Mô Đun Cảm Biến Hồng Ngoại Nhiệt Hc-Sr501

The perfect version of hc-sr 501 is an automatic control module based on infrared technology. it is designed with high sensitivity, reliability and ultra low voltage.

Thermoelectric infrared sensor is a sensor that detects infrared radiation launched by humans or animals and outputs electrical signals.As early as 1938, the use of thermoelectric effect to detect infrared radiation was proposed, but it was not paid much attention to it until the sixties, with the rapid development of laser and infrared technology, it promoted the research of thermoelectric effect and the application of thermoelectric crystal.Thermoelectric crystal has been widely used in infrared spectrometer, infrared remote sensing and thermal radiation detector. it can be used as an ideal detector for infrared laser.Its objectives are being widely used in various automated control devices.In addition to the application of automatic switch and anti-theft alarm in the well-known buildings, the prospects for application in more areas are promising.For example, an air conditioner or water dispenser that automatically stops when the room is empty.The television can judge the institutions that are unobserved or whose audience has gone to bed automatically shut down.Open the application on the monitor or automatic doorbell.Combine camera or digital camera automatically record animal or human activities, etc...You can develop better new products based on your own whims, combined with other circuits.Or automated control devices.

Basic knowledge of thermoelectric sensors

The thermoelectric effect is similar to piezoelectric effect. it refers to the phenomenon of surface charge caused by temperature change.Heat-release electric sensors are temperature-sensitive sensors.It consists of ceramic oxides or piezoelectric crystal elements, which make electrodes on two surfaces of the components, and when temperature changes in the range of sensors, the thermal-release effect produces charge q on two electrodes, i.e. a weak voltage v between the two electrodes.Because of its high output impedance, there is a field effect tube in the sensor for impedance transformation.The charge q generated by the thermoelectric effect is bound by the ions in the air, i.e. the sensor is not output when the ambient temperature is stable. t = 0.When the human body enters the detection area, t output is produced because of the difference between human temperature and ambient temperature; if the human body does not move after entering the detection area, the temperature does not change and the sensor is not output.So this sensor detects the motion sensor of a human body or animal. It is proved by experiments that the sensor does not have an optical lens (also known as the fresnel lens), and that the detection distance is less than 2m, and that the detection distance can be greater than 7m after the addition of an optical lens.

The following points should be noted in their use:

I、Dc operating voltage must m