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Question
what is the function of starter & choke in the tube light 
set & how choke give 1000 volts while switching on.
 Question Submitted By :: Electrical-Engineering
I also faced this Question!!     Answer Posted By  
 
Answer
# 1
function of choke:it produces high voltage in the tubelight
which is essential for ionisation of the gas present in the
tubelight.
 
Is This Answer Correct ?    185 Yes 49 No
Sindhu
 
Answer
# 2
we need around 800 to 1000 volts to start ionisation of the
medium which is present between the 2 electrodes of the
tube.once the ionisation starts the conductivity of medium
increases and 110 volts is sufficient to sustain the
emission of electrons from electrodes.
so to produce such a high voltage we are using choke.
once it starts to reduce the 230V to 110 volts we are using
the same choke.
so how this choke is producing around 800 to 1000 volts at
starting.
as we know inductor opposes the rate of change of current.
here we are making current I which is intially drawn to
zero with the help of bimetallic contacts present in
starter.according to formulae E=L*di/dt here L is constant
and di is equal to I-0 and dt is time taken for I to become
zero.
accordingly high voltage is induced and this voltage is
sufficient to drive the electrons from one electrode to
another electrode inspite of medium present between
electrodes. once tube start conduction, it needs only 110v
to sustain the illumination.so to reduce the 230v to 110v
choke just acts as a voltage limiter by dropping the
voltage.
 
Is This Answer Correct ?    117 Yes 11 No
Arjunkarnati
 
 
 
Answer
# 3
the normal operating voltage of tube light is about 110.
but naturally available voltage is 240v. hence the choke
comes into picture which gives 110v output. but for
initiating the light(to ionise the gas in the tube) the
system system requires 800 - 1000v. to provide this starter
has been used, which block the current flowing from the
choke to light hence the voltage will build up across the
load. once the maximum voltage reached which starter can
withstand, the starter closes the circuit and the builded
voltage applied across tube light.
 
Is This Answer Correct ?    80 Yes 18 No
Shahulsnfa
 
Answer
# 4
it is the starter that short the terminal and produces high
voltage and the purpose of the choke is to limit the hugh
current that will cause the supply line to drop causing it
to dim
 
Is This Answer Correct ?    77 Yes 42 No
Glen
 
Answer
# 5
the starter function is used simply step up the voltage
level at the time of starting by using resistor and
inductor phenomenon and at the same time the starter
maintain the voltage for excitation of gases molecules
after some time by comparable no energy drawn from source
 
Is This Answer Correct ?    14 Yes 8 No
Raj
 
Answer
# 6
chock works as blast in a tube circuit,it give surg voltage(1000v) to circuit which is sufficiant to ionise the gases in tube it only works at starting of tube. 
Is This Answer Correct ?    8 Yes 2 No
Deepak Yadav
 
Answer
# 7
we need around 800 to 1000 volts to start ionisation of the
medium which is present between the 2 electrodes of the
tube.once the ionisation starts the conductivity of medium
increases and 110 volts is sufficient to sustain the
emission of electrons from electrodes.
so to produce such a high voltage we are using choke.
once it starts to reduce the 230V to 110 volts we are using
the same choke.
 
Is This Answer Correct ?    15 Yes 10 No
Sudhakar
 
Answer
# 8
gases present in the tube light is of such nature that once the gas ionised then it has a tendency to increase continuously accompanied by a fall in the circuit resistance . in order to limit the current to a safe value choke is used .
choke performs two function
1) providing ignition voltage
2) limiting the current
 
Is This Answer Correct ?    5 Yes 1 No
Vinod Yadav
 
Answer
# 9
dear Rupashree Goswami .plz dont post wrong answers 
Is This Answer Correct ?    0 Yes 0 No
Redtedtert
 
Answer
# 10
When the switch is pressed current cannot pass through the tube initially because the gas inside it is not ionized and hence the tube light circuit behaves as open circuit. Once the gas is ionized, it will provide a conduction path for the current to flow. In order to ionize the gas, an initial high voltage of 800-1000 V is required for a short period across the filaments of the main tube. A starter initially provides a path to complete the circuit and once tube light starts the current flows through the ionized gas in the main tube.
Now we know that voltage across inductor E=L*di/dt.when ac switches from positive half cycle to negetive half cycle,magnetic flux changes its direction as well as magnitude and according to farady's law it will produce a large voltage accross inductor and so across the electrode and producing a voltage strike of 800 to 1000v and thus heats up(ionise) the gas.
 
Is This Answer Correct ?    0 Yes 0 No
Soumitra Debnath
 

 
 
 
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