The motion sensor, popular today , was developed as a device for guarding objects, which makes it possible to detect “unexpected guests” with its suddenness. Now, without it, it’s hard to imagine a “smart home”.
Is it really necessary?
Not so long ago, it was rather difficult to find a switch, especially in an unfamiliar room. A little later, manufacturers began to equip the switches with a light indication. But it is at home. At entrances and crowded places, things were much worse. Especially in common areas without windows. The light in such places burns for days. In modern realities, in order to save electricity, lighting control devices are gaining more and more popularity. They turn on the light as needed and turn it off when the illuminated area is empty. This device is a motion sensor to the light.
Application area
Devices that respond to movement and turn on and turn off the light make it possible to enter an already lit room, find out what is happening in the yard (adjusting the motion sensor allows you to configure it for any movement), and at the same time significantly save on paying electricity bills. Most often, these smart devices install:
- on the stairs leading to the cellar or basement,
- above the front door to the entrance,
- to the flight of stairs or to the hall, which do not have natural light, because they are located indoors,
- in the basement or cellar,
- in toilets, bathrooms, showers, etc.
Modern motion sensors allow you to configure the inclusion (with or without it) of any household appliance. An air conditioner, for example, or a television.
An optimal installation is considered if the motion sensor to the light is duplicated by a switch. Usually, a circuit for installation, including this nuance, is included with the device.
Types and methods of installation
The principle of operation of the motion sensor to turn on the light allows you to separate them as follows.
- The sensor responds to ultrasound. That is, the device detects movement by means of a reflected sound wave.
- The sensor uses high-frequency waves for its work.
- A sensor based on infrared radiation detects any movement of warm-blooded creatures.
The installation of a motion sensor to turn on the light may depend on the motion detection system. There are two of them;
- The device is active and emits a signal itself, and then reads reflected from a possible object. The design of these devices usually consists of two elements: the emitter and the receiver. It is this structural complexity that makes the device more expensive;
- The device is passive. It is able to register only its own radiation, an object that fell into the coverage area of the device. The design of the device is simple, therefore, it is much cheaper. The downside, quite sensitive, is the high level of false positives.
Ultrasonic motion sensor
Most often it can be found in security systems in transport and parking lots. The benefits include:
- resistance to external influences and environmental factors,
- readability of the reflected signal from any object,
- average price category.
It is quite possible to assume that the installation of a motion sensor to turn on this type of light is suitable for residential premises. But here you need to consider that:
- Ultrasound animals hear perfectly.
- The device reacts to sudden movements, so objects that move slowly are not perceived by them.
- The range of the device has certain limitations.
Microwave sensor
A motion sensor for light of this type, like the previous one, is active. It differs only in waves. They are electromagnetic. The device emits them, then registers reflected from possible objects. If they move, the wave frequency changes, which causes the sensor to trigger. If they are static, then the wave returns unchanged.
This is the most commonly used device in security systems. The benefits are significant:
- large radius of action,
- small dimensions, due to which the device is almost invisible,
- greater accuracy and the reading of minor movements in the coverage area of the device;
- fixes the movement behind the fence, if it is made of non-conductive material.
In living quarters, a microwave motion sensor for light is used infrequently. Firstly, it is hypersensitive and often works for no reason, and secondly, it is quite high in comparison with similar devices. Well, we must not forget that the prolonged exposure to microwave rays has a negative effect on the human body.
Infrared sensor
As you know from the school physics course, any object has infrared radiation. The pyroelements located in the registration sensor react to temperature changes and pick up the signal.
If there is a movement in the sensor’s operating area, which, of course, is accompanied by the emission of infrared waves, then the value of the output potential changes, and the sensor is triggered. If there is no movement, like radiation, then the potential is constant and there is no reason for triggering either.
Infrared sensors are ideal for any room, including residential. They perfectly cope with their duties and have undeniable advantages:
- setting the motion sensor of this type has additional adjustments to the angle of the coverage area and the threshold of operation,
- the device is passive (no radiation of its own), therefore, does not adversely affect living organisms,
- the device is in an affordable price category,
- The sensor can be used outdoors and indoors.
The disadvantages are not so significant, but still there are:
- a temperature difference can lead to a malfunction of the device,
- heaters emitting heat can cause false alarms,
- objects with a coating that does not conduct infrared rays are not read by the sensor.
Motion sensor adjustment
Modern devices allow you to adjust the installation angle, turn-off delay time, illumination and sensitivity. Models of previous years of release have only a tincture of the level of illumination and the delay time, or the latter and sensitivity.
It is possible to adjust the sensor coverage only by adjusting the installation angle. The sensor models available today have hinges for this. They are fixed so that infrared rays cover the maximum area for detecting movement. The installation height of the device is of no small importance: 2.40 m is considered optimal.
