PWM调光具有以下优点：

(1)无论调光比有多大，LED-直在恒流条件下工作。

(2)颜色一致性好，亮度级别高。在整个调光范围内，由于LED电流要么处于最大值，要么被关断，通过调节脉冲占空比来改变LED的平均电流，所以该方案能避免在电流变化过程中出现色偏。(3)能提供更大的调光范围和更好的线性度。-PWM dimming has the following advantages:

(1) no matter how much the dimming ratio is, LED- is working under constant current condition.

(2) the color consistency is good, the brightness level is high. In the dimming range, due to the LED current is either a maximum value, or is turned off, by adjusting the pulse duty ratio change led average current