Do-it-yourself motion sensor repair. How does the proximity sensor work in a smartphone

Permanent availability small canisters of gasoline in a car or a car owner voting on the highway asking for refueling, all this is a consequence of the fact that the fuel sensor in the car does not work. The failure of this sensor does not affect the operation of the main mechanisms of the iron horse, but it significantly affects the comfort of using the car, since it constantly becomes necessary to calculate how much the car has driven since the last refueling and how many more kilometers you can drive without stopping at a gas station.

Article author: mudriy_lev
Specialization: repair of autogenerators and servo drives in the car.
Place of work: service center. Experience: 2 years.
Education: higher - electrical engineer, secondary special - mechanical assembly work mechanic.

Consider the main reasons.

Potentiometer and its problems

On modern cars a wide variety of fuel level sensors are installed. The widest niche was occupied by sensors based on potentiometers. This type of conversion of fuel level information into electrical signal It has a large number of merits.
There are two types of sensors based on this method of measuring the fuel level:

• lever (became widespread)
• tubular (used mainly on large vehicles)

If the lever-type fuel level sensor does not correctly indicate the fuel level, then the reason associated with the potentiometer that caused this malfunction may be as follows:

• Potentiometer contacts oxidized
• there was a natural wear of the tracks or the slider of the resistor
• natural aging of the resistor
• resistor mismatch nominal value

Potentiometer Troubleshooting

A symptom that the contacts of the potentiometer have oxidized is the temporary absence of true information about the fuel level in the gas tank. The owner notices that from time to time the indicator shows reliable information. Usually in this case, the light indicating the end of fuel works flawlessly.

To diagnose this malfunction, it is necessary to visually inspect the variable resistor of the fuel level sensor. Oxides will stand out in a different color than normal. According to their number, a decision is made what to do next:

• clean (in case of low amount of oxides)
• move the slider (if only part of the tracks is oxidized)
• replace the fuel level sensor with a new one (if the oxides are significant and have damaged the tracks or the slider)

A symptom of the natural wear of the tracks and the slider is either a complete failure of the sensor, or its correct operation only in certain areas. A visual inspection in this case shows the run-down of the tracks, and in more rare cases, damage to the slider.

If it is possible to move (bend) the slider to an undamaged area, then the sensor will please the owner with its long, trouble-free operation. But if the slider is damaged, or there has been a serious destruction of the tracks, the repair does not make sense. Must be purchased new sensor fuel level.

To establish the next reason why the fuel sensor does not work, you need a multimeter, or an ohmmeter of any design. The resistor can change its resistance and, as a result, show false information. Checking the resistance value with an empty, full and half-filled gas tank will reveal this problem. Repair in this case is not advisable, since it is more reliable to install a new sensor.

If problems with inaccurate fuel level arose after installing a new sensor, then common cause is the discrepancy between the resistance and the nominal value. This situation arises due to the fact that the sensors are similar in appearance, but their various modifications have different resistance values.

The float is not informative

Problems when the fuel gauge does not work are often related to the float. 2 types of floats are installed on cars:

• hollow (plastic, plastic, metal)
• made of lightweight porous material

The first type of float faces the problem of mechanical damage. As a result, gradually the pointer arrow does not reach the maximum with a full tank more and more. The float is filled with gasoline and the gasoline sensor shows the wrong level every day more and more. Repair in this case is carried out by replacing the float.

The second reason why the fuel sensor is lying is faced by both types of float. As a result of mechanical damage to the gas tank, the float seizes. In this case, the indicator will either show a single value, or work only in a small range. Elimination of this breakdown is possible only by replacing the gas tank.

"Bona fide" previous owner

It makes no sense to control this type of “malfunction” on devices. If the car was only purchased on the secondary market and the fuel level sensor does not work in it, it is necessary to remove the fuel pump and see if this sensor is present. There are times when this sensor (or part of the sensor) is simply missing as a result of the "pre-sale preparation" of the previous owner.

The sensor incorrectly shows the fuel level due to the bending of the lever

The main symptom of such a problem is that the indicator needle does not reach one of the extreme marks. The elimination of this malfunction is carried out by editing the lever. But since such a malfunction does not appear on its own, but is the result of a mechanical effect on the gas tank, the float may jam after the lever is adjusted. In this case, repair or replacement of the gas tank will be required.

