The key device in security alarm systems is the motion sensor. This is a device that detects in a controlled area in various ways.
Depending on the complexity of the device or security system and the connection method, various motion sensor functions are used:
- Activation of light and sound alarm;
- Transmitting a signal about unauthorized entry to the security console;
- Activation of the video recording system;
- Transmitting a signal to a mobile communication device to the owner.
- Turning on the lighting in the protected area.
The latter energy-saving function is often used in smart home lighting systems both for the local area and for rooms.
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What is a motion sensor and why is it needed?
Finder motion sensors are special wave detectors powered by electricity. It detects movements in the room. That is, any moving object entering the coverage area of the motion sensor activates the sensor system, which transmits it to the mechanism attached to it.
The device will not harm your health and will significantly save energy, and therefore the money that you could pay for it.
This device has many advantages:
Installing a motion sensor in any warehouse will make your life easier. As a rule, in such rooms the switches are located quite far from the entrance. This means that if the room is creatively cluttered, you can easily get injured by tripping over an object.
Multifunctionality is one of the main advantages of motion sensors. Not only is it compact and ideal for any interior, but it can also be wireless, which is convenient. The motion sensor can be used for various purposes, be it opening a gate or signaling.
Types of motion sensors
Now there are several types of motion sensors. Before purchasing, you should understand a little about the characteristics of these devices. There are a large number of them so that everyone can choose a device that suits their specific requirements.
Motion sensors are divided into several types, depending on the location where it is located:
- Type internal. This type of sensor is located indoors. You can install it absolutely anywhere in your house or apartment.
- External type. Such a device operates at a distance of 100 to 500 meters. They are usually installed in the courtyard of a house or in large areas of various industries.
The installation, like the devices, is divided into two types:
- Ceiling installation type. This alarm device is mounted in the ceiling. Typically, it works 360 degrees.
- Wall-mounted or, another name, corner type of installation. The advantage is considered to be a smaller opening angle, which reduces the number of false reactions.
The power supply of the alarm is divided into several types:
Wired power supply – they work well throughout the entire period of operation, almost like new. This happens because electricity is transmitted through wires. The alarm has a minus - it turns off if there is no electricity.
Autonomous or wireless power supply. It runs on one or more batteries that are pre-built. More modern models are powered by sunlight. However, such an environmentally friendly option requires control of electricity. It should not be too little or too much.
Application
Lighting control indoors and outdoors . To automatically turn on lighting in residential premises and outdoors, PIR detectors are mainly used. The range of such sensors is 12 meters.
Some of the models have a limited viewing angle, which helps turn on artificial lighting only at the moment when a person is in the required area.
Modern PIR detectors are equipped with a light sensor, so they do not turn on artificial lighting during daylight hours. This helps save electricity.
Security
In the event of unauthorized entry into the territory of a protected facility, motion sensors are capable of triggering video cameras, alarms, sirens and other necessary devices.
To protect residential premises and offices, IR sensors are usually used; they effectively detect movements in open space. But due to the nature of PIR detector optics, they are not suitable for working in narrow corridors or detecting broken windows. In this case, ultrasonic or microwave detectors are used.
To protect outdoor areas, active and passive infrared detectors, as well as combined devices, are most often used.
For car alarms, microwave sensors and ultrasonic detectors, which are not large in size, are used. – rules for operating security detectors and sensors for switching on electrical appliances.
Installation
The sensors also differ in installation. There are external or overhead ones, as well as devices that are built-in. The first ones are easy to install; you only need to connect electrical wiring to them. The second type has the main advantage of being able to be manufactured to suit the interior and overall design of the room.
To better understand what it looks like, it’s worth looking at photos of such motion sensors. Thanks to this advantage, the sensor can be planned at the design stage of the entire house. Both types differ from each other in their operating principle.
Ultrasonic motion sensor
It works quite simply. The waves that come from the moving object are read by a built-in wave catcher. This type of sensor lasts a long time and is easy to use. The price of the ultrasonic sensor is reasonable and it is also environmentally friendly.
However, it has some disadvantages:
- Often does not respond to slow moving objects.
- It has a negative effect on animals, so if you have pets you should not choose a sensor of this type.
