Commonly used in infrared lamp remote control transmitter and receiver systems are generally divided in two parts. The main components of transmitter infrared light-emitting diodes. It is actually a special light-emitting diodes, different from ordinary materials because of its internal light-emitting diodes, and thus a certain voltage is applied at both ends, it will send the infrared rather than visible light. Current heavy use of infrared LEDs emit infrared wavelength of about 940nm, the same shape and general light-emitting diode, but a different color. Infrared light-emitting diodes are generally black, dark blue, transparent colors. Infrared light-emitting diodes to determine good and bad ways to determine the ordinary diode with the same: look at the amount with a multimeter power block infrared light-emitting diode, the reverse resistor. Infrared light-emitting diode light-emitting efficiency to use a special instrument to accurately measure, but only under the condition of amateur pull away from the method used to determine the rough. Receiving part of the infrared receiver is a photodiode. In practice, to give the infrared receiver diode is reverse biased, it can work, that the infrared receiver diode in the circuit is reverse-use applications, in order to obtain higher sensitivity. Infrared receiver diodes generally have round and square.