Many people who have fallen into an unfamiliar room spend a lot of time looking for each section of the wall near the front door in search of the light switch. And it will be very lucky if the backlight is installed on the switch, but not all manufacturers worry about it. In addition, the building is not always flat floors, and this is dangerous. More recently, to solve this problem, we simply left the emergency lighting, especially in places of large concentrations of people: entrances, stairs and parking lots.
But progress does not stand still and in modern realities of constant energy saving it is advisable to use lighting control devices, which allow the inclusion of light sources only if it is really necessary. That is, at the moment when a person enters the illuminated zone. For this purpose, special motion control devices were created to turn on the lighting.
1 Varieties of motion control sensors
- 1.1 Ultrasonic motion sensor
- 1.2 Microwave Motion Sensor
- 1.3 Infrared motion sensor - the best choice to turn on the light
- 2 Features of technical characteristics of devices
- 3 Features of placement of the motion sensor to turn on the light
Varieties of motion control sensors
Under motion sensor, based on its name, means the device that detects the movement of any objects in the zone of direct action. Thanks to the development and improvement of various technical devices, such devices have turned out to be quite compact and inexpensive. Moreover, their use is advisable in buildings of a certain type.
- In the basement, garage and storerooms, where to find and turn off by touch is quite difficult, and the illumination from natural sources of light does not penetrate there.
- In the premises of the passage type, where there is a constant, but short-term movement of people: the staircase, the entrance or the corridor.
- In buildings where the light must be switched on in advance of the immediate appearance of people.
- To improve comfort, a motion sensor to turn on the light used in bathroomsHowever, such a device may, in addition to the lighting device, include an exhaust system.
- Such a device has gained wide popularity in security systems.
At the same time working principle All motion control devices are divided into specific groups.
- Ultrasonic powered devices. Such systems are used to capture movement through a reflected sound wave.
- A microwave based device uses high frequency waves for its operation.
- Infrared devices are devices that register movement by means of infrared radiation, which is inherent in all heat sources and warm-blooded organisms, including humans.
Motion fixation systems, depending on the method of receiving signals from objects, are also divided into several types.
- The active device itself emits and registers the signal reflected from the object. Such devices consist of a receiver and a radiator. But for this reason, the design of the device, and accordingly the price, is significantly complicated.
- A passive device registers its own radiation of objects. Structurally, such a device is much simpler and, naturally, cheaper. But passive devices have a high level of false positives.
Ultrasonic motion sensor
Such devices have received the greatest application in parking and security systems for motor vehicles. At the same time, such devices have the following advantages:
- the price that is available to middle-income people;
- resistance of the device to the effects of external environmental factors;
- reception of the reflected signal from any object.
Naturally, the use of such sensors, perhaps, to turn on lighting, but it is impractical for several disadvantages of ultrasound:
- ultrasound frequency is well audible to pets;
- limited range of the device;
- the sensor is triggered by sudden movements, so slow moving objects fall out of its field of action.
Microwave Motion Sensor
By analogy with an ultrasonic device, such a device is active. Simply put, they emit a wave, which is received after reflection from the object. The only difference with such a device is the use of not electromagnetic, but electromagnetic waves.
Microwave motion control devices emit radio waves reflected from all objects in the zone of the device. If no movable objects are detected, the reflected signal will return without changing the frequency. When any movement occurs, a frequency shift occurs that triggers the sensor.
Due to a number of advantages of microwave devices, they have received the maximum distribution in security systems:
- microwave sensor has a small size, thanks to which it is almost invisible;
- the device has a large range;
- microwave device for fixing movements can function even behind fences from non-conductive material;
- the device has great accuracy and catches even a slight movement in the range of the sensor.
Microwave motion sensors are extremely rarely used to control light for a number of specific drawbacks:
- microwave devices have a high enough price in comparison with other analogues;
- Due to the high sensitivity of the device, false positives may occur.
High-power microwave rays are very detrimental to human health. For this reason, it is not desirable to find living organisms for a long time near a device of a large radius of action.
Infrared motion sensor - the best choice to turn on the light
It's no secret that absolutely all objects have infrared radiationwhich is detected by the motion detection sensor by means of pyroelectric elements that respond to temperature changes.
