PIR Sensor Module


Pyroelectric sensor is a kind of sensor, also known as human body infrared sensor, used for life burglar alarm, visitor notification, etc., the principle is to release the charge through the amplifier into a voltage output.
The piezoelectric ceramic dielectric can maintain a polarization state after being polarized, which is called spontaneous polarization. Spontaneous polarization decreases with increasing temperature and the temperature drops to zero at the Curie point. Therefore, when the material is exposed to infrared radiation and the temperature rises, the surface charge will decrease, which is equivalent to releasing a part of the charge, so it is called pyroelectric. The discharged charge is converted to a voltage output by an amplifier. This is how the pyroelectric sensor works.
When the radiation continues to act on the pyroelectric element and its surface charge is balanced, the charge is no longer released. Therefore, the pyroelectric sensor cannot detect constant infrared radiation.
Working principle: The human body has a constant body temperature, generally at 37 degrees, so it will emit infrared rays with a specific wavelength of about 10UM. Passive infrared probes work by detecting infrared rays of about 10UM emitted by the human body. The 10 UM infrared rays emitted by the human body are enhanced by the Philippine filter and collected on the infrared sensing source. The infrared sensing source usually adopts a pyroelectric element, which loses the charge balance when receiving the temperature change of the infrared radiation of the human body, and discharges the charge outward, and the subsequent circuit can generate an alarm signal after being detected and processed.
Pyroelectric effect: When some crystals are heated, an equal number of oppositely charged charges will be produced across the crystal. This phenomenon of polarization due to thermal changes is called pyroelectric effect.
Fresnel lens: According to the Fresnel principle, the Fresnel lens is divided into two types: refractive and reflective. Its role is to focus and refract (reflect) the pyroelectric infrared signal on the PIR. Second, the detection area is divided into a number of bright areas and dark areas, so that moving objects entering the detection area can produce a modified pyroelectric infrared signal on the PIR in the form of temperature changes, so that the PIR can generate a change electrical signal. The sensitivity of the pyroelectric human body infrared sensor (PIR) is greatly increased.

Senba will keep offering human motion sensor module or infrared pir motion sensor module with high quality.


评论

发表评论

此博客中的热门博文

The Application of the Idr Sensor

图片
1. Electronic photometry The photometer can be used to measure the brightness of people and objects, so as to help the photographer choose the appropriate exposure speed. The following is the schematic diagram of the electronic photometer. The ldr sensor  changes the intensity of light into the difference of resistance value, so that the brightness can be displayed directly by different currents flowing through the meter. Among them, R1 and R2 are used to adjust the surface calibration and W is used to control the sensitivity of the meter head. 2. Infrared thermometry The infrared light radiated by the measured object is modulated into 800Hz optical signal by a modulation disc with a filter, which is approximately sinusoidal wave. The modulated light entering into the idr sensor is converted into electrical signals and then sent to the FET amplifier for amplification. The output U0 can reflect the temperature. In order to reduce the influence of noise and temperature c...
阅读全文

How to Use Ldr Sensors to Realize the Circuit Control of Photoswitch?

图片
       The company head quarter and the manufacturer facility are located in a beautifully landscaped industrial park, named after Senba, in Nanyang, Henan. In order to provide better customer services, we also have set up branches in Shenzhen, Ningbo, Wenzhou. Until now, Senba   has become the most advanced manufacturer specialized in PIR sensor technology   in China.   How to Use Ldr  Sensors to Realize the Circuit Control of Photoswitch? Ldr sensors are sensitive to light sticking. The stronger the light, the smaller the resistance value; the darker the light, the greater the resistance value. So we can use this characteristic to construct the ldr sensor circuit , and cooperate with relay/triode/MOS transistor to realize the photoswitch. Next, the ldr switch circuit   of realizing photoelectric switch by using ldr sensor, ldr transistor  and relay is introduced.   1. What is Ldr Sensor The working principle of ldr sensor is based...
阅读全文

How to Use Ldr Sensors to Realize the Circuit Control of Photoswitch?

图片
  Ldr sensors are sensitive to light sticking. The stronger the light, the smaller the resistance value; the darker the light, the greater the resistance value. So we can use this characteristic to construct the photosensitive circuit, and cooperate with relay/triode/MOS transistor to realize the photoswitch. Next, the circuit of realizing photoelectric switch by using ldr sensor, transistor and relay is introduced.       1. What is Ldr Sensor The working principle of ldr sensor is based on the internal photoelectric effect. The ldr photocell is very sensitive to light. Without light, ldr sensor presents a state of higher resistance value. Under strong light, its resistance value decreases rapidly, and presents a lower resistance value. The following is the physical diagram and characteristic curve of the ldr sensors.       2. Design of Optical Switch Circuit-Triode Implementation The circuit of the photoelectric switch is mainly composed of ldr sensor...
阅读全文