18-02-2011, 03:58 PM
fiber optic communication report.docx (Size: 870.93 KB / Downloads: 162)
ABSTRACT
FIBRE-OPTICS COMMUNICATION
Most reference materials that discuss the historical perspective mention about Indian smoke signals. None of these primitive systems was secure due to the spreading of the unguided light. Ideally, a communication system should be secure and should not require installation of a cumbersome physical media. Fiber optics satisfied these desires, and as early as 1958, fiber-optic equipment was being focused for use in the factory. The fiber-optic cable is an important element in the fiber-optic link. Today, in comparison to the early 1970s, the performance of fiber-optic cable in terms of bandwidth and attenuation is far superior to any electrical cable of similar cost. Some consider it a problem of fiber optics that the electronics of the fiber-optic transceivers are unreliable. This is a false, in that the electronics have the same life as any of the other electronic components used in a network. The need for sharing components or modules is the same for fiber optics as for any other critical factory-level electronics. Optical fiber is used as glass or plastic, to contain and guide light wave.
The fiber cable does not transmit electrical current, so it cannot cause ground loops. Therefore ground differentials caused by lightning-induced transients do not affect the communication cable. This characteristic is quite an advantage because lightning strikes are a common phenomenon. A typical fiber-optic cable can allow up to 200 million bits per second (MBS), while a high-quality coaxial cable is required to achieve the same data rate, but can cover only shorter distances. The reduction in the number of repeaters is a prime reason for the telephone companies increasing use of fiber optics. Many control applications require the operator to perform normal duties in the vicinity of high voltages. The use of fiber allows isolation of the high voltage from the operators. An advantage of fiber-optics is that the light signal used for data communication cannot develop a spark above the ignition point, which could cause ignition in hazardous environments.
The fiber-optic cable is susceptible to noise and it does not generate electromagnetic interference. It is very simple to install because of light and small size and is suitable for rugged environments i.e. it can survive high temperatures and other extreme environments.
COMPONENT LIST AT THE TRANSMITTER SIDE
RESISTORS:-
R1-3KΩ
R2-4KΩ
R3, R4-10KΩ
R5-1KΩ
PRI-1MΩ
CAPACITOR:-
C1-1000 µF/16V Electrolytic capacitor
C2-0.047 µF-473-ceramic disc type
SEMICONDUCTOR:-
Q1-BEL 187 NPN Transistor
Q2-BEL 188 PNP Transistor
Zener diode
U1-741-Opamp IC
IC socket-8 pin
MISCELLANEOUS:-
Condenser microphone
White LED
9v Battery snap
Red LED
AT THE RECEIVER SIDE
RESISTORS:-
R1, R2-47KΩ
R3, R4-10KΩ
R5-10Ω
R6-1KΩ
PR1-1MΩ
PR2-10KΩ
CAPACITOR:-
C1-1000 µF/16V Electrolytic capacitor
C10-0.047 µF Disc type Capacitor
C11, C6-10 µF/16V Tantalum capacitor
C7, C8, C9, C2-0.1 µF-100KPF-104-Disc Ceramic
C3, C4, C5-100 µF/16V-Electrolytic Capacitor
SEMICONDUCTOR:-
IC1-LM741-Opamp IC Socket 8 Pin-2pcs
IC2-LM386-power amp IC
Q1-Photo transistor
MISCELLANEOUS:-
L1-LED 9V Battery
Loud Speaker 8Ω
Transformer 9V