A switch with a motion sensor that detects a person’s proximity will help the owner of an apartment or private house save energy. To optimize the operation of the device and minimize the likelihood of false alarms, you need to choose the installation location and configure the device.
Principle of operation
The motion switch provides automatic switching on and off of lighting devices, focusing on certain environmental disturbances. The light turns on when detecting the movements of living organisms within the spatial boundaries of the susceptibility of the detector. Models are designed for different types of waves: infrared, ultrasound, microwave. This allows you to choose a product that suits the goals of the consumer and the conditions in which it is planned to operate.
By the method of detecting the appearance of a person in the susceptibility zone of a motion sensor (DD), the switches are classified as active and passive. The former themselves emit waves and track the nature of their reflection. The operation occurs when the distances traveled by the pulse from the sensor to the obstacle and vice versa are not identical - this indicates that the object is a moving object. Such mechanisms work with radio waves or ultrasound. The latter, although not perceived by the human ear, causes a lot of concern to pets, so pet owners are not recommended to choose such products.
Passive sensors do not emit waves, but only capture thermal impulses from a living organism of sufficient weight. They are more affordable in terms of price, easier to arrange than active ones, but when used, the probability of an erroneous operation is higher.
There are mixed-type DDs that integrate the mechanisms of active and passive devices.
Varieties of motion sensors
Switches with motion sensors can work with various types of wave radiation. This makes a difference in the preferred conditions of use of the devices. In addition, they also differ among themselves by such parameters as the size of the working area, the signal transmission distance, the number of simultaneously working lighting devices, and the viewing angle.
Overview of Sensor Types
The sensors used in automatic light switches are able to recognize moving objects using different mechanisms. They differ among themselves in the nuances of application and the accuracy of the result.
The following types of sensors are distinguished:
- Infrared - react to thermal radiation emitted by humans and warm-blooded animals, which is why false inclusions are possible, especially in the case of large dogs. They have a democratic price and a large radius of the working area.
- Acoustic - respond to sound: creaking doors, knocking heels, clap your hands. Like the previous type, they belong to the class of passive devices. Since the sound vibrations arising in the field can have different origins, the scope of application of this group of devices is very limited: they are suitable for the basement of private houses, where the approaching host is always the source of sound. Also, such a switch can be connected in the corridor of a public building.
- Generating microwave radiation and tracking the movement of waves. When a moving object appears, the contacts close or open. Particularly susceptible models are able to recognize the approximation even because of an obstacle, so they are often used in security systems.
- Emitting ultrasound. The principle of operation is similar to the previous type, only the nature of the radiation is different. In apartments and private farms where there are animals, it is not worth using such devices.
-
- Infrared
-
- Acoustic
-
- Microwave
-
- Ultrasonic
To improve the accuracy of reading signals, various types of detectors can be mounted in the sensor. Such models are more expensive, but more precisely in action, have a low percentage of false positives and flexible configuration options.
How to choose an installation location
In order for the sensor to read the environmental readings correctly, it is necessary to place the device in an area where factors that distort the readings will not act on it. Do not block the switch with large pieces of furniture. Also, batteries or heating equipment should not be near the DD - this is especially important in the case of infrared options that respond to heat waves. Lighting devices should also not be located next to the switch.
Wiring diagrams
The simplest scheme involves connecting the DD to the gap of the phase cable heading to the bulb (LED, fluorescent or simple). This option is suitable for a room devoid of windows. Otherwise, you will need to install a device simultaneously with DD that does not allow the inclusion of light in the daytime. This can be a photo relay, operating in automatic mode, or a switch controlled by the user.
Both of these devices are installed in the same wire break. In this case, the photo relay is placed in front of the DD - then electricity will be supplied to it only in the dark, and the structure will not function idle. This scheme will extend the life of the DD: they are all created with the expectation of a limited number of operations.
Schematic diagrams of installation
Usually, an instruction is attached to the sensor that describes how to install it and is equipped with a connection diagram. In general terms, the installation looks like this:
- the sensor is placed in a wire break;
- in the terminals marked with the letters L (phase) and N (zero), connect the wires of the relying wires;
- exit from the third terminal lead to the lamp.
If automatic detection is not enough and the user wants to implement a manual lighting control method, there are two ways to do this. In the first case, the switch is mounted in a phase wire that extends to the DD from the shield - then in the open state the device does not read signals and does not supply voltage to the lamp. In the second, the key is put in a line going from the phase to the bulb input, and then when the circuit is closed, the light will remain on, even if the DD does not work.
If necessary, put more than one DD they are connected in parallel, while the wires from each sensor go to the lamp input, and the lighting is turned on if any of them worked. Another option is the purchase of lamps with a DD mounted in the housing.
Energy-saving lamps have the property of quickly failing when they are often turned on and off from the network, so without a special protection unit, you should not use them for a network with a DD - the saving effect will be reduced to zero.
The block is placed in front of the lamp after DD. It provides the leveling of voltage drops in the network, because of which the bulbs will not burn out so quickly.
Connection setup
To optimize the functioning of the switch with DD must be correctly configured. Calibration is necessary for three indicators - the time delay off, susceptibility and illumination.
Time setting
The delay time is a highly variable parameter: in some models it is 3 seconds, in others the maximum possible value reaches 10-15 minutes. The regulator itself is usually indicated as “Time”. Calibration can be done as follows: by setting the desired value, wait until the lights turn off.If the time interval seems too long or short, adjust it to the desired direction.
Degree of illumination
Only a model with an integrated photo relay has its regulator. It is signed as “Lux”. Making the connection, the sensor is set to the maximum value, and when it starts to get dark, it is reduced until the light turns on.
Sensitivity setting
The parameter is indicated by “Sen”. It determines the frequency of false inclusions associated with pet movements. Owners of large dogs will not be able to avoid such triggers, but for smaller animals this is real. Calibration begins with setting the minimum value and the test on yourself and on the animal. As necessary, the indicator is added.
Device selection
In order to choose the right model of a switch with DD, the user needs to take into account the restrictions imposed by different types of devices. The operating conditions of the device must also be taken into account.
Buyer Tips
IR sensors are often used in kitchen switches and other devices designed for use strictly inside the house. They are also suitable for street lighting, and for corridors and stairs it is better to choose other options that are less prone to erroneous operations.
When installing the switch, you need to consider its location so that direct sunlight and radiation from lighting devices do not fall on it, otherwise it will quickly fail. For flexible lighting settings, you must choose a model equipped with a built-in photo relay.
It is necessary to pay attention to the power of the load connected to the device. If the total power of the bulbs exceeds that for the sensor, the load will have to be divided between two DDs.
