1, light emitting diode
LED (Light Emitting Diode):
LED is a photoelectric element made of semiconductor material, element has two pin, a voltage is applied between the pin, via a tiny current can be lighting.
Namely: light emitting principle of LED is a voltage applied to the AlGaAs (AlGaAs), AlGaInP (AlInGaP) and GaInN (indium gallium nitride compound semiconductor) and so on,
Through the recombination of electrons and holes to release excess energy and luminescence, luminescence phenomena is not heating luminescence, belongs to cold light.The changes of LED by 3-5 compound semiconductor materials and device structures, and design of solid state power output in different colours, due to different materials release out of the wavelength is different, including red, orange, blue, green, yellow light, and infrared and other invisible light LED, variety.
2, The infrared light emitting diode Brief
forward bias injection current to the excitation of infrared light. Spectral power distribution of the center wavelength of 830 ~ 950nm,Infrared radiation from the high efficiency of material (often made of PN junction GaAs)， the infrared light is excitation when forward bias injection current to the PN junction. The spectral power distribution of the 830 ~ 950nm central wavelength, half peak bandwidth of about 40nm or so, it is a narrowband distributed, feel the range of the ordinary CCD camera. Its biggest advantage is completely without red storm, (with 940 ~ 950nm wavelength infrared LED) or only faint red storm (red storm for visible light) and long life.Light is an electromagnetic wave, its wavelength range from several nanometers (1nm=10-9m) to 1 mm (about mm). Visible only a part of them, which we call visible light, visible light wavelength range is 380nm ~ 780nm, visible base on long to short wavelength is divided into red, orange, yellow, green, cyan, blue, purple, violet wavelength than known as the short wavelength ultraviolet light, longer than infrared light is called infrared light.
3, Recognition of infrared emitting diode
Infrared light emitting diode, similar shape to ordinary light-emitting diode, photodiode and photoelectric triode, extremely easy to cause confusion, should pay attention to distinguish. Infrared light emitting diode is used mostly colorless transparent resin package, light blue or black resin package in three forms, a colorless transparent resin packaging tube, can through the resin material for observation, if the tube core with a platter, which is an infrared light emitting diode,other LED without the platter.
4,Polar of infrared emitting diode
Usually long pin is positive, the other foot is negative. If unable to recognize from the pin length (for example has been cut short pin), can be determined by measuring the positive and negative resistance. Digital multimeter, is smaller than the measured forward resistance, the red measured pen is positive. (If the Analog Multimeter contrary, it has a relationship with the meter internal battery polarity)
Added: usually by measuring the infrared light-emitting diode negative resistance can also speculate the quality of IR LED. If the measured forward resistance values close to zero, it should be scrapped. If the reverse resistance only a few thousand ohms, or even close to zero, the IR LED will undoubtedly is bad; reverse resistance has greater the resistance, indicating that the leakage current is smaller, more good quality.
5, product characteristics
Infrared light emitting (IR LED) and transistor integrated circuit matching. Small volume, light weight, strong shock resistance, high reliability structure.
6, infrared emitting diode applications
The signal source is suitable for all kinds of photoelectric detector. Application of automatic control instrument for all kinds of hotoelectric conversion, sensor etc..According to the driving mode, can obtain stable pulse light, slow light, commonly used in remote control, alarm, wireless communication etc..
7, Application notes of infrared emitting diode:
Infrared light emitting diode should be kept clean and in good condition, especially in the front part of its spherical launch both can not exist like dirty dirt contaminants, more not by friction damage, otherwise, the infrared light emitted from the tube core will produce a reflection and scattering phenomenon, directly affect the infrared communication.
Other Application notes please refer to (Application Notes———-infrared light-emitting(IR LED))