The three-legged infrared receiving head is a component that combines a photosensitive receiving tube and an amplifying circuit, and these components perform functions of receiving, amplifying, demodulating, and the like. The output of all infrared remote controls is generated by pulse amplitude modulation of a 30 to 56 kHz square wave using encoded serial data. The three feet are: +5V, output, ground. Therefore can not be used instead of photosensitive tube.
Your laser tube should be 980nm wavelength, 50mW in a dust-free air with a range of up to 1000m
1 infrared receiving head 3 feet, photosensitive tube 2 feet. The structural difference is that there are PD and IC in the infrared receiving head, which has the function of receiving infrared signals and amplifying and decoding, and the photosensitive tube has only PD, that is, it can only receive signals.
2 Infrared receiving tube is to convert the optical signal (invisible light) into an electrical signal. Generally, it is a receiving, amplifying and demodulating integrated head. After the infrared signal is demodulated by the receiving tube, the difference between the data “0” and “1” is usually reflected in the height. The length of the level or the signal period, when the MCU decodes, usually the output pin of the receiving head is connected to the external interrupt of the MCU, and the timer is used to judge the time of the external interrupt interval to obtain the data. The point is to find the difference in waveform between the data "0" and "1".
3 The photosensitive receiving tube and other core components are all a photoresistor. The principle is that when light is irradiated onto the photoresistor, the resistance of the photoresistor will be significantly smaller. Within a limited range, the resistance is reduced and the light is reduced. The intensity is proportional to the intensity, that is, the stronger the light, the smaller the resistance. The photosensitive receiving tube or the like utilizes this characteristic of the photoresistor to convert the optical signal into an electrical signal, thereby performing mechatronic control, so that it is widely used.