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Automatic charger. How and which one to choose a charger for a car battery. Useful tips, as well as a video version Automatic charging of a car battery diagram

I tried to insert into the title of this article all the advantages of this scheme, which we will consider, and naturally I did not quite succeed. So let's now look at all the advantages in order.
The main advantage of the charger is that it is fully automatic. The circuit controls and stabilizes the required battery charging current, monitors the battery voltage and when it reaches the desired level, it reduces the current to zero.

What batteries can be charged?

Almost everything: lithium-ion, nickel-cadmium, lead and others. The scope of application is limited only by the charge current and voltage.
This will be enough for all household needs. For example, if your built-in charge controller is broken, you can replace it with this circuit. Cordless screwdrivers, vacuum cleaners, flashlights and other devices can be charged with this automatic charger, even car and motorcycle batteries.

Where else can the scheme be applied?

In addition to the charger, this circuit can be used as a charging controller for alternative energy sources, such as a solar battery.
The circuit can also be used as a regulated power supply for laboratory purposes with short circuit protection.

Main advantages:

• - Simplicity: the circuit contains only 4 fairly common components.
• - Full autonomy: control of current and voltage.
• - LM317 chips have built-in protection against short circuits and overheating.
• - Small dimensions of the final device.
• - Large operating voltage range 1.2-37 V.

Flaws:

• - Charging current up to 1.5 A. This is most likely not a drawback, but a characteristic, but I will define this parameter here.
• - For currents greater than 0.5 A, it requires installation on a radiator. You should also consider the difference between input and output voltage. The greater this difference, the more the microcircuits will heat up.

Automatic charger circuit

The diagram does not show the power source, but only the control unit. The power source can be a transformer with a rectifier bridge, a power supply from a laptop (19 V), or a power supply from a telephone (5 V). It all depends on what goals you are pursuing.
The circuit can be divided into two parts, each of them functions separately. The first LM317 contains a current stabilizer. The resistor for stabilization is calculated simply: “1.25 / 1 = 1.25 Ohm”, where 1.25 is a constant that is always the same for everyone and “1” is the stabilization current you need. We calculate, then select the closest resistor from the line. The higher the current, the more power the resistor needs to take. For current from 1 A – minimum 5 W.
The second half is the voltage stabilizer. Everything is simple here, use a variable resistor to set the voltage of the charged battery. For example, for car batteries it is somewhere around 14.2-14.4. To configure, connect a 1 kOhm load resistor to the input and measure the voltage with a multimeter. We set the substring resistor to the desired voltage and that’s it. As soon as the battery is charged and the voltage reaches the set value, the microcircuit will reduce the current to zero and charging will stop.
I personally used such a device to charge lithium-ion batteries. It's no secret that they need to be charged correctly and if you make a mistake, they can even explode. This charger copes with all tasks.

To control the presence of charge, you can use the circuit described in this article -.
There is also a scheme for incorporating this microcircuit into one: both current and voltage stabilization. But in this option, the operation is not entirely linear, but in some cases it may work.
Informative video, just not in Russian, but you can understand the calculation formulas.

The charger with automatic shutdown (hereinafter referred to as the UZ-A device) is designed to charge 6 and 12-volt starter batteries installed on motorcycles and personal cars.

Before using the UZ-A device, you must study this manual, as well as the rules for the care and use of the battery.

The UZ-A device is designed for operation in temperate climates at ambient temperatures from minus 10 °C to plus 40 °C and relative humidity up to 98% at 25 °C.

This device produces a charge when there is a voltage on the battery of at least 4 volts.

Technical data

• Supply voltage - 220 ± 22 V;
• Mains frequency - 50 ± 05 Hz;
• Charge current setting range - 0.5 - 7.5 A;
• Automatic disconnection from the battery after - 10.5 ± 1 h;
• Power consumption, no more than -145 W;
• AC voltage for powering a portable car lamp 36 ± 2 V.

