Motion sensors were created to protect various objects, but today these devices are actively used in everyday life. With the help of automation, you can create more comfortable living conditions. By using street motion sensors to turn on the light, you can save on energy bills. After their installation, the lighting will turn on only if a person appears in the range of the device.
Content
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Types and principle of work
- Infrared devices
- Ultrasonic detectors
- Selection recommendations
- DIY installation of the sensor
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Sensor adjustment
- Tilt angle and sensitivity
- Light level and delay time
Types and principle of work
The detectors are classified according to two main features - the method of recording the incoming signal and the principle of operation. In accordance with the first type of classification, devices can be passive and active. The simplest design is possessed by passive ones, since they consist only of an element that detects movement. The design of active devices assumes the presence of a receiver and an emitter.
Infrared devices
This group of sensors can be associated with a directional thermometer. Of course, this is a rather rough description of the principle of operation of the device, but it reflects the essence of the process. An infrared type device will work if a source of thermal energy appears in its visibility zone. For correct operation of the device, it must be configured. Even when Body temperature an adult and a child are the same, a properly calibrated sensor will perceive them as two different objects.
If the device is adjusted to a minimum, then it can be triggered when pets appear. In most models, the configuration is done manually, but this should not be a major problem. It should be noted that it is infrared sensors that are widely used.
Ultrasonic detectors
Their area of use is the protection of various objects. These devices are active unlike infrared sensors. The principle of their work is to fix the reflected signal from objects in the field of view. When one of them is moved or when a new one appears, the picture “saved” by the detector changes, which leads to its triggering.
Ultrasonic devices are constantly active and send a signal with a certain frequency, then analyzing its reflection. The cost of such devices is higher in comparison with infrared, which has made them less popular.
There are also microwave sensors that scan the field of view constantly. This makes them as effective as possible, because any movement will be noticed. However, the extremely high cost makes their use in everyday life unprofitable.
Selection recommendations
When choosing a sensor, it is necessary to focus not only on the cost of the device, but also on its technical characteristics. One of the most important of these is the horizontal viewing angle. This indicator can be 90-360 °. If people can approach the object from any direction, then a light sensor with a viewing angle of 180 to 360 ° should be installed. When the sensor is mounted indoors, devices that track movement in a narrower range can be used.
The second important characteristic of detectors is range. If their installation is planned on the street, then it is worth choosing "long-range" sensors. Each device is designed for a specific load that can be connected to it. This indicator is the sum of the power of all light sources connected to the sensor. To achieve maximum energy savings, it is worth using LED or fluorescent lamps for lighting. Before purchasing sensors, it is worth remembering that they differ in the place of installation:
- Hull. Can be wall or ceiling mounted.
- Embedded. They have small dimensions and are used for concealed installation.
In everyday life, detectors of the first type are most often used because of their lower cost. Also, when choosing a motion sensor, you should pay attention to some additional functions. For home use, the following may be most helpful:
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Built-in light detector. The device is equipped with a photo relay and will start working only when a certain illumination indicator of the surrounding space is reached. - Protection from animals. If the owner of the house has a cat or a dog, then this feature will be useful.
- Light off delay. Some models of motion sensors turn off the light immediately after the object leaves their field of vision, which is not always convenient.
DIY installation of the sensor
At home, you can use the simplest circuit for connecting a motion sensor for lighting by connecting it to the break in the phase conductor. It will be most effective in a windowless room. To solve this problem, the phase and neutral wires are connected to the L and N terminals of the sensor, respectively. The output contact of the sensor is connected to one conductor of the lamp, and the other to neutral.
If the detector is planned to be placed in a room with windows or on the street, then it is worth adding a switch or a photo relay to the circuit. This will avoid turning on the lights during the day. Both devices are connected to a break in the phase conductor. If the home owner wants to completely automate the process of turning on the light, then it is worth using a photo relay.
However, all these schemes have one drawback - the lighting will not turn on for a long time. For example, if a motion sensor is mounted to turn on the light on the stairs and there is a need for repair work in the evening, then you will have to constantly move. To avoid this, a switch can be connected in parallel with the sensor.
Sensor adjustment
After completing the installation work, the motion sensor must be calibrated. Almost all parameters of the device are adjusted using small rotary knobs. Since today sensors with a built-in light sensor are quite popular, it is worth talking about setting up the device using their example.
Tilt angle and sensitivity
If the sensor is mounted on a wall, then first of all it is necessary to set the required angle of inclination. It is selected to provide the maximum control area. It is difficult to give precise recommendations in this matter, since it all depends on the placement conditions of the model used. The optimum mounting height for the detector is 2.4 m.
On imported devices, this regulator is most often designated by the letters SEN. The regulation is infinitely variable, so the parameter can be smoothly changed from minimum to maximum. Perhaps, it is the setting of this indicator that is the most difficult. If you make a mistake during calibration, the sensor will be triggered even when animals appear in the field of view. The adjustment algorithm is as follows:
- The minimum value is selected, after which the sensor's operation on pets is checked.
- If the device is triggered, then the sensitivity is reduced.
Light level and delay time
The detector models differ in the turn-off delay range. Most often, this figure is from 3 to 900 seconds. There should not be any serious problems with the adjustment, since there is a scale next to the regulator. As a result, the home owner can only choose the desired delay time and set it. Most often, the dimmer is designated LUX. It is necessary to adjust the sensor in the evening, slowly turning the regulator from the maximum position to the minimum position until the lighting turns off.
A person gets used to comfort quickly. Many users, after installing one motion sensor, decide to automate the entire lighting system of the house and site. When choosing a detector, you should carefully study its technical characteristics. There should be no problems with connecting the device, since it is a fairly simple process.
