The relatively recent LED lamps have quickly gained a lot of fans among consumers. This was facilitated by a number of factors, including the spectral composition of radiation well perceived by the eyes, low power consumption, seat compatibility with traditional incandescent lamps and a range advantages. The industry, trying to build on its success, masters the serial production of all new products.
Currently, LED lamps are divided into two main groups in terms of performance, which are known as Filament and SMD. Accordingly, the buyer who is inexperienced in lighting technology is faced with the question of choosing the best type.
Design features of LED lamps
Any LED lamp always contains a driver and several LED crystals, which are mounted in a typical case, the base of which allows the ramp to be screwed into a regular holder. The constant current required for the operation of the emitting crystals is generated and stabilized at the desired value by the driver.
The SDM-type lamp has a direct luminous flux formation circuit and contains several emitting crystals, which are located on a mounting base. The latter, in addition to the actual supporting platform, takes on the role of a radiator. An LED as a light source is distinguished by a narrow directivity of the generated radiation (it has a relatively low aperture) and a relatively low power. Therefore, the lamp designer compensates for these disadvantages by increasing the number of crystals and their location on the radiator. Additionally, the radiator is shaped to increase the source aperture as a whole. Figure 1 shows an example of such a construction.
Another advantage of the SDM source, though not in great demand in practice, is its potential maintainability.
The Filament lamp uses an indirect scheme for obtaining radiation: LEDs are located on filaments and are additionally coated with a phosphor layer. The latter immediately widens the aperture, but due to its small area, it noticeably toughens the cooling conditions for LEDs, which begin to operate in intense thermal conditions. This is accompanied by accelerated crystal degradation and a noticeable decrease in lamp life.
Focal Applications of LED Bulbs
The presence of filamentous luminous working elements of Filament lamps makes them very similar to the good old incandescent lamps, which is clearly seen in Figure 2. Due to their visual similarity, it is most advisable to use them in chandeliers and table lamps, the purpose of which is initially to create a wide luminous flux.
In contrast, the directional radiation of SDM lamps becomes an advantage primarily in table lamps with their narrow directional radiation. Taking into account this feature, in such luminaires, sometimes they even refuse a screw base. Figure 3 shows an example of a cylindrical embodiment of a connection unit.
Conclusion
As you can see, there is simply no definite answer to the question in the title. Lamps complement each other in their areas of use. In any case, we recommend the use of modern LED lamps, and when choosing a type and a specific model, in addition to radiation characteristics and visual indicators, it is necessary to take into account additional information.