Indicator and its problems

Also, the reason why the fuel sensor does not work may be hidden not in the sensor itself, but in the indicator, which shows the wrong fuel level as a result of wedging of the movable winding of the indicator and, as a result, the impossibility of its free movement.

Does your phone's screen go blank when you make a call and won't turn back on even if you don't put it to your ear? This means that the proximity sensor does not work on your phone, or it does not function correctly.

What is a proximity sensor?

The proximity sensor in the phone reacts to the approach of an object to the phone and performs 2 very convenient and important functions:

• Screen fade. When the phone screen is brought close to, for example, your ear, the screen turns off to conserve battery power.
• Screen lock. The screen is blocked from accidental clicks.

Usually, the proximity sensor is located on the top, next to the speaker and front camera. If it is hidden, it is easy to find it by covering a certain area with your finger when making a call. If the screen goes blank, it has been found.

Causes of a malfunctioning proximity sensor?

The problem can arise both in the case of mechanical impact, and errors in software. If the defect occurred after updating or installing a third-party application, you should not be upset at all, because you can solve the problem yourself. If the defect arose as a result of a fall, impact or pressure, then it is best to contact the service center. IT-LAB SC performs quality repair damaged (peeled) housing or replacement of the proximity sensor!

However, if the problem is related to a bug in the software, you can fix the phone yourself. We will tell you about several ways to fix this problem.

How to turn on / off the proximity sensor?

If the proximity sensor stops working, you can simply turn it off so that the screen does not turn off when you make a call. Of course, this solution does not solve the problem, but at least it allows you to disconnect from the interlocutor when making a call or use other functions (digital dialing, speakerphone, etc.).

On Android, this is done in the following way:

1. Go to "Challenges"
2. Go to "Options"
3. Go to "Incoming Calls"
4. In the paragraph, move the slider "Proximity sensor".

Ways to fix the proximity sensor

1st way. Sometimes the sensor is interfered with by phone accessories. Try removing the cover and check the result. Poor quality strained glass can also cause glare interference with the sensor. Even though it seems that this advice banal, on the net you can find many negative reviews owners of low-quality accessories whose devices began to work incorrectly.

2nd way. Incorrect operation of the proximity sensor can be caused by errors in the software. To correct in such cases, you can use the sensor calibration. Calibration can be done using third-party applications that can be downloaded from PlayMarket or the AppStore.

3rd way. If the 2 previous methods did not help you, the easiest and most reliable solution to the problem is to restore the factory settings.

Attention! This method not only restores all phone settings to factory settings, but also deletes all data, including photos, videos, applications, phone numbers, etc. Don't forget to transfer them to external media.

If all of the above methods did not help, then it is better to take the phone to the IT LAB service center for repair of the proximity sensor. Convenient location, many points of repair throughout the city. Our experts will cope with the breakdown of any complexity. More detailed description and prices for phone repairs can be found in the appropriate section.

Each smartphone consists of dozens of parts, sensors and elements that are responsible for various functions of the device. One of these parts is the proximity sensor. Often people are faced with a violation of its work: the sensor is buggy, does not work, or has stopped working altogether. What to do in these and other situations, you will learn from this article.

What is the Xiaomi Proximity Sensor and what does it do?

The proximity sensor or, as it is also called, the light sensor is responsible for approaching, or rather for turning off the screen when telephone conversation and for adjusting the brightness level.

Sometimes the question comes: "Where is the proximity sensor?". In fact, the word “sensor” is rather arbitrary, denoting the presence of a special sensor in the design of the device next to the front camera and earpiece.

Disruption of this function has many inconveniences. For example, during a conversation, you can accidentally press unwanted buttons or even drop the call altogether. If the proximity sensor does not work, the phone, while in your pocket, may involuntarily perform any actions or call someone, guided by the screen touching the clothes.

Causes of problems

Speaking about the appearance of a sensor problem, you can identify some cases that are conducive to malfunctions. The main part refers to the settings inside the phone.

