LED downlight all welcomed by consumers, because it not only has a very long life, high efficiency and, more importantly it also adapted to the development needs of the market, with energy saving features. Also worth mentioning is, LED ceiling light, was based on the tone light and adjust the brightness of the environment, it is not only more humane, is the best embodiment of energy-saving.
LED down light dimming method the most major, there are three common, these three kinds of skills are based on changes for dimming of the LED drive current input. According to the different circuits can also be divided into imitating dimming and PWM dimming.
First: the dimming method is called to imitate dimming method or linear dimming method. Advantage of the dimming method is: when the drive current of linear growth or decrease, reducing the current overshoot effect on service life of LED downlights chip in the process, and dimmer circuit resistance to disturbance of strong. Its drawbacks are the size variation of drive current has some effects on the color temperature of the LED chip.
Second: this dimming method is done through the modulation LED drive current dimming of the LED down light, due to the brightness of the LED chip with LED drive current into a certain percentage, so we can adjust the LED drive current controlled LED tube lamp shade.
Third: this dimming method called pulse width modulation (PWM). This method is a square wave-shaped after the drive current, the pulse width is variable, based on pulse width modulation into LED tube light continuous time, and also changes the input power, so as to achieve energy-efficient, dimming the target.
Frequency is probably as usual at 200Hz~10KHz because the human eye Visual lag does not feel light on dimmer shining phenomenon produced in the process. The dimming method is able to improve the benefits of LED thermal performance, defect is driving current overshoot of the life of the LED chip must have some effect.
LED tube lamp dimming performance is one of its key characteristics, its automatic Adaptive versatile adjustable light is not possible with any other lamp, it is one of the key development directions for the future.