1 Overview The human proximity sensor, also known as the non-contact proximity sensor, is an ideal electronic switching sensor. When the metal detector is close to the sensing area of ​​the sensor, the switch can be contactless, no pressure, no spark, and quickly emit electrical commands, accurately reflecting the position and stroke of the moving mechanism, even for general stroke control, its positioning accuracy, operation Frequency, service life, ease of installation adjustment, and ability to withstand harsh environments are not comparable to conventional mechanical travel switches. It is widely used in machine tools, metallurgy, chemical, textile and printing industries. It can be used as a limit, counting, positioning control and automatic protection in the automatic control system. Proximity sensors have long service life, reliable operation, high repeatability, no mechanical wear, no spark, no noise, strong anti-vibration ability. So far, the application range of proximity sensors has become more and more extensive, and the speed of its own development and innovation is extremely rapid. Human proximity sensors have been gradually recognized and applied as a means of technical defense. In order to better implement the national standard of GB/T10488-1997 human proximity sensor, the principle and application of human proximity sensor are better understood. Now, the human proximity sensor developed by Nanjing Yuantuo Technology is introduced to introduce the principle of human proximity sensor. And the basics of the application. Application of human proximity sensor in ATM cash machine monitoring: ATM-specific human proximity sensor YTMW8631 and human activity monitor YT-EWS, a control device for detecting human body proximity, can accurately detect the proximity of nearby people, and is currently the best choice for alarm and state detection. The sensing part has high detection sensitivity to the movement of the attached person and has strong interference ability to the sound signal suppression of the surrounding environment. It can be widely used in the anti-theft device of ATM insurance and the like, and can be installed horizontally or vertically. The sensitivity to human body sensing is continuously adjustable, which allows the human proximity sensor to be adapted to many different situations. Widely used in financial industry and commerce, self-service banking, ATM monitoring human body proximity alarms, etc. The internal use of micro-circuit chip for program control processing, with high detection sensitivity and trigger reliability detection and control two parts into one, low standby power consumption, switching signal output, direct trigger alarm recording, easy to use. Performance characteristics: (1) It has the function of penetrating walls and non-metal doors and windows, suitable for concealed built-in installation of bank ATM monitoring system; (2) The detection of the proximity distance of the human body is adjustable, and the adjustable radius is (about) 0-5 meters; (3) The detection area has a double sector shape and covers a large space; (4) Double comparison of the amplitude and width of the detection signal, and the false alarm is small; (5) It has a high ambient temperature adaptability and does not affect the detection sensitivity at -20 to 50 degrees Celsius. (6) Non-contact detection. (7) It is not affected by temperature, humidity, noise, airflow, dust, light, etc., and is suitable for harsh environments. (8) Strong anti-radio interference capability. 2. Classification and structure of Yuantuo technology human proximity sensor 2.1 two-wire proximity sensor The two-wire proximity sensor is simple to install and convenient to wire; it is widely used, but has the disadvantages of large residual voltage and large leakage current. 2.2 DC three-wire type The output types of DC three-wire proximity sensors are NPN and PNP. In the 1970s, most of the Japanese products were NPN outputs, and NPN and PNP were available in Western European countries. PNP output proximity sensors are generally used in PLCs or computers as control commands. NPN output proximity sensors are used to control DC relays. In practical applications, the output form should be selected according to the characteristics of the control circuit. 