Technical solution: comparison and analysis of LED thyristor dimming scheme (Figure)

Editor's Note: As a new and most promising light source, LED lighting is gaining more and more attention due to its energy saving and environmental protection advantages. Coupled with the policy encouragement of the state and local governments, China's LED lighting industry has entered an accelerated development stage, using the market to grow rapidly.

In terms of indoor lighting, replacing traditional dimmable incandescent lamps or halogen lamps with LED lamps will also be the trend. Since the traditional incandescent lamp dimmer uses a thyristor dimmer, when replacing the incandescent lamp with an LED lamp, it is required to be able to change the original line and to adapt to the existing thyristor dimmer. Aiming at this target market, many large semiconductor manufacturers (including internationally renowned semiconductor manufacturers) have already launched their own LED dimming ASICs. However, due to the inherent light-emitting principle of LEDs, the LED ASIC dimming cases currently on the market are not yet available. Very mature, have their own inherent problems, this article will be a detailed analysis of the current dimming scheme, and introduce our MCU-based dimming scheme.

Therefore, in the LED dimming, in order to adjust the LED to a fixed brightness, it must be guaranteed to be a fixed, that is, to use constant current control. There is another way: constant power control. This is also the common method used in dimming ASICs on the market today. However, constant power control has its inherent drawbacks.