14 important parameters of LED lighting

　　1 Forward Current If:

　　It refers to the positive value of forward current normal light emitting diodes when . In actual use, should be selected in 0.6  IFm IF less .

　　2 forward voltage VF:

　　Parameters given in the table operating voltage is at a given forward current to get. Generally in the IF = 20mA when measured . Light emitting diodes in the forward voltage VF of 1.4 ~ 3V. When the outside temperature , VF decreases.

　　3.V-I characteristics :

　　Relationship between voltage and current light-emitting diodes , the forward voltage being less than a certain value ( called the threshold ) , the current is very small , not light. When the voltage exceeds a certain value, the forward current increases rapidly with voltage , light.

　　4 Luminous Intensity IV:

　　Luminous intensity of the light emitting diode is generally fingering line ( refer to the cylindrical axis of the arc tube ) in the direction of the luminous intensity . If the radiation intensity (1/683) W / sr in the direction , the light emitting candela ( symbol cd). Due to the small two general LED luminous intensity , luminous intensity so common candle ( candela , mcd) for the unit .

　　5.LED emitting angle:

　　-90 ° - +90 °

　　6 spectral half width grind :

　　It means that the spectral purity of the arc tube .

　　7 half-value angle 1 / 2 and perspectives :

　　1/2 is the angle between the value of the luminous intensity is half the axial strength of the axial direction of the light emission (normal ) of .

　　8 full form :

　　The LED light-dimensional translation of the angle of view, also called plane angle .

　　9 Perspective:

　　Means the maximum angle of the light-emitting LED , depending on the viewing angle , different applications are also called light intensity angle .

　　10 half-width :

　　0 ° with the normal value of the maximum luminous intensity angle / between the two . Strictly speaking , the angle corresponding to the maximum value of the maximum luminous intensity of the luminous intensity value / 2 .

　　LED packaging technology resulting in maximum luminous intensity angle is not the normal value of 0 ° , the introduction of the deviation angle refers to the angle of maximum luminous intensity corresponding to the angle between 0 ° and the law .

　　11 Maximum forward DC current IFm:

　　The maximum allowed plus the forward DC current. Exceed this value can damage the diodes .

　　12 Maximum reverse voltage VRm:

　　The maximum reverse voltage applied allowed . Exceeds this value, light-emitting diodes may be breakdown.

　　13 work environment topm:

　　Light-emitting diodes can work in normal ambient temperature range. Lower or higher than this temperature range, the light-emitting diodes will not work normally, efficiency is greatly reduced.

　　14 allowable power dissipation Pm:

　　Allow applied across the LED forward voltage DC current flowing through the maximum value of the product of it . Exceeds this value , LED heat damage .