We make a charger with your own hands. Charger for the car battery do it yourself. How to make the simplest transformer device

Compliance with the operation mode of batteries, and in particular charging mode, guarantees their trouble-free operation during the entire service life. Charging batteries produce current, the value of which can be determined by the formula

where i is the average charging current, A., and q - passport electrical container rechargeable battery, A-h.

The classic charger for the car battery consists of a lowering transformer, rectifier and charging current regulator. Wire rigs are used as wire regulators (see Fig. 1) and transistor current stabilizers.

In both cases, there are significant thermal power on these elements, which reduces the efficiency of the charger and increases the likelihood of its failure.

To adjust the charging current, you can use a capacitors store included in series with a primary (network) winding of the transformer and performing the function of reactive resistances, excessive network voltage. Simplified such device is shown in Fig. 2.

In this scheme, the thermal (active) power is allocated only on the VD1-VD4 diodes of the rectifier bridge and the transformer, so the heating of the device is insignificant.

Disadvantage in fig. 2 is the need to ensure the voltage on the secondary winding of the transformer is one and a half times greater than the rated load voltage (~ 18 ÷ 20V).

Charger diagram, providing charging of 12-volt batteries to 15 A, and the charging current can be changed from 1 to 15 A steps 1 A, shown in Fig. 3.

It is possible to automatically turn off the device when the battery is fully charged. It is not afraid of short-term short circuits in the load chain and cliffs in it.

Switches Q1 - Q4 you can connect various combinations of capacitors and thereby adjust the charging current.

A variable resistor R4 set the C2 trigger threshold, which should be triggered at a voltage on the battery clips equal to the voltage of a fully charged battery.

In fig. 4 shows another charger, in which the charging current is smoothly adjustable from zero to the maximum value.

Change current in the load is achieved by adjusting the angle of opening the VS1 trinistore. The adjustment node is made on a single-pass transistor VT1. The value of this current is determined by the position of the engine of the variable resistor R5. The maximum charge current of the battery 10a is installed as an ammeter. The devices are provided on the network side and load fuses F1 and F2.

The variant of the charger printed circuit board (see Fig. 4), the size of 60x75 mm is shown in the following figure:

In the diagram in fig. 4 The secondary transformer winding must be calculated on the current, three times the larger charge current, and, accordingly, the transformer power should also be three times more power consumed by the battery.

Named circumstance is a significant drawback charger with a trinistor current regulator (thyristor).

Note:

VD1-VD4 rectifier bridge diodes and vs1 thyristor must be installed on radiators.

Significantly reduce power loss in trinistore, and consequently, to increase the efficiency of the charger, it is possible that the regulatory element is transferred from the secondary winding chain of the transformer into the primary winding circuit. Such a device is shown in Fig. five.

In the diagram in fig. 5 The adjusting node is similar to the device applied in the previous variant. Trinistor VS1 is included in the diagonal of the VD1 rectifier bridge - VD4. Since the primary transformer winding current is about 10 times less than the charge current, on VD1-VD4 diodes and the VS1 trinistore is relatively small thermal power and they do not require installation on radiators. In addition, the use of trinistora in the transformer primary winding circuit allowed a slightly to improve the shape of the charging current curve and reduce the value of the current curve coefficient (which also leads to an increase in the CPD of the charger). The lack of this charger should include electroplating with the network of the elements of the regulatory assembly, which must be taken into account when developing a constructive design (for example, use a variable resistor with a plastic axis).

The variant of the printed circuit board in line 5, the size of 60x75 mm is shown in the figure below:

Note:

VD5-VD8 rectifier diodes must be installed on radiators.

In the charger in Figure 5, the diode bridge VD1-VD4 type KC402 or KC405 with letters A, B, V. Stabilitron VD3 type KS518, KS522, KS524, or compiled from two identical stabilion with a total stabilization voltage of 16 ÷ 24 volts (KS482, D808 , KS510, etc.). Transistor VT1 single-pass, type CT117A, B, B, Diode bridge VD5-VD8 is composed of diodes, with workers current at least 10 amp (D242 ÷ D247, etc.). Diodes are installed on radiators with an area of \u200b\u200bat least 200 sq. Cm, and radiators will be very hot, a fan can be installed in the charger body.

For car batteries, since industrial samples are pretty high cost. And to make such a device itself can be pretty quickly, and from the priest materials that are practically available. From the article you will learn how to independently manufacture chargers with minimal cost. Two designs will be considered - with automatic adjustment of the charge current and without it.

Charger Basis - Transformer

In any exercise, you will find the main component - a transformer. It is worth noting that there are schemes of devices constructed by a batranformator scheme. But they are dangerous, since there is no protection against network voltage. Consequently, during the manufacture, you can get a blow to an electric shock. Much more efficiently and easier turns out to be transformer schemes, they have a galvanic isolation from the network voltage. To make the charger, you will need a powerful transformer. It can be found by breaking an unsuitable microwave. However, spare parts from this electrical appliance can be used to make the battery charger with their own hands.

