The vast majority of modern foreign-made cars, especially prestigious equipment options, are equipped with a device that automatically turns on the headlights when certain or given conditions are created.

Often this device is combined with a rain sensor or is triggered when the illumination level is lowered by sensitive photocells. However, the use of the above options becomes insufficient when it comes to a car operated in the Russian Federation. "Rules of the Road" (hereinafter referred to as traffic rules) in force on its territory require the inclusion of dipped headlights while the vehicle is moving, regardless of the time of day and the degree of illumination.

The appearance of this requirement in the traffic rules has caused the need for a significant revision of the electrical supply system not only for domestically produced cars, but also for foreign cars of the older age category.

The main requirements for a device or system that provides automatic switching on of dipped beam headlights are:

• Guaranteed automatic turning on of headlights when the vehicle starts moving.
• Turning off the dipped beam when the vehicle is parked.
• Economical consumption of electrical energy in all operating modes of the power unit.

Filling the created niche in the car parts market, the development of these devices was undertaken not only by enterprises specializing in electrical equipment for cars, but also by so-called "folk craftsmen". The devices they offer, both ready-made and at the level of schematic diagrams, are a great variety. The devices differ not only in the principle of operation, but also in the complexity of execution.

1 Diagrams of automatic headlight switching devices

Consider several possible options for automatically turning on the vehicle headlights.

1.1 One of the simplest and most effective protection schemes against turning on headlights on an idle car is a scheme that provides a supply voltage to the button (relay) for turning on the headlights through. Switching off the engine (starter) opens the headlight supply circuit. The fears of some motorists in increasing the load on the circuit are unfounded, provided that the devices are correctly connected.

1.2 The method described below for organizing the automatic switching on of the dipped beam involves connecting an additional relay or an electromagnet of the relay that turns on the headlights into the circuit of the "battery charging" warning lamp. A practical implementation looks like this (see the diagram in fig. # 1):

• add a five-pin relay to the circuit (type 90.3747);
• contacts "30" and "85" are connected to the ignition switch;
• contact "86" is connected to the output of the generator connected to the charge control lamp;
• contact "88" is connected to the relay that turns on the headlights (or the headlight circuit fuse);
• turning on the ignition provides current supply to the coil windings of the relay electromagnet and its flow (through the generator winding) to the negative terminal;
• actuation of the relay contributes to the opening of contacts "88" and "30";
• as a result of starting the engine and the subsequent start of the generator's operation, a positive current comes to the output of the generator warning lamp;
• switching off the relay leads to the closure of contacts "88" and "30", that is, the dipped headlights are automatically turned on.

The use of a diode in series with the relay coil and directed to the generator will help prevent a “bad” loop from occurring. The headlights will light up only if the circuit is continuous, which is controlled by the "battery charging" lamp.

Figure # 1

1.3 The third connection method is based on the use of an emergency oil pressure sensor in the power plant in the automatic switching on of the headlights. In fact, this method is a variation of the one described above. The difference lies in the connection of the relay coil to the pressure transducer and not to the generator. The headlights are switched on immediately after the pressure in the lubrication system rises to the required level.

A significant disadvantage of this scheme is the flashing of the headlights when the oil pressure in the system decreases and, as a result, the sensor is triggered (coasting, idling, etc.).

The schemes and methods considered above, which provide automatic switching on of headlights, are simple in technical design and do not require significant material costs for implementation. This is their undoubted advantage. However, a fairly large group of domestic motorists, due to the lack of free time, technical illiteracy and other objective reasons, prefer to use devices manufactured by the factory.

2. The device "AutoSvet AS", as an alternative to handicraft schemes

The functional purpose of the "AutoSvet AS" device is to smoothly turn on the dipped headlights at the moment:

a) the beginning of the movement of the vehicle;

b) starting the engine and reaching 10-100% of the rated power.

This significantly extends the service life of incandescent lamps.

The dipped headlights automatically go out when the side lights are turned on (mains voltage< 12,7 Вольт), зажигания. Схема подключения контроллера предполагает коммутацию «+», то есть включение в цепь «+» выключателя или реле.

Drawing number 2

1. The device can function in several ways:

The control wire of the controller is connected to the injector or hall sensor circuit;

Connection to the speed sensor circuit

2.2 Installation of the "AutoSvet AS" controller on the car is carried out as follows:

• turn off the "-" battery terminal;
• a red wire (D \u003d 1.5 mm) is connected through a 15 amp fuse to a power source (12 Volts);
• black wire (D \u003d 1.5 mm) is connected to the "╧" ("ground") terminal;
• a blue wire (D \u003d 1.5 mm) is connected to the dipped-beam headlamp circuit (“+” terminal ≤ 9 Amperes) after the relay;
• brown wire (D \u003d 0.35 mm) is connected to the input contact of the speed sensor;
• a blue wire (D \u003d 0.35 mm) is connected to the parking light input contact or connected via a toggle switch to the “+” 12 Volt terminal.

