With the popularization of the LED traffic light, its types have become much more plentiful. Traffic lights have different classification methods according to the LED's specifications of light color, light structure, features of luminous surface, chip material, function, light intensity and current. Today I would like to introduce to you four kinds of classification methods of traffic lights:
1. Classification according to the structure of LED
According to the structure of light-emitting diode, or LED, the LED traffic light can be divided into epoxy encapsulation, metal epoxy encapsulation, ceramic epoxy encapsulation and glass encapsulation types, etc.
2. Classification according to the characteristics of the luminous surface of LED
According to the different characteristics of the luminous surface of LED, it can be divided into round light, square light, rectangle light, surface luminous tube, side tube, micro-tube for external installation, etc.
Generally speaking, round lights are divided into 2mm, 4.4mm, 5mm, 10mm and 20mm types by diameter. Generally 3mm LEDs are labeled T-1, 5mm as T-1 (3/4) and 4.4mm as T-1 (1/4).
The LED traffic light can estimate the distribution of circular luminous intensity angle based on the half-value angle. Moreover, according to the distribution diagram of luminous intensity angle, it can be divided into three categories:
(1) Normative type. This kind of light is generally used as the indicator light and its half value angle is from 20° to 45°.
(2) Scattering type. This is the LED traffic light with a large angle of view, which is generally used to display the car traffic signal. Its half-value angle can be from 45°to 90°or larger, and it has a relatively large amount of scattering diluent, so that it is used as the car traffic light.
(3) High directivity type. It is generally encapsulated by the pointed
epoxy or metal reflective chamber, and generally does not contain a scattering diluent. Its half-value angle is from 5°to 20°or less, so that it has a high directivity and can be used as a mini traffic light.
3. Classification according to the light color of LED
Depending on the light color of LED, LED traffic lights can be divided into light, orange light, green light (further subdivided into yellow green, standard green and pure green), blue light types, etc. Some LEDs contain chips that come in two or three colors. According to whether scattering diluent has been added into the luminous surface of LED and whether it has any color, the foregoing LEDs of various colors can also be divided into four types: Colored illumination, colorless illumination, colored scattering and colorless scattering.
4. Classification according to the light intensity and operating current
The LED traffic light can be classified into general brightness (the light intensity <10mcd), high brightness (10-100mcd) and ultra-high brightness (the light intensity >100mcd) based on the light intensity and operating current. The operating current of the general LED is from 10mA to dozens of mA, but the operating current of the LED with a relatively low current is below 2mA (the brightness is the same as that of the general LED).