Home lighting sensor. Light sensors. Types and device. Operation and application Automatically switching on indoor lights
Twilight switch, lighting (light) sensors are a device for automatically controlling sources of artificial (electric) light. Depending on the degree of illumination of the surrounding space, the sensor is capable of sending a signal to turn on/off lamps, spotlights, lanterns and other lighting devices. Properly installed and programmed equipment operates without human intervention. In other words, the light sensor (twilight relay) is circuit breaker, which monitors and controls the brightness of lighting in a certain area or room. When twilight occurs, it will turn on the light, and after sunrise, it will turn off. When using this equipment, you can achieve energy savings of up to 10-15%.
Design, installation and principle of operation of the light sensor
The main area of application of light sensors is automatic control light. They are used to automate lighting in garages, entrances of residential buildings, on highways, garden areas of private cottages and other places where the space is illuminated during the day natural light, and at dusk - electric.
The principle of operation of light sensors is to monitor the level of light radiation entering the field of “visibility” of the device. The light rays are focused by a photocell (light relay) and directed to the detector. When a certain brightness threshold (minimum or maximum) is reached, the detector generates a voltage that is used by the device as a signal to close the circuit and lock electrical devices. It is this signal, obtained as a result of the voltage created, that turns on the lamp when dusk occurs, and with the onset of dawn, turns it off. In order to save money at night, it is possible to turn off the sensor for a certain time.
Thus, any lighting sensor (street, home) is a photosensor - a primary transducer, an element of a regulating, signaling, measuring or control device of the system. It converts the monitored and controlled quantity into a signal that is easy to use.
The required illumination at which the light sensor is triggered is 5 - 50 lux. It can be adjusted depending on the location and installation conditions.
Equipment classification
Sensors for automatically turning on lighting differ in several respects:
- in size - they are small-sized (built into lighting) and standard (installed independently);
- according to the control method - they are divided into programmable, automatic, with a night energy saving function, with the possibility of forced shutdown;
- by load power - up to 1000, up to 2000, 3000 W;
- by type of load - energy-saving, LED, fluorescent or halogen lamps 220V, incandescent 220V, halogen 12V with an electronic transformer (or with a winding transformer);
- according to the design option - overhead (wall-mounted), internal (built into the electrical panel on a DIN rail) or external installation;
In some cases, to control the lamps, the connection of a motion sensor for lighting, which reacts to the presence of a person, is also used.
Currently, light sensors of such brands as CAREL, HAGER, ELTAKO, GIRA THERMOKON and others are common. The price of a light sensor depends on the type, functions of the equipment and manufacturer.
To increase driving comfort, vehicle manufacturers equip their cars with a variety of various devices. Twenty years ago it would have been impossible to think that windshield wipers could turn on automatically when it rains, and headlights could turn on automatically when it gets dark. what it is - basic information regarding such devices is given below.
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Description of the light sensor
So, what is a light sensor, what is it used for in a car and how does it work? First, let's look at the description of the device.
Purpose, location and operating principle
Light controllers are designed to automatically activate the light of the optics when it gets dark or when driving along unlit sections of the road. When it gets dark outside, the controller itself activates the side lights, as well as the low beam lighting. The same applies to trips in a tunnel - when entering the sensor, the sensor will turn on the lights, and when leaving the tunnel, it will turn them off.
How does the sensor work? According to the diagram, the principle of operation of the device is quite simple. The device uses a special photocell designed to measure the ambient light vehicle.
A control module is used to process the photocell signals, and the relay directly performs the function of activating and switching off the lighting. The photocell measures light in two zones - around the vehicle, as well as directly in front of it. This principle allows us to eliminate possible false positives.
If necessary, the car owner will be able to adjust the device at any time so that the device activates the optics at a certain decrease in the degree of light. In other words, the driver can set a certain response threshold. The controller itself operates quite quickly - when the street illumination drops to the specified threshold, it will take no more than two seconds to activate the optics. As for turning off, this requires at least six seconds.
The control module, which performs the function of processing pulses, transmits the corresponding signal to the relay when the illumination on the road decreases. The module has a special bolt used to adjust the sensitivity of the controller. The relay itself is directly connected to the optical control wiring. As for the location, it may vary depending on the car. As a rule, the devices are installed inside the car, under the windshield. It can also be mounted on the center console or on the rearview mirror.
Photo gallery “Location of the controller”
Varieties
Currently, manufacturers produce many machine models that are initially equipped with controllers of this type. The device may not always function, since the car owner can turn it off if necessary.
Based on their types, these devices can be divided into two types:
- Universal controllers. Their installation is possible in accordance with the diagram on any vehicle model due to the versatility of the device and the method of its connection.
