Working , Components of tubelight and uses of tube light ,, all in one ,,,

1. Presented By :-
M.Waqas Ashraf 2k15-ELE-054
M.Naeem 2k15-ELE-070
Rukan Abdullah 2k15-ELE-060
M.Mashab Khan 2k15-ELE-066
M.Daud Arslan 2k15-ELE-056
Presented To :-
Engineer Nida Saleem

2. Fluorescent Tube Light :-
A fluorescent tube light does not have the usual glowing filament of an incandescent
bulb, but instead contains a mercury vapour that gives off ultraviolet light when ionized.
The ultraviolet light makes particles that coat the inside of the tube, and these particles
glow or fluoresce.
Components :-
1- Fluorescent Tube
2- Ballast (Choke + Capacitor)
3- Starter
4- Filaments

3. 1- Fluorescent Tube :-
A fluorescent tube is filled with a gas containing low pressure MERCURY vapors and any other
NOBLE GAS.
The inner side of tube is coated with a Fluorescent Coating.
2- Ballasts (Choke + Capacitor) :-
The ballast used in tube light is basically a Choke and a Capacitor connected in series.
 CHOKE :-
A choke coil is an inductance coil of very small resistance used for controlling current in an a.c.
circuit. If a resistance is used to control current, there is wastage of power due to joule heating
effect in the resistance. On the other hand there is no dissipation of power when a current
flows through a pure inductor.

4.  Capacitor :-
The capacitor corrects the PHASE LAG caused by choke and improves the efficiency of Tube
Light.
3 - Starter :-
The starter provides initial current to the filaments of Tube Light.
It frequently changes the current. Without Starter, a steady stream of electrons is never created
between the two filaments of the tube light.
If it happens then the light starts to Flicker.

5.  WORKING :-
When the switch is ON, current cannot pass through the tube as gas is not in ionized
condition. In order to ionize the gas, an initial high current (800V-1000V) is required for short
interval across terminals. A starter provide a path to complete the circuit. It switches ON and
OFF the current through the choke. As a result, a very high BACK EMF is formed between the
ends of the choke and then b/w the ends of TUBE.
It heats up the filament which emits the electrons in the tube gas thermo-ionic emission.
Within seconds, the current through filaments is interrupted leaving full line voltage applied
between filaments at the ends of the tube.On excitation, the mercury atom emits light at
wavelength of 254nm which is deep UV. The colour of emitted light is determined by
PHOSPHOR.

6.  USES OF FLUORESCENT TUBE-LIGHT :-
• It is used for commercial lightening. For example in Offices, Factories, Stores and Schools etc.
• It converts about 22% of the power input to visible light.
• It has little energy loss in terms of heat.
• It operates best around room temperature but for outdoor uses, It is covered by a metal shade
.

7. THE END
THANK YOU ALL