12 problems existing in the application of high-power LED in the LED lighting industry

Problems of high-power LED in LED lighting

1. LED color difference problem

There is basically no color difference problem in the application of a single LED, but if many LEDs are put into use together or a lamp has multiple LEDs at the same time, the color difference problem will be prominent. Let's talk about a group of lamps first. If you can see at a glance that the colors of the lights are inconsistent, I think my happy mood will be discounted. Although like LUXEON, LEDs are divided into eight major regions according to color temperature, and each region is divided into several small areas, the color difference in a large range is controlled to a certain extent, but there are still differences in the same batch of LEDs in the same color region, and this difference still cannot escape the provocation of the naked eye.

2. LED insulation problem

(The insulation mentioned here refers to the heat dissipation substrate to the positive and negative poles of the LED.) We dare not say that we are the first to discover the insulation problem of LED, but at least the big manufacturers are surprised by our doubts. So far, the fundamental problem has not been solved, but compensatory measures have been taken, such as using aluminum substrates to handle insulation (the original aluminum substrates were not insulated, but now almost all have done so). You may find it incomprehensible. If a single LED is not insulated, the impact is not great, but there will be problems when multiple LEDs are connected in series.

3. LED anti-pulse problem

This issue is still controversial with the manufacturer. It does exist in my actual application. It is mainly reflected in the cold pulse, that is, the moment of power-on. A few LEDs break down or disconnect at the moment of power-on in the cold state. I don’t think it is caused by static electricity or high voltage (the power-on voltage is within the range).

4. The problem of LED light emitting angle

Since the LED lens packages of different manufacturers are different, even at the same emitting angle (nominal angle), the effect is different, making the selection of spotlights even more difficult, and still not universal.

5. Potential blinding risks of LED

The LED light points are too concentrated, making the center point extremely bright, which can easily hurt people's eyes. Although some lighting manufacturers have made efforts in this regard, due to the lag in regulations, it can only be a moral issue for people.

6. LED heating problem

Theoretically, LEDs do not generate much heat, but due to the current immaturity of technology, it is well known that LEDs generate heat, so I don't want to say more.

7. Low LED efficiency (luminous efficiency)

At present, the electrical conversion efficiency of LED is too low (because there is no instrument test, I dare not give specific data).

8. Insufficient LED brightness

Due to insufficient brightness, LEDs can only play a supporting role in the lighting industry and are mainly used for decoration.

9. LED light decay and lifespan

At present, the light decay and lifespan of LEDs produced by mainland or Taiwan companies are more serious. I won’t say much about it. Big brands such as LUXEON claim a lifespan of 100,000 hours, but I’m afraid only they themselves know it. In addition, the quality of heat dissipation and driver matching may affect the light decay and lifespan of LEDs, so 100,000 hours is just a selling point!

10. Problems with LED driver power supply

At present, most of the driving circuits are borrowed from switching power supplies. Of course, there are also a few circuits that are specifically used for driving LEDs, but the effect is basically the same. Since LEDs require DC drive and constant current control, the driving circuit is quite large and cannot be compared with electronic transformers. In addition, the efficiency is relatively low, reaching 80% is considered good (not even a single chip can reach it). In addition, in pursuit of applicability, manufacturers claim that a driver can connect a dozen or so chips at will (one, two, ... are all OK). In fact, this is a misunderstanding. Although it is a constant current, the excessively high starting voltage will often kill the LED instantly.

11. LED shape is limited

Due to the single-sided light-emitting characteristics of LEDs, the shape of LED lamps is subject to certain restrictions.

12. LED unit price is too high

An imported 1W-3W LED costs about 3 US dollars, and a domestic one costs more than 10 yuan (poor quality, no intellectual property rights). A lamp with about 6 LEDs costs about 1,000 yuan to consumers. Do you want to buy a color TV or a lamp?