- Models for specific vehicles. That is, designed for a specific car model (the author of the video is Evgeniy off).
As for the differences, there are practically none. The only difference is that universal devices are not equipped with a selector with the “Auto” position, which can be installed on the steering column switch.
However, it should be noted that there are also types of controllers:
- For low beam lighting, used only to perform this function.
- To activate side lights, as a rule, such devices are used to illuminate trucks. They will not function during daylight hours or when the optics are activated. But when it gets dark outside, the car itself will begin to glow.
- Salon-type devices. With the help of such devices, you can adjust the level of illumination in the car interior.
Typical malfunctions and methods for their elimination
What problems can occur in the operation of sensors:
- Failure of the photosensitive element. Such an error will lead to the device being inoperable, and replacing the sensitive component itself can be problematic. As a rule, in case of such malfunctions, the device is simply replaced with a new one.
- Failure of the control module. It is also an unpleasant problem, since it risks a complete replacement of the control unit if it cannot be repaired.
- Relay failure. Least expensive option. Since the relay itself cannot work forever, sooner or later it will fail in any case, to solve the problem this element simply needs to be changed.
- Damage to wiring. In case of such a problem, you need to ring the electrical circuit and look for a break or breakdown in the wire; damaged areas must be replaced (the author of the video is the KingSyze911 channel).
Instructions for installing a light controller with your own hands
How to install a light sensor with your own hands (for example, Volkswagen Polo):
- First of all, the location for installation is selected. The controller can be installed on Windshield or on the center console, but keep in mind that the device should not be covered.
- After installing the device, the wiring is laid. The wires must be arranged in such a way that they do not hang and interfere with the driver’s view. Therefore, all cables are laid under the interior trim. The end of the wire should be inserted into the console itself to the place where the selector is mounted.
- Next, the selector is removed, the connector with the wiring should be disconnected from it. The control module must be connected to the new lever, as well as a connector with wires. The switch is put in place, after which you can check the functionality of the controller.
Light sensor LXP-02 and LXP-03. Installation
In this article we will consider the issues of installing and connecting a light sensor. Also given electrical circuits the most popular models of light sensors.
Let me remind you that this device is widely used in the field of home automation to turn on/off electric lighting depending on the light level outside. The names may be different - light sensor, light sensor, light control switch or photo relay, but the essence is the same.
I spoke in detail about such a sensor in the first part of the article -. Its structure, operation and characteristics are discussed in detail there.
Therefore, I’ll get straight to the point:
Connecting the light sensor
I will give three options for the connection diagram, they are all identical, the only difference is in the display method.
1. Circuit similar to a motion sensor
The connection diagram for the light sensor is completely identical to. Only the “filling” of the sensors differs.
The diagram is taken from the article about the motion sensor, link above.
2. Light sensor connection diagram from the instructions
This is how the light sensor connection diagram is shown in the instructions:
Light sensor LXP. Connection diagram from the instructions
3. Connection based on photo sensor
For those who like everything to be “at their fingertips,” here is the following picture:
A short explanation of the connection diagrams:
- The brown wire receives phase.
- On blue wire zero is connected.
- A load is connected to the red wire (the first terminal of the lamp).
- The second terminal of the lamp is connected to zero (in the same place as the blue wire of the sensor)
It is worth adding that light sensors can be connected in the same way as conventional switches - in series and in parallel, if necessary. An example can be seen in the article about.
So, we figured out the connection, now
Light sensor installation
It would seem, what is wise here? I screwed it on (see the picture at the beginning of the article), connected it, configured it, and that’s it! But sometimes the installation location is chosen poorly, and problems begin.
It's time on our street Street lights in the evening they turned on intricately. They will turn on, go out, turn on again, and so on with a period of about 1 minute. Then, with the onset of good darkness, they turned on completely.
Why is that? The light sensor was simply mistakenly installed in the illumination zone of the flashlight being turned on. It turns out: it became dark - the sensor worked - the flashlight came on - it became light - the sensor turned off - it became dark... And so on, a vicious circle.
Setup and calibration
When setting up the light sensor, it is important to use the black bag that comes with the sensor. This bag serves to simulate night.
Bag for setting up the light sensor
Of the adjustment controls in the light sensor, there is only a light level control (LUX). It sets the level at which the sensor's internal relay is triggered.
The level setting is described in more detail in the description. schematic diagram, below.
There are the simplest light sensors (for example, LXP-01), which have no adjustments at all. There are advanced ones that also have an on/off delay time regulator.
Well, now the most interesting thing -
Light sensor circuits
Undoubtedly, for quick and easy repair For a light sensor, you need a circuit diagram that will immediately make it clear what is connected where and how it works. Below are a couple of sensor diagrams and repair recommendations. If you have questions about repairs, ask in the comments.
