Many people tend to confuse infrared receivers with infrared receivers and treat them as the same thing. After all, judging from the name, the two are very similar. In fact, the two are still different. The biggest difference is that the former has three feet and the latter has two feet. The appearance can also be seen from the picture.

　　 From the inside structure, it is also different, let's talk about the infrared receiver first.

　　Inside the circuit includes infrared monitoring LED, amplifier, clipper, band pass filter, integrating circuit, comparator and so on.

　　 After the infrared monitoring LED detects the infrared signal, it sends the signal to the amplifier and the clipper, and the clipper controls the pulse size to a suitable size, regardless of the distance between the infrared transmitter and the receiver.

　　 The AC signal enters the band-pass filter. The band-pass filter can pass the load wave from 30khz to 60khz, from the demodulation circuit and the integration circuit to the comparator. The comparator outputs high and low levels and restores to the signal waveform of the transmitting point.

　　Be careful that the high and low levels of the output are opposite to the transmitting point. This is to increase the sensitivity of the reception.

　　 is an infrared detection LED, which can only detect infrared signals, and cannot expand the signal and subsequent processing.

　　 So when using the infrared receiver, you need to design the amplifier circuit yourself.

　　Of course, each has its own advantages. The infrared receiver is an integrated integrated circuit, so it reduces the trouble and cost of circuit design during use, and it is small in size and convenient to use. Although the infrared receiver does not have an integrated circuit, it also has its advantages, that is, you can design a circuit suitable for yourself according to your needs.