In old tube TVs, TC-270 transformers, TS-160 were used. These models are perfect for the design of the charger. It is even more efficient to use them, since they already have two windings of 6.3 volts. Moreover, you can collect current up to 7.5 amps. And when charging car battery A current is required equal to 1/10 from the tank. Therefore, when the battery capacity is 60 a * h, you need to charge it with a current strength of 6 amps. But if there are no windings that satisfy the condition will need to be done. And now about how to make a self-made charger for the car as quickly as possible.

Transformer rewind

So, if you decide to use the converter from the microwave oven, then you need to remove the secondary winding. The reason lies in the fact that these increasing transformers, they convert the voltage to a value of about 2,000 volts. Magnetron is needed in 4000 volts, therefore the doubling scheme is used. You do not need such values, so mercilessly get rid of the secondary winding. Instead, wind the wire with a cross section of 2 square meters. mm. But you do not know how much turns needed? It is necessary to find out, you can use in several ways. And it must be done when the battery charger is manufactured with your own hands.

The easiest and reliable is experimental. Make winding ten turns of the wire you will use. Clean its edges and include a transformer on the network. Produce the voltage measurement on the secondary winding. Suppose these ten turns are issued 2 V. Consequently, 0.2 V (tenth) is collected from one turn. You need not less than 12 V, and better if the output will be a value close to 13. One volt will give five turns, now you need 5 * 12 \u003d 60. The desired value is 60 turns of the wire. The second way is more complicated, you will have to consider the cross section of the transformer magnetic pipeline, you need to know the number of turns of the primary winding.

Rectifier block

It can be said that the simplest homemade chargers for automotive batteries consist of two nodes - a voltage converter and rectifier. If you do not want to spend a lot of time to assemble, you can use a single-alipesome diagram. But if you decide to assemble the charger, what is called, conscience, then it is better to use the pavement. It is advisable to choose diodes, the reverse current of which is 10 amps and above. They, as a rule, have a metal housing and a fastening with a nut. It is also worth noting that each semiconductor diode should be installed on a separate radiator to improve the cooling of its housing.

Small modernization

However, you can stay on it, a simple home-made charger is ready to use. But it can be supplemented with measuring devices. Collecting in a single case all the components, securely securing them in their places, you can also do the design of the front panel. It can arrange two devices - an ammeter and a voltmeter. With their help, you can control the voltage and charging current. If there is a desire, set the LED or the incandescent lamp, which connect to the rectifier output. With such a lamp you will see if the charger is enabled. If necessary, add a small-sized switch.

Automatic charging current adjustment

Not bad results show self-made chargers for automotive batteries that have the function of automatic current adjustment. Despite the seeming complexity, these devices are very simple. True, some components will be required. The diagram uses current stabilizers, for example LM317, as well as its analogues. It is worth noting that this stabilizer has deserved confidence in radio amateurs. It is trouble-free and durable, the characteristics of it exceeds domestic analogues.

In addition to it, an adjustable stabilion is also required, for example TL431. All chips and stabilizers used in the design must be mounted on separate radiators. The principle of operation of the LM317 is that the voltage is "superfront" to heat. Therefore, if you have a 12 V, and 15 V, then the "extra" 3 V will go into the radiator. Many home-made chargers for car batteries are made without complying with strict requirements to the outer shell, but better if they are enclosed in an aluminum case.

Conclusion

At the end of the article I would like to note that such a device, as a car charger, needs high-quality cooling. Therefore, it should be provided for the installation of coolers. Use the best ones that are mounted in computer power supplies. Just pay attention to the fact that they need 5 volts nutrition, and not 12. Therefore, it will have to complement the scheme, to introduce a voltage stabilizer to 5 volts. You can still talk about charging devices. The auto-charger scheme is easy to repetition, and the device will be useful in any garage.

Homemade battery chargers usually have a very simple design, and additionally to that and increased reliability just because the simplicity of the scheme. Another plus from the manufacture of charging with your own hands is the relative cheapness of components and as a result - the low cost of the device.

Why the prefabricated design is better than purchased

The main task of such equipment is to maintain the charge of the car battery at the required level, if necessary. If the discharge of the battery occurred next to the house, where there is a necessary device, then there will be no problems. Otherwise, when there is no suitable equipment for nutrition, the battery is also not enough, you can collect the device with your own hands.

The need to use auxiliary tools for feeding the car's battery is due primarily by low temperatures during the cold season, when half the discharged battery is the main one, and sometimes not soluble the problem at all, if not in time not to recharge the battery. Then home-made chargers for powering car batteries will be salvation for users who do not plan to invest in such a technique at least at the moment.