The circuit is copied exactly from the board shown in the link at the beginning of the article. It is worth noting that the manufacturer is constantly working to improve its device (price/quality), so the scheme may change.
Light sensor LXP-02. Electrical circuit diagram
But the principle remains the same:
The supply voltage of 220 Volts is supplied through terminals L (phase) and N (zero).
Phase and zero can be “confused”, just as in principle it is possible (but not recommended) to turn off the zero and not the phase in conventional switches. Only safety and common sense suffer.
The voltage is rectified by a diode bridge (4 diodes of type 1N4007), filtered (smoothed) by an electrolytic capacitor, and stabilized at a level of +22...24 Volts by a zener diode of type 1N4748.
Next, the constant voltage powers the rest of the circuit, which works like this. At the output of the 68k resistive divider - VR - Photoresistor, a voltage is generated that is inversely proportional to the illumination. Trimmer resistor VR with a resistance of 1 MOhm is the same “twist” with which the desired response level is set.
It is not a fact that a photoresistor is installed in such circuits; a photodiode may also be installed, but the principle is the same.
If you want to save energy, set the maximum resistance, turn it clockwise ( LUX-), and it will work when it is already completely dark.
If you want the street lighting to turn on at the slightest cloud, turn the regulator in the other direction ( LUX+).
When darkness sets in, the illumination drops, the resistance of the photoresistor increases, and the voltage at the base of the transistor increases. And it reaches such a level that the transistor opens, a current sufficient to turn on the relay flows through the collector CA. The relay with its contacts turns on the load, which is connected through the output LOAD.
At the same time, the LED lights up, and a 47 uF capacitor in the base circuit smoothes out all processes so that the relay does not click too quickly, for example, if it is blocked by a tree branch swaying in the wind.
In conclusion, here is a diagram of a more powerful model, LXP-03:
Additional features in modern cars make driving more convenient and safer. One such option is a car light sensor. In the article we will talk about its structure and operating principle.
What is a light sensor in a car
Another name for this option is light sensor. Its device is quite simple. It consists of a photocell, a control unit and a small relay. The element itself is installed in the most illuminated place of the car, not subject to contamination. Usually above or below the windshield. Indirectly, a light sensor can be classified as a security system. The driver may simply forget or ignore the need to turn on the headlights when entering a tunnel or other darkened area. The system will do this itself.
Light sensor in the cabin
A photocell records changes in illumination in space. If there is not enough light, a signal is transmitted to the control unit, and then the relay turns on the low beam and side lights. If the system detects sufficient illumination, the lighting equipment turns off.
Light sensor device
The design of the component and the entire system is quite simple. If such an option is present in basic configuration car, it is located in a special recess in front of the windshield. The sensor housing contains an LED and photosensitive elements. The sensor is connected to the control unit, relay and contacts for turning on the headlights and low beam.
The lighting control switch must be set to AUTO for the system to operate in automatic mode.
Lighting system switch. AUTO position Special photodiode filters detect daylight and electric light. Very convenient, for example, when entering a tunnel or indoor parking. You can also adjust the dimming time of the headlights after turning off the ignition or in normal lighting.
Types of light sensors
Regular light sensor
If the car is not equipped with such a device, then you can easily install it yourself. The system is inexpensive. It is enough to fix the sensor, connect the relay and correctly connect the wires to the vehicle's electrical wiring. The system will work properly.
Built-in light sensor
Built-in light control components are included in more expensive car trim levels. As a rule, their range of functions is wider. You can configure the system to turn on the interior lights and turn on and off the instrument panel lights.
Combined light sensor
Often a light sensor can be combined in one device with a rain sensor. In this case, it is mounted at the top of the windshield. If everything is clear with the light sensor, then the operation of the rain sensor is also based on photodiodes and photocells. If raindrops fall on the windshield, the passing light is refracted differently and scattered on the way back. Photocells pick up this and... In heavy rain, the headlights also turn on automatically. Drivers note that the system works correctly and correctly. The driver does not need to turn on the windshield wipers every time the glass gets wet. The photocell detects the level of water on the glass and the intensity of rain and adjusts the frequency of the windshield wipers independently. In some models, when it rains, the glass is heated to prevent fogging.
How to check device functionality
This option is very convenient and drivers quickly get used to it. No need to worry about turning the headlights on or off - the system does it itself. But if the system fails, the car owner may not notice the breakdown in time.
Checking the light sensor is very simple. It is enough to cover it with dark material or rags. If everything is in order, the system will perceive it as night and turn on the lights and side lights.