3 Proximity sensor selection and detection 3.1 ? For different material detectors and different detection distances, different types of proximity sensors should be used to make them have high performance-price ratio in the system. For this reason, the following principles should be followed in the selection: 3.1.1 When the test object is a metal material, a high-frequency oscillating proximity sensor should be used. This type of proximity sensor is most sensitive to the detection of iron-nickel and A3 steel samples. For aluminum, brass and stainless steel samples, the detection sensitivity is low. 3.1.2 When the test object is a non-metallic material, such as wood, paper, plastic, glass and water, a capacitive proximity sensor should be used. 3.1.3 Metal body and non-metal For the long-distance detection and control, photoelectric proximity sensor or ultrasonic proximity sensor should be used. 3.1.4 When the test object is metal, if the detection sensitivity is not high, a low-cost magnetic proximity sensor or a Hall-type proximity sensor may be used. 3.2 Proximity sensor specification detection 3.2.1 Determination of the working distance; when the action piece is close to the sensing surface of the proximity sensor, the distance that the proximity sensor acts is close to the maximum operating distance of the sensor, and the measured data should be within the parameter range of the product. 3.2.2 Determination of the release distance; when the action piece leaves the proximity sensor's sensing surface from the front, and the switch changes from action to release, the maximum distance of the action piece from the sensing surface is determined. 3.2.3 Determination of the hysteresis H; the absolute value of the difference between the maximum operating distance and the release distance. 3.2.4 Determination of action frequency; use the speed control motor to drive the bakelite disc, fix some steel pieces on the disc, adjust the distance between the switch sensing surface and the action piece, about 80% of the switch action distance, rotate the disc, The action piece is sequentially brought close to the proximity sensor, and a speed measuring device is mounted on the spindle of the disk, and the switch output signal is shaped and connected to the digital frequency meter. At this time, the motor is started, and the rotation speed is gradually increased. Under the condition that the product of the rotation speed and the action piece is equal to the frequency count, the frequency of the switch can be directly read by the frequency meter. 3.2.5 Repeating accuracy measurement; Fix the action piece on the measuring tool, except for 120% of the switching action distance, from the front of the switch sensing surface to the action area of ​​the switch, the motion speed is controlled at 0.1mm/s. When the switch is actuated, read the reading on the gauge and then exit the action zone to open the switch. This is repeated 10 times, and finally the difference between the maximum value and the minimum value of 10 measurements and the 10 average values ​​is calculated. The difference is the repeat accuracy error. What is the working principle of Yuantuo Technology Human Proximity Sensor? 1 The human proximity sensor has a high frequency transmitter that causes the coil to emit a high frequency magnetic field. 2 The object being measured close to the high-frequency magnetic field will cause eddy currents on the surface of the object to be detected, and the eddy current will induce a magnetic field in the opposite direction. 3 The transmitter is cancelled by the influence of the eddy current caused by the eddy current and stops the vibration. 4 Turn the control output ON/OFF by the presence or absence of vibration. Among the various types of switches, there is a displacement sensor that is "perceived" to its object. The sensitivity of the displacement sensor to the approaching object is achieved by controlling the on or off of the switch. This is the proximity switch. Because the displacement sensor can be made according to different principles and different methods, and different displacement sensors have different "perception" methods for objects, so the common proximity switches are as follows: Eddy current proximity switch, capacitive proximity switch, Hall proximity switch, photoelectric access switch, pyroelectric proximity switch, other types of proximity switches The main uses are: Nanjing Yuantuo Technology Human Body Sensors and Human Activity Monitors are widely used in bank cash machine triggering surveillance video, aviation, aerospace technology, safes and industrial production. In daily life, such as automatic doors for hotels, restaurants, garages, automatic hot air blowers are used. In terms of security and theft, such as data files, accounting, finance, museums, treasury, etc., it is usually equipped with anti-theft devices composed of various proximity switches. In measurement techniques, such as length, position measurement; in control technology, such as displacement, velocity, acceleration measurement and control, also use a large number of proximity switches. Concerned about surprises Tag: Proximity sensor Proximity switch Repeatability Anti-radio frequency interference Switching quantity Previous: Temperature sensor in medical institutions Next: How pressure sensors work Brass Rings,Brass Synchronizer Rings,Automobile Synchronizer Brass Ring ShaoXing Change Auto Synchronizer Ring Co.,Ltd , https://www.sxcjautoparts.com