Often hear the contractor involved in the project, in some energy-saving renovation project many customers require the installation of induction switch instead of the original switch, and some people will ask the microwave radar sensor switch and IR Switch that is better, the first time to hear The user asked many contractors to Mongolia, I do not know how to answer, so good Yang Sheng summed up the microwave radar sensor switch and IR Switch PK advantage.
One: microwave radar sensor switch principle
Through the plane antenna to send electromagnetic waves, when a moving object into the electromagnetic wave environment, the waveform reflection fold back, the plane antenna to receive the feedback waveform, the follow-up circuit by detecting the trigger signal work. Which up to open and close the role.
Second: microwave radar sensor switch features:
Microwave is widely used, the main is the full use of light-like, penetrating, sensing distance of these three characteristics.
1. Shine: refers to it with the lower frequency of radio waves, more like the same light to spread and focus;
2. Penetration: refers to it compared with infrared, when the medium is easier to penetrate the material inside.
3. Sensing distance: up to 8-18 meters.
A: The IR Switch principle: the absolute temperature (-273 degrees) when the object will produce infrared spectra, different temperature objects, the release of infrared energy wavelength is not the same.
Second: IR Switch features:
1. A pyroelectric infrared sensor (PIR), it can be wavelength between 8 and 12um infrared signal changes into electrical signals, and can inhibit the white light signal in nature, so the passive infrared detector Of the warning area, when no human body movement, the pyroelectric infrared sensor sensor is only the background temperature, when the human body into the warning area, through the Fresnel lens, pyroelectric infrared sensor sensor is the human body temperature and Background temperature difference signal, therefore, infrared detector infrared detection of the basic concept is to move the object and the background object temperature difference.
2. Another device is the Fresnel lens, Fresnel lens in two forms, namely, refraction and reflection. Fresnel lens has two roles: one is the role of focusing, that is, the pyroelectric infrared signal refraction (reflection) on the PIR, the second role is to distinguish the area into a number of clear areas and dark areas, so that into the alert The moving object in the zone can change the pyroelectric infrared signal on the PIR in the form of temperature changes so that the PIR can produce a changed electrical signal.
In short: IR Switch sensing distance is short, usually 2-4 meters, vulnerable to changes in temperature changes. The microwave radar sensor switch is easy to penetrate the light, the sensing distance of these three features can work around the clock, microwave radar sensor switch through most objects can be hidden in the installation of lamps or other places; can control the energy-saving lamps and Incandescent lamp. The movement of the object, there is a rapid response, it is particularly suitable for fast action on the detection of objects. So it is widely used in the detection of the earth, census of the Earth resources, mapping terrain, as well as reconnaissance military objectives and other major work.