Infrared emitting diode drives a noisy modulated infrared beam. At a certain distance from the IR transmitter, the alignment is positioned with an IR receiver. It receives the infrared radiation energy discovered by the emitter through the photosensitive transistor and converts it into an electrical signal by the photoelectric conversion abstraction. The electrical signal is sent to the alarm controller circuit after proper processing.
In the optical system, which is placed in the receiving and the originator, the optical lens is used in general, and the infrared beam is focused into a finer parallel beam, so that the energy of the infrared light can be transmitted centrally. Infrared light in the invisible spectral range, some people through this invisible blockade, the inevitable all or part of the infrared beam occlusion. The intensity of the signal produced by the receiving end will change so that the alarm signal is activated. The characteristic of IR pair-shot alarm is that the detection reliability is very high.