Infrared LED beads have been widely used in automobiles, indicator lights, audio equipment, and various electrical products. The control distance of the remote control is usually 6-8 meters, which is particularly convenient for application. Due to the large usage of infrared remote control methods, their infrared emission and reception circuits are equipped with complete supporting devices, which are not only low-priced but also reliable, with extremely simple circuits. Electronic enthusiasts can use these devices to assemble remote controllers for various purposes, which are not only practical but also can enhance their interest in production.

Infrared light is invisible and cannot be detected by the human eye. The common infrared LED beads have a similar appearance to ordinary LED beads. Reducing the pulse duty cycle can also greatly increase the emission distance of low-power infrared light-emitting diodes. The common infrared light-emitting diodes are divided into three categories of power: low power (1mW~10mW), medium power (20mW~50mW), and high power (50mW~100mW or more). When using infrared light-emitting diodes with different powers, corresponding power driver tubes should be equipped. To make the infrared light-emitting diode generate modulated light, simply apply a pulse voltage of a certain frequency to the driving tube.

When using infrared light-emitting diodes to emit infrared radiation to control a controlled device, there are corresponding infrared photoelectric conversion elements in the controlled device, such as infrared receiving diodes, phototransistors, etc.

There are two methods for infrared emission and reception, one is direct radiation and the other is reflection. Direct type refers to placing the light-emitting tube and the receiving tube at opposite ends of the emitting and controlled objects, with a certain distance in between; Reflective refers to the situation where the light-emitting tube and the receiving tube are placed side by side, and the receiving tube is always without light. It only works when the infrared light emitted by the light-emitting tube encounters a reflector, and the receiving tube receives the reflected infrared light.