Factors affecting the quality of LED lamps

 

       First of all, what kind of LED white light to choose.

 

       This is very important. The quality of the LED white light can be said to be a very important factor. To give some examples, the same is represented by Epistar’s 14mil white light segment chip, and the LED white light encapsulated with ordinary epoxy resin and white light glue and packaging glue, a single light is lit in an environment of 30 degrees, After one thousand hours, the attenuation data is 70% of the luminous maintenance rate; if it is packaged with D-type low-attenuation glue, under the same aging environment, the thousand-hour light attenuation is 45%; if the C-type low-attenuation glue is packaged, it will be under the same aging Under the environment, the 1000-hour light decay is 12%; if the B-type low-decay glue is encapsulated, under the same aging environment, the 1,000-hour light decay is 3%; if the A-type low-decay glue, under the same aging environment, 1,000 hours The light decay is 6%.

 

Secondly, the working environment temperature of LED lamp beads.

 

      According to the aging data of a single white LED light, if only one white LED light is on and working, and at the same time, the ambient temperature is 30 degrees, then the temperature of the bracket when a single white LED light is working will not More than 45 degrees. At this time, the life of this LED will be ideal.

 

      If there are 100 white LED lights working at the same time, and the interval between them is only 11.4mm, then the temperature of the bracket of the white LED lights around the lamp stack may not exceed 45 degrees, but the middle of the lamp stack Those LED white lights may reach a high temperature of 65 degrees. At this time, the LED lamp bead is a test. Then, the LED white lights gathered in the middle will have a faster light decay in theory, while the LED white lights around the pile will have a slower light decay.

 

     Anyway, everyone should know that LEDs are resistant to heat. The higher the temperature, the shorter the life of the LED, and the lower the temperature, the longer the life of the LED. The ideal working temperature of LED is of course between minus 5 and zero degrees. But this is basically impossible.

 

      Therefore, after we understand the ideal working parameters of LED lamp beads, we will try our best to strengthen the heat conduction and heat dissipation functions when designing the lamp. Anyway, the lower the temperature, the longer the life of the LED.

 

Third, the working electrical parameter design of LED lamp beads.

 

      According to the experimental results, the lower the driving current of the LED white lamp, the smaller the heat emitted, of course, the smaller the brightness. According to the survey, the design of LED solar lighting circuit, the driving current of LED is generally only 5-10mA; for products with a large number of lamp beads, such as 500 or more, the driving current is generally only 10-15mA However, the driving current of general popular LED application lighting is only 15-18mA, and very few people design the current to be above 20mA.

 

      The experimental results also show that under the driving current of 14mA, and the cover is airtight, and the air temperature inside reaches 71 degrees, the low decay product has zero luminous decay in 1,000 hours and 3% in 2000 hours. This shows that the use of this low-decay LED white light in such an environment has reached its maximum, and no matter how big it is, it will be a kind of damage.

 

      Because the burn-in board used for burn-in has no heat dissipation function, the heat generated when the LED is working is basically unable to be conducted to the outside. The experiment proved this. The air temperature inside the aging board has reached a high temperature of 101 degrees, and the surface temperature of the cover on the aging board is only 53 degrees, a difference of tens of degrees. This shows that the designed plastic cover basically does not have the function of heat conduction and heat dissipation. But in general lamp design, the function of heat conduction and heat dissipation is considered. Therefore, in summary, the design of the working electrical parameters of the LED lamp beads should be based on the actual situation. If the heat and heat dissipation function of the lamp is good, it does not matter if the driving current of the LED white lamp increases a little, because the LED lamp beads work The heat can be exported to the outside instantly, no damage to the LED, it is the best care for the LED. On the contrary, if the heat conduction and heat dissipation function of the lamp is so-so, it is best to design the circuit smaller to let it emit less heat.