First, LED introduction
LED structure and principle of illumination
LED (Light Emitting Diode), a solid-state semiconductor device that directly converts electricity into light. The heart of the LED is a semiconductor wafer, LED
One end of the wafer is attached to a bracket, one end is a negative pole, and the other end is connected to the positive pole of the power source, so that the entire wafer is encapsulated by epoxy resin. The semiconductor wafer consists of two parts, one part is a P-type semiconductor, in which the hole dominates, and the other end is an N-type semiconductor, which is mainly electrons here. But when the two semiconductors are connected, they form a P-N junction. When a current is applied to the wafer through the wire, the electrons are pushed to the P region. In the P region, the electrons recombine with the holes, and then the energy is emitted in the form of photons. This is the principle of LED illumination.
Second, the characteristics of LED light source
1. Voltage: LED uses low voltage power supply, the power supply voltage is between 6-24V, depending on the product, so it is a higher than the use of high voltage LED light source
A safer power supply for power supplies, especially for public spaces. 2. Efficacy: 80% less energy consumption than incandescent lamps with the same effect. 3. Applicability: Very small, each unit LED is 3-5mm square, so it can be made into various shapes and suitable for easy Changing environment 4. Stability: 100,000 hours, the light decay is the initial 50% 5. Response time: the response time of the incandescent lamp is millisecond, and the response time of the LED light is nanosecond. 6. Environmental pollution: none Harmful metal mercury 7. Color: Change the current to change color. The light-emitting diode can easily adjust the energy band structure and band gap of the material through chemical modification to realize multi-color luminescence of red, yellow, green and blue. For example, a red LED with a small current can turn orange, yellow, and finally green as the current increases. Price: The price of the LED is not expensive. 9. Drive: LED can be driven by low-voltage DC. Small, weak interference, low requirements on the use environment 10. High color rendering: LED color rendering is high, will not cause damage to human eyes