Causes of problems:

• The sensor function is disabled;
• Activation of unnecessary options;
• Incorrect film or protective glass. Operation may be impaired if there is no special hole on the glass or film for the speaker or front camera. In such a situation, you just need to change protective material.
• Incorrect operation of the device itself. Only in this case it is necessary to calibrate the sensor

Now let's deal with each case separately.

How to turn on the proximity sensor: troubleshooting

The first two problems require simply accessing the settings and doing some simple work. Be sure to study these sections in the settings without proceeding to the calibration right away - everything may be easier than you think.

Turn on the light sensor function:

• Go to the "Phone" application and open the menu located at the top right (three dots);

Xiaomi Proximity Sensor

• Click on the "Settings" field, then you will be taken to the call settings, where you need to scroll down the page and find the "Incoming calls" section - go there;

• Find the "Proximity sensor" field and pay attention to its status;

• If the option is disabled, enable it;

You can also adjust the operation of the sensor using the disable extra function- Pocket lock.

This can interfere with sensory processes.

Turning off the lock in your pocket:

• You again need to get into the call menu through the Phone application;

• There, in the “Incoming Calls” tab, there is an option “Pocket Lock”, which should be disabled;

Please note that the "Pocket Lock" feature is not present on all Xiaomi models or is located in a different location. As a rule, these are older versions of smartphones. For example, on Xiaomi Redmi 3, Xiaomi Redmi 4 and Xiaomi Redmi 5 models, the path to this option will be different.

Another way to prevent unwanted clicks on Xiaomi:

• Open "Settings" and scroll the page a little;

• Open the "Lock screen" section and activate the "Prevent accidental clicks" function;

If none of the above methods of setting up the sensor helped you, move on to more time-consuming operations.

Proximity Sensor Calibration

Calibration is a rather serious process that requires utmost care, since it is carried out through the engineering and main menus, that is, you will deal directly with the hardware.

First, let's check if the sensor works:

• You must first call . This is done as follows: in dialing a phone number (the "Phone" application), enter the following combination: "*#*#6484#*#*". After that, the following functionality appears on the screen:

Xiaomi Proximity Sensor - Calibration

• Select "Single item Test", then - "Proximity Sensor";

• A test will appear on the screen, during which, when the finger is close to the screen (to the speaker), there will be a corresponding inscription: “Close”, and at a distance - “Far”. If you see this, then everything is in order. You can start calibrating. Otherwise, contact the service center.

4. Done.

Calibration is the same for all models: Xiaomi Mi 6, Xiaomi Redmi 3, Xiaomi Redmi Note 4, Xiaomi Redmi Note 5, Xiaomi Redmi 4x, etc.

Instruction:

• Turn off your phone;
• Now you need to call the Main Menu. To do this, simultaneously hold down the volume up and power buttons. After the vibrating signal, release the power button, but keep holding the volume key until the Xiaomi logo appears.
• If the opened functionality is in Chinese, translate it into English - click the "中文" button, located to the right of the "download" key.

Xiaomi proximity sensor - instructions

• To open the engineering menu, press the topmost button;

• Next, click on "Proximity Sensor".
• Place the gadget horizontally, putting it on something flat, it is also worth opening it completely, cleaning it, ridding the sensor of bright lighting.
• Press the "Calibration" key to start calibration.
• At the end of the process, “Successfully” will appear, and then you will be prompted to check the sensor.
• Exit the menu and turn on the phone.

As practice shows, work should be restored.

Sensor calibration

Another rare but existing cause of sensor failures can be sensor failures. To fix this, you can also do a calibration, which is much easier and faster than the previous one.

Instruction:

• Call the engineering menu as described above;
• Find the "TouchPanel" function;
• The smartphone will offer instructions that you should follow by swiping your fingers across the screen;
• At the end of the work, you will receive a notification;

Xiaomi Proximity Sensor

• Turn on the device;

For this, use special applications that are available in the Play Market: Display Calibration, TouchScreen Calibration, etc.

How to disable the proximity sensor

To disable the sensor, cancel all the functions that were mentioned at the very beginning.

If the calibration did not help

However, in some situations, the problems do not go away.

This may happen for the following reasons:

1. The smartphone is defective;
2. Wrong flashing;
3. The display was replaced. Perhaps the new display that you have installed is of poor quality or not new;
4. other individual situations.

