Now the market produces too many to count LED daylight lamp enterprises, product quality and performance difference is very big, so do not understand the foreign trade enterprises, energy companies, engineering companies, foreign companies in China procurement office and other professionals in the procurement of products in the process of how to distinguish the production of LED daylight lamp quality and performance, to buy products from the unknown, may spend high price and did not want to buy their products ideal. Buy LED fluorescent lamps can be from the following several aspects: profiles, power, chip select
One, section, structure
Now on the market basically is divided into two sections: the plastic, half sulptare half tubes.
In 1, the plastic tube: early LED fluorescent lamp is used in plastic tube, because mainly adopts a non-isolated power supply, in order to avoid the electric shock, so that the plastic tube. It is used for the straw hat LED 5. The fluorescent lamp is the biggest problem in the heat problem, because the quantity of heat sealed in tube, unable to escape, attenuation is very serious, coupled with the straw tube was life is very short, less than 2000 hours are bad.
2, half sulptare half tubes : now on the market sell LED daylight lamp basically is the half half of PC aluminum alloy, in need of light half of the used plastic, transparent and without need of heat dissipation that half is made of aluminum alloy. The power of course on the tubes inside, so, LED heat plus power heating quantity is quite large, because this kind of lamp power is usually around 20W. Power again big point, half tubes and can not solve its problem of heat dissipation. It also proposed another radiating tube structure: a fan shape aluminium tube. A fan shape aluminium tube with a fan shape structure of the heat dissipation, greatly increased the area of a radiator. It put the power into the pipe, which can put half aluminum shell made completely of radiator. Relative to the semicircular tubes, the radiating area is increased by more than 3 times at least. Coupled with the power supply is not placed on the inside of the tube, but also can reduce the heat, which greatly extended the life of LED
In two, power supply
LED daylight lamp power is divided into two kinds of built-in and external. The built-in type refers to the power supply can be placed inside the tubes. This type has the greatest advantages can be made directly replace the prior fluorescent lamp circuit, without any changes. So the built-in shapes are made in long, so into the semicircular tubes.
1 non isolated constant current power supply: non isolation refers to the load terminal and the input terminal is directly connected, so touching loads on the risk of electric shock. Non isolated constant current source has the advantages of simple circuit design, high manufacture cost. The drawback is that will put the AC power to the high pressure is introduced to the end of the load, thus causing a risk of electric shock.
2 isolated constant current power supply: isolation type is defined in the input end and the output end with the isolation transformer isolation. But all the input and output isolation. Isolated constant current source has the advantages of circuit design, can avoid the danger of electric shock complex. Drawback is that the efficiency of power supply will be reduced, the manufacturing cost is high, volume is large, into the T10 lamp can also, but put into T8 lamp has been tense.
3 centralized external power supply : to get the highest performance of the best use of centralized external power supply. Because of the promotion of LED fluorescent lamp is the main site of government agencies, office, shopping malls, schools, underground parking, subway and other places, often in a room with more than one daylight lamp, may be in 10 above. At this time we should adopt centralized external power supply. The so-called centralized refers to the use of a high power AC / DC switching power supply, power supply, and each fluorescent lamp is used to separate the DC / DC constant current module. In this way we can get the highest efficiency and maximum power factor. Centralized power supply has the advantages of obviously. Moreover, it is an isolated power supply, this structure is also very easy to achieve a variety of light modulation scheme,
LED daylight lamp basically is nothing, under normal circumstances, such as CREE, Osram, HP ( HP ), Nichia chemical ( Nichia ), Toyota Lumileds synthesis such as first-line brand quality must be larger than the second or the Taiwan. Currently used in fluorescent lamp is 3528, 3020, 3014 and other specifications, this several kinds specification is its size, the heat is not the same. The same brand of chips, packaging manufacturers are not the same, its quality is not the same.