LED Application Range

1. AC power indicator

As long as the circuit is connected to a 220V/50Hz AC power supply line, the LED will be lit to indicate that the power is on. The resistance value of the current-limiting resistor R is 220V/IF.

2. AC switch indicator

LED is used as the circuit of the incandescent lamp switch indicator. When the switch disconnects the bulb and goes out, the current forms a loop through R, LED and bulb EL, and the LED is on, which is convenient for people to find the switch in the dark. At this time, the current in the loop is very small, and the bulb will not light up. When the switch is turned on, the bulb is lit, and the LED is off.

3. AC power socket indicator

Use two-color (common cathode) LED as the circuit of the AC power socket indicator. The power supply of the socket is controlled by the switch S. When the red LED is on, the socket has no electricity; when the green LED is on, the socket has electricity.

4. Fuse holder indicator

The LED is used as the circuit for the indicator light of the fuse holder of the factory equipment distribution box. When the fuse is intact, the LED will not light up; when the fuse is blown, the LED will be lit to indicate the user which fuse has been blown for replacement. This is very convenient for porcelain core fuse which cannot be observed with the naked eye.

5. LED monochrome or color display

Generally, monochrome display screens are used to display single-line Chinese characters, and color display screens are used for outdoor large-screen TVs.

Reference source: Baidu Encyclopedia-LED

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In view of the advantages of LED, it is currently mainly used in the following aspects:

(1) Application of display screen and traffic signal display light source. LED lights have the characteristics of shock resistance, shock resistance, fast light response, power saving and long life. They are widely used in various indoor and outdoor display screens, and are divided into full-color and three-color And monochrome display screens, more than 100 units are developing and producing across the country. Traffic signal lights mainly use ultra-high brightness red, green, and yellow LEDs. Because the use of LED signal lights is energy-saving and reliable, traffic signal lights are gradually being updated across the country, and the promotion speed is fast, and the market demand is large. Is a good market opportunity;

(2) Applications in the automotive industry Automotive lights include the dashboard, audio indicator lights, switch backlights, reading lights and external brake lights, tail lights, side lights, and headlights. Incandescent lamps for automobiles are not resistant to vibration and impact, are easily damaged, and have a short life span. They need to be replaced frequently. In 1987, China began to install high-position brake lights on automobiles. Due to the fast response speed of LED, it can remind the driver to brake as soon as possible to reduce rear-end collisions. In developed countries, the central rear high-position brake light made of LED has become a standard part of the car. The LED car tail light model launched by HP in the United States in 1996 The group can be combined into various car tail lights at will. In addition, the light source of the car dashboard and other various lighting parts can be used as ultra-high-brightness luminous lamps, so LED displays are gradually being adopted. China's automobile industry is in a period of great development, and it is an excellent time to promote ultra-high-brightness LEDs. In recent years, an annual output value of 1 billion yuan will be formed, and an annual output value of 3 billion yuan within five years.

(3) LED backlights are most eye-catching with high-efficiency side-emitting backlights. As LCD backlight applications, LEDs have the characteristics of long life, high luminous efficiency, non-interference and high cost performance. They have been widely used in electronic watches, mobile phones, BP On computers, electronic calculators and credit card machines, as portable electronic products become smaller and smaller, LED backlights have more advantages. Therefore, backlight manufacturing technology will develop towards thinner, low power consumption and uniformity. LED is a key component of mobile phones. An ordinary mobile phone or PHS needs about 10 LED devices, while a color screen and a mobile phone with camera function need about 20 LED devices. At this stage, the backlight consumption of mobile phones is very large, and 3.5 billion LED chips are used a year. At present, the production volume of mobile phones in China is very large, and most of the LED backlights are imported. For domestic LED products, this is an excellent market opportunity.

(4) The early products of the LED lighting source had low luminous efficiency, and the light intensity generally only reached a few to dozens of mcds. It is suitable for indoor applications, such as household appliances, instrumentation, communication equipment, microcomputers and toys. At present, the direct goal is to replace incandescent lamps and fluorescent lamps with LED light sources. This replacement trend has begun to develop from local application areas. In order to save energy, Japan is planning to replace the incandescent light-emitting diode project (called "Illuminate Japan"). The budget for the first five years is 5 billion yen. If LED replaces half of the incandescent and fluorescent lamps, the annual savings can be equivalent to The energy of 6 billion liters of crude oil is equivalent to the power generation of five 1.35×106kW nuclear power plants, and can reduce the production of carbon dioxide and other greenhouse gases, and improve the living environment of people. China also invested 5 billion in 2004 to vigorously develop energy-saving and environmentally friendly semiconductor lighting projects [4].