2012, 06:03 PM
IR BASED HOME ELECTRICAL APPLIANCES USING MICROCONTROLER
IR BASED HOME ELECTRICAL APPLIANCES.ppt (Size: 1.1 MB / Downloads: 65)
INTRODUCTION&OVERVIEW
It is an microcontroller circuit to switch on and off electrical appliances.
This system will use general purpose remote control to send the control signal
REMOTE TRANSMITTER
The remote transmitter used in this project is a general purpose remote control used for Phillips TVs.
It sends the control signals, which are in RC5 protocol modulated on a 40khz carrier signal.
MICRO CONTROLLER
The 89S52 micro controller is used in this project.
It is in the family of Intel 8051. It is having 256 instructions. It has a 16-bit timer .
The controller receives the signals, which are in RC5 protocol. It decodes the control signals .
REMOTE RECEIVING UNIT
These signals are converted into electrical signals by the help of IR receiver.
The general purpose remote control sends the control signals with RC5 protocol.
The micro controller receives the signals and it decodes the control signals.
IR RECEIVER
The IR sensor will receive the Infra Red signals send by the general purpose remote control.
The sensor converts the IR signal into electrical signals with the help of photo diode and amplifies it.
It also includes the filter circuit to demodulate the 40khz carrier signal.
CENTER TAPPED STEP DOWN TRANSFORMER
The center-tapped step-down transformer is used to step down the supply voltage of 230v ac from mains to lower values, as the various IC’s used in this project require reduced voltages.
The outputs from the secondary coil which is center tapped are the ac values of 0v, 15v and-15 .
RECTIFIER UNIT
The rectifier circuit is used to convert the ac voltage into its corresponding dc voltage.
The most important and simple device used in rectifier circuit is the diode.
The simple function of the diode is to conduct when forward biased and not to conduct in reverse bias.