Three ways of dimming for LED lights

　　There are mainly 3 commonly-used ways of dimming for LED lights. These three ways of dimming are all based on the changing of input current. According to the different circuit system, it can also be divided into imitation dimming and PWM dimming.

　　The first: This dimming method achieves the dimming by modulating the current of LED driver due to the fact that the brightness of light is in certain proportion to the current of LED driver, so we can adjust the LED driver current to control the brightness of LED lights.

　　The second: This method is called imitation dimming or linear dimming. The advantage of this kind of dimming is as follow: When the current linear grows or decreases, it reduces the influence on the lifespan of LED chip in the current overshoot process of LED driver. Besides, it is strong in the magnetic disturbance resistance. The defect is that the changing of driver current has an impact on LED chip.

　　Third: This dimming method is called pulse width modulation (PWM). The method is adjusting the driving current to square wave and making the pulse width variable. Through the modulation of pulse width, it controls the continuous light time of LED light and also changes the input power so as to achieve the goal of dimming. Frequency is as usual at about 200Hz ~ 10KHz. Because of the hysteresis quality of human eyes, people could not feel the glare of light source caused in the process of dimming. The advantage of this dimming is that it could improve the heat dissipation performance of LED light, and the defect is d that the changing of driver current has an impact on LED chip.