Why does the LED lamp with a few watts of power have a very high temperature in the housing? This is because the efficiency of converting electrical energy into light energy is not high, and a large part of electrical energy is converted into heat energy. The efficiency of converting the electrical energy consumed by LEDs into light energy is only about 40%, and most of the rest are converted into thermal energy, so the temperature of the seemingly low-power LED lamp housing is very high.
LEDs are also called light-emitting diodes. They are a type of diode and are also made of a PN structure. They are composed of III-IV gallium arsenide (GaAs), gallium phosphide (GaP), and gallium phosphide (GaAsP) compounds. Manufactured, the principle of light emission conforms to the characteristics of PN junction, reverse cutoff, forward conduction, overvoltage breakdown, etc. When the PN junction is applied with a forward voltage, electrons move from the N region to the P region, and the holes are When the P region is injected into the N region, a large amount of energy is released when electrons and holes recombine. Most of the energy is converted into heat energy, and a small part is released in the form of photons. This is the principle of LED light emission.
Because the conversion rate of LED light energy is not high, a large part of the energy is consumed in the form of heat energy, so when designing high-power lighting LED lamps, heat dissipation is the focus of design! Poor heat dissipation. The heat of the LED cannot spread quickly, resulting in LED burnout, short life, and poor optical performance. The following picture is a high-power LED lamp design. It can be seen from the picture that the high-power LED lamp beads are directly welded on the aluminum substrate, and a high-power fan heater is closely attached to the back of the aluminum substrate to fully radiate excess heat. .
Summary: The conversion efficiency of LED electric energy into light energy is low, only about 40%, and the rest of the energy is converted into heat energy. Therefore, the LED lamp with a power of only a few watts, but its housing temperature is very high, which is quite normal.