The conditions that determine the automatic switching on of the dipped headlights depend on the state of the controller loop:

The cut loop ensures that the light is turned on when the vehicle starts moving;

The whole loop ensures that the headlights are turned on when the power plant is started.

Attention! Connect the brown wire directly to the coil pins absolutely forbiddenas high voltages will cause the controller to malfunction.

• avoid getting moisture inside the device;
• avoid deformation of the controller due to mechanical and thermal loads;
• do not use gas-discharge lamps in the electrical system of the vehicle.

So, since I constantly forget to turn on, and even worse - turn off the low beam, I decided to try to automate this process. The usual relays sold in the store did not suit me with the fact that the light either turns on immediately after turning on the ignition / starting the internal combustion engine, or after reaching a certain voltage, and the voltage, as you know, is a fickle thing.

Therefore, the relay used a standard five-pin, because I did not find a four-contact normally closed one. To the terminal "30" of the relay, we connect a wire connected to the red paired wire from the ignition switch, which turns on the starter retractor relay. To the conclusion "86" we catch the wire from the generator bulb chip. Conclusion "85" - mass. We connect the green wire from the button for turning on the outdoor lighting to the “87a” terminal. We don't connect anything to pin 87.

Principle of operation:
The ignition is off - there is no voltage on the relay and the headlights are off.
The ignition is on - there is a minus on the generator lamp and the headlights are off.
Starting the internal combustion engine - a plus appeared on the lamp, but a plus appeared on the retractor starter, the relay is open and the headlights are off.
The internal combustion engine is working, we release the starter, the relay closes, and so on. on the generator lamp plus, this plus goes to the three-lever light switch. Well, the actual scheme:

That is, the headlights come on only when the engine is running and the starter is turned off. This is especially true in winter, because the fewer extra consumers during engine start-up, the more chances to start.
Switching the light in the three-lever steering column switch is as follows: 0 - headlights off, 1 - dipped beam is on, 2 - high beam is on.

Here is a photo of the implementation:

Dimensions are included separately with the button for turning on the outdoor lighting. About the dimensions, I reasoned this way: they are needed only at night, and at night you will not forget to turn them on 100%, because as soon as it gets dark, the readings of the instruments will become invisible. Forgetting to turn off is also possible only for a very large parking lot, because the burning dimensions at night will immediately catch your eye. You can make the dimensions turn off automatically, but these are extra relays and extra wires. IMHO it's useless.
I consider this scheme to be almost ideal. The only thing that I would like to improve is that the near one burns both in zero and in the first positions of the steering column switch. But then an additional relyuha is needed, so that when switching to the far extinguisher, the near one and also forcibly turning off the headlights from the button or the parking brake.

Changes to the traffic rules introduced in November 2010 oblige the vehicle driver to turn on daytime running lights, or dipped headlights, or fog lights, regardless of the time of day and visibility conditions.

This device will be a good addition for those vehicles that are not equipped with an automatic dipped beam system. The diagram given in this article is designed to automatically turn on the headlights when the car engine starts. As you know, a working generator creates a voltage in the on-board network in the region of 14 ... 14.4 V, and this is higher than the battery voltage (12V).

The circuit of the machine monitors the voltage in the car's network, and if it exceeds 13.2 V, then after about 1 second it activates two relays. The first relay is used to power the side lights and dashboard, the second is used for daytime running lights or dipped headlights. The lighting is switched off after the engine is switched off.

The schematic diagram is shown below. Comparator DD1.1 () compares the reference voltage coming from the 5.6 V Zener diode (VD2) with the voltage coming from R1, R2, R3. R3 is used for fine tuning so that the machine responds to an input voltage in the range of 13.2 ... 13.3.

Material: ABS + Metal + Acrylic Lenses. LED lights...

Resistor R5 between the comparator output and the non-inverting input provides positive feedback, allowing the comparator to operate with hysteresis. For the comparator state to change again, the voltage must drop below 10.6 V.

Thus, there is no fear that as a result of any heavy load on the vehicle's on-board network, the headlights will turn off. This will happen only after turning off the ignition, or, for example, at the time of an attempt to start the engine with a starter.