Principles of operation of motion sensors
The principle of operation of the motion sensor is quite simple. When a moving object appears in the motion sensor's viewing area, the built-in detector will turn on the relay and with its help, electricity will be transmitted to the light bulbs, thereby turning on the light.
The device operates for the time you specify in the settings. You can select from 5 seconds to 10 minutes. That is, for example, you set a timer for 5 minutes, if there is no movement during this entire time, the device will turn off the light.
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Even before purchasing a sensor, you need to decide on its location. The type of device will depend on this. For example, an infrared sensor will not respond to a person if he has not entered the room. If you want the light to turn on when the doors are opened, install an ultrasonic type device.
Important Features
The choice of device is based not only on the principle of operation, operating conditions and installation methods. An important parameter is the range of the device.
Viewing angle
The indicator is measured in degrees. Varies between 60-360 units in the horizontal plane and 15-20 units in the vertical plane. Ceiling sensors have the maximum value, wall sensors have the minimum value.
Street sensors are designed for maximum coverage of the protected area. Therefore, the viewing angle is over 180 degrees.
Range
The units of measurement are meters. Range is considered in three planes:
- perpendicular to 40 m in diameter (movement along a tangent circle);
- frontally up to 20 m (towards the device);
- presence (under the sensor).
Installation method and location
Installation work depends on the design features of the sensors. There are devices for indoor and outdoor use. The latter have a body protected from the effects of natural phenomena. A wider range of permissible operating temperatures is also provided.
The following areas are excluded for installation of sensors:
- near air conditioners and humidifiers;
- near natural or forced ventilation;
- near heating appliances.
To avoid false alarms, it is recommended to install devices on supporting structures, where the presence of direct sunlight is minimal. The latter can illuminate sensitive detectors. Based on the installation method, the following models are distinguished:
- Cabinets for outdoor use.
- On the ceiling, the device covers the entire perimeter around the circumference (with a diameter of 10-20 m). Installed for lighting, security or turning on any mechanisms at a height of 2.5-3 meters from the floor.
- Sensors on the wall have a limited effect relative to the area covered.
Built-in models are partially recessed into the base. That is, only the receiving surface and the decorative frame remain visible. The entire mechanism is located in a niche in the wall.
Additional features
Modern devices are designed to have advanced features. That is, they not only triggered movement and signaled it, but also additionally performed other tasks.
Light sensor
The radius of action is often 180 degrees, but there are models with full circle coverage. During movement, the circuit closes and the light turns on.
Animal protection
Ultrasonic and radio wave sensors automatically repel animals because they perceive them and cause discomfort. The waves also have a negative effect on humans, but imperceptibly.
IR devices can be configured so that they are not triggered by animal movement. This feature is also available in some models of combined sensors.
There are devices in which the settings are carried out in accordance with the weight of objects. So, if the permissible value is adjusted to exceed the animal data, then there will be no reaction.
Light off delay
There are detectors that have a built-in light switch-off timer (timer). Then the operation will occur within the time required by the consumer.
Autonomy
A stand-alone motion sensor is powered by batteries or rechargeable batteries. Can be equipped with a GSM module to work with a mobile phone. Compatibility with CCTV cameras is allowed.
How to install a motion sensor correctly?
You already know what a motion sensor is, their types, and how they work. Now let's talk about how to properly connect a motion sensor. When placing the device, be sure to take into account the size of the room where the windows and doors are located. All this affects the correct operation of the sensor.
Consider these factors when installing the device:
- There should be no dirt or dust.
- Any objects in front of the sensor, especially outdoors, can cause the device to trigger.
- If you are installing an alarm with wiring, its insulation must be moisture resistant.
- Mounting the sensor next to or opposite devices that emit light or electromagnetic waves is not a good idea.
- Set the desired angle and direction, because the device will react to objects that fall within the coverage area.
- Select lamps according to power, take with a margin of 15%.
So now you know everything there is to know about motion sensors. I hope after reading this article, you have decided for yourself which motion sensor is better to choose.
Malfunctions
| The trigger illumination threshold is incorrectly set. | Adjust using the regulator. |
| The sensor window does not track movements. |
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| The sensor is triggered falsely. |
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