Contrary Light
To do this, the flask is filled with gas under high pressure to the filament does not evaporate at higher temperatures – and you can halogen bulb. Such lamps are used in a variety of projectors in car headlights, etc. Halogen emits in the visible range up to 15% consumed power. If, however, such efficiency does not suit us (and you want 100%), then we have to use other principles of light emission. Here we consider two fundamentally different light sources: first (briefly) fluorescent lamps, and then – LEDs. Fluorescent tubes glow when they light up an electric charge: in filling up a gas the number of electrons detached from their atoms, and moves with an acceleration in an electric field. When an accelerated electron collides with an atom, it gives up energy in the form of ultraviolet radiation. The tube is covered from the inside phosphor, which absorbs this ultraviolet light and re-emits it as visible light is. From the standpoint of efficiency is already much better, because in principle nothing prevents collect all the ultraviolet light and convert it into visible light. A bulb, on the contrary, the lights in the main infrared light, which has nothing to do – he lost by heating the bulb itself and the surrounding area. Fluorescent lamps is approximately 4 times more efficient incandescent lamps. But there is a more promising option – LEDs. led emits visible light directly. Validity indicator – a few years of continuous operation. He has no beating a glass bulb, it safe and does not contain mercury and other harmful substances, not blows when you turn on / off, does not require high power, it is compact and can be built anywhere, works with any ambient temperature.