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LEDs are optoelectronic devices that make pn junctions from compound materials. It has the electrical properties of a pn junction device: IV, CV, and optical: spectral response, luminescence, directional, time, and thermal properties. Now many companies are saying that their LED lamps can last more than 5W hours. Is this really the case? The life of the LED itself can reach 3W-5W hours, but the life of the LED will be very different.
In the middle-class LED lamps, he uses a better power supply, and the average service life of the lamps is 3-4 years (8-15 per day) without damaging the lights (without turning off the lights for 24 hours). Hours), but this requires you to use LEDs and power requirements that are very high. Like the ones that are said to be cheaper now, and how many hours of life, there are many LED lamps that are deceptive. Anyone who can do this can do it. It’s no problem to use cheaper ones and then repair it. What are you afraid of? So choosing LED lamps can't just look at the price.
In terms of certification, LED certification is now mostly done in domestic laboratories. No matter what kind of LED lamps are made, you can make the corresponding expenses for the lab, so you can't believe what kind of company we are talking about. There are certifications, and then the life is good, the price is cheaper than other lamps (such as ceramic lamps, crystal lamps, etc.). The cost of LED is transparent. If you change the size of the chip, it seems to reduce the cost. In fact, you are cheating on consumers and deceiving.
In order to avoid the deception of the majority of consumers, the following describes the method of measuring the life of LED lamps: the time t that is usually used to reduce the brightness to Bt=1/2BO is called the life of the diode. It takes a long time to measure t, and the life is usually calculated by calculation. Measurement method: Give the LED a certain constant current source, after igniting for 103~104 hours, measure BO, Bt=1000~10000, substitute Bt=BOe-t/; then substitute Bt=1/2BO. Find the life t. LED lifetime has long been considered to be 106 hours, which means that a single LED is at IF = 20 mA. With the development and application of power LEDs, foreign scholars believe that the percentage of light attenuation of LEDs is the basis of life. For example, the light attenuation of the LED is 35, and the lifetime is >6000h.
LED lighting life problem "hidden rules"