How to choose LED fluorescent lamp?

There are countless companies that produce LED fluorescent lamps on the market, and the product quality and performance vary greatly. This allows non-professionals such as foreign trade companies, energy-saving companies, engineering companies, and foreign-funded companies to purchase products in China to purchase products. I don’t know how to distinguish the quality and performance of the LED fluorescent lamps produced by various companies. I don’t know what to do when buying products. I may have spent a high price instead of buying the ideal product I want.

You can purchase LED fluorescent lamps from the following aspects: profiles, power supplies, and chips.

1. Profile and structure.

There are basically two types of profiles on the market: all-plastic and half-plastic and half-aluminum pipes.

1. All-plastic tube: The early LED fluorescent lamp used all-plastic tube, because it mainly uses non-isolated power supply, in order to avoid electric shock problems, it is more desirable to use all-plastic tube. The φ5 straw hat tube LED is used inside. The big problem of this kind of fluorescent lamp is the heat dissipation problem. Because all the heat is sealed in the tube, it cannot be dissipated at all, and the light decay is very serious. In addition, the straw hat tube has a very short lifespan, and it will be broken in less than 2000 hours.

2. Semi-plastic and half-aluminum tube: The LED fluorescent lamps sold on the market are basically half of PC and half of aluminum alloy. Plastic is used for the half that needs light transmission, and the half that does not need light transmission but needs heat dissipation. Use aluminum alloy. The power supply is of course placed in the aluminum tube, so that the heat generated by the LED plus the heat generated by the power supply is quite large, because the power of this kind of lamp is usually about 20W. If the power is bigger, half of the aluminum tube will not solve its heat dissipation problem. Therefore, another aluminum tube structure for heat dissipation is proposed: a fan-shaped aluminum tube. The fan-shaped aluminum tube adopts a fan-shaped heat dissipation structure, which greatly increases the area of ​​the radiator. It puts the power supply outside the tube, so that the half aluminum shell can be completely made into a radiator. Compared with the semicircular aluminum tube, its heat dissipation area has increased by at least three times. In addition, the power supply is not placed in the tube, and the heat can be reduced, which greatly extends the life of the LED. (Please forgive me if you can’t put the picture)

2. Power

The power supply of LED fluorescent lamp is divided into two kinds of built-in type and external type. The so-called built-in type means that the power supply can be placed inside the tube. The greater advantage of this built-in type is that it can be made to directly replace the existing fluorescent tube without any circuit changes. Therefore, the built-in shape is made into a long strip to fit into the semi-circular lamp tube.

1. Non-isolated constant current power supply: Non-isolated means that there is a direct connection between the load end and the input end, so there is a risk of electric shock if the load is touched. The advantage of the non-isolated constant current source is that the circuit design is simple and the manufacturing cost is not high. The disadvantage is that the high voltage of the AC power supply will be introduced to the load end, causing the risk of electric shock.

2. Isolated constant current power supply: Isolated type refers to the isolation transformer at the input end and output end. But it can isolate the input and output. The advantage of isolating the constant current source is that the circuit design is complicated and the danger of electric shock can be avoided. The disadvantage is that the efficiency of the power supply will be reduced, the manufacturing cost is high, and the volume is relatively large. It is OK to put the T10 tube, but the T8 tube is more tight.

3. Centralized external power supply: In order to obtain higher performance, a centralized external power supply is used. Because the main places to promote flexible led strip lamps are government agencies, offices, shopping malls, schools, underground parking garages, subways and other places, often a room uses more than one fluorescent lamp, possibly more than 10. At this time, a centralized external power supply should be used. The so-called centralized type refers to the use of a high-power AC/DC switching power supply, unified power supply, and each fluorescent lamp uses a separate DC/DC constant current module. In this way, higher efficiency and larger power factor can be obtained. The advantages of centralized power supply are obvious. Moreover, it is also an isolated power supply, this structure is also very easy to implement various dimming schemes,

Third, the chip

There is basically nothing to say about this. In general, the quality of first-tier brands such as CREE, Osram, HP, Nichia, and Toyota Gosei Lumileds must be better than second-tier or Taiwanese brands. Currently used in fluorescent lamps are specifications such as 3528, 3020, 3014, etc. These specifications are mainly due to their different sizes and heat dissipation methods of the chips. Chips of the same brand are packaged by different manufacturers and their quality is also different.

Four, other

1. Power supply protective cover: The built-in power supply is placed in the aluminum alloy radiator, so there must be a way to insulate it, otherwise leakage will occur. This phenomenon does not exist with an external power supply. There are three ways currently on the market.

1) Insulation sheet, wrap around the power supply with a piece of insulation paper, and then put it into the lead alloy radiator together. Disadvantages of this method: during the operation of inserting the power supply into the aluminum alloy radiator, the insulating paper is easily scratched by the corners of the aluminum alloy; because there is nothing fixed at both ends of the power supply, the power supply is easy to move in the aluminum alloy tube . 2) Heat shrinkable tube, which is a kind of PC material that shrinks when exposed to heat. A section of heat shrinkable tube is used to cover the outside of the power supply, and then blow with heat to make the heat shrinkable tube tightly wrap the power supply inside. , So as to achieve the purpose of insulation. Disadvantages: The heat shrinkable tube is closely integrated with the electrical components on the power supply, and the heat emitted by the power supply cannot be dissipated, thus shortening the service life of the power supply.

2) Insulation box, which is a kind of insulation box customized according to the size of the power supply. It has heat dissipation holes and fixing parts, which is a method with better insulation effect at present. (Please forgive me if you can’t put the picture)

2. Fixed ends: There are many joint methods on the market at present, there are aluminum skin, PC material, and aluminum skin plus PC material. According to the fixing method, there are glue fixed on both ends of the lamp tube, and screws can be used to fix the lamp tube. Two tubes. In terms of safety and environmental protection, the method of fixing with screws is adopted by the majority of consumers. (Please forgive me if you can’t put the picture)

3. The light transmittance of PC masks: The light transmittance of transparent masks on the market can reach 88-95%, and the light transmittance of fog masks is 70-86%. If the luminous flux of a tube without a mask is 2000lm, and now a transparent mask with a light transmittance of only 88% is added to it, then its actual luminous flux is only 1760lm. If you add a transparent mask with a light transmittance of 95% to it, then its actual luminous flux is 1900lm, which is also a transparent mask. Why is there such a big difference between the two? The answer lies in the material of the mask. At present, the materials of PC masks on the market include ordinary PC materials and optical grade PC materials. Because of the different manufacturers, the difference in light transmittance is quite large.

4. Substrate: At present, the LED chips are surface-mounted on the PCB or aluminum-based electronic circuit board through a certain arrangement, and then fixed on the aluminum alloy radiator. The thermal conductivity of PCB is 20w/mk, and the thermal conductivity of aluminum alloy is 200w/mk. The greater the thermal conductivity, the better the heat transfer and heat conduction effect.

5. Lifespan: The lifespan of lamps and lanterns mainly depends on the reasonable combination of chips, power supply, heat dissipation, etc., but it is still difficult for non-professionals who do not know how to make a choice. In the final analysis, except for the more basic uses In addition to materials, there is also a more basic reference is the light effect, the higher the light effect, to a certain extent, this lamp does a better job! Generally strong manufacturers have this test equipment.

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