Since the frequent change of laptop, and LCD’s fast development inch by inch, the power adapter of laptop is move on stage by stage, even reaching more than 100W or so, almost equals a small desktop computer power supply! Like these laptop AC adapters, it’s common ones that the watt is from 60 to 100 W.While putting your hand on it, you may be worried that will it not fire? Compaq, IBM, such big companies have brought back their power adapter due to it may have the power design flaws, and lead to fire!
In fact, as long as the temperature of power adapter is not higher than the designed temperature, in another word, the temperature belongs to the normal range; the power adapter generally is safe! As these laptop AC adapters, it has the same problem. So, why are the power heated? What temperature range is in the normal scope? Switching power conversion efficiency can only reach about 75% -90% at present. The answer is here. Switching power efficiency is high enough, and it is still difficult to find a better conversion, Some energy lost during voltage conversion, which in addition to a small part of the loss is in the form of waves, the majority are distributed by way of heat. Higher of power, more loss of energy also more amount of heat being distributed. That is why some desktop power supply to add a fan for cooling reasons.
Therefore, while designing and producing Laptop Power adapter, It is very important to select the components that can withstand high temperature. Of course, the temperature must be controlled in the range that application environment permits. First, the conversion efficiency should be designed to be as high as possible, and secondly, components and parts of low pressure and low loss should be adopted. The third is design good heat output system. Heat exchanging area should be as large as possible. For example, generally more than 100W should have metal perforated casing, or be with cooling fan.