Here it is already worth contacting directly the place of purchase, the service center or those who replaced the screen for you.

Video instruction

The fuel level meter in the tank is a fairly simple mechanism that any car enthusiast with a basic level of technical knowledge can figure out. Consider why the fuel level sensor does not work, as well as ways to eliminate all possible breakdowns (the arrow twitches, “lies”, shows only a full or empty tank).

Conditions for correct operation

If you have not previously encountered electrical devices and do not know how the fuel level indication system works, familiarize yourself with the following concepts:

• variable resistance (rheostat) - a device with which you can adjust the value of resistance. The greater the resistance in the circuit, the less current flows in it;
• fuel level indicator (UUT) - an element of the instrument panel that indicates the amount of fuel in the tank. May be analog or electronic;
• fuel level sensor (FLS) - a meter located in the tank.

Most systems for indicating the level of fuel in the tank work on the same principle. There is a float in the tank, on the counterpart of which there is a sliding contact. The sliding contact moves along the plate with contacts (resistive substance) rigidly fixed on the meter body. Moving the sliding contact changes the amount of resistance, thereby increasing or decreasing the amount of current flowing in the circuit. The lower the resistance, the more current flows in the circuit and the more the needle of the fuel level indicator deviates.

The chain includes:

The principle of operation of a lever-type FLS is described, but in the case of a tubular-type meter, the difference is only in the method of changing the resistance in the circuit. Tubular type meters can be found on BMWs. In the new generation of VAZ vehicles and foreign-made models, the DUT is most often of a lever type and is attached to the plastic housing of the pump section.

Pilot lamp

One of the contacts of the low fuel warning lamp can be attached to the rheostat. In this case, when the volume of fuel decreases, the resistance in the circuit drops so much that the current becomes sufficient to ignite the lamp.

In some systems, a separate thermistor is included in the lamp circuit (resistance depends on its temperature). The thermistor is fixed in the casing of the pumping section. When the amount of gasoline / diesel is reduced to a certain level, it ceases to be washed and cooled by fuel. The passing current heats the thermistor, reducing its resistance. As the resistance decreases, the light on the dashboard starts to light up.

Faults

For what reasons the fuel gauge may not work:

• absence good contact on any of the sections of the circuit (breaking off wires, oxidation at the junction of connectors, cracks at soldering points);
• malfunction of the dashboard indicator (for example, violations of the soldering points);
• disconnecting the float from the sliding contact;
• fuse blown;
• no contact between the resistive track and the sliding contact. The reason may be the formation of oxides, plaque on the surfaces, the weakening of the pressure of the sliding contact on the resistive layer, the abrasion of the tracks of the resistive layer.

Pointer "lies", works intermittently

The reasons why the gauge incorrectly shows the fuel level in the tank:

• the presence of additional resistance in the circuit (oxidation at the connectors, poor mass contact, the formation of oxides, deposits on the resistive layer and sliding contact);
• float casting defect, due to which it is filled with fuel. Breakage is extremely rare, but still possible, however, as is the bending of the float thrust due to mechanical impact during unskilled repairs;
• formation of plaque on the guide post (only typical for tubular type sensors). In this case, the movement of the float will be difficult.

The arrow always shows a full tank if the system:

• there was a separation of the float from the sliding contact (in this case, the slider will always be in the extreme position);
• the wire going to the pointer is shorting to ground somewhere, due to which the resistance in the circuit decreases.

The twitching arrow of the UUT indicates partial abrasion of the resistive track of the potentiometer. This will also cause interruptions in the operation of the pointer. Since most often the car is used with a fuel tank filled by 40-60%, it is in this range that the abrasion of the resistive layer occurs most quickly. Therefore, the pointer can only work properly when the position of the sliding contact falls on an intact resistive layer.

DIY diagnostics

To find the reason why the fuel level sensor does not work, you will need a multimeter (we recommend reading) and a control. First of all, it is necessary to determine whether the cause of the breakdown is in the sensor located in the tank, or in the indicator. To do this, remove the connector connected to the fuel section (located at the gas tank hatch, which in most cases is accessible from the passenger compartment). According to the wiring diagram of your car model, determine which of the wires goes to the dashboard indicator. Turn on the ignition, then apply a negative potential through the test lamp to the corresponding pin of the connector. If the arrow of the pointer rapidly went up, then the problem is in the sensor. For further diagnostics, it is necessary to get the fuel section. A multimeter will measure the resistance of the potentiometer.