On the front panel there are:

1. LED "NETWORK", signaling that the device is turned on;
2. current indicator for monitoring the charge current;
3. adjustment knob for setting the charge current;
4. LED indicating the end of the charge cycle.

There is a radiator on the back wall of the charger to cool the rectifier.

The radiator is equipped with a socket for powering a portable 36 V lamp (electric soldering iron, etc.) and a fuse.

At the bottom of the body of the device there is a niche into which the power cord and cables with contact clamps “+” and “-” are placed for connecting the charger to the corresponding battery terminals.

Note. The operating principle of the charger circuit with automatic shutdown is almost similar to the operation of the automatic “Electronics” charger circuit described above.

Rice. 1. Appearance of the charger with automatic shutdown "Electronics".

Checking the functionality of the charger

In the conditions of selling a charger in a store in the absence of a battery, as well as at the consumer’s place to check the functionality of the charger, it is allowed to use dry cell batteries with a total voltage of at least 4 V instead of a battery for a short time (it is most convenient to use a battery with a voltage of 4.5 V, it is allowed to use series-connected elements of 1.5 V each - at least 3 elements).

Check as follows:

1. Set the adjustment knob to the extreme left position.
2. Connect the contact clamps of the charger to the battery terminals, observing the polarity: the “+” terminal of the device to the “+” battery, and the “-” terminal of the device to the “-” battery.
3. Connect the charger to a 220 V AC mains voltage, and the “NETWORK” LED on the front panel of the device will light up and, depending on the state of the electronic circuit, the LED may light up.
4. Turn the adjustment knob clockwise to make sure the current changes (the current will gradually increase). This is a criterion for the performance of the device. Note. To avoid premature failure of the test battery, it is recommended to check the current for no more than 5 + 10 seconds and set the current value to no more than 3 5 A.
5. After checking, move the adjustment knob (counterclockwise until there is no reading of the charging current. Disconnect the charger from the mains and from the battery.

Safety requirements

When operating the UZ-A device, the following is not allowed:

• replacing the fuse, as well as repairing the device while it is on;
• mechanical damage to the insulation of the power cord, the wires of the output terminals, as well as exposure to a chemically active environment (acids, oils, gasoline, etc.).

During the charging process, the temperature of the device case is allowed to exceed the ambient temperature by no more than 60 °C.

Rice. 2. Schematic diagram of a charger with automatic shutdown Electronics.

Rice. 3. Circuit board of the charger with automatic shutdown "Electronics".

Rice. 4. Circuit board of the charger with automatic shutdown "Electronics.

A charger (charger) is a device for charging an electric battery from an external energy source, usually from an alternating current network. Monitoring the condition of a car battery includes periodic checking and timely maintenance of it in working condition. For cars, this is often done in the winter, since in the summer the car battery has time to recharge from the generator. In the cold season, starting the engine is more difficult and the load on the battery increases. The situation worsens with long breaks between engine starts.

Modern battery charger

A variety of circuits and devices exist in large numbers, but in general, batteries are organized based on the following elements:

• voltage converter (transformer or pulse unit);
• rectifier;
• automatic charge control;
• indication.

The simplest charger

The simplest is a device based on a transformer and rectifier, shown in the diagram below. It's easy to do it yourself.

Circuit diagram of a simple car charger

The main part of the device is the TS-160 transformer, used in old TVs (picture below). By connecting its two secondary windings of 6.55 V each in series, you can get an output of 13.1 V. Their maximum current is 7.5 A, which is quite suitable for charging the battery.

Appearance of a homemade charger

The optimal voltage of a classic charger is 14.4 V. If you take 12 V, which the battery should have, it will not be possible to fully charge, since it will not be possible to create the required current. Excessive charging voltage leads to battery failure.

As rectifiers, you can use D242A diodes, which correspond in power.

The circuit does not provide automatic regulation of the charging current. Therefore, you will have to sequentially install an ammeter for visual control.

