Motion sensor for light: operating principle, installation and adjustment

Popular motion sensor was designed as a device for the protection of objects, allowing its suddenness to detect "unexpected guests." Now without him it is difficult to imagine a "smart house".

Is it necessary?

Not so long ago, finding a switch, especially in an unfamiliar room, was quite difficult. Hardly later manufacturers began to equip switches with light indication. But it's at home. In the entrances and places of a large congestion of people, things were much worse. Especially in public areas without windows. Light in such places burns day and night. In modern realities, in order to save electricity, lighting control devices are gaining in popularity. They turn on the light as needed and turn it off when the illuminated area is empty. This device is a sensor for movement to light.

Application area

Devices that react to movement and turn on and off light make it possible to enter an already illuminated room, to find out what is going on in the yard (adjusting the motion sensor allows you to adjust it to any traffic), while significantly saving on paying bills for electricity. Most often these smart devices are installed:

- on the stairs leading to the cellar or cellar,

- above the entrance door to the entrance,

- on a flight of stairs or in the hall, which do not have natural light, because they are located inside the room,

- in the basement or cellar,

- in toilets, bathrooms, shower cabins, etc.

Modern motion sensors allow you to configure the inclusion (with or without) of any home appliance. An air conditioner, for example, or a TV.

The optimum setting is considered if the traffic light sensor is duplicated by a switch. Usually the circuit for mounting, including this nuance, comes complete with the device.

Types and methods of installation

The principle of the motion sensor for switching on the light makes it possible to separate them in the following way.

1. The sensor responds to ultrasound. That is, the device captures motion through a reflected sound wave.
2. The sensor uses high-frequency waves for its work.
3. A sensor based on infrared radiation records 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;

- The device is active and itself emits a signal, and then reads the reflected from a possible object. The design of these devices usually consists of two elements: a radiator and a receiver. It is this constructive complexity that increases the cost of the device;

- The device is passive. It is able to register only its own radiation, an object that has fallen into the range of the device. The design of the device is simple, therefore it is much cheaper. The minus, quite sensitive, is a large level of false positives.

Ultrasonic motion sensor

Most often it can be found in security systems in transport and parking. The advantages include:

- resistance to external influences and environmental factors,

- the readability of the reflected signal from any object,

- The average price category.

It is quite possible to assume that the installation of a motion sensor to turn on the light of this type is suitable for living quarters. But here it is necessary to take into account that:

1. Ultrasound is well heard by animals.
2. Reacts the device to sudden movements, so objects that move slowly, they are not perceived.
3. The range of the device has certain limitations.

Microwave sensor

The light sensor of this type, like the previous one, refers to the active. It differs only in waves. They are electromagnetic. The device emits them, then registers reflected from possible objects. If they move, the frequency of the wave changes, which triggers the sensor to operate. If they are static, then the wave returns unchanged.

This is the most frequently used device in security systems. The advantages are significant:

- a large range of action,

- small dimensions, due to which the device is practically invisible,

- greater accuracy and reading of minor movements in the range of the device;

- fixes movement behind the fence, if it is made of non-conductive material.

In residential areas, the microwave light sensor is used infrequently. Firstly, it is hypersensitive and often works without cause, and secondly, it costs quite high, in comparison with similar devices. Well, we must not forget that the long-term exposure to microwave rays has a negative effect on the human body.

Infrared sensor

As is known from the school course of physics, any object has radiation from the infrared spectrum. Pyroelements located in the detection sensor, respond to temperature changes and capture the signal.

If motion occurs in the sensor operating area, which, naturally, is accompanied by the emission of infrared waves, the value of the output potential varies, and the sensor is triggered. If there is no movement, like radiation, then the potential is constant and there are no reasons for triggering either.

Infrared sensors are ideal for any room, including residential. They perfectly cope with their duties and have undeniable advantages:

- adjustment of the motion sensor of this type has additional adjustments of the angle of coverage and the threshold of operation,

- the device refers to the passive (there is no own radiation), therefore it does not have a negative impact on living organisms,

- the device is in an affordable price category,

- the sensor can be used outdoors and indoors.

Disadvantages are not so significant, but still there are:

- the temperature drop can lead to malfunction of the device,

- Heating devices, radiating heat, can cause false alarms,

- objects with a coating that does not conduct IR rays, are not read by the sensor.

Motion sensor adjustment

Modern devices allow you to customize the installation angle, turn-off delay time, illumination and sensitivity. Models of the past years of release have only tincture of the level of illumination and delay time, or the latter and sensitivity.

Adjust the range of the sensor is possible only by adjusting the installation angle. Sensor models, produced today, have hinges for this. They are fixed so that the infrared rays cover the maximum area for motion detection. An important factor here is the installation height of the device: the optimum is considered 2.40 m.