Leaving the lights on on the streets or indoors all night is unreasonable and irrational. In order for the bulbs to shine only when necessary, a motion sensor is installed in the power supply circuit of the lighting devices. If a moving object appears within its range, a signal is sent to the detector, and the illumination lights up.

When the object disappears from the sensor area, the light goes out. This mechanism of action proved to be excellent in lighting:

• streets;
• utility room;
• warehouses;
• corridors;
• flights of stairs;
• entrances;
• basements, etc.

Movement sensors are used in places where people periodically appear. Devices help save energy and provide convenience in the use of lighting.

However, like other devices, motion sensors sometimes break down, fail, or work incorrectly. This may be due to malfunctions inside the device or incorrect connection and setup. If the sensor malfunctions, you need to find out the cause and eliminate it.

Motion sensor failure will bring a lot of trouble

Features of work

An electrical sensor records the movements of people and other objects in its area of ​​action. When a person enters the activity radius of the device, a person launches the sensor system of the detector, which transmits the information received to the mechanism to which it is connected.

Work principles different types sensors:

• Ultrasonic- operate by the method of reflection of the rays of the ultrasonic spectrum from the surrounding objects. When a moving body enters the detector's operating area, the frequency of the reflected wave from the object changes, this is recorded by the receiver. It sends a signal to turn on the light;
• infrared sensors work by analyzing thermal infrared radiation. The device has two sensitive receivers - pyroelectric elements. Both analyze IR radiation. If there are no movements of objects radiating heat in the coverage area, the signals received by the elements will be the same. Therefore, the sensor does not turn on. And when a living object moves, falling into the zone of operation of one of the elements, the signals coming from both receivers are different. Therefore, the sensor detects the presence of movement and the light comes on. infrared devices perceive temperature fluctuations environment. In this regard, it is forbidden to install them in the kitchen or near entrance doors. To prevent turning on the light from the movement of small animals within the radius of the sensor, it is necessary to correctly set the operating temperature range;
• Microwave devices emit high frequency electromagnetic waves of 5.8 GHz. Waves reflected from objects are recorded by the sensor, and when the slightest difference in the reflected signals appears, the sensor's microprocessor is triggered and turns on the lighting. The device is sensitive to movement. But it has its drawbacks: high flow energy, which is important to consider when operating the device on batteries, as well as high cost.

Infrared motion sensor

Typical breakdowns and how to fix them

Motion sensors for lighting operation are subject to the following faults:

• Lack of inclusion.
• No timely shutdown.
• Switching on and off occurs spontaneously.

If the motion sensor for the light does not work, first check that it is connected correctly. At this stage, determine after which the device stopped working, under what circumstances this happened. Reasons why the device could break:

• There was a power surge.
• There was a power outage in the area.
• Accidental impact with a foreign object.
• There was an unpleasant smell.
• The device was caught in the rain or flooded by neighbors from above.
• Previously, the device did not always work properly, etc.

Knowing the cause of the breakdown, you will understand in which direction to move on. Check if the device is properly connected to see if the required power is coming to the device and if there are indicators, if they are lit.

The first step is to check the wiring diagram

Another important point- Sensors often fail if their operation parameters are configured poorly or not configured at all. The user could make a mistake when setting the regulators. After fixing the error, the device will work properly. To do this, put all the controls in a position in which the light will turn on with the greatest probability. Set the highest sensitivity value and the shortest operating time. Under such conditions, you will analyze the operation of the sensor and its ability to respond to movement.

The sensor does not work due to broken settings

If your appliance does not turn off the light or does not function properly, first look at the settings. On the body of the device you will see three controls labeled SENS, TIME and LUX.

• The SENS value controls the sensitivity of the motion sensor.
• The TIME parameter defines the delay time before turning off the light.
• The LUX indicator determines the degree of illumination at which the bulb will light up. If the ambient light intensity is higher than the set value, the light will not turn on until it gets dark outside or indoors to the set threshold.

