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  1. #1
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    tube light choke

    hi i have a question about the common tubelight. what does the choke and the starter do in the tubelight.

    i heard from someone that the starter is basically a capacitor and it works simillar to the capacitor of a fan. it gives the initial boost to start the tubelight. and the choke is an RL circuit. it filters the line voltage. it only lets 50Hz (or 60Hz) pass through it.

    is this right. please guide me????

  2. #2
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    tube light circuit

    The starter gets the gas inside the tube heated and is wired in series of the filaments. Once fired, the choke(ballast) limits the current flow through the tube.



    •   Alt26th June 2004, 17:27

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  3. #3
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    tube light starter

    All circuit of neon tube light is like this: L(live), inductor, first heater, starter, second heater, N(neutral) connected in series. Starter is gas glow bulb where one of electrodes is made of bi-metal, and parallel capacitor for RFI. When you switch on starter bulb is short circuited and heating current flows through series circuit. After some time (few second) gas bulb is heated enough and bi-metal electrode break the series circuit. Sudden reduce in circuit current causes induction of high voltage on inductor and so on the opposite electrodes of neon tube. Neon tube starts to glow giving the light. At the same time the starter bulb continue to glow and keep hot preventing bi-metal electrode to close again. Start of neon tube may be clean or through few attempts (flickering). Inductor limits the neon tube voltage when it glows to abt. 50V.



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    tube light connection

    Hi Samcheetah,

    There is a great tutorial on fluorescent lights, ballasts etc here:

    http://members.misty.com/don/f-lamp.html

    Cheers,
    FoxyRick.



    •   Alt26th February 2005, 10:16

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  5. #5
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    choke tube light

    in starting periode before tube energized the choke will save the current flowing through it as magnetic energy then there's voltage diffrent on stater (because stater connecting paralell with tube) that making the elctrode on stater became short circuited (you may see as burs of fire, blanking periodicaly with short periode on stater) and all energy stored on choke suddenly exited making high voltage diffrent between elctrode on tube. and the gases on tube became lighten (because proses of electron collition on gases) and the voltage between the electrode on tube droped less then starting periode and bacause of characteristics of gasess on stater could not make shotr circuited when it is low voltage and bacause of pararell connection between tube and stater, then the curren no w flowing thrugh choke, tube. the choke is now used to resisit current through the tube.



    •   Alt27th February 2005, 15:10

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  6. #6
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    purpose of choke in tube light

    Im a apprentice electrician. i have a test coming up. ive already had a go at it. you have to measure 3 phase circuits and a fluorescent light circuit. you have to comment why if you measure the voltage between the choke and then the voltage between the lamp why when the two voltages added up they dont come to the supply voltage. can any one help. im looking through my notes but cant get a clear answer and theres no websites to help me. please help

    (sorry about the spelling mistakes)



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    how tubelight works

    You have there a series circuit= tube and the choke.

    The tube =resistance

    In a resistor, the current is in phase with the voltage always. This means that the peaks and valleys of the two waveforms occur at the same times. Resistors can simply be defined as devices that perform the sole function of inhibiting the flow of current through an electrical circuit.

    the choke=inductor
    In inductors, current is the negative derivative of voltage, meaning that however the voltage changes the current tries to oppose that change. When the voltage is not changing there is no current and no magnetic field.
    In an AC Circuit, voltage leads current by a quarter phase or 90 degrees.

    http://www.physics.sjsu.edu/becker/p...c_circuits.htm

    http://en.wikibooks.org/wiki/Electro...ge_and_Current
    http://www.allaboutcircuits.com/vol_2/chpt_6/1.html
    http://www.play-hookey.com/ac_theory/ac_inductors.html


    http://www.play-hookey.com/ac_theory/ac_inductors.html


    This is the same with a 3 phase circuits.
    All 3 voltages have the same amplitude, have the same frequency but the voltages are 120° in phase
    http://eece.ksu.edu/~starret/581/3phase.html
    http://www.physclips.unsw.edu.au/jw/power.html



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    function of starter in tube light

    startter is a capacitor and it just gives a conduction path in start and as later on current flows through tube so its removal doesnt effect at alll, while choke is used to control current in circuit. also to avoid transient currents.



  9. #9
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    tube light chock

    @pkbhardwaj
    Your answer is incomplete... 8)
    did you read this: ?
    Quote Originally Posted by Borber
    All circuit of neon tube light is like this: L(live), inductor, first heater, starter, second heater, N(neutral) connected in series. Starter is gas glow bulb where one of electrodes is made of bi-metal, and parallel capacitor for RFI. When you switch on starter bulb is short circuited and heating current flows through series circuit. After some time (few second) gas bulb is heated enough and bi-metal electrode break the series circuit. Sudden reduce in circuit current causes induction of high voltage on inductor and so on the opposite electrodes of neon tube. Neon tube starts to glow giving the light. At the same time the starter bulb continue to glow and keep hot preventing bi-metal electrode to close again. Start of neon tube may be clean or through few attempts (flickering). Inductor limits the neon tube voltage when it glows to abt. 50V.



  10. #10
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    tubelight choke

    In Canada, our fluorescent tube lights use "Rapid Start" ballasts without starters. The filaments are in series with the inductor and are lighted all the time the light is on which wastes power and causes the tube to fail when a filament burns out.

    Rapid start ballasts and tubes are being discontinued and replaced by electronic ballasts. I don't know if the new tubes have filaments. If they do, they are used only for starting.



  11. #11
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    use of choke in tube light

    In Canada, our fluorescent tube lights use "Rapid Start" ballasts without starters. The filaments are in series with the inductor and are lighted all the time the light is on which wastes power and causes the tube to fail when a filament burns out.

    Rapid start ballasts and tubes are being discontinued and replaced by electronic ballasts. I don't know if the new tubes have filaments. If they do, they are used only for starting.



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