The LED total luminous flux measurement principle
The LED total luminous flux measurement has absolute and relative measurement two methods. Relative measurement’s method is more simple than absolute measurement’s method, less investment in equipment . Be used for luminous flux’s relative measurement of integrating sphere is a complete hollow spherical shell, The sphere’s in wall evenly sprayed white diffuse layer,Open a window […]
The LED total luminous flux measurement
As a new light source, LED compared with the traditional light source is very different in their structure and luminescence properties. Due to the LED itself since the absorption effect and integrating sphere inside block screen bring out measuring error, continue to use the traditional integrating sphere for measuring leds luminous flux error is bigger. By […]
Select the LED light source from nine aspects
With the development of the market, as a consumer, choose LED is still should to be calm, scientific analysis, choose the best cost-effective light source and lamps and lanterns, the following introduce the basic performance of several kinds of LED: 1、Luminance：the Luminance of LED is different, the price is different.Used for LED lamps and lanterns, […]
LM – 80 luminous flux to maintain life prediction
LED as a new type of light source get rapid development in recent years, according to the national bureau of statistics data, the number of street lights around the country about 90 million lamps.If calculated on every street lamp 5000 yuan, the market scale will be close to 500 billion.Although LED lighting with energy saving, environmental […]
Input/Outpur protection against abnormal load
LED is drove by the constant current, the forward voltage range is from 2 to 4.5V, which is related to the color and current. The old design relies on a simple resistor to limit the LED drive current, but the typical forward voltage drop of LED circuit design that is based on the manufacturer rules […]
How to control the heat of LED
If you only use a simple bias resistance control drive current, VF will decrease with the temperature increasing, the drive current will increase. Especially for the high power LED, it will cause the thermal breakdown and the component failure. The common practice is to accelerate the thermal conductivity by installing the LED in the metal […]
The optical proper of LED has obvious difference in different temperature.
The optical proper of LED has obvious difference in different temperature. The luminous quantity (Luminous Intensity) of LED can reduce with the junction temperature increasing, for some technology, the emission wavelength will also change with the temperature. If we don’t control the drive current and junction temperature, the efficiency of LED will decrease rapidly, which […]
LED lighting source needs accurate power and thermal management system
LED lighting source needs accurate power and thermal management system, because compared with other light sources, the electric energy that provided to the LED mostly transfers to heat. If there is no proper heat management, the heat can influence the LED life and color output. At the same time, because the LED drive device belongs […]
Thermal management decides the LED life
Using a 60 Watt incandescent lamp products about 900 lumen brightness(Brightness Meter), and it must dissipate 3 Watt heat via conduction. Using the typical DC LED as light source to reach the same 900 lumen brightness needs 12 LEDs. Suppose that the forward voltage (VF) is 3.2 voltage, current is 350mA, the input power of […]
Overheat and improper use both can greatly reduce the performance of LED light source.
Light emitting diode (LED) technology has made a rapid progress, and the improvement of chip design and materials promote the development of lighter and more durable light source, and make the application of light source become larger. But the manufacture of LED lighting must still continue to overcome the problem of the strong thermal sensitivity of […]
