ljusskyltar ledresearch

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One problem for these LEDs could be the temperature and all specifications are usually guaranteed at 25 degrees centigrade. Of course the operation/storage temperature could usually vary from -40 to +85 degrees centigrade but temperatures close to these limits are not well-advised. There is usually a chart that shows how the temperature of the LED is changed in time and the critical temperature which could destroy the LED and of course the time (usually in seconds) which the LED could endure the temperature before it is permanently damaged.

The thermal problems of the high-power ljusskyltar ledresearch are maybe the most important aspect of their technology and this is why we will discuss them on a large scale.

Unlike other light sources like the incandescent tungsten light bulbs, high-power LEDs do not radiate heat. Instead of that, they conduct heat to their thermal slug. That means that heat goes a longer way to reach the atmosphere.

In the tungsten bulb the heat trajectory is short. It starts with the thermal resistance from the filament to the glass and it ends with the resistance from the glass to the atmosphere. In high-power LEDs it is not that short because of other parts that stand on the way like the slug, the board and the heat sink. However it is very crucial for us to understand the difference of the heat delivering - in high-power ljusskyltar ledresearch we talk about conduction, not radiation.

The temperature of the LED is directly linked to its colour and if a precise colour is needed the optical design should be optimized. Different colours are made by combining base colours and for white colour - all colours are used. That means that if a white colour is used, the temperature will be higher than the temperature in all other cases. Usually a colour sensor is used to insure the proper colour during the temperature changes and the aging of the LED.

Almost every aspect of the high-power LEDs is linked to the junction temperature of the LED. These aspects are the dominant wavelength, luminosity and the forward voltage and they are the most important criteria of the high-power LED.

One significant thermal problem with high-power ljusskyltar ledresearch is called "thermal runaway". It happens because when the colour sensor reports that the luminous intensity is not high enough the processor drives the LED harder and by doing this it uses more power and when more power is used more heat is generated. More heat means higher junction temperature and higher junction temperature again decrease the luminous intensity. And again the colour sensor reports low light emission and the process circles all over again until the temperature of the LED reaches critical state and the LED overheats and permanently fails.