The working principle of human proximity sensors
② The proximity of the object to the high frequency magnetic field causes eddy currents to be generated on the surface of the object, and the eddy currents in turn cause magnetic fields in opposite directions.
③ The transmitter is offset by the influence of the magnetic field caused by the eddy current and stops vibrating.
④ The control output is turned ON/OFF by the presence or absence of vibration.
Among the various types of switches, there is a component that has the ability to "sense" the proximity of an object - the displacement sensor. Using the sensitivity of the displacement sensor to the proximity of the object to control the switch on or off, this is the proximity switch.
The main performance characteristics of the human proximity sensor
Has the function of penetrating walls and non-metallic doors and windows; can detect the distance of the human body, and the distance can also be adjusted, adjustable radius of about half a meter; detection area wide range, because the detection area is a double sector; high adaptability to the ambient temperature range, and high sensitivity; to achieve a flying contact detection; can adapt to harsh environments, such as high temperature, humidity, noise, airflow, dust, light, etc.; to RF has a strong anti-interference ability
What can human proximity sensors do
Human proximity sensors are widely used in many fields and have won recognition and popularity, such as in the fields of trigger monitoring video for ATMs, aerospace, safes, and industrial production, etc. In daily life, they can be used in hotels and restaurants, automatic garage doors, automatic heaters, etc. Human proximity sensors can also be used in the field of security and anti-theft, such as data files, Finance, accounting, museums, vaults and other important places, at the same time, in the measurement technology and control technology is also widely used, such as length and position measurement, displacement, speed, acceleration measurement and control. In the application of machine tools, metallurgy, chemical industry, light textile, printing and other industries, when the metal monitoring body passes through the detection area, the switch will quickly issue electrical commands without contact, spark or pressure, accurately reflecting the specific position and travel of these objects.
