This slide discusses about the working and usage of an fm transmitter.It can help you with a physics project

1. FM TRANSMITTER

2. INTRODUCTION
Information transmission is very vital to
human life just as the early men used sticks to
produce sound which indicates the location of
each other as they wander about also down
to the middle era when town crises come into
play for the same information propagation to
be transmitted from one point to another
with the aid of radio communication which
necessities the application of radio
transmitter and receiver.
FM was invented and developed by Edwin
Armstrong in the 1920’s and 30’s, and the first
commercial FM radio station began
broadcasting in 1945 (Mohn, 2007).
A radio transmitter is device whose major
function is to send information (intelligence)
from one point to another in most cases the
information to be transmitted are voice music
and code signals.

3. The
working of
an fm
transmitter
can be
broken into
6 phases
Microphon
e
1
Amplificat
ion
2
Crystal
oscillator
3
Modulatio
n
4
Antenna
5
FM
reviever
6

4. WORKING
1)MICROPHONE:
Human sound is made up of audio wave ,and
audio wave is produced due to and rarefaction
.Human sound cannot travel through long
distance.
So audio wave is converted into electrical
wave /impulse .To convert the sound wave into
electrical wave , condense microphone is
used.

5. 2)AMPLIFICATION:
Electrical wave ,produced by condenser
microphone is very weak .Its amplitude is
very low like figure.
Amplifier is used to increase the
amplitude of low electrical wave like in
figure.
AMPLIFIER

6. 3) CRYSTAL OSCILLATOR:
Electrical wave cannot travel through
air .We use carrier wave which is
produced by crystal oscillator .Carrier
wave is basically a electromagnetic
wave .
Carrier wave is different from audio
wave(electrical wave) .See in figure:

7. 4)MODULATOR:
Modulator is used to combine electrical and carrier wave .
In figure ,audio sound has less frequency because it is human sound ,carrier
wave has continuous frequency ,and when both combine ,it becomes
modulated frequency.
There is gap between modulated frequency which is audio wave .This audio
wave travel on carrier wave and reaches to our fm receiver.

8. 5)ANTENNA:
In radio an antenna is the interface between radio
waves propagating through space and electric
currents moving in metal conductors, used with a
transmitter or receiver.
Antenna is used to transmit the combine signal of
electrical and carrier wave and you get this signal
on your mobile ,radio and laptop.

9. 6)FM RECEIVER
The radio wave from FM
transmitter ,is propagated
,and received by FM receiver
.Then you hear the news
,sport and many more.

10. Conclusion
This concludes our presentation
and tells us about the working of
an FM transmitter. Extensive use
of which is found by the law
enforcing agencies, in concerts
and seminars and in devices like
mobile phone and TV.