A variety of sensors surround people everywhere; they are used in a wide variety of fields and systems. One of the most common types is the mobility sensor. Such devices are used both in everyday life and in security systems. Often with their help, automatic lighting systems are created.
Content:
- The principle of operation of the motion sensor ↓
- Application area ↓
- Where and how to mount ↓
- Necessary materials and tools ↓
- Walkthrough ↓
- How to connect ↓
- One sensor / several sensors per circuit ↓
- Connection to lighting devices / to the switch ↓
- How to setup ↓
- Tips / Tricks ↓
The principle of operation of the motion sensor
Movement or presence recorders are characterized by a reaction to a change in infrared radiation caused by the appearance or disappearance of a person (object) on a sensitive element. For this type of sensor, the sensing element is a photocell. Often the work of household appliances is related to a change in infrared radiation. In this case, erroneous operation of the device is possible.
Infrared radiation depends on the temperature of the object, so a person gives a stronger signal, which allows him to quickly detect. Detection occurs when the thermal radiation of the photocell lens is reached, which forms a signal of parameter change in the system.
The main difference between motion and presence devices is their sensitivity. Thanks to wider susceptibility, presence sensors pick up even the smallest finger movements. For the motion recorder, the composition is as follows: it is equipped with a signal processing microcircuit based on a pyroelectric infrared element.
The main lens combines many small ones that help focus the infrared signal on the photocell itself and on the object. When the object moves, it is fixed by the lens in the segment of which it is located. Accordingly, when leaving the range, the signal disappears, so more accurate sensors have more lenses.
Application area
The installation of motion recorders helps automate the room (residential, industrial, office). The scope of such devices is quite wide. When turned on motion sensor in the control loop, you can provide the response of any electrical device to human movements in range.
When lighting is turned on in office premises, motion sensors are installed in corridors and utility rooms, where it is necessary to turn on lighting for a short period of time. Do not forget that there is always a need to adjust the duration of the included lighting. Such systems are often installed in the entrances, at the entrance to a house or office.
With the help of the intellectualization of rooms by such lighting systems, it is possible to achieve the inclusion of light in the dark the room at the entrance, when moving along staircases or entering a private house (multi-story staircase), entrance to garage.
In addition to turning on the lighting, the function of turning it off during prolonged absence of movement is also important. For example, after exiting the corridor, pantry, bathroom, the light will go out after ten minutes (the interval may be necessary for the user).
Where and how to mount
Installing motion registrars is simple and straightforward, making the procedure for introducing them into an automatic lighting system affordable. In addition, such devices are small in size, respectively, will not violate the appearance of the premises after installation.
Among the common installation sites note:
- Ceiling;
- Walls;
- Near the controlled device;
- Over the door, etc.
After choosing the installation location, you must correctly determine the model of the sensitive device, since the ceiling devices must have a viewing angle of 360 degrees, and for wall mounted viewing angles from 90 to 240 degrees are allowed.
In addition, the installation site is carefully selected in order to minimize the presence of blind spots. To do this, analyze the visibility rays of the device and their coverage of the space from the installation site.
Do not forget that in order to minimize false alarms, installation near:
- fans and air conditioners;
- passing transport;
- elements of the heating system;
- trees;
- sources of electromagnetic radiation and interference.
Necessary materials and tools
Among the basic materials and tools that will be required when installing motion sensors in a selected place, we can distinguish:
- tester (useful when calling the wiring);
- electric standard wire;
- motion sensor and installation diagram;
- stationery knife;
- self-tapping screws;
- drill or punch for mounting fixtures, etc.
Walkthrough
When installing the sensor in question, the following algorithm is used:
- Disconnect the electrical network in the room, since the sensors are connected directly to the network with 220 V.
- Run the wiring tester to find the wire going from the switch to the lamp.
- Open the sensor box.
- From the wire found, the contact stretches to the red terminal of the device.
- The second side of the wire connects to the brown terminal of the device.
- We find the wire going to the lamp from the back of the switch, and connect it to the blue terminal of the device.
- All exposed wires are necessarily insulated.
- We assemble the sensor and fix it in the chosen place.
- For reliable mounting, you can install the device on a bracket or a special metal (wooden) plank.
- Test the operation of the sensor entering and leaving its visibility zone.
- Set up the device.
How to connect
To connect the sensor, it is enough just to carefully assemble the circuit for connecting it to the electrical network, presented in the instructions for the device. Consider the features of some connection options.
One sensor / several sensors per circuit
When one sensor is connected, everything is extremely simple, it is necessary to correctly connect three electrical terminals: phase, zero and the inclusion of a lighting device. To ensure a constantly working lighting, even if there is no movement in the room, it is necessary to additionally connect a sensor adjustment switch.
This is realized by connecting a new logic element (key or switch) to the network between the phase and the wire connecting the sensor and the lamp.
In cases where the sensors have a small radius of action, or the rooms have an intricate shape, it may be necessary to include several motion sensors in the network at once. To solve this problem, it is necessary to turn on the devices in parallel to one phase. Otherwise, a short circuit will occur.
Connection to lighting devices / to the switch
Motion sensors can be connected directly to the lighting device and to the switch. The latter option will allow you to control the lighting and the entire light switching system if necessary. To implement these options, you need to correctly connect the sensor terminal provided for connecting devices or devices with the necessary object (lamp, switch, etc.).
How to setup
One of the important points in creating automatic systems for turning on and off lighting using motion sensors is the adjustment of the most sensitive element. Most models of the considered devices have additional potentiometers for adjusting the operation parameters. The main settings are Time, Lux.
The first one is responsible for the duration of the lighting. With the help of tuning, you can achieve that the lighting was turned on from 1 second to 10 minutes.
The Lux parameter helps ensure that the sensor is operational during daylight hours. With its help, a threshold value of illumination is set, if the illumination level is lower than the threshold, the sensor will work and the artificial light source will light up.
Tips / Tricks
When installing and connecting a motion recorder, you can give several recommendations:
- Avoid the presence of obstacles in the field of view of the sensitive element, for example, the presence of trees or other moving objects.
- Minimize magnetic and electromagnetic radiation in the area of the sensor.
- Consider the viewing angle during installation to minimize blind spots. Since the device will only trigger when the movement is detected in the visibility sector.
- The surface of the device must be clean, it is necessary to regularly clean it from dirt to prevent a decrease in sensitivity.
- Sensors of this kind can not withstand heavy loads (maximum 1000 W), so you should pay attention to the connected lighting device.
