LED flashlight is a LED (light-emitting diode) as a light source of a new flashlight. Because LED has high brightness, low power consumption, long life, small size and other characteristics, it is ideal for portable lighting. Luminous principle
Atomic electrons have a lot of energy levels, and when electrons transitions from high energy levels to low energy levels, the energy of electrons is reduced, and the reduced energy is converted into photon emission. A lot of these photons are laser.
LED light principle is similar. But the difference is that the LED does not emit light through the electronic transitions inside the atom, but by adding a voltage across the PN junction of the LED so that the PN junction itself forms an energy level (in fact, a series of Level), and then electrons jump on this level and produce photons to glow.
The new LED display parts have the advantages of low power consumption, high brightness, long life and small size. This paper starts with the development of LED display parts, discusses the LED, LED and LED for automotive applications. Development trend, for the development of display devices in Chinese engineers have a certain reference value. The world's first commercial light-emitting diode (LED) was made in 1965 with germanium material, the unit price of 45 dollars.
In 1968, LED research and development has made a breakthrough, the use of nitrogen doping process to GaAsP device efficiency to 1 lumens / watt, and can send red, orange and yellow light. To 1971, the industry has introduced the same efficiency GaP green die LED. In 1972 began a small number of LED display for watches and calculators. The world's first LED watch was originally sold in expensive jewelry stores, the price was as high as 2,100 US dollars. Almost at the same time, HP and Texas Instruments also introduced a 7-segment red LED display of the calculator. To the 20th century, 70 years, due to LED devices in the home and office equipment in a large number of applications, LED prices plummeted. In fact, LED is the era of flagship and text display technology. However, in many commercial devices, LED display has also been subject to fierce competition from other display technologies, such as LCD, plasma and vacuum fluorescent tube display.
This competitive incentive LED manufacturers to further expand their product types, and actively seek LED has a clear competitive advantage in the application areas. Since then the LED has been used in the dot matrix display, the background pattern with the light grid and bar graph array. The size and complexity of the digital display is growing from 2 digits to 3 digits or even 4 bits, from 7 digits to a 14- or 16-segment array capable of displaying complex text and pattern combinations. By 1980 the manufacturer began to provide intelligent dot matrix LED display. This technological advancement enables the LED to be used in outdoor sports information releases as well as automotive central high stop stop lighting (CHMSL) equipment. The invention of the bright blue LED makes it possible to realize the true color display display, which can display true color, full motion video images.
The presence of blue LEDs enables people to partially convert high-energy blue light into other colors using retroreflective phosphorescent materials. Only the LED light source can completely cover all the saturation colors in the CIE chromaticity curve, and the organic integration of the various colors of LEDs with phosphorus can produce almost unlimited
What color? In terms of reliability, the half-life of the LED (ie, the amount of light output to the original half of the time) is about 10,000 to 100,000 hours. In contrast, the half-life of a small indicator incandescent lamp (here half-life refers to the time that half of the lamp's failure time) is typically 100,000 to several thousand hours, depending on the rated operating current of the lamp.
How to buy high power LED flashlight
Take a look at the bulb
1, the number of head, the number should be moderate. The general use of the household should not be more than 12, the use of the battery in 2 to 3 as well, and then a little waste, for other special needs can be determined according to their needs. Of course, high-power Hight Power LED flashlight generally can not reach the number of 12.
2, see the brightness, good LED flashlight high brightness, slow decay.
3, look at the bulb, in the case of extinguished, the naked eye is difficult to distinguish it from good or bad, you can see the light bulb in the case of consistency.
4, look at the aperture, good LED flashlight aperture for a uniform circle, poor LED flashlight spot is divided into yellow and blue uneven distribution. Earthen polished surface as much as possible. This flashlight does not like the ordinary flashlight can adjust the focal length, the purchase should be careful not to astigmatism.
Two internal structures
1, see welding, welding to prison. Each diode is connected by welding on the circuit board, if there is poor contact with the Weld, it may cause the ball does not shine or affect the overall use.
2, see the battery, there are two kinds of ordinary batteries and lithium, although the lithium battery is rechargeable, but low life, about 2 years, LED life of about 10 years, according to the actual situation to choose.
Three external structures
1, see waterproof, good LED flashlight with waterproof function, good seismic performance, that is resistant to fall. Because it belongs to the electronic products, flashlight in front of a circuit board, once the water prone to short circuit, causing damage.
2, look at the appearance, you can choose aluminum alloy shell, nice.
3, look at the shape, according to the specific use of occasions and use, you can choose the appropriate size of the size of the flashlight.