LED will have obvious advantages in road traffic information system

Since 2001, with the GB14887-1994 "road traffic signal lamp technical requirements and test methods" revision, LED signal lamp technology level into a period of overall improvement. In the past two years, many cities, such as Beijing, Shanghai, Chongqing, Nanjing, and so on in the bulk of the traditional incandescent lamp as a light source to replace the LED as the light source signal lights.

The traditional traffic signal lights mainly consists of the following parts: power supply, lamp shell, reflective bowl, colored lens, the light source part. Traditional signal lamp has the following disadvantages: first, due to the existence of reflective bowl, resulting in false display effect. Two short life, high maintenance costs. Three is due to the color of the light is made of plastic materials, in the light of the sun for a long time, there will be varying degrees of color change, leading to the light color drift, prone to accidents and other serious consequences.

With LED as the signal lamp has obvious advantages: first, because the beam emitted from the LED is a certain divergence angle and forward, so that you may not need to install like incandescent lamp reflector, and LED itself is a light, so there is no need for the coloured lenses to filter, so as to solve the problem of false display and light color drift, improve the utilization rate of light. Secondly, long service life, 5 to 10 years, low maintenance costs. Third, the power consumption is small, generally about incandescent lamp light source of 10% ~ 20%.

This is in line with the country's energy policy. Fourth, because the single LED is only a special unit of the signal lamp luminous discs, as long as the circuit board signal lamp design is reasonable, even if the individual LED burned, it will not affect the other LED light emitting unit, thus affecting the overall effect of signal lamp.

According to the recommendation of the illuminating engineering society of the United States, the cost of energy saved using the LED light source can be calculated by the following formula: A=8760 * D * (PI-PL) * C. Among them: A for the annual energy savings; D for the LED duty cycle; PI for incandescent lamp power consumption (kW); PL for the LED signal power consumption (kW); C for every kilowatt hour of electricity (yuan / kWh). According to this formula to calculate the use of LED light source instead of an incandescent lamp can save a year of electricity is 263 yuan.

In addition to traffic lights instead of the traditional LED application, in the field of transportation is very extensive, including: civil aviation flight information display, aviation terminal check-in counters, baggage arrival display, railway station and port passenger ticketing system, guide rail car display, information display, subway and light rail information release display, bus station electronic stop sign, bus information display, LED display variable speed road traffic signs, highway toll system LED monitors, city traffic information outdoor display screen.

But the cost of high brightness LED is still relatively high, especially high brightness green LED prices are still relatively expensive. The price of the LED single tube is several times or even more than ten times that of the incandescent bulb, which is one of the reasons why the LED lamp has not been used in large quantities, especially in the economically underdeveloped areas.

In the transportation industry in our country, relatively speaking, the airport flight information display system, a display terminal in general are more advanced in the system; the system is the rapid rise of road traffic induced, in the development and improvement process. LED applications will also play an important role in intelligent transportation systems and traffic guidance.