To prevent the transformer from burning out, fuses are installed at the input and output, respectively 0.5 A and 10 A. The diodes are mounted on radiators, since during the initial charging period the current will be high due to the low internal resistance of the battery, which causes them to heat up greatly.

When the charging current decreases to 1 A, this means that the battery is fully charged.

Device Features

Modern models have replaced outdated devices with manual control. The device circuits provide automatic maintenance of the charging current with selection of its required value as the battery condition changes.

Modern devices have a declared charging current of 6 to 9 A for batteries with a capacity of 50-90 Ah, used for passenger cars.

Any battery is charged with a current of 10% of its capacity. If it is 60 Ah, the current should be 6 A, for 90 Ah - 9 A.

Choice

1. Ability to restore a completely discharged battery. Not all memory devices have this function.
2. Maximum charging current. It should be 10% of the battery capacity. The device should have a shutdown function after full charging, as well as a support mode. When charging a completely discharged battery, a short circuit may occur. The device circuit must be protected.

The multifunctionality and versatility of new devices with reasonable prices makes it inappropriate to make chargers yourself. In essence, they are multi-purpose power supplies with different operating modes.

Charger - power supply

Manufacturers

Models are selected mainly with power from a 220 V network. To select, you need to know their features. The general characteristics of modern chargers for car batteries are as follows:

• pulse type;
• presence of forced ventilation;
• small dimensions and weight;
• automatic charging mode.

“Berkut” Smart Power SP-25N

The model is professional and is designed for charging 12 V lead-acid batteries. The automatic operating principle includes the following operating modes:

• charging any car batteries under normal conditions;
• charging in “Winter” mode – at an ambient temperature of 5 0 C and below;
• “desulfation” – recovery with increasing voltage to maximum;
• “power supply” – used to supply voltage at a load of up to 300 W (not battery).

Charger “Berkut” Smart Power SP-25N

Charging is carried out in 9 stages. It is difficult to make such a device with your own hands. First, the battery is checked for its ability to charge. Afterwards, restoration is carried out with a small current with a gradual increase to the maximum. At the last stage, a saving mode is created.

The model can have different protection classes, for example, IP20 (normal conditions) and IP44 (against splashes and particles measuring 1 mm or more).

The battery can be charged without removing it from the car: through the cigarette lighter or alligator contacts.

When charging, the “+” terminal of the battery must be disconnected from the vehicle circuit.

“Orion” (“Pennant”)

The device for pulsed energy conversion makes automatic charging. The circuit provides smooth manual control of the current strength using a rotary knob. Control indicators can be arrow or linear. The battery discharge level can be 0-12 V.

Charger “Orion”

“Orion” is a power source for other loads, for example, tools operating on a voltage of 12-15 V.

The main advantage of the device is the price, which is several times less than its analogues. As power and additional features increase, the cost can increase significantly.

Device overview. Video

You can learn a lot of useful information about the automatic battery charger from the video below.

There is a large selection of pulse chargers for lead-acid batteries for cars on the market. A special feature is a simple interface and many functions. Circuits for simple chargers can be easily found and assembled with your own hands, but it is better to have a reliable device on hand that guarantees long-term operation of the car battery.

A. Korobkov

Having supplemented the charger at your disposal for a car battery with the proposed automatic device, you can be calm about the battery charging mode - as soon as the voltage at its terminals reaches (14.5 ± 0.2) V, charging will stop. When the voltage drops to 12.8...13 V, charging will resume.

The attachment can be made in the form of a separate unit or built into the charger. In any case, a necessary condition for its operation will be the presence of a pulsating voltage at the output of the charger. This voltage is obtained, say, when installing a full-wave rectifier in the device without a smoothing capacitor.

The diagram of the machine attachment is shown in Fig. 1.

It consists of a thyristor VS1, a control unit for thyristor A1, a circuit breaker SA1 and two indication circuits - LEDs NL1 and NL2. The first circuit indicates the charging mode, the second circuit controls the reliability of connecting the battery to the terminals of the machine. If the charger has a dial indicator - an ammeter, the first indication circuit is not necessary.

