why do i need a special dimmer for led lights

This method is not ideal for high-precision lighting equipment.ĭigital dimming, also known as PWM ( Pulse Width Modulation) dimming, uses PWM waves to turn on and off the LED to change the on-time of the forward current to achieve the effect of brightness adjustment. Its advantage is that the current can be continuous, but the range of adjustable current is often limited by hardware, and there are few adjustment gears. Many analog dimming is an extension of this method. The power supply voltage remains unchanged, and the current in the loop is changed by changing the resistance value to achieve the effect of changing the brightness of the LED.

Analog dimming is to achieve dimming by changing the current in the LED loop.

LED dimming methods can be divided into analog dimming and digital dimming. In addition, the waveform of the sine wave of the LED is different from the waveform of the incandescent lamp, so it cannot simply change its conduction angle to achieve the purpose of dimming. Therefore, from the volt-ampere characteristics of the LED, we can know that the dimming of the light source cannot be achieved simply by reducing the input voltage or input current of the LED. Therefore, when the current is lowered, the voltage of the LED will also decrease, which will change the relationship between the power supply voltage and the load voltage.įigure 1. It can be seen from the figure that the change of the forward current will cause the corresponding change of the forward voltage, to be precise, the decrease of the forward current will also cause the decrease of the forward voltage. The forward voltage of the LED is also determined by its forward current. When the voltage exceeds a certain threshold, the current will rise exponentially, thereby breaking down the LED PN junction. Generally, the reverse characteristic curve changes steeply. That is, the characteristics of the current flowing through the LED PN junction with voltage.

Regarding the LED dimmer switch, we must first understand the volt-ampere characteristics of the LED. Although variable voltage devices can be used for various purposes, this regulation is aimed at controlling lighting. By reducing or increasing the rms voltage, the light output of different intensities produced by the average power lamp is promoted. The purpose of the dimmer is to adjust the different brightness of the light. LED dimmer switch is an electrical device that changes the luminous flux of the light source in the lighting device and adjusts the illuminance level. Ⅰ Dimming LED Lights 1.1 What is Dimming?

Why do i need a special dimmer for led lights