For the first time, a rain sensor was used in the middle of the last century by the American automaker General Motors on one of its premium models. But mass production due to imperfect technology, it was not mastered. And only by the mid-nineties, first Japanese automakers, and then others, began to install rain and light sensors on expensive models.
Nowadays they will no longer surprise even the owners of compact and very inexpensive cars. Modern rain and light sensors are combined into a single module located at the top of the windshield, but the principles of operation of these sensors are different.
Hella light and rain sensor device:
1 - binding medium; 2 - upper sensor housing with optics; 3 - curtain; 4 - printed circuit board with sensor with connector connector; 5 - lower body sensor; 6 - clamp.
Rain sensor
A- dry windshield; b- wet windshield.
1
- LED transmitter; 2
- prism; 3
- photodiode receiver; 4
- water drop.
Detects the presence of water droplets on the windshield using an optoelectronic measurement method. The sensor's sensitive element consists of one or more LEDs (transmitter), a prism and a photodiode (receiver).
The infrared rays emitted by the LED enter the windshield through a prism, are reflected from the outer surface and enter a sensitive photodiode. The beam is reflected almost completely from dry and clean glass, and therefore the signal on the photodiode has large amount . When water drops hit the glass, the light rays are refracted, and therefore only a small part of them reaches the signal receiver. The heavier the rain, the fewer rays hit the photodiode.
The electronic unit continuously determines the amount of water on the glass and adjusts the frequency of strokes and operating speed. The system even knows how to assess whether the glass is dirty: if after one double stroke of the wipers transparency has not been restored, the windshield washer automatically turns on.
Light sensor
V- front light sensor; G- external light sensor.
1
- light guide with lens; 2
- light guide with light filter.
In the first combined light and rain sensors, there was only one element that measured illumination. When it got dark or entered a tunnel, he turned on the headlights and instrument lighting. Then, up to three photosensitive elements were placed in the same assembly, each with its own area of responsibility.
The light intensity in front of the vehicle is measured by a narrow-angle front light sensor. Using the signal from the sensor, the electronics recognize day and night and turn the headlights off or on accordingly.
Light sensor response zones:
Using a wide-angle light guide, the ambient light sensor (also known as sun sensor) detects the level of light above the vehicle. An additionally installed light filter allows you to distinguish between solar and artificial light . This is necessary so that, for example, the automation turns on when entering a lighted tunnel during the day; and if the car is under the scorching sun, the climate control should cool the interior more intensively.If the car is equipped with a head-up display, a narrow directional HUD sensor is installed. It measures the illumination of the area where information is projected. A electronic system adjusts the brightness of the backlight of elements displayed on the display.
Interaction of light and rain sensors with other vehicle systems
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On your own
If your car does not have a standard rain and light sensor, you can. For example, there are rain sensors on sale, both domestic and foreign (usually Chinese) made. They are a small plastic box that is glued to the inside of the windshield and connected to the car's electrical system with a wiring harness. There is even a version for 24-volt electrical equipment. Simple universal rain sensors cost up to a thousand rubles, the most sophisticated ones cost a little more than two thousand.
If you don't want to understand the car's electrical circuits to adapt the sensors, search for a specific model. In addition to the sensor, the kit includes a central light switch with the Auto position, wiring harnesses, and plastic sensor covers that fit onto the rear view mirror bracket. The price of such sets is in the range of 3800–4500 rubles, and complete with a self-dimming rearview mirror they can cost up to 9500 rubles.
Destroying MYTHS
- The rain sensor is triggered by the impact of water drops.
No. The operation of the sensor is based on optoelectronic measurement. - At night the rain sensor is powerless.
No. External lighting does not affect the operation of the system since it uses its own infrared light sources. - You can say goodbye to the sensor when replacing the windshield.
No. Glass manufacturers provide a window in the tinted or silk-screened layer. Installing an old sensor on new glass is possible, but subject to the technology, and after installation you need to check the correct operation of the sensor. - In winter, the sensor acts up.
No. The sensor may not respond correctly to snow. But the reaction to water droplets from melted snowflakes will be correct. The worst thing is if the sensor installation site is covered with a crust of ice.
In this case, it is better to switch to manual control of the windshield wipers. - Rain sensors work the same on all cars.
No. The car manufacturer is responsible for adapting the rain sensor to the vehicle. At the same time, a full range of finishing work is not always carried out with all possible types of glass (thermal different colors, equipped with electric heating, with a tinted strip in the upper part). With some options, slightly less correct operation of the sensor is possible.
Cars almost always have manual adjustment of the sensor sensitivity. And only on some cars this function is software disabled.
Photo: manufacturing companies, depositphotos.com
