Homemade battery charger. Charger with regulation in the primary winding of the transformer Charger with regulation in the primary winding

Simple scheme charger for car battery

As is known from the laws of transformer operation, the current in the primary winding, if the transformer is step-down, is less than the current in the secondary winding in relation to the voltage or number of turns of the transformer. I consider a good charger if it is capable of delivering 10A output. At the transformer input there will be 10/(220/15)= 0.7A. Agree, it is easier to control the current if it is smaller. Charger with current regulation on the primary winding is given below:

The circuit is very simple and does not require adjustment. The bridge diodes in the low-voltage network must be installed on the radiator. Since the KU202N thyristor will be loaded less than 10% on the radiator, there is no point in installing it; it can be installed directly on the printed circuit board. Example assembled circuit on printed circuit board is given below.

This charger is highly reliable and easy to assemble. The only thing you need to have is a transformer of 200 W or more, although this condition applies to almost all chargers.
This scheme can be used not only for car charging but also for any one in which there is a transformer...
Also, this circuit can be used for a high-power laboratory source...
Again, if you find a powerful 220/220 transformer, you can get LATR

THINK FOR YOURSELF FOR ITS FURTHER APPLICATION......

Sometimes a radio amateur on the farm needs a simple adjustable source for testing and tuning some equipment, as well as charging batteries that are not capricious to the regime.

A laboratory autotransformer, LATR, which allows you to regulate the input voltage from zero to maximum, is quite suitable for this purpose.

You can purchase an LATR, connect a ready-made rectifier to its output, in the form of a diode bridge and a capacitor, and if required low level ripples, then add a smoothing LC filter.

However, such a source has some disadvantages:

The first drawback can be eliminated by adding an additional transformer isolating from the network, which will lead to an increase in the second drawback.

Somehow I was interested in welding current regulator circuits online and came across this circuit:

The diagram shows that a powerful welding transformer is regulated along the primary winding with back-to-back switches turned on powerful thyristors VS1, VS2, which form an analogue of a triac. The regulator does not disrupt the operation of the transformer; the variable resistor R7 regulates the opening delay of the thyristors relative to the beginning of the half-cycle of the mains voltage, due to which the adjustment occurs.

This is what the current shape looks like in the primary winding of the transformer:

The regulator circuit can be simplified, while the number of circuit components
decreases:

You can make such a regulator yourself, or you can purchase a ready-made one, since the circuit is identical to commercially available regulators for incandescent lamps - dimmers.

Photo of the dimmer itself:

Let's take a 250W network step-down transformer and assemble a circuit.

It remains to supplement the circuit with a simple rectifier and we get this simple but universal device:

The end result is classic simplest block power supply, with output voltage adjustment function. This unit can be used to power and configure various designs, as well as to charge car batteries.

This article was sent to me by the author of the channel Blaze Electronics, the article was written based on this video. It will be especially interesting for those who have little understanding of electronics

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A simple charger with LED indicator charging, green battery is charging, red battery is charged.

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This type of charger is capable of automatically charging almost any type of 12V car and motorcycle batteries up to 80A/H. Has a unique charging method in three stages: 1. Charging DC, 2. Charging constant voltage, 3. Drop recharging up to 100%.
There are two indicators on the front panel, the first indicates the voltage and charging percentage, the second indicates the charging current.
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Charger for a wide variety of 12-24V battery types with current up to 10A and peak current 12A. Able to charge Helium batteries and SA\SA. The charging technology is the same as the previous one in three stages. The charger is capable of charging both automatic mode, and manually. The panel has an LCD indicator indicating voltage, charging current and charging percentage.

A good device if you need to charge all possible types of batteries of any capacity, up to 150Ah

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With uv. Eduard Orlov

The device (see diagram) is based on a triac regulator, with additionally introduced low-power diode bridge VD1 – VD4 and resistors R3 and R5.

