The physical characteristics of light emitting diode:

The longer the two leads led one of the anode cathode connected power supply for. Two leads some of the light emitting diode as long, but there is a convex uvular shell and tube, wire near the uvula is positive.

Light emitting diode with small compared to incandescent light bulbs and neon, characteristics of light emitting diode is: working voltage is very low (some only a few volts); the working current is very small (a few tenths of Ma some only can be light); and the good performance of the seismic resistant, impact resistance and high reliability, long service life; current intensity modulation can be conveniently through through modulation of light intensity. Because of these characteristics, the light emitting diode is used as a light source in a number of photoelectric control device, used as a signal display device in many electronic equipments. The tube core which made of strips, with a luminous tube composed of 7 segment semiconductor digital tube 7 strip, each digital tube can display 0 ~ 9 ten number.