What are the advantages and disadvantages of LED spotlights and traditional spotlights?

one，The structure and light-emitting principle of LED

The basics of how semiconductor materials can produce light have been understood 50 years ago, with the first commercial diodes produced in 1960. LED is the abbreviation of English light emitting diode (light emitting diode). Its basic structure is a piece of electroluminescent semiconductor material, which is placed on a lead frame, and then sealed with epoxy resin around it to protect the inner core wire. Therefore, the anti-seismic performance of LED is good.

The core part of the light-emitting diode is a wafer composed of p-type semiconductors and n-type semiconductors, and there is a transition layer between the p-type semiconductors and the n-type semiconductors, called p-n junction. In the PN junction of some semiconductor materials, when the injected minority carriers recombine with the majority carriers, the excess energy is released in the form of light, thereby directly converting electrical energy into light energy. When a reverse voltage is applied to the PN junction, it is difficult for minority carriers to inject, so it does not emit light. This kind of diode made by the principle of injection electroluminescence is called light-emitting diode, commonly known as LED. When it is in a forward working state (that is, a forward voltage is applied to both ends), when the current flows from the LED anode to the cathode, the semiconductor crystal emits light of different colors from ultraviolet to infrared, and the intensity of the light is related to the current.

Second, the characteristics of LED light source

1. Voltage: LEDs use low voltage power supply, the power supply voltage is between 6-24V, which varies according to the product, so it is a better choice than using high voltage power supply

Safer power supply, especially suitable for public places.

2. Efficiency: consumes 80% less energy than incandescent lamps with the same luminous efficiency

3. Applicability: very small, each unit LED chip is 3-5mm square, so it can be prepared into various shapes of devices, and is suitable for easy

changing environment

4. Stability: 100,000 hours, the light decay is 50% of the initial

5. Response time: the response time of incandescent lamps is milliseconds, and the response time of LED lamps is nanoseconds

6. Environmental pollution: no harmful metal mercury

7. Color: Changing the current can change color, light-emitting diodes can easily adjust the energy band structure and band gap of the material through chemical modification methods to achieve red and yellow

Green blue orange multi-color glow. For example, the LED that is red when the current is small can turn orange, yellow, and finally green as the current increases.

8. Price: The price of LEDs is relatively expensive. Compared with incandescent lamps, the price of several LEDs can be equivalent to the price of one incandescent lamp.

Usually each group of signal lights needs to be composed of 300 to 500 diodes.