A chain of elements R6, C3 is responsible for the delay in turning on the headlights after starting the engine. For these values, the delay is approximately 1 second. The second comparator DD1.2 is designed to implement this delay. It compares the voltage across capacitor C3 with the reference voltage obtained from the Zener diode VD2.

A transistor is connected to the output of the comparator DD1.2, which controls the output relay. To the relay coils, in parallel in the opposite direction, diodes VD3 and VD4 are connected, which protect the transistor from voltage surges at the moment the relay is turned off. Diode VD1 protects against power connection error (reversal). The load capacity of the circuit depends on the relays used.

To set up the device, an adjustable power supply or a 13.2 V voltage source is required. Move the potentiometer R3 to the extreme left position. Then we drop the power supply to 13.2 V. Gradually turn the potentiometer R3 to the right until we hear the relay turn on. Then we reduce the voltage and the relay should turn off. Increase the voltage again to test. A correctly adjusted circuit should turn on at a voltage of 13.2 ... 13.4 V.

The operation of this circuit has been tested in Proteus:

(12.6 Kb, downloaded: 617)

The wires from the relay must have a minimum cross-section of 1 mm 2. It is worth additionally installing a power switch on the case so that in some cases it is possible to turn off the machine.

A small disadvantage of this scheme is the fact that the dipped beam headlights will be on when switching the high beam. This operation is not recommended and will significantly reduce lamp life. Hence the recommendation - during long night trips, it is recommended to turn off the circuit breaker with a switch on the case.

Any modern car has a device such as a light switch. With its help, the vehicle lighting is activated. You can learn more about the purpose of the device and its connection at home from this material.

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Headlight switch characteristic

What is a central light switch (DSP) for, how can a plug-in light switch be used and what is its wiring diagram? First, consider the purpose, as well as the principle of operation of the device.

Purpose and principle of operation

We will not talk much about the appointment. Everyone knows how important it is to have high-quality road surface lighting in poor visibility conditions. largely determines the safety of a motorist while driving; in his absence, movement in a vehicle at night is prohibited. Indeed, without marking the car, not only the offender, but also the drivers of other cars can suffer.

So, the steering column headlight switch is designed for:

• ensuring safe movement at night thanks to the possibility of activating lighting;
• designation of vehicle dimensions in the dark.

The steering column switch is used to activate:

• side lights;
• low beam lighting;
• high beam;
• turning lights when turning the car.

High-beam lighting is usually used in poor visibility conditions, as well as when driving on an unlit section of the road.

As for the principle of operation, in general, everything is also simple here:

1. At a certain moment, the driver presses a button on the switch.
2. The switch sends the generated impulse to the control unit or directly to the optics, depending on the design of the vehicle.
3. The block processes this impulse and determines what type of lighting needs to be turned on - clearance, near or far. The corresponding impulse is transmitted to the optics.
4. In accordance with the received signal, the light is activated.

Scheme

If you are interested in the switch connection diagram, then it is provided below.

Types

There can be several types of devices for switching lighting. The most popular type is a mechanical device, in this case switching is carried out as a result of the mechanical action of the driver's hand on the device. The person selects the type of lighting required at the moment and, in accordance with this, selects the mode on the device. A more modern type of device for activating optics is an automatic light switching system.

The system automatically determines when to turn on and which light, based on some parameters:

• poor level of illumination of the road surface;
• exceeding the vehicle speed threshold (high beam turns on);
• no other cars or obstacles ahead;
• when driving outside the village.

Malfunctions

Now let's briefly talk about the faults.

There are two types of malfunctions that can occur with the switch:

1. Mechanical caused by mechanical failure of elements. Such a malfunction may manifest itself in the form that when the corresponding button is pressed, the vehicle lighting does not work. Or, after turning on the turn signal, the device, instead of returning to its place with the return of the steering wheel, continues to remain in this position until the driver himself returns it to its place.
2. Electrical. Such a malfunction can be caused by a breakdown of the circuit inside the device, disconnection or oxidation of the contacts. If the problem lies in the contacts, then it is enough to simply clean or replace them, re-solder them. If the essence of the malfunction lies in the circuit, then it will be easier to completely replace the device than to repair it (the author of the video about repairing the mechanism with his own hands is the SamaraRovenki channel).

Diy light switch connection instructions

If you are faced with a problem with the device inoperability, then it will probably be useful for you to learn how to replace it and how to connect a new switch. In general, this task is quite simple and anyone, even an inexperienced car enthusiast, can cope with it. However, the procedure may differ depending on a specific car, in this case, below are instructions for replacing the device on a Daewoo Nexia car.

