White LED lamp beads failure or necrosis of the main reasons
The Core Tip: white LED lamp beads are voltage-sensitive devices, packaging companies in different packages have different operating current and operating voltage, in a typical package as an example (2835); in the actual work of white LED lamp beads are voltage Sensitive devices, packaging companies in different package under the different operating current and operating voltage, in a typical package as an example (2835); in actual work is to 60mA current for the upper limit, but often due to the use of Of the various causes of the current increase, if not take protective measures, this increase in the current exceeds a certain time and amplitude after the LED lamp beads will be damaged.
Cause LED lamp beads damage are the main reasons:
① sudden increase in power supply voltage, beyond the lamp power supply voltage range, resulting in increased output voltage, so the lamp beads burned.
② part of the line or printed wiring or other short-circuit and the formation of LED lamp bead power supply local short circuit, so that the local voltage increases, and thus burn the lamp beads or other components of the circuit board.
③ a LED lamp beads because of their own quality damage and thus the formation of short circuit, it is the original voltage drop passed on to other LED lamp beads.
④ lamp temperature is too high, so that LED lamp beads current increases, so that lamp beads burned.
⑤ lamp beads do not do waterproof treatment, the surface condensation to form condensate, causing the line or lamp beads burned.
So, how can we avoid the above problems, the protection of LED lamp beads circuit?
First, in order to avoid the occurrence of the first problem we should take measures.
Lamp power is generally the exchange of 180 ~ 240V AC power through the rectifier, filter, regulator to ensure that the output of low voltage 12 ~ 72V DC power LED light beads for use.
1, To improve the performance of the power itself, so wide voltage input; generally can guarantee 130V ~ 265V input voltage, the output voltage changes within 3% range.
2, In the regulator output to increase the linear constant current circuit, so that the lamp current does not change with the input voltage changes.
Second, in order to avoid the occurrence of the second and third problems we should take measures
1, The choice of light beads as far as possible the use of qualified components to ensure the stability of the light source board.
2, The light source of the internal light source board as little as possible to install circuit components, it is best to install only lamp beads and constant current IC. The following are the same as the "
Third, in order to avoid the fourth and fifth problems occurred we should take measures
1, In order to ensure that the internal temperature of the lamp is not high, increase the cooling body area, to ensure that the cooling area of W 50 square meters.
2, The lamp board must be done with epoxy resin to do waterproof treatment, to avoid the surface of the lamp beads because of weather and condensation.
To sum up:
But in the actual production process we have to do the above measures is not difficult, but in the existing market environment to fully meet the above criteria, under the existing conditions will increase the production cost of the product a lot, so that our product quality is Go up, we lost the price in the price. How can we do on the one hand to improve the quality of the product, the price down again?