Answer / sanket patil

THE MAJOR COMPONENTS OF A TUBELIGHT ARE CHOKE(INDUCTOR),
FTL (FLUROSCENT TUBELIGHT) AND STARTER.
THE FTLs AVAILABLE NOW A DAYS ARE TRIPHOSPHATE TYPE i.e.
TRIPHOSPATE COATING ON INNER SIDE(FOR HIGHER EFFICACY=(O/P)/
(I/P) IN LUMENS).
A FTL CONTAINS INERT GAS LIKE ARGON FILLED AT LOW
PRESSURE AT ABT 1/10 OF ATMOSPHERIC PRESSURE AND CONTAINS A
LITTLE AMOUNT OF MERCURY INSIDE WHICH VAPOURISES SLOWLY
WHEN TUBELIGHT IS STARTED IMPROVING THE CONDUCTION INSIDE
GIVIND STEADY LUMEN OUTPUT.
THE TUBELIGHT STARTS ALTER A PHEMOMA CALLED "GASEOUS
DISCHARGE".INITIALLY WHEN IT IS STARTED IT HAS CHOKE
(INDUCTOR) IN SERIES WITH TUBELIGHT AND STARTER IS IN
PARALLEL WTIH TUBELIGHT. AT START AS THE TUBE DONOT CONDUCT
CURRENT FLOWS THROUGH CHOKE AND STARTER. THE STARTER
CONSISTS OF A NEON LAMP(FUNCTIONING AS A BIMETALLIC STRIP)
WHEN CURRENT INCREASES BEYOND A LIMIT THE CURRENT PATH IS
BROKEN. AND WHEN CURRENT FLOEING THROUGH INDUCTOR(CHOKE) IS
FORCED TO ZERO HIGH VOLTAGE IS APPLIED ACROSS THE TUBELIGHT.
THUS GASEOUS BREAKDOWN OCCURS WHICH CANNOT OCCUR AT
NORMAL SUPPLY VOLTAGE.
IF THE TUBELIGHT FAILS TO START THEN AGAIN THE
BIMETALLIC CONTACT IS MADE AFTER A BIT COOLING AND FINALLY
IT STARTS, THIS IS THE REASON WHY STARTER FLICKERS AT THE
STARTING OF THE TUBELIGHT.
NOW ULL ASK WHY TUBELIGHT REMAINS ON EVEN IF STARTER IS
REMOVED IN RUNNING CONDITION????????
THE ANSWER IS THE NEON LAMP GLOWS ONLY IF VTG ACROSS IT
>180 V.AND NORMAL RUNNING CONDITIONS
SUPPLY VOLTAGE(230V)=VTG ACROSS CHOKE(115V APPROX.)+VOLTAGE
ACROSS TUBELIGHT(105V APPROX).
AND AS STARTER AND TUBELIGHT ARS CONNECTED IN PARALLEL
THE CURRENT FLOWS THROUGH TUBELIGHT AND NOT THROUGH THE
STARTER(CONTAINING NEON LAMP WHICH BEHAVES AS A BIMETALLIC
STRIP).THUS REMOVAL OF STARTER UNDER RUNNING CONDITION
DOESNOT AFFECT THE FUNCTIONING OF TUBELIGHT.

Answer / princess

A fluorescent lamp works by striking an arc between the two
electrodes at the end of the tube. This arc passes through
the gas that is filled inside the tube. The emissions from
the arc hit the fluorescent coating on the inner surface of
the tube to produce light.

A high voltage is required to strike this arc. This is
produced by the choke. The choke is nothing but a coil
wound over a core; in other words, an inductor. When you
switch on the tube light, the sudden surge of current
induces a back-EMF across the choke. This voltage is
applied across the electrodes of the tube light and it
strikes an arc.

Once the arc is struck, the current flows through the gas
inside the tube. There is no further point in letting it
flow through the choke after the tube glows steadily, as
this would only result in losses. Therefore, the choke
needs to be cut-off after the tube light glows steadily.
This is done by the starter, which cuts off the current
through the choke after some time. (It allows the current
to flow through the choke only during the starting, and
hence it is called a starter).

Answer / sirisha

tube light has a CRT,choke(inductor),starter.
some noble gases are there inside the tube.(neon)
when supply is given the choke converts the small voltage
to high voltage and a spark is produced which is
responsible for the lightning of the tubelight.
choke is active only during the starting.

Answer / anandb

major parts of fluroscent set are FLT,chock,starter and
frame.when supply is giver the chock is applied with ac
voltage through starter.(supply-chock-starter-lamp holders-
again supply.starter close and open when voltage across it
is sufficient to heat or cool the bimetallic strip
respectively. when the current through the chock is made to
zero due to opening of starter the voltage across the chock
is enormously high as v= L.(di/dt).
this hi vtg s enough to start ionization of noble
gae(Neon). the closing and opening of starter and hi
voltage induction s continues till the discharge by
ionization takes place completely... Once the ionization
starts the discharge takes b/w the elements of the FLT
there s no need for starter and chock.The ckt s closed
through the FLT.

Answer / angel

1. The starter (which is simply a timed switch) allows
current to flow through the filaments at the ends of the
tube.
2. The current causes the starter's contacts to heat
up and open, thus interrupting the flow of current. The
tube lights.
3. Since the lighted fluorescent tube has a low
resistance, the ballast now serves as a current limiter.

Answer / abid ali khattak

Fluroscent consit on: Element, Fluroscent powder and gas.
Working Principle: When we apply the voltage to the
furoscent tube through starter. its creat a suffeciant
current and the gas which inside the tube make short the
element, which located both end of tube light.

Answer / venkat

Actually... i hav a doubt...
wat will happen if we connect a dc source to a tubelight.,,
will it work or wont it work...
if it does nt work is it due to the blockage of dc by capcitor...????

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