The control unit contains a trigger on transistors VT2, VT3 and a current amplifier on transistor VT1. The base of the transistor VTZ is connected to the engine of the tuning resistor R9, which sets the switching threshold of the trigger, i.e. the switching voltage of the charging current. The switching “hysteresis” (the difference between the upper and lower switching thresholds) depends mainly on the resistor R7 and with the resistance indicated on the diagram it is about 1.5 V.

The trigger is connected to conductors connected to the battery terminals and switches depending on the voltage across them.

Transistor VT1 is connected by a base circuit to the trigger and operates in electronic key mode. The collector circuit of the transistor is connected through resistors R2, R3 and the control electrode section - the cathode of the SCR with the negative terminal of the charger. Thus, the base and collector circuits of transistor VT1 are powered from different sources: the base circuit from the battery, and the collector circuit from the charger.

SCR VS1 acts as a switching element. Using it instead of the contacts of an electromagnetic relay, which is sometimes used in these cases, provides a large number of switches on and off of the charging current necessary to recharge the battery during long-term storage.

As can be seen from the diagram, the thyristor is connected by the cathode to the negative wire of the charger, and by the anode to the negative terminal of the battery. With this option, the control of the thyristor is simplified: when the instantaneous value of the pulsating voltage at the output of the charger increases, current immediately begins to flow through the control electrode of the thyristor (if, of course, transistor VT1 is open). And when a positive (relative to the cathode) voltage appears at the anode of the thyristor, the thyristor will be reliably open. In addition, such a connection is advantageous in that the thyristor can be attached directly to the metal body of the set-top box or the body of the charger (if the set-top box is placed inside it) as a heat sink.

Switch SA1 can be used to turn off the set-top box by placing it in the “Manual” position. Then the contacts of the switch will be closed, and through resistor R2 the control electrode of the thyristor will be connected directly to the terminals of the charger. This mode is needed, for example, to quickly charge the battery before installing it on the car.

Transistor VT1 can be the series indicated on the diagram with letter indices A - G; VT2 and VT3 - KT603A - KT603G; diode VD1 - any of the D219, D220 series or other silicon; Zener diode VD2 - D814A, D814B, D808, D809; SCR - KU202 series with letter indices G, E, I, L, N, as well as D238G, D238E; LEDs - any of the AL102, AL307 series (limiting resistors R1 and R11 set the desired forward current of the LEDs used).

Fixed resistors - MLT-2 (R2), MLT-1 (R6), MLT-0.5 (R1, R3, R8, R11), MLT-0.25 (rest). Trimmer resistor R9 is SP5-16B, but another one with a resistance of 330 Ohm...1.5 kOhm will do. If the resistance of the resistor is greater than that indicated in the diagram, a constant resistor of such resistance is connected parallel to its terminals so that the total resistance is 330 Ohms.

The control unit parts are mounted on the board (Fig. 2)

Made from one-sided foil fiberglass laminate with a thickness of 1.5 mm.

The tuning resistor is fixed in a hole with a diameter of 5.2 mm so that its axis protrudes from the printing side.

The board is mounted inside a case of suitable dimensions or, as mentioned above, inside the charger case, but always as far as possible from heating parts (rectifier diodes, transformer, SCR). In any case, a hole is drilled in the housing wall opposite the axis of the trimming resistor. LEDs and switch SA1 are mounted on the front wall of the case.

To install an SCR, you can make a heat sink with a total area of ​​about 200 cm2. For example, a duralumin plate with a thickness of 3 mm and dimensions of 100X100 mm is suitable. The heat sink is attached to one of the walls of the case (say, the back) at a distance of about 10 mm - to ensure air convection. It is also possible to attach the heat sink to the outside of the wall by cutting a hole in the housing for the thyristor.

