Types Of Light

Incandescent lamps: These lamps use a tungsten filament placed in an inert gas or in a vacuum inside a glass bulb. The inert gas eliminates the evaporation of the tungsten and reduces the blackening of the casing. There is a wide variety of lamp shapes whose appearance is primarily for decorative purposes. Incandescent lamps are still widely used for domestic lighting because of their low cost and compactness. However, for commercial and industrial lighting, their low efficiency makes them expensive to use, which is why gas discharge lamps are the most common choice. Thus, a 100W lamp has a typical efficiency of 14 lumens/watt, while a 36W fluorescent lamp provides 96 lumens/watt. Incandescent lamps whose flow can be easily varied by reducing the supply voltage are still used when the variation in light is an important feature of use. Tungsten filament is a compact light source that is easy to focus with reflectors or lenses. Incandescent lamps are very useful for l...

Most lamps will need to be replaced several times during the life of the lighting system. Designers should, therefore, minimize the inconvenience that occasional maintenance and breakdowns can cause to occupants. The lamps are used in a wide range of applications. The average life is often a compromise between cost and performance. Thus, the lamp of a slide projector will have a lifespan of one hundred hours, because it is important for the quality of the image to have a maximum luminous flux. On the contrary, some street lighting lamps can be changed every two years, after some 8,000 hours of operation. In addition, the life of the lamps is affected by the operating conditions, so that there is no single value applicable to all cases. Similarly, the effective life of a lamp can be determined by different failure modes. A physical failure, such as a break in the filament or lamp, may be preceded by a decrease in the luminous flux or a change in its color appearance. The lif...

The photoluminescence occurs when the radiation absorbed by a solid is re-emitted with a different wavelength. When the re-emitted radiation is in the visible spectrum, the phenomenon is called fluorescence or phosphorescence. Electroluminescence is a phenomenon that is taking place when the light is produced by an electric current passing through certain solid, such as phosphorous materials. It is used in illuminated signs and dashboards, but it has not proved to be a practical light source for indoor or outdoor lighting. The evolution of electric lamps Although technological progress has made it possible to manufacture different lamps, it is the constraints of the external market that have been the main factors to influence their development. Thus, the production of filament lamps used in the early XX century became possible after the development of efficient vacuum pumps and drawing tungsten. However, large-scale electricity generation and distribution to meet the...

A lamp is an energy converter. Although it can find other applications, its primary purpose is the transformation of electrical energy into electromagnetic radiation in the visible range. There are many ways to create light. The standard method of creating general lighting is to convert electrical energy into light. Glow: When heating solids or liquids, they emit visible radiation at temperatures above 1000 K; this phenomenon is called "incandescence". It forms the basis of light production in filament lamps: an electric current passes through a thin tungsten wire, whose temperature reaches 2500 to 3200 K, depending on the type of lamp and its use. This method is subject to a limit, described by Planck's Law for Emissivity of the Blackbody, according to which the spectral distribution of radiated energy increases with temperature. At around 3600 K and above, there is a significant gain in the emission of visible radiation, and the wavelength of the emission ...