If there are no changes in the range of the IR sensor, the potential produced at the output of the device has a constant value. With the appearance of any movement of objects emitting infrared rays, the magnitude of the output potential changes, which leads to the sensor triggering.
Infrared sensors are most widely used as devices for automatic switching on of light in various rooms, which is due to their advantage over other analogues:
- infrared sensor - a passive device that emits nothingtherefore it does not harm humans or animals;
- such devices have additional adjustments of both the angle of coverage and the threshold;
- such devices can be used both indoors and outdoors;
- The price of IR sensors is available to a wide range of consumers.
But, like other electrical devices, IR sensors, have several disadvantages:
- due to the thermal radiation of heating devices, false sensor triggerings may occur;
- the device can function normally only in a certain temperature range;
- Objects with a coating that does not conduct infrared rays will not be detected by the sensor.
Infrared motion control devices for switching on lights are the optimal choice for controlling lighting products from the existing variety of such devices.
Features of technical characteristics of devices
The motion control sensor is subdivided into a bipolar and tripolar device. The first only work with incandescent bulbs and have consistent wiring diagram light sources. In turn, the three-pole model is universal and can be used with any kinds of electric lamps.
All motion sensors can be distributed over the range of the device. Simply put, the device will work properly at a certain distance from the advancing object. Depending on the design features of the device, the distance of stable response can vary from 2 to 15 meters.
Another important characteristic of such devices is the angle of detection of objects in the horizontal plane. In most cases, this parameter depends on the sensor model and can vary from 60 to 360 degrees. In turn, vertically, such a device operates in the range of 15-20 degrees.
A very important indicator of motion detection devices is the power of the connected load to the device. If the total power exceeds the acceptable sensor performance, need to install an intermediate relay or distribute the load between the two devices.
If you need to connect fluorescent or energy saving lamps, then reactive power characteristics of such light sources should be taken into account. In most cases, reactive power should be less than 2 times less than what is written in the documentation for the sensor.
It is very important that the motion control sensor does not turn off at the same time when the object leaves the zone of the latter. The wide range of the light-off delay is primarily due to the fact that a person often needs to travel a distance in light that is greater than the range of the sensor. Very often, such a delay is used in devices installed in hallways and on stairwells.
As for the parameters of the electrical power supply of the device - this is a standard AC network. At the same time the sensor consumes only 1 watt of powerthat is very economical. A modern motion sensor for monitoring the switching on of light can assess the degree of illumination on the street or indoors using touch devices. This is necessary to prevent the sensor from tripping when it is light outside. According to the design features of the device, all motion sensors for switching on lighting devices are divided into the following types:
- external - installation of which is carried out with the help of special brackets with a wall corner or swivel structure;
- built-in - installation of which takes place in special boxes for light switches or in the ceiling under a lighting device in a hole specially equipped for this purpose.
Often, the sensors are made in such a way that they cannot be distinguished from a standard luminaire or are combined with a conventional switch that allows you to perform several functions at once - tracking the movement of objects and controlling the illumination in the room, which very comfortably.
Under the conditions in which the device will be used, all motion sensors can be divided into street ones with a high degree of protection and used in premises. However, if outdoor construction in the room can be installedthe sensor intended for use in the room will not withstand the effects of natural factors and will simply fail.
Features of placement of the motion sensor to turn on the light
Before installing such a tracking device you need to clearly divide the room into zoneswhere sensors will be mounted. For this purpose, an instrument pattern is compiled, which makes it possible to achieve permanently on illumination while the person is moving around the room. In drawing up a plan for locating motion control devices, it is important to adhere to certain rules.
- On the motion control system should not fall direct light from lighting devices.
- In the area of the device glass partitions are not allowed, since the IR rays are reflected from it.
- In the area of operation of the tracking device should not be bulky objects that greatly complicate the review.
- A heating system or an air conditioner also interferes with the operation of the motion sensor, since it reacts to the warm air currents of any devices.
- In buildings with a large area efficient installation of ceiling fixtureswhich have a circular area of action. In this case, the device itself must be placed exactly in the geometric center of the room.
The use of motion sensors to control illumination makes it possible not only to save electricity, but also to improve the comfort of using lighting devices. Among the variety of devices for fixing the movement of objects, only IR sensors are suitable for controlling illumination. Such devices can be used in any premises and on the street, and their installation does not cause any particular difficulties and is completely under the power of their own hands.