After connecting the device to the network at its positive half-cycle (plus on the top wire in the diagram), capacitor C2 begins to charge through resistor R3, diode VD1 and series-connected resistors R1 and R2. With a negative half-cycle of the network, this capacitor is charged through the same resistors R2 and R1, diode VD2 and resistor R5. In both cases, the capacitor is charged to the same voltage, only the charging polarity changes.

As soon as the voltage on the capacitor reaches the ignition threshold of the neon lamp HL1, it lights up and the capacitor is quickly discharged through the lamp and the control electrode of the smistor VS1. In this case, the triac opens. At the end of the half-cycle, the triac closes. The described process is repeated in each half-cycle of the network.

It is well known, for example, that controlling a thyristor using a short pulse has the disadvantage that with an inductive or high-resistance active load, the anode current of the device may not have time to reach the holding current value during the action of the control pulse. One of the measures to eliminate this drawback is to connect a resistor in parallel with the load.

In the described charger, after turning on the triac VS1, its main current flows not only through the primary winding of transformer T1, but also through one of the resistors - R3 or R5, which, depending on the polarity of the half-cycle of the mains voltage, are alternately connected parallel to the primary winding of the transformer with diodes VD4 and VD3, respectively .

The main unit of the device is transformer T1. It can be made on the basis of the LATR-2M laboratory transformer by insulating its winding (it will be the primary) with three layers of varnish and winding a secondary winding consisting of 80 turns of insulated copper wire with a cross-section of at least 3 mm2, with a tap from the middle. The transformer and rectifier can also be borrowed from a power source of suitable power. At self-production transformer, you can use the following calculation method; in this case, they are set by a voltage on the secondary winding of 20 V at a current of 10 A.

Capacitors C1 and C2 - MBM or others for a voltage of at least 400 and 160 V, respectively. Resistors R1 and R2 are SP 1-1 and SPZ-45, respectively. Diodes VD1-VD4 -D226, D226B or KD105B. Neon lamp HL1 – IN-3, IN-ZA; It is very desirable to use a lamp with electrodes of the same design and size - this will ensure symmetry of the current pulses through the primary winding of the transformer.

KD202A diodes can be replaced with any of this series, as well as with D242, D242A or others with an average direct tone of at least 5 A. The diode is placed on a duralumin heat-sinking plate with a useful dissipation surface area of ​​at least 120 cm2. The triac should also be mounted on a heat sink plate with approximately half the surface area. Resistor R6 – PEV-10; it can be replaced with five parallel-connected MLT-2 resistors with a resistance of 110 Ohms.

One of the main tools at hand in a radio amateur’s laboratory is, of course, a power supply, and as you know, the basis of most power supplies is power transformer voltage. Sometimes we come across excellent transformers, but after checking the windings it becomes clear that the voltage we need is missing due to a burnout of the primary or secondary. There is only one way out of this situation - to rewind the transformer and wind the secondary winding with your own hands. In amateur radio equipment, you usually need a voltage from 0 to 24 volts to power a variety of devices.

Since the power supply will operate from household network 220 volts, then when carrying out small calculations it becomes clear that on average every 4-5 turns in the secondary winding of the transformer produce a voltage of 1 volt.

How to make a charger for a car battery with your own hands?

This means that for a power supply with a maximum voltage of 24 volts, the secondary winding should contain 5 * 24, resulting in 115-120 turns. For powerful block power supply, you also need to select a wire of the required cross-section for rewinding; on average, the diameter of the wire chosen for a medium-power power supply is 1 millimeter (from 0.7 to 1.5 mm).

To create a powerful power supply, you need to have a powerful transformer on hand; a transformer from a black-and-white TV made in the Soviet Union is perfect. The transformer needs to be disassembled, the cores (pieces) taken out and all secondary windings unwinded, leaving only the network winding, the whole process takes no more than 30 minutes.

Next, we take the indicated wire and wind it onto the transformer frame with the calculation of 5 turns of 1 volt. Thus, you can assemble, for example, a charger for a car battery with your own hands; to charge a car battery, the secondary winding must contain 60-70 turns (charging voltage must be at least 14 volts, current 3-10 amperes), then you need a powerful diode bridge for rectification AC and you're done.

