About bright flashlight and ordinary LED flashlight choice
To take into account the high brightness and life time, can choose the shift (brightness high, medium and low grades) of high power LED flashlight, need light show high-grade, need to open power to resist, even brightness low gear, than 9LED flashlight light, and the life time of up to 50 hours to.
Light and electricity are contradictory, the higher the brightness, the LED drive current is larger, the costs of electricity, to make a compromise in brightness and life time, should be used in high power LED high luminous efficiency and make it work in the high efficiency region;
The luminous efficiency of high power LED than small power high, under the same current, high power LED light, such as the common CREE R5 (3W) can produce 120lm illumination in the 350mA state, more than 20 5mm LED (parallel, each average current is about 17mA) bright;
