Questions Related To Tubelight

eelectrichuman

eelectrichuman

@eelectrichuman-7aKvsm • Oct 26, 2024
why do the ends of the tubelight get blackened after long usage?
and may i know the time taken for the tungsten filament lamp to get heated up to incandescence?
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  • praba230890

    praba230890

    @praba230890-vPFAoQ • Jul 7, 2011

    Blackening of TL(tubelights) occur both in thermionic and coldcathode lamps. The main reason is due to sputtering of emission mix. The emission mix is nothing but mostly the mixture of barium, strontium and calcium oxides over the filament. This mixture helps the proper injection of electrons into the gas(may be mercury, sodium, etc) which results in further process of phosphorescence or fluorescence. The mixture used will sputter more at each start of the light. After some time this emission mix may be gone, resulting in overheating of the coil(the heat required to produce light now increased due to the absence of emission mix). This heat(at coils) is the main reason for the blackening at the ends.
    eelectrichuman
    why do the ends of the tubelight get blackened after long usage?
    and may i know the time taken for the tungsten filament lamp to get heated up to incandescence?
    0
  • Anoop Mathew

    Anoop Mathew

    @anoop-FRTf1L • Jul 7, 2011

    praba230890
    Blackening of TL(tubelights) occur both in thermionic and coldcathode lamps. The main reason is due to sputtering of emission mix. The emission mix is nothing but mostly the mixture of barium, strontium and calcium oxides over the filament. This mixture helps the proper injection of electrons into the gas(may be mercury, sodium, etc) which results in further process of phosphorescence or fluorescence. The mixture used will sputter more at each start of the light. After some time this emission mix may be gone, resulting in overheating of the coil(the heat required to produce light now increased due to the absence of emission mix). This heat(at coils) is the main reason for the blackening at the ends.
    Intriguing. Could you explain the principle behing LED light and why is the LED light Brighter than the Ordinary Tube Light???
    0
  • praba230890

    praba230890

    @praba230890-vPFAoQ • Jul 7, 2011

    Yeah LED is a cool invention which is highly necessary for this century. As we know that lighting is at second next to motors on loads, making them efficient will be the good power conservation measure. Already power electronics started working on motors to reduce energy consumption. The low and medium power electronic device which can give us efficient lighting is LED.
    Light Emitting Diode which is a solid state device which is a diode that simply emits light when current is passed through them. You may ask, "this is what an ordinary lights does?". But in case of ordinary lights like incandescent or filament lamps the electricity is not directly converted into light. There are a lot of energy conversion happens before we get the light.
    Here in LED the electrical energy is directly converted into light energy. Also, The light color is characteristic of the energy bandgap<a href="https://en.wikipedia.org/wiki/Bandgap" target="_blank" rel="nofollow noopener noreferrer">Bandgap</a> or the semiconductor material used to make the LED.
    atf
    Intriguing. Could you explain the principle behing LED light and why is the LED light Brighter than the Ordinary Tube Light???
    0