LED flashlight is a new type of illumination instrument that uses light emitting diode as light sources, with merits of power-saving, long lifespan and high brightness. Immediately after White LED was invented, LED flashlight came into the market. Initially, WLED was only applied on part of military materials, daily uses of it were not widespread as it is expensive and with low brightness. Along with the improvement of its brightness and the lowering of its cost, WLED becomes more and more popular. At present, hight power LED flashlight has occupied a large market share in the European and American markets. With LED flashlight gaining more ground on the market, the potential of replacing traditional flashlight is quite large.

For example: Challenger—Polar Light Hight Power LED flashlight is used exclusively in field practice. It bears the following advantages:

1.    It adopts a-class 1W LED from Taiwan as light source with high brightness of 40~50 lumens.

2.    Constant current circuit design.

3.    Power-saving, low consumption and long life-span (100,000 hours). A set of batteries can be used for 6~8 hours.

4.    The shell is made of Al-Mg alloy that is anodized, bearing characteristics of anticorrosive, wearable, aseismatic and waterproof, applicable to all kinds of bad environments in field.

5.    The lamp holder adopts light-concentration design, enabling the light to reach as far as 50~100 meters. Meanwhile, the light distance can be adjusted manually to achieve best light-concentration effect.

Attentions should be paid to the following items when choosing a good LED flashlight (for reference only):

1. Lamp holder amount: The amount of lamp holders should be moderate. If used in family, the number had better be less than 12, using 2~3 batteries are better. But generally, hight power LED flashlight uses less than 12 lamp holders, except for special uses.

2. The weld: The weld should be firm enough. As every diode is connected to the circuit board through welding, if the weld is not firm enough, the lamp may not shine or the use of the overall flashlight may be influenced.

3. Batteries: There are two kinds of batteries for choice—ordinary batteries and Lithium batteries. Choice can be made according to the actual situation. Although Li batteries can be charged and used repeatedly, the life span is short, only for two years, much shorter than LEDs’ lifespan of 10 years or so.

4. Brightness: The brightness of LED flashlight is high, and the light wanes slowly.

5. Bulbs: To observe the consistency of the bulbs when the lamp is light because when the light went out, it is difficult to make sure whether the bulb is good or bad.

6. Waterproof and aseismatic performance: High quality LED flashlight should be waterproof and aseismatic. In the foreside of the flashlight, there is a circuit board. Once water comes into the flashlight, it is easily to get short circuit.

7. Aperture: The aperture of a good LED flashlight is a symmetrical circle, while bad ones have asymmetrical yellow and blue light spots. The light-concentrating side had better be centralized. Unlike ordinary flashlight, the focus of the LED flashlight can not be adjusted, so a flashlight with astigmatism should not be chose.

8. Appearance: Better to choose Al alloy shell as it looks good.