Infrared pair tube is a general term for infrared emitting tube and photosensitive receiving tube, or infrared receiving tube, or infrared receiving head when used together. The part of the spectrum with a wavelength greater than 0.76 microns is called infrared.

Infrared pair tubes are divided into infrared emitting tubes and infrared receiving tubes, which are also common infrared light-emitting diodes, and their appearance is similar to LEDs.

　　 When transmitting infrared rays to control the corresponding controlled equipment, the controlled distance is proportional to the transmitting power. In order to increase the control distance of infrared light, the infrared pair tube works in a pulsed state. Since the effective transmission distance of pulsating light (modulated light) is proportional to the peak current of the pulse, it is only necessary to increase the peak Ip as much as possible to increase the transmission distance of infrared light. . The way to increase Ip is to reduce the pulse duty cycle, that is, reduce the pulse width т. For some color TV infrared remote controllers, the working single pulse hollow ratio of the infrared light-emitting diode is about 1/4~1/3; some electrical products infrared The duty cycle of the remote control is 1/10. Reducing the duty cycle can also greatly increase the emission distance of low-power infrared light-emitting diodes. Common infrared light-emitting diodes have three types of power: low power (1mW~10mW), medium power (20mW~50mW), and high power (over 50mW~100mW). To make infrared light-emitting diodes produce modulated light, only a certain frequency pulse voltage is added to the drive tube.

      Infrared pair tube application

　　 Infrared pair tube is infrared transmitting and receiving. There are two ways of transmitting and receiving, one is direct type and the other is reflection type. The direct type means that the light-emitting diode and the receiving tube are relatively placed at the two ends of the transmitter and the controlled object, with a certain distance between the middle; the reflective type means that the light-emitting diode and the receiving tube are side by side, usually the receiving tube is always without light, and only emitted by the light-emitting diode When the infrared ray hits the reflector, the receiving tube will only work when the reflected infrared ray is received.

　　 Infrared pair tubes are mainly used in game consoles, coin-operated machines, remote controls, various security monitoring equipment, infrared cameras, mechanical electronics, electric meters, smart water meters, etc.