2. Sensors and detectors
Sensors and detectors are just like human sense organs. They convert the information they see, hear, and smell into electrical signals and transmit them to the control host. The primary sensors and detector products in smart homes include temperature and humidity integrated sensors, combustible gas sensors, smoke sensors, human infrared detectors, glass break detectors, wireless curtain detectors, wireless door magnetic detectors, etc.
Temperature and humidity integrated sensors
Temperature and humidity are closely related to people’s life, so the integrated temperature and humidity sensor is invented. The temperature sensor refers to the equipment that can convert the temperature and humidity into electrical signals that can be easily measured and processed. Temperature sensors on the market generally measure temperature and relative humidity.
Combustible gas sensors
Combustible gas sensors are detectors that respond to single or multiple combustible gas concentrations. Currently, combustible gas sensors mainly include two types: catalytic and semiconductor. The catalytic combustible gas sensor uses the refractory wire resistance change to measure the concentration of combustible gas. When the combustible gas enters the detector, it will cause an oxidation reaction on the platinum wire’s surface. The heat generated will make the temperature of the platinum wire increase. The resistivity of the platinum wire will change, thereby measuring the concentration of combustible gas. Semiconductor type detectors work by using a gas-sensitive semiconductor. When combustible gas enters the sensor, the semiconductor resistance decreases, and the value decreases correspond to the combustible gas concentration.
Smoke sensor is to achieve fire prevention by monitoring the concentration of smoke. It is a device that converts the concentration of smoke in the air into an output signal with specific corresponding relationship. Smoke sensor is divided into photoelectric smoke sensor and ionic smoke sensor.
Human infrared detector
The human body is generally around 37°C, so it emits infrared rays with a wavelength of about I0μm. The human body infrared detector is very sensitive to infrared radiation with a wavelength of about 10μm. It works by detecting the infrared rays emitted by the human body.
Glass break detectors
Glass broken detector is one of the security detectors in smart home. It is used to detect whether the window glass in the house is damaged. If someone breaks the glass and invades the room illegally, it will send out an alarm signal. According to the different working principles, the glass breaking detector can be divided into two types: single technology glass detector and double technology glass breaking detector. The double technology glass breaking detector can be divided into two types: 1. sound and vibration combination 2. detect infrasound wave and high-frequency sound of glass breaking at the same time.
Wireless curtain detector
Wireless curtain detector is widely used in smart home because of its low price and stable technical performance. A wireless curtain detector is a passive infrared detector, which is usually installed beside or on the top of the window. When someone enters the detection area, the detector will automatically detect the human activities in the area. If dynamic movement is found, the wireless curtain detector will send an alarm signal to the control host.
Wireless door magnetic detectors
Wireless door sensor detectors are widely used in smart home security and door and window control. It is a device used to detect whether doors, windows, drawers, etc. have been illegally opened or moved. It does not issue an alarm by itself. Send a coded alarm signal to the control host. When the control host receives the alarm signal, it will pass the signal to the alarm, and the alarm will go off.