LED street light-the relationship of TJ.and life time

So long ago ,we always devoted to development our LED streetlight with long life and low junction temperature .Why we do that ,pls see below :the relationship of the junction temperature and life time :

T(℃) LIFE(HOURS)
25 -------234.000
30---191.000
35---157.000
40---129.000
45---107.000
50---90.000
55---75.000
60---64.000
65---54.000
70---46.000
75---39.000
80---34.000
85---29.500
90---25.700
95---22.300
100--19.500
105--17.100
110--15.100
115--13.300
120--11.700
125--10.500

LED street light- LU1

After our R&D department persist in development new product everyday and test the new product again and again in laboratory , finally ,our high power LU1 is completed and installed in our famous city HuNan province ,Changsha ,LiuYangHe.

After more than 3month passed ,all of our high power LED srreetlight LU1 with solar and wind system goes very well . If you want to know more about this project ,pls contact with us soon .

Jony Huang
Marketing Department

Shenzhen Bang-Bell Electronics Co., Ltd.
Address: Building C, JinXiongDa Industrial Park, Huan'guan South Road, Guanlan Town, Bao'an District, Shenzhen, Guangdong, China.Tel: +86 755 2958 8988 -EXT:861 Fax: +86 755 2958 8616 -EXT:861 Website: http://www.bbeled.com/ MSN ID:Jonymei@hotmail.com ，Skype ID：Jonymei

LED street lighting

LED emits monochromatic light (contains only one wavelength). Then most important information is the so-called color temperature which is expressed in degrees Kelvin [K]. The sun’s surface temperature is 5780 K, and the peak of its radiation’s wavelength is at 500 nm.
Even though the degrees are big in the light devices, it does not mean that the lamp will heat up to this temperature, but that the light emitted by it corresponds to the maximum emission value of this temperature. Attached please find some indicative color temperatures.

Warm white: > 2700 K
Intermediate white:2900 - 3000 K
Cold white :4000 K
Daylight:5000K

Due to monochromatic radiation, a 5000 Kelvin light has proved to be the most popular in use. LED’s typical rated current is 20 milliampers [mA], and the threshold voltage, i.e. the voltage crossed for the LED to start conducting is 1,5 – 5 Volts [V]. The threshold voltage depends on the color of the LED, i.e. the semiconductor materials used in it.
The power should be thus restricted for example with a resistor, so that it does not exceed the allowed value. If a 12 volt voltage is in use and the LEDs threshold voltage is 2,9 volts (voltage when the current begins to circulate) and 20 mA current, the needed series resistor to restrict the current is 470 Ohmns [%uF057].
We must notice that in this case, considerably more power is used in the resistor (172 milliwatts, mW) than in the LED itself (57mW). It is worth it then to use methods in which the conduction voltage in the LED is smaller, and the restricting resistor also consumes less power or is not needed at all, when the whole power in use is focused on LEDs. This can be achieved, for example, with a series connection. In this case, four LEDs in a series would exactly make the used 12 volts.
Since the light efficiency of one traditional LED is really not enough for lighting, power leds have been developed, and their light efficiency (and electric efficiency used) is much greater than that of the traditional LED’s, all the way until one watt. Their light efficiency has also improved, and is even 80 lm/W. However, power leds form much waste heat, and it has to be cooled down. The LEDs’ efficiency starts to fall strongly if they heat up too much. The alternative is to use traditional LEDs connected to a series.
Then also the light pattern can be targeted to a wider area, and the light fitting itself looks beautiful, as the many small light spots form a light source.
The latest LED technology studies done in Meijo University in Japan, have led to the development of even 130 lm/W LEDs. A normal incandescent lamp produces only 15-20 lm/W and 60-110 lm/W. It is clear that in the future the lighting technology will increasingly utilize LEDs. In the future, the LED light fittings’ prices can also be competitive with the current light fittings as mass production and technology develop.
LED lighting has many advantages compared to the traditional incandescent lamp. The biggest is the possibility to save energy when energy becomes scarce, and the climate change caused by energy production causes concern. On the other hand, as LED lights do not heat up, much, they are easy to install in places where the heat is harmful or can cause, for example, a fire danger.
By adding a sufficient amount of luminous LED lamps, we can achieve sufficiently bright lighting in any area requiring resolution. In addition, LED lights are much more durable than any other lighting technology. The lamps can last even 100,000 hours, meaning 10 years of continuous lighting. Traditional lamps only reach a fraction of that time. Although as they get older, the light efficiency of LEDs starts to fade, and they cannot withstand heat. In the lighting of a sauna, the age may be much shorter than, for example, in outdoor use.