(one) according to the color of light emitting diodes
According to LED light color, can be divided into red, orange and green (yellow and green, and subdivided the standard green and pure green blue), etc.. In addition, some LEDs contain two or three kinds of colors.
According to the light emitting diode, the light emitting diode can be divided into four types: colored transparent, colorless transparent, colored scattering and colorless scattering. Scattering type light emitting diode suitable for indicating lamp.
(two) according to the luminous tube features a smooth classification
According to the luminous tube features a smooth round, rectangular, square lamp lamp, surface emitting tube, pipe, tube with micro lateral surface mounting. According to the circular lamp diameter is Phi 2mm, Phi 4.4mm, Phi 5mm, Phi Phi Phi 8mm, 10mm and 20mm etc.. Usually the foreign Phi 3mm light emitting diode is denoted as T-1; the diameter of 5mm is denoted by T-1 (3/4); the diameter of 4.4mm is denoted by T-1 (1/4).
The distribution of circular luminous intensity can be estimated from the angle of the half value.
From the luminous intensity angular distribution graph, there are three kinds of:
(1) high directivity. The general pointed epoxy package or package with metal reflector, and without scattering agent. The half value angle is 5 degrees 20 degrees or less, with a high directivity, can be used as a local illumination light source, or combined with the light detector to form an automatic detection system.
(2) standard type. Usually used as an indicator, the half value of the angle is 20 degrees 45.
(3) scattering type. This is the angle of the larger indicator, the half value of 45 degrees 90 degrees or more, the larger the amount of scattering agent.
(three) classification according to the structure of light emitting diodes
According to the structure of the light emitting diode, the structure of the light emitting diode is composed of an epoxy encapsulation, a metal base epoxy encapsulation, a ceramic base epoxy encapsulation, and a glass package.
(four) classification of light intensity and working current
According to the luminous intensity and the working current, the LED (light emitting intensity 10mcd) is divided into ordinary brightness, and the luminous intensity is between 10 and 100mcd. General LED of the operating current in a dozen mA to tens of mA, while the low current LED of the operating current in the 2mA (brightness and the same as the ordinary light-emitting tube).
(five) according to the classification of power
There are small power LED (0.04-0.08W), medium power LED (0.1-0.5W), high power LED (1-500W), with the continuous development of technology, the more the power of LED to do more.
(six) according to the package form
One is the SMD (SMD) and DIP (line two).
I explained: for the classification of LED, we have a sense of it can be, the real distinction is to see the physical and practical applications to identify.
If the LED product is compared to a person, then LED is the soul of LED products, drive circuit is the whole body of the LED product, the quality of LED products play a vital role in. Since the driver is so important, then what is the LED driver? Drive is divided into several? With these questions, let us learn the following content.
In simple terms, the LED driver is provided to LED normal working conditions (including voltage, current etc.) of a circuit is to make LED work indispensable condition, good driving circuit also can protect the LED, after all, LED is the core of the product.
LED drivers are generally divided into three types:
(1) resistance to limit current drive
In a simple LED circuit in series with a resistor, by adjusting the resistance value, the driving current can change LED.
(two) constant current drive
Keep the LED current constant, LED work in constant current conditions, efficiency and the stability of light in order to improve the LED of LED, reduce the light work degree, constant current drive is the best choice for high power LED is using constant current drive.
(three) constant pressure drive
To maintain the voltage of the LED at both ends of the same, because the voltage of each color of the LED are not the same, so rarely used in a constant voltage way to drive LED.