The sensitivity is slightly more complicated. To adjust it, the swivel lever (Sens) is provided. To adjust it is necessary so that the sensor "did not see" animals, and reacted only to the person. 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 there is an optimal option.

The illumination setting means that the sensor should only be triggered when darkness sets in. Begin, like the previous setting, you need to set the maximum. With the advent of twilight, note the triggering of the sensor and, at its discretion, increase the illumination or reduce it.

The last adjusts the delay time. It ranges from five to ten seconds and is adjusted by personal feelings. There are models of sensors, which increase the delay time with each subsequent turn-on.

As can be seen, the setting of the motion sensor is not particularly difficult.

Ceiling devices for fixing movement

This device is installed, due to its design features, only on a horizontal surface. A spherical body with a 360 ° viewing angle makes it possible to cover a large area. The 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 mechanism of switching on the light. The basic element of such a sensor is the Fresnel lens. When installing, it must be taken into account that it can not be blocked by any objects.

The device installed on the ceiling has a viewing angle of 360 ^° . If you install it at a height of not more than three meters, the diameter of the working area will be 10-20 meters. That is, a small room of one sensor is enough. In large rooms, the ceiling motion sensor is desirable to combine with the wall.

Ceiling devices are overhead, wireless and embedded. The latter can be successfully concealed from prying eyes. Any of them is inexpensive and can be installed independently without much effort.

Stand-alone lamps with motion sensor

It's not the first year in stores you can buy a lamp with a motion sensor on batteries. Virtually everything is captivating in him. For example, you do not need to bang the walls for laying wires, you do not need to pay all the expensive electricity. A montage, a pleasure: took off the protective tape, stuck to the surface and that's it!

The manufacturer supplied models of such lamps with the most economical LEDs. The consumption significantly reduces the smart sensor. It is he who is responsible for triggering and turns on or off the light. Ideal such devices in the corridors without natural light, cellars, cellars, store rooms, hallways and even cars.

The luminaire with the motion sensor on batteries usually weighs no more than 100 g, has a width of just over a centimeter, and the height and length is within 8 - 10 cm. It is installed on any surface. It can be fastened with screws, glued with tape, placed on a shelf of the cabinet or crushed with a magnet.

Equipped with such lamps almost always an infrared motion sensor. Therefore, you need to keep them away from sources of thermal energy. In some models, the photocells activate the sensor only at night.

The timer turns off the device normally after 20-30 seconds, so the 3A batteries last for quite a long time.

There are models of similar luminaires with adjustments to sensitivity, brightness, motion sensor duration of glow (30, 60, 90 seconds) and the shutdown button.

Installing the sensor on the move to turn on the light on the batteries should be borne in mind that heat sources and animals cause the sensor to operate. Therefore, to less frequently change the battery sensitivity is desirable to set at a minimum.

Street lamps with motion sensor

Modern lighting devices are not only used in the house. The adjacent territory as a multi-storey building, as well as a private one, already does not do without lighting devices, in which a traffic sensor for the street is integrated. Today, such lamps are already considered as an element of design. The principle of their work is the same, different devices for the energy carrier, scope and light element. The latter depends on the main technical and operational characteristics of the devices. Therefore, a street lamp with a motion sensor can have lamps:

- Classical . This includes both energy-saving lamps and incandescent lamps. Energy-saving light elements give a dim light flux, and incandescent lamps quickly burn out due to frequent regime changes.

- LED Light . Diodes are famous for their huge working resource, they do not produce heat, they shine brightly - this is all with minimal energy costs. This option is ideal for street lighting.

- Halogen . Intensive light output with extended service life and reduced power consumption. But at the same time they emit a lot of heat, so they are rarely used in flashlights.

On the energy carrier, a street lamp with a motion sensor can be autonomous (powered by batteries), stationary (powered by electric grids) and non-volatile (powered by solar cells with batteries).

Motion sensor for switching on light: connection

It is carried out by means of the terminal. Most often, three conclusions, sometimes four. There are four main connection schemes.

1. Sequential.
2. Parallel.
3. On several devices.
4. With magnetic starter.

Sequential connection means that the motion sensor fully controls the lighting.

Parallel is necessary in case of long illumination of the zone of the motion sensor operation. After turning off the light switch, the sensor, after detecting movement, will turn it on again and turn it off according to the settings.

Several devices will be needed in large walk-through rooms. In this case, the sensors are connected in parallel from one phase. If one sensor is triggered, then the rest are turned on.

A magnetic starter is mounted if motion sensors start powerful light elements or additional electrical appliances.