By correctly setting all of the listed parameters, you will prepare the sensor for operation in certain conditions. They must be installed from the outset by the electrician who installed the sensor, or by the user himself.

The next step is to check the settings for the desired inclusion options

When working with professional equipment, follow the recommended settings. These values ​​are set for the dimmer:

• In the working area (offices, workshops, offices) the threshold is 600 lux.
• In walk-through areas - 75-200 lux.
• In working conditions with increased eye strain - 1000 lux.
• The average value of the range of the degree of illumination is from 2 to 2000 lux.

If you find it difficult to determine correct parameters, then it is better not to change the indicators yourself. Set the initial value to the lowest value. Due to this, the sensor will turn on the light at minimum illumination.

And if you set the maximum degree - 2000 lux, then the light will light up constantly. In this case, from the point of view of serviceability, the device will operate correctly - as the settings indicate to it. But in practice, his work will be useless for the user. In the event of a malfunction, contact a specialist who understands how to adjust the settings.

Failures in the operation of the motion sensor can also be triggered by an incorrectly configured sensitivity value. If the parameter is set incorrectly, the sensitivity of the device in the area of ​​its operation may decrease. For example, at the slightest movement, the device may not turn on.

Often, incorrect setting of illumination, time and sensitivity values ​​leads to the fact that the light does not go out after the disappearance of movements in the area of ​​​​the sensor. If the light bulb does not turn off for too long without moving objects, the turn-off delay time needs to be checked. The reason for this may be an overestimated value of the TIME parameter, which makes it impossible to open the output contacts that control the lighting fixtures. The TIME parameter has its own averages:

• 5 minutes - for passages and corridors;
• 15 minutes - for working rooms.

Adjustment of sensors according to the instructions

Wrong installation location

For all types of sensors, certain rules for installation and location selection are provided. If they are not respected by the installers, then the devices begin to malfunction.

Signs of incorrect installation of the motion detector are as follows:

• Wrong installation height - the device is below 2 meters.
• The sensing head is incorrectly directed. It is required that it be directed in the direction that will be controlled.
• The appliance is located in a strong draft.
• Near infrared sensor there are devices that emit heat.
• The viewport of the detector is obscured by tree branches, corners of the room, a canopy on the roof, or other obstructions.

If the sensor does not respond every time, or only when a live object is very close, carefully check that the device is installed correctly, taking into account the described requirements.

The following parameters are of great importance:

• action distance.
• Viewing angles vertically and horizontally.

When setting up the unit, place it at the desired height and focus in such a way that the specified parameters are optimally suited to the existing terrain conditions. Keep in mind that the area of ​​the sensor has its own boundaries.

Correct location motion sensor

False inclusions

Foreign objects and objects have both direct and indirect influence on the operation of the sensor.

Large moving heat flows, for example, from convectors, fan coil units, have a direct effect on the device. Overall cabinets, racks and glass partitions limit the radius of the detector and create the so-called dead zones in the room.

Heating devices have an indirect effect on the operation of the device. The air currents that they move cause malfunctions, which is why the motion sensor is triggered arbitrarily. To limit the sensor from extraneous influences and prevent false positives, it is necessary to reduce the sensitivity of the device or use mask lenses supplied with the sensor.

Sensors are practically invulnerable to external influences microwave type. They function independently of the heat of the environment and sound vibrations. However, such devices can only be used indoors. They are unsuitable for street lighting, because they will work with any movement, for example, when leaves fall from a tree, when branches sway.

High-frequency sensors are used in rooms with a large number of partitions, for example, in public toilets. Automation of turning on and off the light in this case is provided simultaneously by several sensors.

False switching on of the sensor can also be provoked by technical malfunctions of the device. Such a breakdown will be determined by specialists. technical issues rarely lead to false positives. Most often, the cause of this phenomenon is poor-quality connections and twists, improper installation of the device. And sometimes the reason lies on the surface and consists in incorrectly adjusted settings.

Expert opinion

Alexey Bartosh

Ask an expert

Attention! Properly installed sensor installation almost completely minimizes all false alarms in small areas. And all settings for time and sensitivity are brought to the required "condition" in the process of further operation.

