How to identify the quality of the LED bulbs with
single star LED white light on the aging board detected data, and the white light LED assembled into a lamp aging detected data, it must be a little discrepancy. The size of the differences, depending on the LED work of electrical parameters and the design of lamps and lanterns, as well as the use of lamps and lanterns of the environment.
choose what kind of LED lamp bead
this is important, the quality of the LED lamp bead can be said to be the very important factor. Give some examples, the same represented by wafer 14 mil white light section of the chip, made of common epoxy resin glue and Bai Guangjiao and glue packaging LED lamp bead, single light in 30 degrees environment, after one thousand hours, attenuation data to droop 70%; If encapsulated with low class D failure glue, in the same aging conditions, thousands of hours of light failure is 45%; If the C class low failure glue encapsulation, in the same aging conditions, thousands of hours of light failure is 12%; If a class B low failure glue encapsulation, under the same aging environment, light failure for - thousands of hours 3%; If class A low failure glue, in the same aging conditions, light failure for - thousands of hours 6%.
in general, the average coefficient of thermal conductivity of the epoxy resin is small, therefore, when the LED chip light work, LED chip to emit heat, thermal conductivity and ordinary epoxy resin ability is limited, so, when you fell from the LED light source of external measure the temperature of the LED bracket has 45 degrees, white light LED chip inside the center temperature may have more than 80 degrees. LED is 80 degrees, the temperature of the node, then, when the temperature of the LED chip in the section temperature in the work, is very suffering, it will speed up the aging of LED light source.
the LED light source working environment temperature
according to the list of the LED light source age data, LED light source, if only one light work, at the same time, it's environment temperature is 30 degrees, so, list of the LED lights work support temperature not more than 45 degrees. This time, the service life of the LED will be ideal. If there are 100 leds light up work at the same time, the interval between them is only 11. Under the condition of 4 mm, then the LED light source of the perimeter of the lamp stack stent temperature may also can't more than 45 degrees, but the lamp of the middle of the LED light source could reach the high temperature of 65 degrees. This time, for the LED light source is a test. So, in the middle of the LED light source, theory of glazing failure will be a bit faster, and the light surrounding the pile of LED light source, light failure will be a little more slowly. But if the LED lamp bead more than 25 mm apart, so they radiate heat to each other, it will be less accumulated at this time, each the temperature of the LED lamp bead bracket should be less than 50 degrees, is conducive to the normal work of the leds.
if the LED work environment is a place in the colder, the average temperature all the year round may only be about 15 degrees, or smaller, that for the LED life is longer. Or, LED work, there was a small fan in blowing, help it to disperse the heat, it is helpful to the life of the LED. Anyway, you should know, LED is afraid of heat, the higher the temperature, the shorter the LED life, the lower the temperature, LED the longer service life. LED the ideal working temperature of course is between negative 5 to zero. But it is basically impossible.
LED lamp bead work electrical parameter design
according to the experimental results, LED white light under the condition of the drive current is lower, the smaller the emission quantity of heat, of course, and the smaller brightness. According to the survey, LED solar lighting circuit design, LED drive current generally 5 - 10mA; Lamp bead with large number of products used in the lamps and lanterns, such as more than 500, or more, the drive current is only 10 - in general 15 ma, and generally popular application of LED lighting drive current, just 15 Ma, rarely put to over 20 ma current design. And the experimental results also show that in 14 ma driver power flow, and add the lid not leak, the inside of the air temperature of 71 degrees Fahrenheit, low failure products, thousands of hours of light decays to zero, 2000 hours of light failure is 3%, which means the low failure LED white light is used in such an environment has reached its maximum, again big is a kind of damage of it.
because there is no heat aging with aging board function, so the LED work the heat generated by the transmission is basically can't go outside. The experimental understands that the Shanghai. Aging board on the inside of the air temperature has reached 101 - degree heat, the lid of the aging board surface temperature is only 53 degrees, dozens of degree of difference. This means that, the design of the plastic cover basically do not have heat dissipation function of thermal conductivity. But, in the general design of lamps and lanterns are considering the heat conduction of heat dissipation function. Thus, in summary, the LED lamp bead work the design of the electrical parameters according to the actual situation, if the cooling function of thermal conductivity of lamps and lanterns is very good, the white light LED drive current increasing point is that it doesn't matter, because the heat generated by the LED lamp bead work moment can export to the outside, no damage to the LED, is the best care for the leds. On the contrary, if the cooling function of thermal conductivity of lamps and lanterns so so, had better circuit designed to be a little bit small, let it put less heat.