Five major differences between microwave human radar induction module switch and infrared induction, often hear project contractors discussed, in some energy saving renovation projects, many customers require the installation of induction switch rather than the original switch, some people will ask the microwave human radar induction module switch and infrared induction switch is better, hear users ask many contractors, sometimes do not know how to answer, Therefore, Xiaobian summarizes the differences and advantages of microwave radar induction switch and infrared induction switch. So the contractor can understand.
One: microwave human radar induction module switching principle
Electromagnetic waves are transmitted through a planar antenna. When the moving object enters the electromagnetic wave environment, the waveform reflects and reflects. When the planar antenna receives the feedback waveform, the subsequent circuit detects the trigger signal. To turn it on and off.
Two: microwave human radar induction module switch characteristics
Microwave is widely used mainly because it takes full advantage of three characteristics: light, penetration and induction distance.
1. Photo-like: Compared with low-frequency radio waves, it can propagate and concentrate like light;
2. Penetration: compared with infrared ray, it is easier to penetrate into the interior of the material when irradiating the medium.
3. Microwave human radar induction module switch induction distance: up to 8-25 meters.
One: infrared induction switch principle: when the absolute temperature (-273 degrees), the object will produce infrared spectrum. Objects at different temperatures emit infrared energy at different wavelengths.
Two: infrared induction switch characteristics
1. One is pyroelectric infrared sensor (PIR), it can change the wavelength of 8-12um infrared signal into electrical signal, inhibit the natural white signal. Therefore, in the warning area of the passive infrared detector, when no human body is moving, the pyroelectric infrared sensor only senses the background temperature. When the human body enters the warning area, the pyroelectric infrared sensor senses the difference signal between the human body temperature and the background temperature through the Fresnel lens. Therefore, the basic concept of infrared detectors is to sense the temperature difference between moving objects and background objects.
2. The other one is Fresnel shot. Fresnel lenses come in two forms, refraction and reflection. Fresnel lens has two functions: one is focusing, that is, the pyroemission infrared signal refracts (reflects) on the PIR, the other is to distinguish the warning into several light and dark areas, so that the moving object entering the warning area changes on the PIR in the form of temperature changes, so that the PIR produces changes in electrical signals.
In short: infrared induction switch induction distance is short, generally 2-4 meters, prone to temperature changes.
Microwave human radar induction module switch has three characteristics of good light, strong penetration, long induction distance, can work all weather, microwave radar induction switch can pass through most objects, can be hidden in the lamp or other places; Controlled CFLS and incandescents. Fast response to the movement of objects, especially suitable for fast moving objects detection.
