LED flashlight is LED (light emitting diode) light source, a new type of flashlight. Because the LED has high brightness, low power consumption, long life, small size and other characteristics, so is carry-on lighting ideal choice.
There are a lot of energy levels of electrons in an atom, when electrons from high level to low level transition, electron energy is reduced, and reduce the energy into a photon emission. A lot of these photons is the laser.
LED similar principle. But the difference is that the LED is not by the electrons within the atoms jump to glow, but by the voltage on the LED on both ends of the PN junction, the PN junction itself form a level (in fact, is a series of energy levels), and then the electrons jump on this level and photon to glow.
New LED display units are low power consumption, high brightness, long life, the advantages of small size, this article from the beginning of the LED display a brief history of the development of, surface-mount LED, automobile application is discussed and the development trend of LED lighting, LED to the Chinese engineers engaged in the development of display device has a certain reference value. Global the first commercial light emitting diode (LED) is made with germanium materials in 1965, its unit price is $45.
In 1968, the LED research and development has made breakthrough progress, using nitrogen doping process to make GaAsP device efficiency reached 1 lumens/watt, and can emit red light, orange light and yellow light. To 1971, the industry and introduced with the same efficiency GaP green bare chip LED. Beginning in 1972 with a small amount of LED display for clock and calculator. The world's first using LED watch was initially sold in expensive jewelry store, it will cost up to $2100. Almost at the same time, HP and Texas instruments have also launched calculator with seven red LED display. In the 1970 s, due to the LED devices in the home and office equipment in a large number of applications, LED prices plummeting. In fact, the LED is the era's main text display and digital technology. However, in many commercial equipment, LED display also gradually by the fierce competition from other display technologies, such as LCD, plasma and vacuum fluorescent display.
Such competitive incentive LED manufacturers to further expand their product type, and actively seek the LED application field has obvious competitive advantage. After that the LED has applied to text dot matrix display, background light grid and the map array. Digital display the size and complexity of the growing, from 2 digits to three or even four, from section 7 of figures to display complex words and design combination of 14 or 16 segment array. To provide intelligent lattice LED display manufacturers started in 1980. The advances in technology have made the LED can be used in outdoor sports information release and car central high stop lights (CHMSL) equipment installation. Highlight blue LED to the invention of the realization of image advertising display screen, the screen can display image, full-motion video image.
The emergence of blue leds can make people use backward transformation of phosphorescent materials from high-energy blu-ray partially converted into other colors. Only use LED light source can be completely cover all saturated color of CIE chromaticity curve, and all sorts of color of LED and the organic integration of phosphorus almost able to produce without limit
What color. In terms of reliability, the half-life of the LED (that is, the light output was reduced to half the time of the initial value) is about 10000 to 10000 hours. Instead, small type indicating the half-life of incandescent lamp (half the half-life of here refers to the number of lamp failure time) typical values is 100000 to thousands of hours, depending on the light of the rated current.
Techniques of choose and buy
How to choose and buy high power LED flashlight (for reference only) :
A look at the light bulb
1, look at Numbers, Numbers to moderate. Household generally not more than 12 head, the battery used in 2 ~ 3 day as well, a bit wasteful to again big, used for other special needs according to the need to make sure. Of course, high-power Hight Power LED flashlight generally cannot reach the number of 12.
2, see the brightness, good high brightness LED flashlight, slow attenuation.
3, the light bulb, in the case of extinguishing, is difficult to distinguish the stand or fall of it, to the naked eye can see in under the condition of light bulbs consistency.
4, see the light, the good LED flashlight aperture for a circle evenly and LED flashlight with poor light spot divided into two colors, yellow and blue is not evenly distributed. Buld condenser surface concentration as far as possible. This flashlight is not like a normal flashlight can adjust the focal length, do not have astigmatism phenomenon should be paid attention to when the choose and buy.
The internal structure
1, the welding, welding to prison. Each diode is through welded connection on the circuit board, if there is a virtual welding contact is bad, it is possible to buld not bright or impact to use as a whole.
2, watch batteries, lithium batteries and electric machine has two, although li-ion battery is rechargeable batteries, but life is low, about two years, LED the life of about 10 years, can choose according to actual situation.
Three external structure
1, waterproof, good LED flashlight have waterproof function, the seismic performance is good, the resistance to fall off. Because it belongs to the electronic products, flashlight at the front there is a circuit board, once the water prone to short circuit, damage.
2, see the appearance, can choose aluminum alloy shell, elegant appearance.
3, see figure, according to specific occasions and purposes, can choose the size of the corresponding flashlight of the appearance of moderate size.