LEDs are long-lasting because they don't cause filament […]
LEDs are long-lasting because they don't cause filaments to blow. The LED does not stop working directly, but it gradually degrades over time. Generally, LEDs can be used for more than 50,000 hours, and their luminous intensity will gradually drop from the nominal value to about 70%. The main reasons for the LED life are the following three components: light source, power supply and housing.
LED chip quality is an important reason for life, and the design and materials of the chip can affect the life of the LED. LED packaging technology is also an important reason for the LED life, a reliable packaging manufacturer has a great relationship to LED life.
2. Power supply design
Because the discreteness of the LED is extremely strong, the voltage drop, the wavelength, the color of the light, and the height are very different. Only the LEDs with the above-mentioned several indicators can be used in parallel, and the current with the reduced voltage is large, and the current with a high voltage drop is small. The color and height are uneven, and the life of the current is shortened. The life of the power supply itself is also an important reason. Generally, the electrolytic capacitor has an 8000-hour life at 105 °C, 15,000 hours at 40-60 °C, and 30,000 hours without electrolytic capacitors.
3. Design of heat dissipation
Heat dissipation is one of the important reasons that affect the life of LEDs. LEDs need to be driven by current. Only about 15% of the input LED energy is converted into light, and most (about 85%) are converted into heat due to inefficiency. The ambient temperature is very important, and the ambient temperature can affect the temperature of the LED lamp from 5 to 20 degrees.
First, heat dissipation
The heat accumulation of LED luminaires not only affects the electrical performance of the LEDs, but may also ultimately lead to LED failure. Therefore, in order to ensure the life of the LED lamp, heat dissipation becomes a key technology for white LED applications, and reducing or rapidly dissipating the heat generated by the LED becomes the primary problem in the application design of the white LED.
Second, the light source material
LED is a point light source. If poor LED is used, the LED will release a lot of heat during the working process, which will make the junction temperature rise rapidly. The higher the LED power, the greater the heating effect. The LED chip temperature will rise. The change in the performance of the light-emitting device and the electro-optical conversion efficiency are attenuated, and even in severe cases.
Third, the drive power
The quality of LED power supply directly restricts the reliability of LED products. Therefore, the requirements of efficiency conversion, effective power, constant current accuracy, power supply life and electromagnetic compatibility of LED driver power supply are very high for foreign customers in the international market, because the power supply is throughout The role of a luminaire is just as important as a human heart.
Fourth, the drive current
The greater the current flowing through the LED in the range of its current limit parameter, the higher the brightness of the LED. The brightness of the LED is proportional to its operating current. However, if the current flowing through the LED exceeds the limit parameter range, the LED Saturation occurs, which not only greatly reduces the luminous efficiency, but also shortens the service life.
Fifth, light distribution processing
LED is a directional point source. How to creatively apply this feature of LED to create a comfortable light environment is the core of LED light optical design technology. The LED light source itself generally has a lens or a transmissive material for improving the light exiting efficiency, and at the same time satisfies the light distribution of about 120 degrees of light emission, which is generally called a primary optical design. However, in order to meet the various needs of indoor lighting, it is necessary to redistribute the light according to the needs, and in what way, the light emitted by the LED is secondarily distributed to achieve a comfortable light environment, which also affects the LED product.
An important factor in quality.