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How much heat can LED headlamp produce

popularity:Time of publication:2020-05-16
Generally, the generation of light energy will be accompanied by the generation of heat, and the bulb will generate heat in the process of light-emitting. The LED bulb in the process of light-emitting is the conversion of electrical energy into light energy. In this conversion process, it is impossible to convert all electrical energy into light energy. According to the law of energy conservation, the remaining part of electrical energy will be converted into heat energy. How much heat is produced? It depends on the luminous efficiency of semiconductor LED. If the luminous efficiency of the LED reaches 40% or 50%, the remaining 60% or 50% of the electric energy will be converted into heat energy in other forms. Under the working of P-N structure, electric energy is transformed into light energy which can be seen by our naked eyes through various media. Therefore, the luminous efficiency of LED should consider the input rate of current in LED circuit, luminous efficiency of LED chip, light transfer rate outside the chip and other factors.
With the use of LED bulb, the stability of LED chip will increase, and the temperature rise will further reduce the luminous efficiency, resulting in more heat generation, so that the product has a vicious cycle, resulting in more problems. But how much heat can led bulbs generate?
In the process of LED light-emitting, there is a physical knowledge explanation. In the p-n structure of LED, under the action of electric field, many free electrons obtain electric energy, and jump from the N region to the p region, and compound in the p region. When compound, the free electrons release redundant energy, which is released in the form of photons. The energy difference in the middle will be converted into heat energy.
In the process of electrons entering from one n region to another p region, they will encounter resistance, work and consume part of electric energy, which will eventually be converted into light energy. According to the explanation of physics, the recombination of electron hole pairs in ordinary diodes is due to the factor of energy level difference eg, and the photon spectrum released is not in the range of visible light.
Part of the electric energy consumed conforms to the basic laws of Electronics:
Power: P = I2R = I2 (RN + + RP) + ivth
Where: RN is the n-area body resistance, RP is the p-area body resistance.
The heat generated by the consumed power is:
Q = Pt
Where: t is the time when the diode is energized.
In essence, LED is still a semiconductor diode. Therefore, when the LED is working in the forward direction, its working process conforms to the above description. The electric power it consumes is:
In the above formula: u LED is the forward voltage at both ends of LED light source
I led is the current flowing through the LED.
These consumed electric power is converted into heat emission:
Q=P LED &TImes; t
Where: t is the power on time
But in fact, when electrons transition from n-zone to P-zone and compound in P-zone, they do not directly convert the external electric energy, but the original electronic energy in n-zone is higher than that in P-zone. Only under the action of the external power plant, the electrons in n-zone move to P-zone directionally, and the energy difference between electrons in n-zone and P-zone itself is not provided by the external power plant. This energy difference depends on the material book of LED Body. So to a certain extent, the basic reason for the generation of LED thermal energy is that the LED luminous efficiency is not high, so that electric energy can not be efficiently converted into light energy, which will lead to the release of excess energy in the form of thermal energy. So at this stage, we need to fundamentally improve the luminous efficiency of LED, for example, by improving the packaging technology of LED chip, the reasonable use of LED resistance, the efficient use of LED driver, etc., to reduce the generation of heat.