Remember that light intensity is measured from the surface. Thus, the device takes readings according to the degree of illumination in the place where it is directed. For example, when the coverage area is directed to dark corner or a place with low light, and measures the amount of light in that area. In this case, the light will not light up correctly, because in this place it is darker than in the rest of the territory.

The sensor does not turn off the light

The reasons that the sensor does not turn off the lighting are as follows. Indoors or outdoors, there is always movement within the operating radius of the device. Therefore, the sensor is always triggered. When the time to turn off the system comes up, someone again gets into the radius and the device gives a signal to turn it on. Yes, the light is always on.

Probably, the reasons lie in the device settings:

• Delay time not adjusted - set to high value.
• Light brightness threshold exceeded.

To correct the problem, check each setting and make any necessary adjustments.

In rare cases, the reason for not shutting down artificial lighting sensor lies in the nuances of its electronic circuit. This happens when the device has been energized for a long time. As a result, the contact may not open due to residual load. The problem is solved by briefly disconnecting the device from the power supply and then turning it on after 15-20 seconds.

The light does not turn on when the sensor is working

The failure of the sensor is most often associated with an incorrect setting of the illumination and sensitivity of the sensor, or with a lack of power to the device.

Check your settings first. A common problem is incorrect lighting settings. Optimal value set at a level of 200 to 300 lux. The degree of illumination in some devices is not adjustable - it has factory values, however, manufacturers may make a mistake. In this situation, go to the store where you bought the sensor to replace it.

If everything is in order with the settings, then check if the sensor is installed correctly, if there are any other factors affecting it. For example, if any lighting fixture or other light source, it will not be able to reliably determine the degree of illumination in the area of ​​​​action, and will not work at the right time.

Power check

Inside the motion sensor to turn on the light - electronic circuit. In order for it to start working, it is required to ensure its connection to the supply voltage. Standard sensors are designed to be connected directly to a household electrical network with a voltage of 220 volts. This does not apply to radio wave sensors that are powered by a battery. The connection diagram must be present on the case.

After connecting the power to the device, you need to check if it works circuit diagram and output relay. In the form of a load connected to the relay, you can use an incandescent lamp or an LED lamp.

Expert opinion

Alexey Bartosh

Specialist in the repair, maintenance of electrical equipment and industrial electronics.

Ask an expert

Attention! The sensor operates under high voltage, dangerous to humans. Therefore, when working with electricity, be careful. It is desirable that the work be carried out by a person with the education and experience of an electrician.

When repairing the sensor, turn it on using the lowest current circuit breaker - 1-2 A. Another option is to use it to turn on the difavtomat to protect yourself from current exposure.

When power is applied to the sensor, check the presence of voltage on all its working elements. For this purpose, use the device - multitester. After checking the distribution system and power supply, pay attention to the operation of the output relay. Its contacts are constantly switching external load, which can cause wear of the contact group or the development of its operational resource.

The correct operation of the relay also depends on the operating state of the transistor that controls its operation. Therefore, using a tester, check the operation of the transistor.

To reduce the risk of electric shock, turn off the power light circuit breaker and, with the power off, provide access to the wire connection points on the sensor and the luminaire during operation. Then they should be fixed mechanically to prevent a sudden short circuit. Now apply voltage.

Electricians use for these works indicator screwdriver and see if there is a phase on the terminal. If it is not there, there is clarity in the cause of the breakdown. It remains only to eliminate it. But this test is incomplete. It is required to find out whether the zero potential came to the sensor.

The potential can disappear due to failure or wear of the wires, as well as due to damage to the aluminum conductors. Use a voltmeter to quickly check zero and phase potentials. If the device shows a normal value, then you can not worry. If the situation is the opposite, try to find the cause of the failure. Ring the integrity of the wires by measuring the resistance of the circuit sections.

The correctness of the sensor operation is also checked with a voltmeter. To do this, connect the probes to the zero and phase outgoing wire terminals on the light fixture. When the contact is closed, the device will show the internal voltage.

The sensors are equipped with LEDs that indicate the status of the devices. If the device is connected to the power supply and is in working condition, the LED blinks - on average 1 time per second. When the detector is triggered, the flicker frequency increases, which makes it possible to understand whether the sensor is triggered without connecting a load. It must be remembered that certain types of devices become ready for operation only after 20–30 seconds after turning on the power.