Before attaching the control unit, you need to check it and determine the position of the trimmer resistor motor. A DC rectifier with an adjustable output voltage of up to 15 V is connected to points 1 and 2 of the board, and the indication circuit (resistor R1 and LED HL1) is connected to points 2 and 5. The trimmer resistor motor is set to the lowest position according to the diagram and voltage is supplied to the control unit about 13 V. The LED should light up. By moving the trimmer resistor slider up in the circuit, the LED goes out. Smoothly increasing the supply voltage of the control unit to 15 V and decreasing to 12 V, use a trimming resistor to ensure that the LED lights up at a voltage of 12.8...13 V and goes out at 14.2...14.7 V.

Charger.

In the collection “To Help the Radio Amateur” No. 87, there was a description of K. Kuzmin’s automatic charger, which, when storing the battery in winter, allows you to automatically turn it on for charging when the voltage drops and also automatically turn off charging when the voltage corresponding to a fully charged battery is reached. The disadvantage of this scheme is its relative complexity, since the control of turning charging on and off is carried out by two separate units. In Fig. Figure 1 shows an electrical circuit diagram of the charger, free from this drawback: the indicated functions are performed by one unit.

The circuit provides two operating modes - manual and automatic.

In manual operating mode, toggle switch SA1 is in the on state. After turning on the Q1 toggle switch, the mains voltage is supplied to the primary winding of transformer T1 and the HL1 indicator light lights up. Switch SA2 sets the required charging current, which is controlled by ammeter PA1. The voltage is controlled by a voltmeter PU1. The operation of the automation circuit does not affect the charging process in manual mode.

In automatic mode, toggle switch SA1 is open. If the battery voltage is less than 14.5 V, the voltage at the terminals of the zener diode VD5 is less than necessary to unlock it, and transistors VT1, VT2 are locked. Relay K1 is de-energized and its contacts K1.1 and K1.2 are closed. The primary winding of transformer T1 is connected to the network through relay contacts K 1.1. Relay contacts K 1.2 close variable resistor R3. The battery is charging. When the battery voltage reaches 14.5 V, the zener diode VD5 begins to conduct current, which leads to the unlocking of transistor VT1, and consequently, transistor VT2. The relay is activated and contacts K1.1 turns off the power to the rectifier. By opening contacts K1.2, an additional resistor R3 is connected to the voltage divider circuit. This leads to an increase in the voltage on the zener diode, which now remains in a conducting state even after the voltage on the battery is less than 14.5 V. Charging of the battery stops and storage mode begins, during which slow self-discharge occurs. In this mode, the automation circuit receives power from the battery. The zener diode VD5 will stop passing current only after the battery voltage drops to 12.9 V. Then the transistors VT1 and VT2 will turn on again, the relay will de-energize and contacts K1.1 will turn on the power to the rectifier. The battery will begin charging again. Contacts K1.2 will also close, the voltage on the zener diode will further decrease, and it will begin to pass current only after the voltage on the battery increases to 14.5 V, that is, when the battery is fully charged.

The charger automation unit is configured as follows. Connector XP1 is not connected to the network. Instead of a battery, connector XP2 is connected to a stabilized direct current source with an adjustable output voltage, which is set to 14.5 V using a voltmeter. The variable resistor R3 slider is set to the bottom position according to the circuit, and the variable resistor R4 slider is set to the top position according to the circuit. In this case, the transistors must be locked and the relay de-energized. By slowly rotating the axis of the variable resistor R4, you need to get the relay to operate. Then a voltage of 12.9 V is set at the terminals of connector X2 and by slowly rotating the axis of the variable resistor R3, you need to release the relay. Due to the fact that when the relay is released, resistor R3 is closed by contacts K1.2, these adjustments turn out to be independent of one another. The resistances of the voltage divider resistors R2-R5 are designed in such a way that the relay is activated and released, respectively, at voltages of 14.5 and 12.9 V in the middle positions of the variable resistors R3 and R4. If other values ​​of the relay actuation and release voltages are required, and the adjustment limits with variable resistors are not enough, you will have to select the resistances of constant resistors R2 and R5.