So, how to properly replace and how to connect a new switch:

1. First of all, the device is dismantled. To do this, you need to remove the steering column pads, which are usually fixed with self-tapping screws. After removing the adjustment from the top and bottom, you can see two latches, they must be squeezed out, after which the device can be removed without problems.
2. Having pulled it out of the installation site, it is necessary to disconnect the wires that are connected to it, here you just need to disconnect the block.
3. Using a thin screwdriver or a utility knife, you need to flip off the five case latches and completely disassemble the device if you want to repair it. In case of repair, you need to be careful not to lose small parts of the structure.
4. So, if you decide to repair the device, then after disassembling the case, you need to carefully inspect the internal structural elements. If there are burns on the contacts, they will need to be re-soldered.
5. If you do not plan to make repairs, then you just need to replace the device with a similar one. When buying a switch in a store, be careful as the parts must be identical. You just need to connect the block with wires, disconnected earlier, to the device, and then install it at the installation site. When the switch is installed, you need to check its operability by activating each of its functions. Also make sure that the device works properly when the turn signals are turned on - it should return with the steering wheel to its place and automatically turn off after turning.

Video "Self-repair of the mechanism at home"

A detailed and visual instruction on the topic of repairing the mechanism on your own with the designation of all the points and nuances is shown in the video below (author - SamaraRovenki channel).

Automatic switching on of headlights is necessary to turn on the head lighting in case of a sharp deterioration in visibility without the participation of the driver. In some countries, headlights are required when driving.

On foreign cars, automatic headlights are switched on, for which a corresponding sensor is used. Often this sensor is combined with a rain sensor attached to the windshield. The principle of this sensor is based on light measurement using photocells.

But for a domestic car owner, this method is hardly suitable. According to the rules of the road, the dipped headlights must be turned on not only at night, but also during the day. When this requirement appeared, the need arose to use automatic headlights on when the car was moving and off when parking, for economical use of energy and preventing the headlights from leaving when parked. According to the laws of the market, enterprises of electrical equipment for cars and craftsmen immediately responded to this need. The principle of operation is excellent for everyone, depending on what the car owner wants to get and at what costs and complications he wants to go. Let's consider some of the most common schemes.

A way of inclusion for the forgetful.

The simplest scheme, automatic headlights on, protects the driver from forgetfulness and prevents the headlights from turning on when the ignition is off. On most vehicles this is done by design at the factory, and where it is not implemented it can be easily done. To do this, it is enough to supply power to the on button or the headlight relay through the ignition switch leads, which are closed when the ignition is turned on, but open when the starter is turned on.

This method has a very important advantage - simplicity. There is an opinion that the included headlights will give additional load, but this is not the case. If the connection is done correctly, then when the starter is turned on, the headlights will turn off. Conclusion: simple, reliable and cost-effective.

Automatic switching on of headlights through a relay.

The second way to realize automatic switching on of headlights is to connect the electromagnet of the relay for turning on the headlights or an additional relay into the generator excitation circuit, or rather the circuit of the charging signal lamp. This method is suitable for almost all modern vehicles.

For implementation, it is necessary to add a five-contact relay type 90.3747. Connect the wire from the ignition switch to terminals 85 and 30. Terminal 86 is connected to the generator terminal, to which the wire from the charge control lamp is connected. Terminal 88 is connected to the headlamp switch or directly to the headlight circuit fuses.

In this case, when the ignition is turned on, power from the ignition switch, the coil of the relay electromagnet goes to minus through the generator winding, while the relay triggers and opens contacts 30 and 88. After starting the engine and starting the generator, a plus appears at the output of the generator warning lamp. The relay is disconnected and closes contacts 30 and 88 including the headlights.

To prevent a harmful circuit in this case, it is desirable to use a diode connected in series with the relay coil directed towards the generator. The headlights in this case will light up only when there is a charging current, provided that the circuit is intact, which can be monitored by the battery charge lamp.

Automatic switching on of headlights via a pressure sensor.

In the third method of connecting the automatic switching on of headlights, the kulibins suggest using an emergency engine oil pressure sensor. The connection diagram is identical to that described earlier, only the relay coil is connected not to the generator, but to the emergency oil pressure sensor. In this case, the headlights will light up immediately after the pressure builds up in the lubrication system. The disadvantage is the inclusion of headlights regardless of the health of the generator. With low oil pressure at idle, if the engine condition is not the best, the headlights will flash when the sensor is triggered.

Here only the simplest and possibly primitive ways of implementing automatic headlights are considered. On the Internet, you can find many more schemes, both simple and quite complex. Also in stores you can be offered ready-made blocks for the implementation of this function.

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