1. the lamps and lanterns are also life

In fact, lamps and lanterns have the same lifespan as ours. With the passage of time, the functional mechanism of lamps and lanterns will continue to decline. Whether incandescent lamp, fluorescent lamp, energy saving lamp or LED lamp can not avoid "dying", and this is the problem of light decay of lamps and lanterns.

LED light source

What is light failure? At present, our country has not yet established the definition of light failure and general standard, but generally speaking, light failure means that after a period of lighting, the light intensity of LED lamps will be lower than the initial light intensity and can not be restored, that is, the reduction part is the light decline of the LED lamp. (different types of lamps cause different reasons for the decay of light).

In addition, the US Energy Star LM-80 stipulates that 6000H's luminous flux maintenance rate is more than 94.1%, which is considered invalid.

The cause of light failure

For the cause of light failure, there are still a lot of controversy, and the micro mechanism of the recession has not been conclusive, but generally speaking, the light failure of LED is mainly caused by heat dissipation.

LED fever is well known to the industry, LED ideal work temperature is between -5 ~0 degrees, but this is basically impossible, heat will affect the light decay and life of LED lamps and lanterns, LED in the work, there will be about 80% of the electricity into light energy, LED radiator is a LED heat dissipation, because the LED chip at work, it itself Environmental temperature

The higher the temperature, the lower the light emission rate. When the temperature reaches the highest temperature of LED chip, the luminaire will be broken.

In addition, the thermal resistance of LED chips, the influence of silver glue, the heat dissipation effect of substrates, and the colloidal and gold lines are also related to the decay of light.

How to solve light failure of lamps and lanterns

In fact, in a strict sense, LED lamps and lanterns can not avoid light failure. It is a technical problem to be solved urgently in the industry, but we can minimize the problem of light failure as long as we know the heat dissipation of the lamps.

The heat dissipation structure of LED lamps and lanterns is often seen on the market.

But before we talk about the heat dissipation of LED lamps, we must first understand it: junction temperature.

What is the knot temperature? The so-called junction temperature is the working temperature of semiconductor chip (wafer, bare chip) PN junction. The higher the junction temperature, the earlier the decay occurs.

LED light source

If the junction temperature is 105 degrees, the lifetime of the brightness to 70% is only more than 10000 hours, 95 degrees will be 20 thousand hours, and the junction temperature is reduced to 75 degrees, the life will be 50 thousand hours, and 65 degrees can be extended to 90 thousand hours. So the key to prolong life is to either reduce the temperature, and the key to reducing the temperature is to have a good radiator, so how do we systematically identify the heat and quality of the LED lamp?

The general LED junction temperature increases, and the luminous flux will decrease. Then, as long as we measure the illumination change of the lamp in the same location, we can reverse the change of junction temperature.

1. choose a place that does not interfere with external light. It is better to turn off other lights at night.

2. turn on the lamp in cold state, and measure the illuminance of a location immediately.

3. keep the lamp and illuminometer position unchanged, and the luminaire works continuously.

4. half an hour later, read the illuminance value here and record the reading as "hot illuminance".

5. if the two values are similar (10~15%), the heat dissipation system of the luminaire is basically good.

6. if the two values are far away from each other (greater than 20%), the heat dissipation system of the luminaire is doubtful.

The "half hour illumination" method is simple to measure the change of junction temperature.

In addition, we can not only see the cost to determine the good or bad of the radiator, we want to choose the most cost-effective, and not all of the best, so the summary is:

1. hand touch radiator is very hot, certainly not good, do not touch the radiator is not hot, not necessarily good.

2. in the case of reasonable design, the same weight, the large surface area, the radiator is good.

3. the same surface area, that weight is heavy, that radiator is good. (precondition is the same material)

The fins of 4. fin radiator are not as many as possible, the more dense the better.

Epilogue

Light failure is a required process for the work of lamps and lanterns. When we buy Lamps and lanterns, we must choose lamps with better quality and heat dissipation. In the process of use, we should reduce the working load of lamps and lanterns as much as possible in order to delay the speed of light failure and prolong the life of the lamps.