But to charge a car battery, the wire of the secondary winding of the transformer must be selected with a diameter of at least 1.5 millimeters (from 1.5 to 3 millimeters in order to have charging current from 3 to 10 amperes). In the same way, you can design a welding machine and other power devices.

DIY 12V battery charger

I made this charger for charging car batteries, the output voltage is 14.5 volts, maximum current charge 6 A. But it can also charge other batteries, for example lithium-ion ones, since the output voltage and output current can be adjusted within a wide range. The main components of the charger were purchased on the AliExpress website.

These are the components:

Still needed electrolytic capacitor 2200 uF at 50 V, transformer for the TS-180-2 charger (see this article for how to solder the TS-180-2 transformer), wires, power plug, fuses, radiator for the diode bridge, crocodiles. You can use another transformer with a power of at least 150 W (for a charging current of 6 A), the secondary winding must be designed for a current of 10 A and produce a voltage of 15 - 20 volts. The diode bridge can be assembled from individual diodes designed for a current of at least 10A, for example D242A.

The wires in the charger should be thick and short.

How to charge a car battery

The diode bridge must be mounted on a large radiator. It is necessary to increase the radiators of the DC-DC converter, or use a fan for cooling.

Circuit diagram of a charger for a car battery

Charger assembly

Connect a cord with a power plug and a fuse to the primary winding of the TS-180-2 transformer, install the diode bridge on the radiator, connect the diode bridge and the secondary winding of the transformer. Solder the capacitor to the positive and negative terminals of the diode bridge.

Connect the transformer to a 220 volt network and measure the voltages with a multimeter. I got the following results:

1. The alternating voltage at the terminals of the secondary winding is 14.3 volts (mains voltage 228 volts).
2. The constant voltage after the diode bridge and capacitor is 18.4 volts (no load).

Using the diagram as a guide, connect a step-down converter and a voltammeter to the DC-DC diode bridge.

Setting the output voltage and charging current

There are two trimming resistors installed on the DC-DC converter board, one allows you to set the maximum output voltage, the other allows you to set the maximum charging current.

Plug in the charger (nothing is connected to the output wires), the indicator will show the voltage at the device output and the current is zero. Use the voltage potentiometer to set the output to 5 volts. Close the output wires together, use the current potentiometer to set the short circuit current to 6 A. Then eliminate the short circuit by disconnecting the output wires and use the voltage potentiometer to set the output to 14.5 volts.

Reverse polarity protection

This charger is not afraid of a short circuit at the output, but if the polarity is reversed, it may fail. To protect against polarity reversal, a powerful Schottky diode can be installed in the gap in the positive wire going to the battery. Such diodes have a low voltage drop when connected directly. With such protection, if the polarity is reversed when connecting the battery, no current will flow. True, this diode will need to be installed on a radiator, since a large current will flow through it during charging.

Suitable diode assemblies are used in computer units nutrition. This assembly contains two Schottky diodes with a common cathode; they will need to be paralleled. For our charger, diodes with a current of at least 15 A are suitable.

It must be taken into account that in such assemblies the cathode is connected to the housing, so these diodes must be installed on the radiator through an insulating gasket.

It is necessary to adjust the upper voltage limit again, taking into account the voltage drop across the protection diodes. To do this, use the voltage potentiometer on the DC-DC converter board to set 14.5 volts measured with a multimeter directly at the output terminals of the charger.

How to charge the battery

Wipe the battery with a cloth soaked in soda solution, then dry. Remove the plugs and check the electrolyte level; if necessary, add distilled water. The plugs must be turned out during charging. No debris or dirt should get inside the battery. The room in which the battery is charged must be well ventilated.

Connect the battery to the charger and plug in the device. During charging, the voltage will gradually increase to 14.5 volts, the current will decrease over time. The battery can be conditionally considered charged when the charging current drops to 0.6 - 0.7 A.

DC-DC buck converter TC43200 - product link.

