Features:

Commonly used small light-emitting diodes (leds) main features:

(1) light emitting diode is a one-way conductive device.Only allows current to flow from the positive to negative. 

    Only positive access when conduction and glow. Reverse access is deadline. Of course also don‘t shine.This is 

    similar to ordinary diode.But the light-emitting diode tube pressure drop than ordinary diodes, about to 2 v, 

    the power supply voltage must be greater than the pressure drop, light-emitting diodes (leds) to work.

(2) the brightness of the light emitting diode instead of working current If relevant, generally when the If = 1 ma hui. 

    Increased with the increase of lf brightness. But when lf acuity after 5 ma. Brightness increase was not significant.In addition, 

    the maximum working current light-emitting diodes (leds), as a general rule, be 20 ~ 30 ma, more than this value will damage the 

    light emitting diode.Work, therefore, should be within 5 ~ 20 ma current lF choice, in order to save electricity, generally choose lF = 5 ma.

(3) light emitting diode reverse breakdown voltage is generally around 5 v. Use should not make light emitting diode reverse voltage withstand more than 5 v. 

    Otherwise leds will be broken down.