light bulb?

Discussion in 'General Electronics Chat' started by Mathematics!, Dec 5, 2009.

  1. Mathematics!

    Thread Starter Senior Member

    Jul 21, 2008
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    I am assuming that the light bulbs life is just based on the life of the tunstin is their anyway to make it last forever?

    I am wondering if their is another material out their other then tunstin which uses less power and gives out the same or more a lumanacante intensity?

    That I can use in place of the burned out light bulbs tunstin to make this light bulb last forever for the same price or so.

    I also heard that you can make a light bulb last forever by using a magnet in some way anybody know how these are made.
    And why they don't sell light bulbs that won't burn out.

    Maybe some vaccum tube with a type of magnet and gas with electrical current flowing thru it will work dun ? curious
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
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    Typically, glow discharge lamps are more efficient at translating electrical power into light. Fluorescent lamps, for one example.

    Tungsten gets better life with iodine in the envelope. The gassified tungsten that plates onto the glass gets picked up by the iodine and plated back onto the filament, freeing the iodine to combine with more loose tungsten.

    Didja ever hear of question marks?

    These are the same people who sell 100 MPG carburetors and magnets that soften your water - or is it increase gas mileage?
     
  3. SgtWookie

    Expert

    Jul 17, 2007
    22,182
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    Nothing lasts forever.
    A typical tungsten filament incandescent bulb has a lifespan of about 1,000 hours.
    A typical LED has a lifespan of about 100,000 hours; but it will grow dimmer as it ages - the higher it's current, the more quickly it will grow dim.

    For incandescent bulbs? Not really.
    As Beenthere mentioned, there are other technologies for producing light.
    Flourescent lamps are much more cost-effective than incandescent bulbs.
    Sodium vapor are even more cost-effective, but the light produced is rather harsh.
    LED technology has advanced by leaps and bounds over the last 20 years, with no end in sight.

    Most consumers shop based on cost of acquisition alone nowadays, and don't bother to think about the lifetime operating costs. If they DID think about operating costs, they would buy those screw-in fluorescent replacements for incandescent bulbs. If they were REALLY thinking about lifetime costs, they would figure out a way to use LEDs.

    Poppycock.
    They do sell long-life incandescent bulbs. But why buy them, when you can buy fluorescent bulbs that last longer, generate less heat, and are far more energy efficient? And besides, if manufacturers sold bulbs that never burned out for the same cost that other manufacturers did, they would manufacture themselves out of business in a decade or two. Planned obsolescence.
     
  4. HarveyH42

    Active Member

    Jul 22, 2007
    425
    5
    Magnets are magic, they improve everything.

    I've heard that there are still Edison bulbs burning, not sure if it's the original filament though. Bulbs burn out, so you keep buying more. CFL bulbs last longer, but cost equally more. Led bulbs cost even more. The only real savings, is in the amount of power used, but when you use less, they raise the rates. Just no way to win these days.
     
  5. Mathematics!

    Thread Starter Senior Member

    Jul 21, 2008
    1,022
    4
    Why cann't you just create an ossilating circuit that has a resonanting frequency in the visible light spectrum say red light.

    In theory if the capacitors , inductors , transistors can last forever then your set I would think.

    Ofcourse you would have to some how have it resonante enough waves to get the lluminacant intensity of a regular light bulb.

    In theory it should be doable, in practice maybe not or maybe to inefficiant???

    And yes I heared that they could make a light bulb that could last forever (kind of like tire companies can make a tire that won't pop)

    They said it used magnets but maybe it used way to much power and was inefficient?
    Obviously if their was away the companies won't want it to be used because it would put them out of business....
     
  6. SgtWookie

    Expert

    Jul 17, 2007
    22,182
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    Please, be my guest. :) Tell me, what values of L and C would you use to create a tank circuit that would oscillate with a wavelength of about 645nm or 2.11614173×10e-6 feet? Remember, the speed of light is 299,792,458 m/s.
    Just to make it easier on you, that's about 464.8GHz.

    Neither capacitors, inductors nor transistors last forever.

    Wouldn't it be easier to just use LEDs? We already have those available.
     
    Last edited: Dec 6, 2009
  7. Mathematics!

    Thread Starter Senior Member

    Jul 21, 2008
    1,022
    4
    well if we used L = 1H and C = 1.1724869685860686504147521578712e-25

    Althought their are many different possible combos with LC.

    How long will typical capacitor , inductors , and transistors last ?
    Since inductors are basically just a coil of wire I cann't see these ever die out with in a reasonable amount of time.

    The capacitors are just metal plate with dielectric material between the plates cann't see these dieing out fast unless ofcourse it is by voltage overrateing ,,...etc use.

    For the transistor I dun maybe semiconductor material goes bad eventually ?

    As for the LED being better ---> not if we can get the same a light intensity , same power usage , and never dies out or lasts a very long time and only goes bad if a electric component goes....

    Also wondering since I have an open light bulb with no glass if I place another tunstin strip in it will it be twice as bright.
    And why the heck did they use glass to incase the light why not something else. And just sell tunstin to replace died tunstin instead of wasting glass and metals all the time???

    Also could I connect the tunstin ends directly to the white and black wires and plug it into the 120volt outlet?
    Or will this flip the circuit breakers i.e wondering if all the resistance is in the tunstin or is their something else in a light bulb providing resistance??? I am assuming it will work and the standard light bulbs with different wattages are because of more resistive tunstin , .....
     
