Led outdoor flood lights are different from traditional lamps, and generally have a very obvious sign: there is a heatsink behind. It is not because the LED temperature is very high need to heat. On the contrary, it is because the LED belongs to the cold light source, the chip is very “afraid of heat”, to do a good job of cooling, so that he can work safely.
Ability to resist high temperature and cold. In some areas the external temperature can be as high as 50 ℃, and the lowest is often low to -30℃, which requires the power supply must have a wide range of work ring temperature, in -40 ℃ to 70 ℃ wide range of work to ensure product reliability, stable performance. Heat generation and direction, the professional term is called “heat management.” As shown above, LED chips, is the source of heat emitted, but also the most afraid of high temperature position. We need to send the heat quickly to the substrate, and then spread to the radiator, and then distributed to the outside, to ensure that the chip temperature is not too high.
The whole process, is a set of “cooling system”, generally divided into three large blocks:
① Heat Generation: LED chip work fever,
② heat conduction: Heat through the substrate and other intermediate path to the radiator;
③ heat distribution: Heat through the radiator to the outside world. How to judge the advantages and disadvantages of heat dissipation? A reasonable heat dissipation design, making fine lamps, heat dissipation capacity and the corresponding relationship between power. Heat sink volume, weight determines the heat storage capacity, so the heat sink is generally a big tuo tuo. The area of the heat sink determines the final distribution capacity, in order to increase the area, will generally be made into a variety of columns, nets, slices and other shapes. The radiator occupies a large portion of the cost of the led dimmable flood lights. Some jerry-cut factories in order to save costs, will be shoddy, small charge big. So here’s the question: how do we judge if a luminaire’s radiator is doing well?
Of course, the most direct method is to measure the temperature of the LED chip when the lamp is working, which is called “Knot temperature”. Pipe him how to blow, temperature control in the acceptable range, that is done well, vice versa is to cut corners.