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Thyristor current regulators for charging car batteries. Review of car battery charger circuits. General description of the charger circuit

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

where I is the average charging current, A., and Q is the nameplate electric capacity of the battery, Ah.

A classic charger for a car battery consists of a step-down transformer, a rectifier and a charging current regulator. Wire rheostats (see Fig. 1) and transistor current stabilizers are used as current regulators.

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

To adjust charging current You can use a store of capacitors connected in series with the primary (mains) winding of the transformer and performing the function of reactances that dampen excess network voltage. A simplified version of such a device is shown in Fig. 2.

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

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

The charger circuit, which provides charging of 12-volt batteries with a current of up to 15 A, and the charging current can be changed from 1 to 15 A in steps of 1 A, is 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 circuit and breaks in it.

Switches Q1 - Q4 can be used to connect various combinations of capacitors and thereby regulate the charging current.

The variable resistor R4 sets the response threshold of K2, which should operate when the voltage at the battery terminals is equal to the voltage of a fully charged battery.

In Fig. Figure 4 shows another charger in which the charging current is smoothly regulated from zero to the maximum value.

The change in current in the load is achieved by adjusting the opening angle of the thyristor VS1. The control unit is made on a unijunction transistor VT1. The value of this current is determined by the position of the variable resistor R5. The maximum battery charging current is 10A, set with an ammeter. The device is provided on the mains and load side with fuses F1 and F2.

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

In the diagram in Fig. 4, the secondary winding of the transformer must be designed for a current three times greater than the charging current, and accordingly, the power of the transformer must also be three times greater than the power consumed by the battery.

This circumstance is a significant drawback chargers with current regulator thyristor (thyristor).

Note:

The rectifier bridge diodes VD1-VD4 and the thyristor VS1 must be installed on radiators.

It is possible to significantly reduce power losses in the SCR, and therefore increase the efficiency of the charger, by moving the control element from the circuit of the secondary winding of the transformer to the circuit of the primary winding. such a device is shown in Fig. 5.

In the diagram in Fig. 5 control unit is similar to that used in the previous version of the device. SCR VS1 is included in the diagonal of the rectifier bridge VD1 - VD4. Since the current primary winding The transformer is approximately 10 times less than the charging current; relatively small thermal power is released on the diodes VD1-VD4 and the thyristor VS1 and they do not require installation on radiators. In addition, the use of an SCR in the primary winding circuit of the transformer made it possible to slightly improve the shape of the charging current curve and reduce the value of the current curve shape coefficient (which also leads to an increase in the efficiency of the charger). The disadvantage of this charger is the galvanic connection with the network of elements of the control unit, which must be taken into account when developing a design (for example, use a variable resistor with a plastic axis).

A version of the printed circuit board of the charger in Figure 5, measuring 60x75 mm, is shown in the figure below:

Note:

The rectifier bridge diodes VD5-VD8 must be installed on radiators.

In the charger in Figure 5 there is a diode bridge VD1-VD4 type KTs402 or KTs405 with the letters A, B, C. Zener diode VD3 type KS518, KS522, KS524, or made up of two identical zener diodes with a total stabilization voltage of 16÷24 volts (KS482, D808 , KS510, etc.). Transistor VT1 is unijunction, type KT117A, B, V, G. The diode bridge VD5-VD8 is made up of diodes, with a working current not less than 10 amperes(D242÷D247, etc.). The diodes are installed on radiators with an area of at least 200 sq.cm, and the radiators will become very hot; a fan can be installed in the charger case for ventilation.

Hello uv. reader of the blog “My Radio Amateur Laboratory”.

In today's article we will talk about a long-used, but very useful circuit of a thyristor phase-pulse power regulator, which we will use as a charger for lead-acid batteries.

Let's start with the fact that the charger on the KU202 has a number of advantages:
- Ability to withstand charging current up to 10 amperes
- The charge current is pulsed, which, according to many radio amateurs, helps extend the life of the battery
- The circuit is assembled from non-scarce, inexpensive parts, which makes it very affordable in the price category
- And the last plus is the ease of repetition, which will make it possible to repeat it, both for a beginner in radio engineering, and simply for a car owner who has no knowledge of radio engineering at all, who needs high-quality and simple charging.

At one time, I assembled this circuit on my knee in 40 minutes, along with wiring the board and preparing the circuit components. Well, enough stories, let's look at the diagram.

Scheme of a thyristor charger on KU202

List of components used in the circuit
C1 = 0.47-1 µF 63V

R1 = 6.8k - 0.25W
R2 = 300 - 0.25W
R3 = 3.3k - 0.25W
R4 = 110 - 0.25W
R5 = 15k - 0.25W
R6 = 50 - 0.25W
R7 = 150 - 2W
FU1 = 10A
VD1 = current 10A, it is advisable to take a bridge with a reserve. Well, at 15-25A and the reverse voltage is not lower than 50V
VD2 = any pulse diode, reverse voltage not lower than 50V
VS1 = KU202, T-160, T-250
VT1 = KT361A, KT3107, KT502
VT2 = KT315A, KT3102, KT503

As mentioned earlier, the circuit is a thyristor phase-pulse power regulator with an electronic charging current regulator.
The thyristor electrode is controlled by a circuit using transistors VT1 and VT2. The control current passes through VD2, which is necessary to protect the circuit from reverse surges in the thyristor current.

Resistor R5 determines the battery charging current, which should be 1/10 of the battery capacity. For example, a battery with a capacity of 55A must be charged with a current of 5.5A. Therefore, it is advisable to place an ammeter at the output in front of the charger terminals to monitor the charging current.

