Security Sensor Living Presence Sensor Home Intelligent Security Protection Principle Application Radar WiFi Network Version Sensor

The security sensor living body presence sensor home intelligent security protection principle applies the radar WiFi network version sensor, in the home, various security sensors can be installed to achieve comfort, safety, protection and other functions. For example, installing a sensor for harmful gases in a kitchen can transmit information to a central processing system when the harmful gas reaches a critical state. Prompt people to deal with air leaks urgently. If no one is dealing with it at home, they can reflect information to the processing department through the central processing system to prevent a tragedy. A temperature sensor is placed in the room, and the temperature sensor sends the room temperature to the processor. The processor can feed back information to the air conditioner to achieve a comfortable and stable temperature.

How these sensors work and what their principles are, I will introduce them to you today.

1. Living body presence sensor

Living body presence sensor The induction sensor uses the Doppler principle to transmit high-frequency electromagnetic waves through the antenna and receive and process the reflected waves, thereby judging the movement of objects within the coverage area and giving corresponding electrical signals. Compared with the infrared sensor module, the sensing distance is farther, the angle is wider, there is no dead zone, and the lens and lens aging problems are not affected by temperature, humidity, airflow, dust, noise, light and dark, etc. The non-metallic material has a built-in MCU and multiple digital filtering algorithms, which have higher noise immunity. The sensing distance of the living presence sensor radar can be configured through the MCU, and its sensing distance is 20+ meters. The actual sensing distance can be flexibly adjusted as needed. If the use environment is a relatively narrow space, the sensing distance and angle will change accordingly.

2. Temperature sensor

The temperature sensor converts the temperature into a usable output signal using the laws of various physical properties that change with temperature. The temperature sensor is the core part of the temperature measuring instrument, and there are many kinds. According to the measurement method, it can be divided into two types: contact type and non-contact type. According to the characteristics of sensor materials and electronic components, it can be divided into thermal resistance and thermocouple. The small shape of modern temperature sensors makes them widely used in various fields of production practice, providing countless conveniences and functions to our lives.

Although there are many classifications of temperature sensors, the general principle is to sense changes in temperature, so that the resistance value of sensitive elements (such as thermistors, thermocouples, etc.) changes, thereby changing the output voltage in the circuit). Next, take the thermocouple sensor as an example to introduce in detail.

Two conductors of different compositions, called thermocouple wires or thermodes, are connected across a combined circuit. When the temperature of the two junctions is different, an electric potential develops in the circuit. This phenomenon is called the thermoelectric effect, and this electric potential is called thermoelectric potential. Thermocouples use this principle to measure temperature. Among them, the end directly used to measure the temperature of the medium is called the working end (also called the measurement end), and the other end is called the cold end (also called the compensation end); the cold end is connected with the display instrument or supporting instrument, indicating that the thermocouple produces the thermoelectric potential.

3. Water immersion sensor

The water immersion sensor is based on the principle of liquid conduction. The electrode is used to detect whether there is water, and then the sensor is converted into a dry contact output. Based on the principle of liquid conduction, the electrode is used to detect whether there is water, and then the sensor is converted into a dry contact output. There are two output states: normally open and normally closed.

Immersion sensors are divided into contact water immersion detectors and non-contact water immersion detectors. The contact type water immersion detector adopts the principle of liquid conduction for detection. Under normal circumstances, the two-pole probe is insulated by air; the probe is turned on when immersed, and the sensor outputs a dry contact signal. When the probe is soaked to a height of about 1mm, a warning signal will be generated.

Non-contact water immersion detectors use the principle of refraction and reflection of light in different medium sections for detection. LEDs and photo-receivers are placed in plastic hemispheres. When the detector is placed in the air, most of the LED photons are received by the photoreceiver due to total reflection; when approaching the surface of the hemisphere, the LED photons received by the photoreceiver are reduced due to light refraction, thereby changing the output. It is suitable for deployment in general corrosive conductive liquid leakage sites.

3. Gas sensor.

Gas sensors can be used to measure the type, concentration and composition of gas, detect specific components in the gas, and convert the composition parameters into electrical signals. Also called a gas sensor. It mainly includes semiconductor gas sensors, contact combustion gas sensors and electrochemical gas sensors, of which semiconductor gas sensors are the most commonly used.

The specific principle is that the wave speed and frequency on the surface of the acoustic wave device of the safety sensor will drift with the change of the external environment. The gas sensor uses this property to coat the surface of the piezoelectric crystal with a gas-sensitive film that selectively adsorbs gas. When the gas-sensitive film interacts with the gas to be measured (chemical or biological or physical adsorption), the film quality and conductivity of the gas-sensitive film will change, resulting in a shift in the frequency of the surface acoustic wave of the piezoelectric crystal; The degree of change in the quality and conductivity of the film layer is also different, that is, the change in the frequency of the surface acoustic wave is also different. By measuring the change of the surface acoustic wave frequency, the change value of the accurate reaction gas concentration can be obtained. The parameters of the gas sensor mainly include heating voltage, current, measuring circuit voltage, sensitivity, response time, recovery time, voltage in calibration gas (0.1% butane gas), load resistance value, etc.

