The induction switch installed in the home is a smart switch that installs a sensing device. The category of induction switches is divided into human body induction switches, infrared induction switches, microwave induction switches and electromagnetic induction switches, and photoelectric induction switches. If the human infrared intelligent sensor switch is used, it will be automatically activated when someone passes the switch from the infrared sensing detection area.
┃ Inductive switch principle
Human body pyroelectric infrared sensor: the human body has a constant body temperature, generally at 37 degrees, so it will emit a specific wavelength of about 10UM infrared, passive infrared probe is to detect the human body emitted about 10UM infrared and work. The infrared rays emitted by the human body about 10UM are enhanced by the FINUR filter and concentrated on the infrared sensing source. Infrared induction sources usually use pyroelectric elements, which will lose the charge balance when the temperature of infrared radiation changes in the human body, release charge outward, and the subsequent circuit can trigger the switching action after detection and processing. When someone enters the sensing range of the switch, the special sensor detects the change of the infrared spectrum of the human body, the switch automatically turns on the load, and the switch will continue to turn on without leaving the sensing range; After the person leaves or there is no action in the sensing area, the switch delay (time adjustable TIME 5-120 seconds) automatically turns off the load.
┃ Inductive switching circuit
Inductive switch
In this circuit, the relay is released when the metal tongue is inserted between the two halves of the winding, which is particularly suitable for terminal switching. The insertion depth can be adjusted precisely to a few hundredths of a millimeter.
The oscillator oscillation frequency measured in the circuit is about 200kHz. The coil of the collector oscillation circuit is wound on a half ferrite segment core. The base feedback coil is wound around the other half of the core. The distance between the two halves of the iron core is about 5mm. This space enables the magnetic field cross-chain of the two coils.
A 1kΩ potentiometer on the emitter circuit generates a feedback amount. The potentiometer should be adjusted until the oscillator is just starting up.
Coil data: N1: 40 turn, 0.12mm copper enameled wire; N2: 75 turns, 0.12mm copper enameled wire; Ferrite core: 11∮×7.
┃ Induction switch wiring diagram
Different types of induction switches, wiring diagrams are also different. Take human body sensor switch, microwave sensor switch and four-wire sensor switch as examples.
Wiring diagram of human body sensor switch:
Microwave induction switch wiring diagram:
Wiring diagram of four-wire induction switch:
┃ Functional characteristics of induction switch
The types of induction switches are human body induction switches, infrared induction switches, microwave induction switches, electromagnetic induction switches, photoelectric induction switches.
1. Human body sensor switch
The human body sensor switch is an automatic control product based on infrared technology, when someone enters the sensing range, the special sensor detects the change of the infrared spectrum of the human body, and will automatically turn on the load, if the person does not leave the sensing range, the load will continue to be turned on; When the person leaves, the load is automatically shut down with a delay. When people arrive, the lights are on, and when people leave, the lights are out, which is cordial and convenient, safe and energy-saving, and shows humanized care.
2. Infrared sensor switch
Usually mainly used for automatic control of street lamp switches in public places, the switch is composed of infrared detection circuit, infrared signal processing circuit, signal output control switch circuit, power supply circuit several main parts; Infrared signal processing integration mainly completes the processing of infrared signals, the power supply of the circuit according to the requirements of each part of the circuit in the circuit in the circuit separate power supply, to ensure the stable performance of the circuit, infrared induction switch has the advantages of long detection distance, wide range of application, strong anti-interference ability, stable working performance.
3. Microwave sensor switch
3.1 Intelligent sensing: when a person enters the sensing range, the lighting equipment will automatically turn on; When the person leaves the sensing range, the lighting equipment is automatically turned off.
3.2 Intelligent delay: The switch will automatically increase a delay period after detecting each activity of the human body, and take the last activity as the starting point of the delay time.
3.3 Working mode: After the sensor switch is turned on, during the delay period, if there is human activity, the switch will continue to turn on until the person leaves.
3.4 Adjustable light sensitivity setting (optional): the induction switch does not sense during the day or when the light is strong; It can also be adjusted to any light or all-weather sensing.
┃ Sensor switch brand
Well-known brands of induction switches include Siemens, Simon, Legrand-TCL, Qisheng Clipsal, Panasonic, Schneider, Chint CHINT, Langnant LONON, Longsheng Switch Socket, Grand GELAN.
┃ Induction switch installation
The following is the installation, commissioning and precautions of infrared sensor switch.
1. Installation and debugging
1.1 Because the left and right sides of the switch are larger than the sensing range of the upper and lower sides, when installing the switch, the positive axis should be perpendicular to the direction of the human walking channel as much as possible, so as to achieve the best sensing effect.
1.2 Power on after installing the switch, when the ambient light is sufficient, the bulb will flash three times, initialization ends after one minute, the switch enters the monitoring state, and the object is used to cover the ambient light to make the switch work inductively, people do not leave and are active, the switch will continue to work; After the person leaves, the switch automatically delays the shutdown of the load.
1.3 Power on after installing the switch, when the ambient light is insufficient, the switch directly enters the monitoring state, the person does not leave and is active, the switch will continue to work.
2. Precautions
2.1 Do not operate with electricity when installing the induction switch, and it is strictly forbidden to short-circuit the load.
2.2 Do not use beyond the power range.
2.3 If the wall thickness of the sensor switch is less than 10 cm, the switch may have partition wall sensing.
2.4 This switch is suitable for indoor environment. Do not install outdoors in harsh environments.
2.5 Ensure that there are no obstacles or non-moving objects that affect its normal use in the installation area of the induction switch.
2.6 The induction switch should not be installed on an unfixed object.
Inductive switch
Inductive switch
Inductive switch
Inductive switch
Inductive switch
