Type
Classic incandescent lamps are gradually going out of use these days; mainly
halogen,
fluorescent and light-emitting diode (LED) models are presented on the market. At the same time
, LED lamps of a traditional design can be either white or
colored (RGB), and in addition to them, there are models of a rather unusual device -
LED with a battery,
with LED filaments and
phytolamps. Here is a more detailed description of the different types:
— Halogen. A slightly improved version of traditional incandescent lamps. “Halogen” also uses a hot metal coil in a sealed bulb; the difference is that the flask is filled with a special gas containing bromine or iodine vapor. This design increases the service life of the spiral, increases brightness and efficiency, and also provides a more uniform color spectrum. Another advantage of such lamps is their compatibility with brightness controls (dimmers). At the same time, they are not economical, and therefore are gradually losing ground to more advanced types.
- Metal halide. A type of halogen lamps (see above), the luminous flux in which is formed by adding metal halides to the mercury vapor burner. Sodium or scandium iodide are used here as metal halides (special
...emitting additives). The burner of metal halide lamps is made of quartz glass or ceramic, and the outer protective bulb is made of borosilicate glass. Such lamps are often used for outdoor and street lighting, in spotlights, etc. As a rule, they emit natural white light, close to daylight.
- Luminescent. A variety known as "fluorescent light bulbs" or "energy saving light bulbs". The bulb of such a lamp is filled with a special gas through which an electric discharge passes; under the influence of this discharge, a special coating applied from the inside to the flask glows. In terms of efficiency, such lamps are inferior to LED lamps, but they are many times superior to incandescent lamps (including halogen), last longer and hardly heat up during operation. Among the disadvantages of fluorescent lamps, in addition to the rather high price, one can note an uneven emission spectrum and poor compatibility with dimmers - for this it is necessary to provide additional control circuits. In addition, the fill gas contains mercury vapor, which is why the lamp should not be thrown into regular trash, and a broken bulb poses a health hazard.
— LED LED. LED-based lamps that produce light of one shade - usually classic white, but there are also colored models. LED lamps are distinguished by extremely low energy consumption (they are several times more efficient than fluorescent lamps and an order of magnitude more efficient than incandescent lamps), high brightness and good color rendering, as well as almost complete absence of heating during operation. In addition, such light bulbs are quite shock-resistant and much safer from an environmental point of view. And in many models, even a broken bulb does not lead to loss of performance.
— LED with battery. LED bulbs with a built-in battery that provides autonomous lighting regardless of the presence of voltage in the electrical network. Such light bulbs accumulate charge in the battery when there is light, and during power outages they use these reserves, allowing them to independently illuminate the room for a certain time. Also, LED light bulbs with a battery can be useful as mobile light sources outdoors, in the garage, etc.
— LED (RGB). A type of LED lamp (see above) that uses colored LEDs rather than traditional white ones - usually three colors corresponding to the RGB color scheme (red, green, blue), hence the name. This allows you to change the color of the lighting within a fairly wide range - from one and a half dozen to several thousand shades. At the same time, such lamps cost accordingly.
— On LED threads. A type of LED lamps that imitates classic incandescent lamps. Such lamps also have a glass bulb, inside of which luminous threads are installed on special supports; the difference is that these filaments are made of LEDs rather than a thin metal spiral. Thus, the lamp turns out to be as similar as possible to a classic incandescent light bulb, while consuming several times less energy; Such models can be useful, in particular, for “retro” style lamps, where standard “LEDs” do not fit well. It is also worth noting that the glow from a lamp of this type covers almost a full sphere - unlike standard LED lamps, which usually have a narrower focus; in some situations this is an advantage.
— Phytolamps are designed to stimulate the growth and development of plants. The products are used for auxiliary lighting: seedlings, cultural and ornamental plants, indoor and outdoor vegetation. They are especially relevant during periods of the year when solar activity is at a minimum level. The light sources are LEDs of different shades and luminescence intensity. White, red, blue, yellow and green LEDs can be collected within one phytolamp. The use of different color shades makes it possible to obtain light waves of different lengths. As a result, vegetation begins to develop comprehensively. Phytolamps are not suitable for the lighting habitual to a person in conditions of insufficient visibility.Colour temperature
This parameter describes the general coloration of the light of the lamp in "warm" or "cold" tones.
Initially, colour temperature is the temperature (in kelvins) of an object at which it begins to glow in a certain colour. Interestingly, the higher its value, the more “cold” the colour is: for example, the dull red glow of a heated metal corresponds to 800-1000 K, and the bluish-white tint of a fluorescent lamp corresponds to about 6000 K.
The temperatures encountered in modern light bulbs can be described approximately as follows:
2700 – 3000 K — "warm" white light, similar to traditional incandescent lamps;
3000 – 3500 K — "slightly warmer than average";
3500 – 6000 K — neutral white, similar to daylight;
More than 6000 K — cold shades of white.
Note that the colour temperature is not directly related to the quality of colour reproduction provided by the light of a particular lamp — much depends on the features of its design and, accordingly, the spectral colour balance.
Scattering angle
The angle of light dispersion is the space in front of the light bulb, which is illuminated by the source itself, and not by the light reflected from the walls and interior items. In other words, the angle of light scattering determines the zone of the best illumination. Classic incandescent bulbs demonstrate the widest dispersion angle — they shine almost 360˚. LED spotlights have the smallest illumination angle, which are able to illuminate well only the area directly under the bulb — the scattering angle in such cases is about 15˚. Of course, a large angle of light scattering is not always needed. Working in the evening at the table, you need light only in front of you, so as not to disturb anyone. For spotlights that light up only small objects in front of them (a painting, sculpture, bas-relief, etc.), the scattering angle can even be from 4 °. As for the top (general) lighting, in this case it is better to choose something with a wider dispersion angle. These bulbs provide extremely uniform illumination.
Directional light (reflex)
This function is indicated for lamps with a beam angle of less than 180° — in other words, the
luminous flux is directed in a certain direction, usually opposite from the base. One of the varieties of such lamps is models equipped with reflectors; however, the presence of a reflector is not mandatory, there may be other options (for example, a set of LEDs on a flat substrate).
The main application of directional lamps is obvious — situations when there is no need to shine "on the sides", if not even desirable. In particular, they are well suited for luminaires "recessed" into the ceiling or walls. When choosing, note that the scattering angle can be different.