Operating principle

Until a certain level of AKB car can be powered by vehicle, and more precisely, from the electric generator. After this node, a relay is usually set for a voltage setting no more than 14.1V. To charge the battery to the limit, a higher value is necessary. this parameter - 14.4V. Accordingly, the AKB is just used to implement such a task.

The main nodes of this device are transformer and rectifier. As a result, the exit is served d.C. With a voltage of a certain value (14.4V). But why is it observed with a voltage of the battery itself - 12V? This is done to ensure the possibility of charging the ACB discharged to the level when the value of this battery parameter was equated with 12V. If charging is characterized by the same parameter, then as a result, the battery power will be difficult to task.

We watch the video, the easiest device for charge battery:

But here there is a nuance: a small excess of the voltage level of the battery is not critical, while the significantly overestimated value of this parameter will be very bad in the future on the operation of the AKB. The principle of operation that is distinguished by any, even the simplest charger for powering the car battery, is to increase the resistance level, which will reduce the charging current.

Accordingly, the greater the voltage value (striving to 12V), the smaller the current. For normal operation, the battery is desirable to set a certain amount of charge current (about 10% of the tank). In the hurry is greatly a temptation to change the value of this parameter to more, however, it is fraught with negative consequences for the battery itself.

What will required for the manufacture of AKB?

The main elements of simple design: diode and heater. If correctly (sequentially) connect them to the battery, you can achieve the desired - the battery will be charged after 10 hours. But lovers save electricity such a decision may not be approached, because the flow rate in this case will be about 10 kW. The operation of the device received is not characterized by high efficiency.

Basic elements of simple design

But to create a suitable modification will have to somewhat modifying individual elements, in particular, the transformer, the power of which should be at the level of 200-300 W. In the presence of old technology, suitable this detail From an ordinary tube TV. To organize the ventilation system, the cooler is useful, it is best if it is from the computer.

When a simple charger is created to power the battery with your own hands, another transistor and resistor are still as the main elements. To establish the work of the design, it will take a compact outside, but a rather roomy metal body, a good option is a box from the stabilizer.

In the theory of this kind, even a novice radio amateur will be able to collect, who had not previously encountered complex schemes.

Scheme simple device For battery charge

The main difficulty lies in the need to modify the transformer. With this level, the winding power is characterized by low voltage indicators (6-7V), the current will be equal to 10a. Usually 12V voltage is required or 24V, depending on the type permissive battery. To obtain such values \u200b\u200bat the device output, you must provide a parallel connection of the windings.

Phased assembly

A homemade charger for powering a car battery begins with the preparation of the core. Wire winding on the winding is performed with a maximum seal, it is important that the turns are tightly fit to each other, and there are no lumen. We must not forget about the isolation that is put at 100 turns intervals. The primary winding wire section is 0.5 mm, secondary - from 1.5 to 3.0 mm. If we consider that at a frequency of 50 Hz 4-5 turns can provide a voltage 1B, respectively, it takes about 90 turns.

Next, a diode of suitable power is selected to withstand the load submitted to it. The best option is the generator diode of the car. To eliminate the risk of overheating, it is necessary to ensure efficient circulation of air inside the case of such an instrument. If the box is not perforated, you should take care of it before the start of the assembly. The cooler must be connected to the output of the charger. The main task is to cool the diode and winding the transformer, which is taken into account when choosing a plot for installation.

Watch the video detailed instructions By production:

A simple charger for powering a car battery contains a variable resistor. For the normal functioning of charging, it is necessary to obtain resistance at the level of 150 Ohm and the power of 5 W. More than others complies with these requirements model KU202N resistor. You can choose a different option from this, but its parameters must be similar to the value with the specified. The task of the resistor is to adjust the voltage at the output of the device. The CT819 transistor model is also best option From a number of analogs.

Evaluation of efficiency, cost

As can be seen if it is necessary to assemble a self-made charger for a car battery, its scheme is more than easy to implement. The only difficulty is the layout of all the elements and install them into the case with the subsequent compound. But such work is difficult to call the time consuming, and the cost of all the parts used is extremely small.

Some of the details, and, perhaps, everyone will surely have a radio amateur at home, for example, a cooler from an old computer, a transformer from a lamp television, an old body from the stabilizer. As for the degree of efficiency, such devices collected by their own hands are not distinguished by very high efficiency, however, as a result, they still cope with their task.

Watch the video useful advice Specialist:

Thus, large investments in the creation of homemade charging is not required. On the contrary, all elements are extremely small, which favorably sends this solution in comparison with the device that can be purchased in the finished form. The scheme discussed above does not differ by high efficiency, but its main plus is a charged battery of the car, although 10 hours later. You can improve this option or consider many others offered for implementation.

!
Today we will look at 3 simple charges schemes that can be used to charge the most different batteries.