    Last edited: Dec 6, 2009
  8. SgtWookie

    Expert

    Jul 17, 2007
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    OK, what are the physical dimensions of a capacitor of the size you specified?

    Don't forget, you also have to account for the capacitance in the transistor that's driving the tank circuit.

    But first, you'll need to find a transistor who's unity gain BW is greater than 464.8GHz.

    I wish you luck in finding one.
     
  9. Mathematics!

    Thread Starter Senior Member

    Jul 21, 2008
    1,022
    4
    what about a vaccum tube instead of a transistor
     
  10. The Electrician

    AAC Fanatic!

    Oct 9, 2007
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    I think that's more like 464.8 Terahertz.
     
  11. rjenkins

    AAC Fanatic!

    Nov 6, 2005
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    Filament bulbs (lamps) cost approximately five times as much to run as 'Compact fluorescent' bulbs.

    When they were first introduced (and very expensive - around UKP 20.00 each), I worked out that over the quoted 5000 hour life, a 20W CF lamp would save around UKP 40.00 against a it's equivalent 100W filament lamps, after allowing for the costs of the respective lamps.

    As CF lamps are now very cheap (or even free at some places, in exchange for a filament lamp) and electricity costs have gone up significantly, I'd guess the saving to now be at least UKP 60.00 / $100.00 over the life of a 20W CF lamp.

    Who wants filament lamps??

    Also, filament bulbs are now being phased out in the UK - before long it will be illegal to sell them for general domestic lighting use.

    For some years, new built houses have been required by law to have some percentage of light fittings that are incompatible with conventional filament bulb fittings.

    ps. Re. 'transistor oscillator' generation of light, I'd suggest you work out the physical sizes of the inductor (or resonant line) and transistor geometries, I think the present state of the art is quite a way short of what would be required.
     
    Last edited: Dec 6, 2009
  12. Mathematics!

    Thread Starter Senior Member

    Jul 21, 2008
    1,022
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    Ok , well 503292.121 Mhz = approx 500 Thz and this can be made with an L = 1 nH and C = 0.0001pF.


     
  13. The Electrician

    AAC Fanatic!

    Oct 9, 2007
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    503292.121 Mhz isn't 503 THz; it's only 503 GHz.

    To make a tank circuit resonant at 503 THz you would use .001 pH and .0001 pF.
     
  14. loosewire

    AAC Fanatic!

    Apr 25, 2008
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    You can blast me. Don't you have a porch and a dog.Just following your post.
     
  15. AlexR

    Well-Known Member

    Jan 16, 2008
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    Very good, now all you have to do is just find a 1femtoH inductor, a 100attoF capacitor and a transistor with zero output inductance, zero output capacitance and unity gain with reasonable power output at 500THz. Shouldn't be too much of problem should it?:rolleyes:
     
  16. studiot

    AAC Fanatic!

    Nov 9, 2007
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    A proper study of the science of the subject would go a long way to achieving your own answers to the questions you have thrown out, as would a study of the English language help other provide them for you.

    Tungsten, chemical symbol W from the Latin name Wolfram, has the highest melting point of any substance known.
    This property is the important reason for its choice as an incandescent filament material.
    The efficiency and quality (colour) of any incandescent light source is determined by its temperature - the hotter the better.
    Sparks in gasses are even hotter, which is why arc and vapour lamps are even more efficient.
    A corollary of this is that you can make ordinary tungsten bulbs last a very long time by running them at a lower temperature. This used to be done in mining illumination. Unfortunately the penalty for this is the colour shift towards the red (seen as more yellow) which is disliked in domestic use.

    Photographers talk about the 'colour temperature' of their light sources.

    None of these comments apply to non thermal sources such as LEDs or chemiluminescence.
     
  17. BillB3857

    Senior Member

    Feb 28, 2009
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    The filament in a vacuum tube is a tungsten filament, so you would use a device with a filament in order to create a device designed to eliminate a filament????????? I'm confused!

    Also, the reason glass is use is that it is clear to let the light out. A metal container could be used, but it would only produce the end result of dark light.

    Have you explored the possibility of creating a "dark sucker". Check out this site........
    http://www.theatrecrafts.com/humour_darksuckers.html

    It seems to be well in line with this topic.
     
  18. creakndale

    Active Member

    Mar 13, 2009
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    A soft turn-on circuit to keep the tungsten filament from being "shocked" should increase bulb life. Typically, bulbs pop during the turn-on inrush when the filament is cold.

    creakndale
     
  19. k7elp60

    Senior Member

    Nov 4, 2008
    478
    69
    This is true. You can also reduce the normal operating voltage of the lamp to extend its life. Reducing the operating voltage by about 15% increases the life pretty close to 5 times.

    I have some 12V RV lamp fixtures that I use for reading they have been modified to have a soft turn-on circuit. These lamps are used daily and have been in use for about 10 years. I finally replaced one bulb about a month ago. A side benifit of the soft turn-0n circuit is longer life on the on/off switches.
     
  20. russ_hensel

    Well-Known Member

    Jan 11, 2009
    818
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    Even with a bulb that last forever you need to take the law of conservation of enery into account.
     
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