2011年4月11日 星期一

And Why CFL’s Are Overrated

The Chemistry Of Light Bulbs—And Why CFL’s Are Overrated

Light bulbs rely not only on simple materials but on esoteric ions and compounds. And while we take their emissions, visible light, for granted, the inner workings of these deceivingly simple gadgets depend on the complex behavior of electrons.

We’ll discuss four types of light bulbs:incandescent bulbs, halogens, fluorescent lights (including CFL’s) and LED’s.


A) INCANDESCENT BULBS

The light bulb of the short-lived variety, is the traditional tungsten incandescent bulb. Inside the glass, electricity flows through a thin filament of the element tungsten (chemical symbol, W,China Merchants Securities researcher appear in the future, more space for led lighting business development is the LED lighting tube, said: "At present, the target has entered a stage of maturity, LED t5 tube applications directly in the existing areas have a high penetration rate, therefore, for companies to get the development needed to show tube LED light tube and five areas of development. for its old name wolfram).Huge market space has also been perceived by the star power of the country, and last year led light the industry chain of distribution.

Because the wire is so thin, resistance is high,Led Tube assembly points with manual welding and machine welding of two, is to use hand soldering iron, using the most primitive cfl bulbs way to carry out welding. Such practices out of the product first appearance of the ugly and it raises the temperature of the tungsten wire, so chosen because of its high melting point of 3410 oC. At the bulb’s temperature, which is about 1000o cooler, excited electrons that return to lower energy states release photons of a frequency that is visible to the human eye. The radiation is intense in the red to yellow regions but compared to daylight, the

spectrum of an incandescent light bulb is very weak in the 400 to 500 nm region (blue). This would be nice to verify with a prism, and is the reason that plants don’t do as well if grown under such light. Although the heat is not sufficient to melt the tungsten it would certainly fry the heck out of it in an oxidizing atmosphere. Thus manufacturers replace oxygen with a mixture of the less reactive nitrogen and the noble gas argon. Note that a vacuum would not be a good solution because the tungsten would vaporize even more easily and dramatically shorten the bulb’s lifespan.

Even within an argon-nitrogen atmosphere, however, the heat causes some of the tungsten to sublimate. Some of it returns to the wire as it bounces off the argon gas, but a good deal ends up on the glass. This is one of the reasons incandescent bulbs tend to get darker with increased use. The glass suffers more abuse from plain old electrons which fly off the filament as if it were a cathode ray tube from a conventional television set. Such electrons cause tiny black spots to appear.the brightness of LED with different different prices, the general highlighted the table lamps and compare the price difference between the poor. Therefore, the procurement must be clear when they need to know what kind of brightness, so as to accurately position their products. These first caught Edison’s attention, but he had never time for further investigations; otherwise, as David Bodanis suggests, Edison may have discovered electrons before J.J.rolled copper is high purity with Rolling Method of copper マジコンds attached to the FPC on - because FPC with copper foil has excellent adhesion, copper foil adhesion strength and high temperature, 260 can be immersed in the molten solder from the solder without bubble. Thomson. To create a more diffuse light but perhaps in an attempt to camouflage all the future damage, manufacturers treat light bulb glass with hydrofluoric acid one of the few acids that can attack glass) which creates that familiar frosty look.




1 則留言:

  1. More about CFL and LED problems....

    http://ceolas.net/

    CFL Safety
    Home Safety -- Radiation -- Health

    The CFL Mercury Issue
    Breakage -- Recycling -- Dumping -- Mining -- Manufacturing --
    Transport -- Power Plants

    LEDs:
    The Lead and Arsenic Issue
    Lead, arsenic and other toxic content, home breakage and disposal concerns

    The Overall Small Energy Savings from light bulb regulations:
    USA Dept of Energy data, less than 1% of society energy usage saved
    .

    回覆刪除