LED power supply is mainly divided into LED external power supply and LED built-in power supply. External power supply is simply that with the shell of the LED power supply, mainly used in the ceiling, panel lights, floodlights, downlights, mining lamps, street lamps, waterproof lamps and so on. External power supply is divided into two kinds of a waterproof, a non-waterproof, waterproof main use of outdoor, indoor use is not waterproof (the price is not waterproof glue your point.) Built-in power supply, can also be said to be Bare board power supply, placed in the lamp cup built-in, mainly used in bulb lights, spotlights, candle lights, PAR lights and so on.
External power supply features is simple to install, easy to replace, can reduce the heat led lamp beads, effectively reduce the light failure. But the external power supply also has some obvious shortcomings, taking up space, not beautiful and so on.
Built-in power supply is characterized by the installation of slightly complex and beautiful. But can increase the heat led lamp beads, LED light attenuation increase the service life.
Some users that: built-in power supply Another major drawback is the low life expectancy. T8 fluorescent lamp for example, because the power must be placed in the aluminum tube, so the aluminum tube can not be made into the form of fins, but only ordinary half-cylindrical type, at most, on the surface with some very shallow strip The surface area of this half-cylinder: 2πR * h / 2 = πR * h. For T8 lamp, its diameter is 26mm, so the radius of 13mm.1.2 m T8 lamp, Π * 1.3 +120 = 490cm2, we know that the surface area of the LED heat sink usually requires 60cm2 / W., so this semi-aluminum tube can only about 8W of heat dissipation. The T8 LED fluorescent lamp is usually the input power of 20W, assuming the luminous efficiency of LED is only 20%, then 16W of input power into heat. And now can only be dispersed 8W of heat, but also 8W of heat can not be dispersed, the result is to make the LED junction temperature rise, shorten life expectancy.
Not only that, because the power built-in, the power of the heat will be added to the tube, assuming that the efficiency of the power supply is 88%, so there 2.4W of heat should be dispersed, equivalent to an increase of 30% of the heat, that is a total of 10.4W of power can not be distributed out. Making the LED heat dissipation has increased a difficult, or that makes LED life is more shortened. Moreover, the length of the power supply is about one-fifth the length of the lamp, the heat generated by the power supply is also concentrated in this section, making the LED near the power of the baking by the hotter, and therefore life than other parts of the LED Short, the lamp in the damaged, close to the power of a black out first. It can be considered that the life of the built-in power supply LED fluorescent lamp will not be higher than 10,000 hours.
Led to a major cause of LED light failure is not timely dissemination of heat, and LED lamp beads heat and power fever is the main reason for the two (but generally more heat than the light beads), the external ambient temperature also has a certain impact, which has a lot Engineers began to power and led light beads isolated from the main body, so you can reduce the heat led light beads, effectively reduce the light failure, but there are some obvious external power shortcomings, take up space, not beautiful, etc., led Lamp, par light, spotlights and other lighting built-in external than the obvious to be convenient and beautiful, the pros and cons more, in order to extend the life of led lamps, the future may be the mainstream external power supply.
Built-in power LED lamp life of only about 10,000 hours, and 50,000 hours of external power compared to its use of cost is clearly 5 times higher. Not only that, in the course of use, whether it is damaged LED, or power is damaged, usually with the two should be discarded. The external power supply LED fluorescent lamp, which can be lost which lost.
In addition, built-in power supply also increased the cost of e-waste recycling. Because the power part must be removed and then dealt with separately. External power supply, not only high efficiency, long life, but also can increase the manual dimming or automatic dimming and other special features, these are built-in can not match!
LED drive power network that different products can not talk about power supply with built-in or external which is better. Some lamps must be built-in, some can use external all try to choose power external use. A GU10 3W spotlight, even if the external power supply no matter how good, it will not hang a shell in the lamp cup mounted power, ceiling lamp 15W who will not force the power into the sunflower inside, naturally select the power external On the ceiling.
So the external LED drive power supply is good or built-in LED drive power a good combination of the actual needs of the problem, it is necessary to consider customer requirements, but also consider the use of the environment, and product appearance.