BY

VIKRAM A S

8TH SEM EEE

UVCE

This circuit allows you to watch your favorite TV

programs late at night without disturbing other family

members.

Most modern TVs are nowadays equipped with audio-

in/out and video-in/out RCA sockets. Using an RCA-to-RCA

cord, connect the audio output of your TV to the transmitter’s

input.

This transmitter draws only a few mill amperes of current and

doesn’t require on/off switch. It can be fabricated on a small

piece of strip board.

ABSTARCT

To design and implement a WIRELESS AUDIO

TRANSMITTER FOR TV USING IR TRANSMITTER

AND RECEIVER

PROJECT BLOCK DIAGRAM

TRANSFORMER OF SUITABLE RATING FOR

POWER SUPPLY

TRANSISTORS BC548 AND BC 547

IR TRANSMITTER AND RECEIVER

RESISTORS AND CAPACITORS

A HEADPHONE TO BE USED

TRANSISTOR

The BC547 transistor is an NPN

Epitaxial Silicon Transistor.

It is used in general-purpose

switching and amplification

BC847/BC547 series 45 V, 100 mA

NPN general-purpose transistors.

The transistor is a "CURRENT"

operated device and that a large

current (Ic) flows freely through the

device between the collector and

the emitter terminals.

The BC548 transistor is an NPN

Silicon Transistor.

The BC548 transistor is a

general-purpose transistor in small

plastic packages.

It is used in general-purpose switching and

amplification BC848/BC548 series 45 V, 100

mA NPN general-purpose transistors.

IR TRANSMITTER AND RECEIVER

The figure shows a typical transmitter or a

receiver

IR transmitter and RECEIVERS are grouped in

OPTO ELECTRONICS field in current

trchnological dictionary. These use Infra Red

ratdiations to transmit data without any

requirements of wires.

An infrared receiver , or IR receiver, is

hardware that sends information from an

infrared remote control to another device

by receiving and decoding signals.

In general, the receiver outputs a code to

uniquely identify the infrared signal that it

receives.

This code is then used in order to

convert signals from the remote control

into a format that can be understood by

the other device. It is the part of a device

that receives infrared commands from a

remote control.

It is a light emitting diode (LED) that is

used in order to transmit infrared signals

from a remote control.

The more they are in quantity and the

better the emitters are, the stronger and

wider the resulting signal is.

An IR emitter generates infrared light that

transmits information and commands from

one device to another.

Typically one device receives the signal

then passes the infrared (IR) signal through

the emitter to another device.

The working wireless audio transmitter can be

explained in the following slides, with the role of each

component being elaborated.

DATA FLOW BETWEEN IR TRANSMITTER

AND RECEIVER

Input to the sending end of the

transmitter is from a transformer, whose

rating is decided based on the design.

Typically the Output of the transformer

will be 12V.

The audio signal is coupled to the base of T1

by an audio transformer. The T1 pre amplifies

the signal

The transistor T2 drives the IR LED’s which

transmit the sound as IR beams.

The red LED provides fixed bias for theT2 as

well as a power on indication.

The photo transistor T3 receives the IR

signals.

The collector of IR is connected to base of T4

which amplifies the signal together with T5 to

regain the audio signal transmitted.

The transistor T6 drives the headphone to

reproduce the sound.

The received sound is reproduced and that

can sound can listened in the headphone.

Due to wireless transmission, cost is reduced.

This can be used not only in TV applications,

but also in portable music systems.

This can be used where noise volume has to

be reduced.

Can be used as an alternative to Bluetooth

technology, as this consumes lesser power.

Simple in construction.

Easy to maintain and repair.

Comparatively the operation cost is less.

Efficient and low cost design.

Low power consumption.

Alternative for Bluetooth

There might be disturbance in the output

during transmission via I.R due to external

factors.

For higher ranges, cost increases.

To connect more than one device is difficult.

This is an excellent way of reducing the

disturbances caused to others while

watching our favorite TV programs, so

this must be encouraged among the

people.