Sensitivity is a little trickier to set up. To adjust it, use the rotary lever (Sens). You need to configure it so that the sensor "does not see" the animals, but only responds to humans. Experts recommend first setting the lever to the maximum, wait until the light goes out and check how the sensor will work. Then you need to gradually reduce the sensitivity until you find the best option.
Setting the light means that the sensor will only need to be activated after dark. To start, like the previous setting, you need to set the maximum. With the arrival of twilight, note the sensor is triggered and, at its discretion, increase the illumination or decrease.
The last to set the delay time. It ranges from five to ten seconds and is adjusted according to personal feelings. There are models of sensors that, with each subsequent switch-on, increase the delay time.
As you can see, setting the motion sensor is not particularly difficult.
Ceiling devices for fixing the movement
This device is installed, due to its design features, only on a horizontal surface. Spherical body, with a viewing angle of 360 ° makes it possible to cover a large area. A ceiling motion sensor is considered a detection device. When a moving object appears in the zone of its action, the contact closes in the electric network, which activates the light switching mechanism. The basic element of such a sensor is a Fresnel lens. During installation, you need to consider that it can not be blocked by any objects.
The device mounted on the ceiling has a viewing angle of 360 ° . If you install it at a height of no more than three meters, the diameter of the working area will be 10-20 m. That is, one sensor is enough for a small room. In large rooms, it is desirable to combine the ceiling motion sensor with the wall one.
Ceiling devices are overhead, wireless and built-in. The latter can be successfully hidden from prying eyes. Any of them is inexpensive and is installed independently without much effort.
Standalone luminaires with motion sensor
It’s not the first year in stores you can buy a lamp with a battery-powered motion sensor. It captivates almost everything in it. For example, you do not need to ditch the walls for laying wires, you do not need to pay for all the rising electricity. And installation, sheer pleasure: removed the protective tape, stuck to the surface and that’s it!
The manufacturer supplied the models of such lamps with the most economical LEDs. Consumption significantly reduces the smart sensor. It is he who is responsible for the operation and turns on or off the light. Such devices are ideal in corridors without natural lighting, cellars, basements, storerooms, hallways and even cars.
A luminaire with a motion sensor on batteries usually weighs no more than 100 g, has a width of just over a centimeter, and a height and length of 8 to 10 cm. It is installed on any surface. It can be fastened with screws, glued with adhesive tape, put on a cabinet shelf or pressed down with a magnet.
Equipped with such lamps almost always an infrared motion sensor. Therefore, they need to be mounted away from sources of thermal energy. On some models, photocells only activate the sensor at night.
The timer turns off the device usually after 20-30 seconds, so 3A batteries last for quite a long time.
There are models of such luminaires with adjusters for sensitivity, brightness, motion sensor with a glow duration (30, 60, 90 seconds) and a shutdown button.
When setting the sensor for movement to turn on the light on the batteries, it must be borne in mind that heat sources and animals cause the sensor to trigger. Therefore, in order to change the batteries less often, it is desirable to set the sensitivity to a minimum.
Street lights with motion sensor
Modern lighting devices are operated not only in the house. The adjoining territory of both a multi-storey building and a private one can no longer do without lighting devices, in which a motion sensor for the street is built-in. Today, such lamps are already considered as a design element. The principle of operation is the same, the devices differ in terms of energy, scope and light element. The main technical and operational characteristics of the devices depend on the latter. Therefore, a street lamp with a motion sensor may have lamps:
- Classic . This includes both energy-saving lamps and incandescent lamps. Energy-saving light elements give a dim light stream, and incandescent bulbs quickly burn out due to the frequent change of modes.
- LED . Diodes are famous for their huge working resource, they do not emit heat, they shine brightly - this is all with minimal energy consumption. This option is ideal for street lighting.
- Halogen . Intense luminous flux with extended life and reduced power consumption. But at the same time they emit a lot of heat, so they are rarely used in flashlights.
According to the energy source, a street lamp with a motion sensor can be autonomous (powered by batteries), stationary (powered by electricity) and non-volatile (powered by solar panels with batteries).
Motion sensor to turn on the light: connection
It is carried out using the terminal. Most often, three conclusions, sometimes four. There are four main connection schemes.
- Sequential.
- Parallel.
- To multiple devices.
- With magnetic starter.
A series connection means that the motion sensor controls the light completely.
Parallel is necessary in case of prolonged illumination of the motion sensor operating area. After turning off the light with the switch, the sensor, having detected a movement, will turn it on and off in accordance with the settings.
Several devices will be needed in large passage rooms. In this case, the sensors are connected in parallel from one phase. If one sensor is triggered, then the rest are turned on.
The magnetic starter is mounted if the motion sensors trigger powerful light elements or additional electrical appliances.