The first 2 schemes operate in linear mode, and the linear mode primarily means strong heating. But the charger thing is stationary, and not portable so that the efficiency is a decisive factor, so that the only minus of the shown schemes is that they need a large cooling radiator, and otherwise everything is fine. Such schemes have always been applied and will be applied, since they have undeniable advantages: simplicity, low cost, not "shy" to the network (as in the case of impulse schemes) and high repeatability.

Consider the first scheme:

The chip is necessarily installed on a massive radiator, not a stabilized voltage is applied to the input to 30-35V, it is slightly smaller than the maximum allowable input voltage for the LM317 microcircuit. It must be remembered that the LM317 chip can dispel a maximum of 15-20W power, be sure to consider it. It is also necessary to take into account the fact that the maximum output voltage of the circuit will be 2-3 volts less input.

Charging occurs with stable voltage, and the current cannot be larger than the threshold. This scheme can be used even for charging. lithium-ion batteries. With short closures at the outlet, nothing terrible will not happen, just goes the current limit and, if the cooling of the chip is good, and the difference in the input and output voltage is small, the scheme in this mode can work endlessly for a long time.

Second scheme It is a powerful stabilized power source with a maximum output current to 10a, was built on the basis of the first option.

The output voltage of the circuit is adjusted in the range from 3 to 30V, which will make it possible to charge almost any batteries. Adjust the output voltage using the same rapid resistor.

Now let's look at the principle of operation of the scheme. At low current values, the power transistor is closed. With an increase in the output current, the voltage drop on the specified resistor becomes sufficient and the transistor begins to open, and the entire current will flow across the transistor open.

It is very desirable and even necessarily the use of an additional fan if the scheme is operated on high currents.
To charge the batteries, the rotation of the trimmed resistor you need to set the voltage of the charge and all. The maximum charge current is limited to 10-amps, as the battery charge will fall. The short circuit diagram is not afraid, the current will be limited to CW. As in the case of the first scheme, if available good coolingThe device will be able to longer tolerate such a mode of operation.
Well, now several tests:

To whom there is no time to "bother" with all the nuances of charging a car battery, follow the charge current, turn off, so as not to recharge, etc., can be recommended simple schema Charge automotive AKB With automatic shutdown when charging the battery. This scheme uses one non-powerful transistor to determine the voltage on the battery.

Scheme of a simple automatic car battery charger

List of necessary parts:

• R1 \u003d 4.7 kΩ;
• P1 \u003d 10k trimmed;
• T1 \u003d bc547b, kt815, kt817;
• Relay \u003d 12V, 400 ohms, (automobile, for example: 90.3747);
• TR1 \u003d secondary winding voltage 13.5-14.5 V, current 1/10 from the capacity of the AKB (for example: AKB 60A / C - Current 6A);
• Diode bridge D1-D4 \u003d on the current equal to the nominal transformer value \u003d at least 6a (for example, D242, CD213, CD2997, CD2999 ...) installed on the radiator;
• D1 diodes (parallel to the relay), D5,6 \u003d 1N4007, KD105, KD522 ...;
• C1 \u003d 100UF / 25V.
• R2, R3 - 3 com
• HL1 - al307
• HL2 - al307b

The diagram does not have a charge indicator, current control (ammeter) and a charge limitation. If you wish, you can put an ammeter at the output to the gap of any of the wires. LEDs (HL1 and HL2) with restrictive resistances (R2 and R3 - 1 com) or light bulbs parallel to C1 "Network", and to the free contact RL1 "End of charge".

Changed scheme

The current equal to 1/10 on the capacity of the battery is selected by the number of turns of the secondary winding of the transformer. When winding a transformer secondary, you need to make several chains for selection optimal option Charging current.

The charge of the automobile (12 volt) battery is considered to be finished when the voltage on its terminals will reach 14.4 volts.

The shutdown threshold (14.4 volts) is installed by the P1 stroke resistor when the connected and fully charged battery.

When charging a discharged battery, the voltage on it will be around 13V, during charging the current will fall, and the voltage increase. When the voltage on the battery reaches 14.4 volts, the T1 transistor will turn off the RL1 relay circuit will be broken and the battery will turn off from the charging voltage from D1-4 diodes.

When the voltage is reduced to 11.4 volts, the charging is renewed again, such a hysteresis provides D5-6 diodes in the transistor emitter. The schema threshold becomes 10 + 1.4 \u003d 11.4 volts, which can be considered as to automatically restart the charging process.

Such a homemade simple automatic car charger will help you control the charging process, not trace the ending charging and do not recharge your battery!

Website materials used: homemade-circuits.com

Another version of the charger circuit for a 12 volt car battery with automatic shutdown after charging

The scheme is a bit more complicated by the previous one, but with a more clear triggering.