LED Lamping will be the mainstream technology. Technology matures, one of many features LED Lamping standards and regulations have been proposed. Strict efficiency requirements have existed for a long time and will continue to grow. Recently, however, the work of LED Lamping designers has been difficult because of the two requirements that are met: dimmer dimming control for incandescent dimmers and implementation of high power factor LED dimming performance, current-analog dimming and PLED The situation is described below.
With the LED application market will continue to grow rapidly, LED's product range continues to grow, increase the demand for high-end products LED brightness control function is also very necessary. Attend the meeting, for example, LED Lamps and monitors should pay attention to the link.
Dimming is a very common feature of Lamping systems. For incandescent lamps, it can be easily realized at low cost. Dimmable LED lamps but there is a certain degree of difficulty, but for architects and residential users, when converted to LED Lamping, do not want to lose the dimming control should have the advantage. This involves a lot of LED Lamping related knowledge.
Power factor is a very important factor, because high power factor can reduce the loss of distribution network. The most effective way to reduce the environmental impact of electricity use is to reduce waste, LED Lamp so regulators around the world are further tightening their power factor specifications. An example of this is the ENERGY STAR Solid State Lamping Energy Efficiency Code (09/12/07), which states that the PF for residential Lamping products should be greater than 0.7 and the PF for commercial Lamping products greater than 0.9.
Lamping dimming method is the most important, there are three common, these three dimming skills are based on LED drive current input changes to dimming. According to different circuit systems can also be divided into imitation dimming and PWM dimming.
The first: This method of dimming by adjusting the LED drive current to complete the LED dimming, the LED chip brightness and LED drive current into a certain proportion of stakeholders, LED Lamp so we adjust the LED drive current can control the LED Lamps Lamp and dark.
The second: This dimming method is called pulse width modulation (PWM). This method is adjusted so that the drive current was a square wave, the pulse width is variable, LED Lamp after the pulse width modulation LED Lamps into a continuous Lamping time, but also change the input power, so as to achieve energy saving, dimming aims. Frequency as usual about 200Hz ~ 10KHz; because of the human eye vision lag, will not feel the Lamp source in the process of dimming shine.
Third: This method is called imitation blackout blackout or line method metod.Vid dimming method has the advantage that when the drive current linearly increases or decreases, LED Lamp reducing the emission of the drive current in the process of LED chip life, the coloring scheme is strong The current change of disk size is, of course, the color temperature of a certain degree of LED chips.