Buck review DC-DC converter CC CV TC43200.

The device can be used to recharge automobile batteries with a capacity of up to 100 Ah, for charging motorcycle batteries in a mode close to optimal, and also (with simple modifications) as laboratory block nutrition.

The charger is made on the basis of a push-pull transistor voltage converter with autotransformer coupling and can operate in two modes - a current source and a voltage source. When the output current is less than a certain limit value, it operates as usual - in voltage source mode. If you try to increase the load current above this value, the output voltage will decrease sharply - the device will switch to current source mode.

DIY car battery chargers

Current source mode (having a large internal resistance) is ensured by including a ballast capacitor in the primary circuit of the converter.

Schematic diagram charger is shown in Fig. 2.94.

Rice. 2.94.Schematic diagram of a charger with a quenching capacitor in the primary circuit.

The mains voltage is supplied through the ballast capacitor C1 to the rectifier bridge VD1. Capacitor C2 smoothes out ripples, and zener diode VD2 stabilizes the rectified voltage. Zener diode VD2 simultaneously protects the transistors of the converter from overvoltage idling, as well as when the device output is closed, when the voltage at the output of bridge VD1 increases. The latter is due to the fact that when the output circuit is closed, the generation of the converter may be disrupted, while the load current of the rectifier decreases and its output voltage increases. In such cases, the zener diode VD2 limits the voltage at the output of bridge VD1.

The voltage converter is assembled using transistors VT1, VT2 and transformer T1. The converter operates at a frequency of 5 ÷ 10 kHz.

The VD3 diode bridge rectifies the voltage taken from the secondary winding of the transformer. Capacitor C3 is a smoothing capacitor.

The experimentally measured load characteristic of the charger is shown in Fig. 2.95. When the load current increases to 0.35 ÷ 0.4 A, the output voltage changes slightly, and with a further increase in current it decreases sharply. If an undercharged battery is connected to the output of the device, the voltage at the output of bridge VD1 decreases, the zener diode VD2 exits the stabilization mode and, since input circuit capacitor C1 with high reactance is turned on, the device operates in current source mode.

If the charging current decreases, the device smoothly switches to voltage source mode. This makes it possible to use the charger as a low-power laboratory power supply. When the load current is less than 0.3 A, the ripple level at the operating frequency of the converter does not exceed 16 mV, and the output resistance of the source decreases to several Ohms. The dependence of the output resistance on the load current is shown in Fig. 2.95.

Rice. 2.95. Load characteristics of a charger with a quenching capacitor in the primary circuit.

Setting up a charger with a quenching capacitor in the primary circuit

Installation begins with checking the correct installation. Then they make sure that the device is working when the output circuit is closed. The circuit current must be at least 0.45-0.46 A. Otherwise, resistors R1, R2 should be selected in order to ensure reliable saturation of transistors VT1, VT2. A higher fault current corresponds to a lower resistance of the resistors.

If you need to use the device to charge small-sized batteries with a capacity of up to units of ampere-hours and regeneration of galvanic cells, it is advisable to provide regulation of the charging current. To do this, instead of one capacitor C1, a set of capacitors of smaller capacity, switched by a switch, should be provided. With sufficient accuracy for practice, the maximum charging current - the closing current of the output circuit - is proportional to the capacity of the ballast capacitor (at 4 μF the current is 0.46 A).

If you need to reduce the output voltage of a laboratory power supply, it is enough to replace the VD2 zener diode with another one with a lower stabilization voltage.

Transformer T1 is wound on a ring magnetic core of standard size K40x25x11 made of 1500NM1 ferrite. The primary winding contains 2×160 turns of PEV-2 0.49 wire, the secondary winding contains 72 turns of PEV-2 0.8 wire. The windings are insulated with each other by two layers of varnished fabric.

Install the VD2 zener diode on a heat sink with a useful area of ​​25 cm 2

The transistors of the converter do not need additional heat sinks, since they operate in switching mode.

Capacitor C1 is paper, designed for a rated voltage of at least 400 V.