The charger can use the same mains transformer as in K. Kazmin’s device, but without winding III. Relay - any type with two groups of breaking or switching contacts, operating reliably at a voltage of 12 V. You can, for example, use a relay RSM-3 passport RF4.500.035P1 or RES6 passport RF0.452.125D.

Electronic battery charging indicator.

A. Korobkov

To extend the life of a car battery, effective control over its charging mode is necessary. The described device signals the driver when the voltage on the battery is high and when it is low, and the generator is not working. In the case of increased current consumption in the on-board network at a low generator rotor speed, the alarm does not operate.

When developing the device, the goal was to place it in the housing of the RS702 signal relay existing in the car, which determined the design features of the signaling device and the types of transistors used.

A schematic diagram of the electronic signaling device along with its communication circuits with the elements of the on-board network is shown in Fig. 1.

On transistors VT2, VT3 there is a Schmitt trigger, on VT1 there is a unit for prohibiting its operation. The collector circuit of transistor VT3 includes an indicator lamp HL1, located on the instrument panel. When hot, the filament has a resistance of about 59 ohms. The resistance of a cold thread is 7... 10 times lower. In this regard, the VT3 transistor must withstand a current surge in the collector circuit of up to 2.5 A. The KT814 transistor meets this requirement.

Similar transistors are used as VT1 and VT2. But here the reason for their choice was the desire to obtain small geometric dimensions of the device - three transistors are installed one under the other and secured with a common screw and nut.

The on-board network voltage minus the voltage on the zener diode VD2 is supplied to the base of transistor VT2 through a divider R5R6. If it is higher than 13.5 V, the Schmitt trigger switches to a state in which the output transistor VT3 is closed and the HL1 lamp is not lit.

The base of transistor VT2 is also connected to the middle point of the generator winding through a zener diode VD1 and a divider R1R2. When the generator is working properly, a pulsating voltage is created in it relative to its positive terminal with an amplitude equal to half the generated voltage. Therefore, even if due to a large current load in the on-board network the voltage drops below 13.5 V, the current from the divider R1R2 flows into the base of the transistor VT2 and does not allow the lamp to burn. To eliminate the prohibition on turning on the alarm when there is no current in the excitation winding of the generator, a circuit consisting of a divider R1R2 and a zener diode VD1 is used. It prevents leakage current from entering the generator rectifier diodes (in the worst case, up to 10 mA) into the base of transistor VT2.

The on-board network voltage, minus the voltage on the zener diode VD2, is also supplied through the divider R3R4 to the base of the transistor VT1, the collector-emitter section of which shunts the base circuit of the transistor VT2. When the network voltage is above 15 V, transistor VT1 goes into saturation mode. In this case, the Schmitt trigger switches to a state in which transistor VT3 is open and, consequently, lamp HL1 lights up.

Thus, the red light lamp on the instrument panel lights up when there is no charging current and the mains voltage is below 13.5 V, as well as when it is above 15 V.

When using an electronic voltage regulator in a car that does not have a separate wire to the battery terminal, due to a voltage drop (about 0.1...0.2 V) in the circuit to the input terminal of the regulator (most often in idle mode) when When the current consumers are switched off, there is a short-term periodic loss of charging current from the generator. The duration and period of this effect are determined by the time the voltage on the battery drops by 0.1...0.2 V and the time it rises by the same value and is, depending on the condition of the battery, about 0.3...0. 6 s and 1...3 s respectively. At the same time, the signal relay PC702 is triggered with the same clock, lighting the lamp. This effect is undesirable. The described electronic alarm excludes it, since during short-term loss of charging current, the voltage in the on-board network does not reach the lower threshold of 13.5 V.

The electronic signaling device is based on the PC702 signal relay available in the car. The relay itself was removed from the getinaks board (after removing the rivet). In addition, the rivet from the “87” contact tab and the L-shaped post at its base were removed.

