What factors determine the life of led lamps?
How to predict the life of this led lamp.
It seems that it should be very simple to estimate the life from the junction temperature. As long as you check the curve in Figure 1, you can know that the life corresponding to the junction temperature of 95 degrees can get the life of the LED as 20,000 hours. However, this method is still reliable for indoor LED lamps. If it is applied to outdoor LED lamps, especially high-power LED street lamps, there are still many uncertain factors. The biggest problem is that the heat dissipation efficiency of the radiator of the LED street lamp decreases over time. This is due to the accumulation of dust and bird droppings, which reduces its heat dissipation efficiency. It is also because there are strong ultraviolet rays outdoors, which will also reduce the life of the LED. Ultraviolet rays mainly affect the aging of the encapsulated epoxy resin. If silica gel is used, it can be improved. Ultraviolet rays also have some bad effects on the aging of phosphors, but they are not very serious.
However, this method is more effective for comparing the heat dissipation effects of two radiators. Obviously, the smaller the volt-ampere characteristic shifts to the left, the better the heat dissipation effect. In addition, there is still a certain degree of accuracy for predicting the life of indoor LED lamps.