4. Door magnetic sensor.

As the first line of defense of smart home security, the importance of door magnetic system is self-evident. The door magnetic sensor is the basis of the door magnetic system, and its technical principles are mainly as follows:

The wireless door sensor is composed of a wireless transmitter module and a magnetic block. In the two arrows of the wireless transmitter module, there is a steel spring tube element. When the distance between the magnet and the steel spring tube is kept within 1.5cm, the steel spring tube is disconnected. Once the distance between the magnet and the steel spring tube exceeds 1.5cm, the steel spring tube will be closed, resulting in a short circuit, and an alarm signal will be sent to the host when the alarm indicator light is on.

The wireless alarm signal of the wireless door sensor can transmit 200 meters in an open place and 20 meters in an ordinary house, which is closely related to the surrounding environment. Wireless door sensors generally use a power-saving design. It doesn't emit a radio signal when the door is closed. At this point, the power consumption is only a few microamps. When the door is opened, it immediately sends out a wireless alarm signal for about a second and then stops by itself. At this point, even if the door remains open, no signal will be issued.

The wireless door sensor also designs a battery low voltage detection circuit. When the battery voltage drops below volts, the LP LED below will light up. At this time, the special battery for the A23 alarm needs to be replaced immediately, otherwise it will affect the reliability of the alarm.

Radar WiFi network sensor makes UV lamps safer and more environmentally friendly

Based on smart home scenarios, a new radar-sensing Wi-Fi UV disinfection and sterilization lamp solution was launched. It adopts high-power ultraviolet light wave, realizes automation through intelligent control, and can quickly sterilize through obstacles. The sterilization efficiency can reach 99%, the mite removal rate can reach 100%, no odor residue, no liquid leakage, no secondary pollution, and no bacterial virus resistance.

The killing effect of ultraviolet light on bacteria and viruses has been verified in common bacteria and viruses. LED ultraviolet sterilization lamp has the advantages of fast, safe and environmentally friendly. It has been widely used in hospitals as early as the last century. According to the diagnosis and treatment plan of the new coronary pneumonia epidemic, ultraviolet light can effectively inhibit the new coronary pneumonia. Ultraviolet lamps have become Internet celebrity products. It is very popular on Taobao and JD.com e-commerce platforms!

1. Product introduction of radar WiFi network version sensor solution

Wi-Fi network module: Adopt space-saving compact process design, high performance, low cost, low power consumption, high temperature resistance.

Radar sensing module: The sensing distance is long, the angle is large, it can penetrate non-metallic materials, the sensitivity is high, and it is not affected by ambient temperature and dust. Integrating the two modules into one sensor can quickly realize the functions of human body sensing and Wi-Fi network at low cost.

2. Intelligent control function of radar WiFi network version sensor solution

Wi-Fi network: mature technology, low cost, wide coverage and wide demand. Only a mobile phone can remotely control and check the status of the UV lamp anytime and anywhere, which is convenient and fast.

360-degree automatic human body induction: real-time omnidirectional microwave radar detection makes human body induction more comprehensive and three-dimensional. When a person approaches, it will be turned off intelligently; when a person leaves, the mite removal and sterilization will be restarted.

Multiple automatic control methods: The radar sensor switch remotely and centrally controls the lamps and lanterns through timing, quantitative and fixed-point methods such as APP, applet, scan code, etc. Multiple safety protection to protect the human body from UV radiation damage.

Voice remote control: Through the mainstream voice platforms at home and abroad, such as Alexa, Google, Tmall Genie, IFTT, etc., the voice assistant can be completed with simple sentences, and there is enough safety distance to avoid accidental injury.

Intelligent delay: When the lamp is turned on, it will automatically enter the sterilization state after 30 seconds. Make sure the user has enough time to leave the fixture.

Buzzer reminder to leave the scene: When the living body enters the sensing range by mistake, the light will stop working and enter the off state. The buzzer sounded three times to suspend the equipment, reminding that the virus is being disinfected, and warning the personnel to accidentally enter the disinfection site and be injured.

Smart Timing: Turn on/off regularly. Set the working time of the UV disinfection lamp, it will automatically turn on after about 20 seconds within the radar sensing range, and automatically turn off after the disinfection is completed.

Application scenarios: It can also be widely used in public and commercial places such as schools and enterprises. Use technology to pave the way for health and meet the needs of different scenarios!