The alarm elements are mounted on a printed circuit board (Fig. 2)

Made of foil fiberglass laminate with a thickness of 1.5...2 mm. Transistors VT1-VT3 are located along the axis of the central hole of the board: VT3 on the printed circuit side with the collector plate away from the board, and VT2, VT1 (in that order) - on the opposite side of the board with the collector plates towards the board. Before soldering, all three transistors must be tightened with an MZ screw and nut. Their terminals are connected to the points of the plate with tin-plated copper conductors, soldered into the required holes of the board. Resistors R3 and R5 are soldered not to current-carrying tracks, but to wire pins. This makes it easier to replace them when setting up the device. Elements VD1 and VD2 are installed vertically with a rigid lead facing the board. Capacitor C1 is also located vertically, placed in a vinyl chloride tube along the diameter of the capacitor.

The signaling device should use resistors (except R8)-OMLT (MLT) with ratings and power dissipation indicated in the diagram. Tolerance on nominal values ​​is ±10%. Resistor R8 is made of high-resistance wire wound (1-2 turns) around an MLT-0.5 resistor. Capacitor C1 - K50-12. Transistors VT1 - VT3 - any of the KT814 or KT816 series. Element VD1 is a D814 zener diode with any letter index, VD2 is D814B or D814V.

After completing the installation of the printed circuit board, the electronic signaling device is assembled in the following sequence:
remove the nut and screw holding the transistors together;
a vinyl chloride tube with a diameter of 3 mm is placed in the through holes of transistors VT1, VT2;
petals (pins) “30/51” (in the center) and “87” are inserted into the board freed from the PC702 relay; the latter is secured with an M3 screw (head on the output side) with a nut 3 mm high;
an M2.7 screw 15...20 mm long is passed through the hole in the board from the PC702 relay (from the “30/51” output side), then the mounted board with transistors is placed on the ends of the screws;
provide contact between the “30/51” output and the collector plate of transistor VT3 (by tightly fitting it to the flat part of the output);
check the connection between pin “87” and the printed circuit board through the nut and screw;
the short pins of pins “85” and “86” are bent so that they fit into the holes intended for them on the printed circuit board;
using nuts M2.7 and MZ with washers, fasten both boards;
Solder pins of terminals “85” and “86” to the conductive tracks.

When setting up the alarm, a power supply with an adjustable voltage from 12 to 16 V and a 3 W 12 V lamp are required.

First, with resistor R5 disconnected, resistor R3 is selected. It is necessary to ensure that when the voltage increases, the lamp lights up when it reaches 14.5...15 V. Then resistor R5 is selected so that the lamp lights up when the voltage drops to 13.2...13.5 V.

The adjusted signaling device is installed in place of the PC702 relay, while terminal “86” is connected to the vehicle ground with a short wire under the screw securing the signaling device itself. The electrical equipment wires are connected to the remaining terminals, as provided for in the standard circuit of the car with the PC702 relay, i.e. to terminal “85” - the wire from the middle point of the generator (yellow), to “30/51” - the wire from the indication lamp (black) , to “87” - wire “±12 V” (orange).

Tests of the alarm showed the following result. If the regulator is short-circuited, the lamp glows when the generator speed increases and depends on it. When the fuse in the regulator circuit is removed, the lamp lights up after about a minute, regardless of the rotation speed. This information is enough to establish the cause and type of malfunction of the generator-voltage regulator system.

When the ignition is turned on an hour or more after stopping the engine, the indication works as with a relay alarm. If it turns on after a short time (less than 5 minutes), the charging indicator lamp does not light up, but when the engine is started by the starter, it flashes and goes out, indicating that the indicator is working.

Installing the described regulator instead of the standard PC702 in Zhiguli cars (VAZ-2101, VAZ-2102, VAZ-2103, VAZ-2106, etc.) will clearly warn the driver about all deviations in the operating mode of the battery and save it from disastrous overcharging.
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