Thinking of Triac dimming of LED lamps

In any case, the market has actively or passively joined such an unreasonable application. The above paragraph to pick the self-love program network, although a bit rough but had to admit that it is a bit reasonable. And see various IC manufacturers have launched their own Triac dimming solution. First of all, the country's LM3445, Anson's NCL3000, can be said to give a better prelude to dimming. This was followed by the explosion of the primary side control scheme: TI sn090126, NXP SSL2101/SSL2102, Infineon ICL8001 and many other electronic solutions for applications. These ICs have their own advantages and disadvantages. It can be said that this kind of primary side control application leads the dimming to a new platform. All kinds of low-power applications are applying this kind of scheme, and the low-cost and high-dimming effect is very good. But the good times are not always smooth. When everyone used this application, it was discovered that the characteristics of the LED itself are not suitable for such a dimming method. Overall, its compatibility is particularly poor, mainly in the market where a variety of dimmers do not have a uniform specification. This makes it difficult to match the dimmer, which is obviously out of place. So many electronic component technology engineers (including myself) are investing in such a development that blindly optimizes the performance of their LED luminaires without standards. In this process, a lot of manpower, material and financial resources are consumed, but the result is not satisfactory. The reason is that various applications will have its limits of adaptation. You have to take a standard to adapt to a large number of products that are not standardized and have no standards. When are you going to end?

In this process, it can be found that the performance of the LED with the trailing edge dimmer is relatively good, but the problem with the leading edge dimmer is much more. This is based on the fact that LED luminaires are generally capacitive load applications. Because when the trailing edge dimming is adopted, the sudden drop of voltage occurs at the moment of cutting off the correlation, and at this time, because of the capacitive load, the larger load capacitance has the function of renewing energy, which slows down the time of voltage drop. In order to maintain the normal operation of the circuit; when using the leading edge dimmer, the dimmer will have a large turn-on voltage spike when it is turned on, and then the capacitive load will lose its function, so it will not start or flash normally. And so on, but if you switch to an inductive load, this phenomenon can be changed. (Because the high-voltage spikes appearing at the leading edge dimming just make the output stable by the inability of the inductor to mutate.) This has the problem of compatibility between the leading edge and the trailing edge. Of course, some people will definitely say that they use the combination of the two. But what will happen to this, the results can be imagined.

Originally because of the rich color of LED, it is an excellent application for natural dimming changes. The LED also has a dimming method that is very suitable for him: PWM dimming. This is a way to achieve digital control. It can also avoid many application restrictions and achieve effective control. However, when I introduced the market, I encountered the trap of Triac, which was to turn people's intentions into conformity with it. This is an impatience option. It is also a choice to pay.

Perhaps we are not in a position to evaluate such a market-oriented problem, or that almost all new products will be encountered in the early stage of promotion. Just like the footsteps of the pioneers to find their own direction. This may be considered a choice, what do you think?