Three kind LED dimmer analysis

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    Nowadays the common use LED dimmer : Triac/ELV dimmer,Led 0/1-10v dimmer,PWM 

dimmer,The working principle of other dimmer is to achieve LED dimming function through 

control of the output current and voltage,frequency size. 

  Pls see the detailed principle under various dimming mode

1 LED triac dimming  is used in incandescent lamp and energy saving lamp,is one of the most 

widely used  dimming modes in Led dimming.

Its working principle is that the input voltage waveform generates a tangential

output voltage waveform  by conducting angle shear wave,The application of the principle of 

tangential, can reduce the effective value of the output voltage.so as to reduce the common 

load  (resistive load) power.The advantages of triac dimmer is high efficiency, stable 

performance.

2 LED 0/1-10V dimmer ,the power supply design with control chip.0-10V dimmer,

 through the 0-10V voltage change, change the output current of the power source

when 0-10V dimmer modulate to 0V, down to current 0,the brightness of the light is

closed ( a switch role),when the 0-10V dimmer tune the maximum 10V, the output current will 

reach 100% power output, the brightness will also 100%.output voltage is constant

 1-10V dimming principle: as noted that, just a dimmer is 1-10V: when the resistance dimmer to 

minimum 1V,change the output current is 10%,as to 10V (at maximum), the output current will 

reach 100%power output, the brightness will also 100%. (output voltageis constant)

   Note: 1-10V has no a switching function.

3 PWM dimming power  digital dimming is also called PWM dimming, through the PWM wave to open 

and close the LED forward current to change the conduction time, in order to achieve the effect 

of brightness adjustment.The method is based on properties that  human eye is not sensitive to 

brightness scintillation. If the bright and dark  frequency exceeds 100Hz,the average brightness

 is seen by the human eye, instead of LED in the blink. PWM can adjust brightness by adjusting 

the proportion of time of dark and light,because the human eye to  more than 100Hz in the flicker 

of light, the perception of brightness is a cumulative process.