At present, LED dimming technology is as follows:
1: linear dimming
Using the dedicated dimming pin of the constant current chip to adjust the current of the LED to achieve the purpose of dimming, this technique works well. The advantage of this dimming method is that the driving current is reduced when the driving current linearly increases or decreases. The influence of the overshoot process on the life of the LED chip, and the anti-noise of the dimming circuit is strong. The defect is that the process of changing the magnitude of the driving current definitely has a certain influence on the color temperature of the LED chip.
2: PWM dimming
PWM: Dimming pulse width modulation is an analog control method that modulates the bias of the gate or base of a transistor according to the change of the corresponding load to realize the change of the on-time of the output transistor or transistor of the regulated power supply. The way to make the output voltage of the power supply constant while the operating conditions change is a very effective technique to control the analog circuit by using the digital output of the microprocessor. The method is characterized in that the driving current is square wave-shaped, and the pulse width is variable. After the modulation of the pulse width is converted into a time for modulating the continuous illumination of the LED lamp, the input power is also converted, thereby achieving energy saving and dimming. aims. The frequency is about 200Hz~10KHz as usual; because of the hysteresis of human eye vision, it will not feel the sparkle caused by the light source during the dimming process. The advantage of this dimming method is that it can improve the heat dissipation performance of the LED.
3: Remote dimming
There are two kinds of infrared remote control and wireless remote control, which are more complicated to implement, but can achieve the effects of changing color temperature, color and other dimming methods.
4: Segment dimming
This dimming mode utilizes the switch for the specified time to achieve the purpose of dimming. It does not require an additional dimming component, and can be dimmed according to the existing installation method. The other is because the dimming is completely controlled by the power switch chip. Internal control, high efficiency and high power factor can be achieved in the full voltage range regardless of the brightness at work.