Regarding the power supply, for this circuit we select a transformer with an alternating voltage of 18-22V, preferably in terms of power without reserve, because we use a thyristor in the control. If the voltage is higher, raise R7 to 200 Ohm.

We also do not forget that the diode bridge and the control thyristor must be installed on the radiators through heat-conducting paste. Also, if you use simple diodes such as D242-D245, KD203, remember that they must be isolated from the radiator body.

We put a fuse at the output for the currents you need; if you do not plan to charge the battery with a current higher than 6A, then a 6.3A fuse will be enough for you.
Also, to protect your battery and charger, I recommend installing mine or, which, in addition to protection against polarity reversal, will protect the charger from connecting dead batteries with a voltage of less than 10.5V.
Well, in principle, we looked at the charger circuit for the KU202.

Printed circuit board of the thyristor charger on KU202

Assembled from Sergei

Good luck with your repetition and I look forward to your questions in the comments.

For safe, high-quality and reliable charging of any types of batteries, I recommend
With uv.Admin-check

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Let's make a gift to the workshop. Throw a couple of coins at digital oscilloscope UNI-T UTD2025CL (2 channels x 25 MHz). An oscilloscope is a device designed to study the amplitude and time parameters of an electrical signal. It costs 15,490 rubles, I can’t afford such a gift. The device is very necessary. With it, the number of new interesting schemes will increase significantly. Thanks to everyone who will help.

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Device with electronically controlled charging current, made on the basis of a thyristor phase-pulse power regulator.
It does not contain scarce parts; if the parts are known to work, it does not require adjustment.
The charger allows you to charge car batteries with a current of 0 to 10 A, and can also serve as an adjustable power source for a powerful low-voltage soldering iron, vulcanizer, or portable lamp.
The charging current is similar in shape to pulse current, which is believed to help extend battery life.
The device is operational at temperatures environment from - 35 °C to + 35 °C.
The device diagram is shown in Fig. 2.60.
The charger is a thyristor power regulator with phase-pulse control, powered from winding II of the step-down transformer T1 through the moctVDI + VD4 diode.
The thyristor control unit is made on an analogue of the unijunction transistor VTI, VT2. The time during which capacitor C2 is charged before switching the unijunction transistor can be adjusted with variable resistor R1. When its motor is positioned to the far right in the diagram, the charging current will become maximum, and vice versa.
Diode VD5 protects the control circuit of thyristor VS1 from reverse voltage that appears when the thyristor is turned on.

The charger can later be supplemented with various automatic components (switching off upon completion of charging, maintaining normal battery voltage during long-term storage, signaling the correct polarity of the battery connection, protection against output short circuits, etc.).
The shortcomings of the device include fluctuations in the charging current when the voltage of the electric lighting network is unstable.
Like all similar thyristor phase-pulse regulators, the device interferes with radio reception. To combat them, it is necessary to provide a network LC- filter similar to that used in pulse network blocks nutrition.

Capacitor C2 - K73-11, with a capacity of 0.47 to 1 μF, or K73-16, K73-17, K42U-2, MBGP.
We will replace the KT361A transistor with KT361B - KT361Ё, KT3107L, KT502V, KT502G, KT501Zh - KT50IK, and KT315L - to KT315B + KT315D KT312B, KT3102L, KT503V + KT503G, P307. Instead of KD105B, diodes KD105V, KD105G or D226 with any letter index are suitable.
Variable resistor R1- SP-1, SPZ-30a or SPO-1.
Ammeter PA1 - any direct current with a scale of 10 A. You can make it yourself from any milliammeter by choosing a shunt based on a standard ammeter.
fuse F1 - fusible, but it is convenient to use a 10 A network circuit breaker or an automobile bimetallic circuit breaker for the same current.
Diodes VD1+VP4 can be any for a forward current of 10 A and a reverse voltage of at least 50 V (series D242, D243, D245, KD203, KD210, KD213).
The rectifier diodes and thyristor are placed on heat sinks, each with a useful area of about 100 cm*. To improve the thermal contact of devices with heat sinks, it is better to use thermally conductive pastes.
Instead of the KU202V thyristor, KU202G - KU202E are suitable; It has been verified in practice that the device operates normally even with more powerful thyristors T-160, T-250.
It should be noted that it is possible to use the iron casing wall directly as a heat sink for the thyristor. Then, however, there will be a negative terminal of the device on the case, which is generally undesirable due to the threat of accidental short circuits of the positive output wire to the case. If you strengthen the thyristor through a mica gasket, there will be no risk of a short circuit, but the heat transfer from it will worsen.
The device can use a ready-made network step-down transformer of the required power with a secondary winding voltage of 18 to 22 V.
If the transformer has a voltage on the secondary winding of more than 18 V, the resistor R5 should be replaced with another one of the highest resistance (for example, at 24 * 26 V, the resistance of the resistor should be increased to 200 Ohms).
In the case when the secondary winding of the transformer has a tap from the middle, or there are two identical windings and the voltage of each is within the specified limits, then it is better to design the rectifier according to the usual full-wave circuit with 2 diodes.
With a secondary winding voltage of 28 * 36 V, you can completely abandon the rectifier - its role will simultaneously be played by a thyristor VS1 ( rectification - half-wave). For this version of the power supply you need a resistor between R5 and use the positive wire to connect a separating diode KD105B or D226 with any letter index (cathode to resistor R5). The choice of thyristor in such a circuit will be limited - only those that allow operation under reverse voltage are suitable (for example, KU202E).
For the described device, a unified transformer TN-61 is suitable. Its 3 secondary windings must be connected in series, and they are capable of delivering current up to 8 A.
All parts of the device, except transformer T1, diodes VD1 + VD4 rectifier, variable resistor R1, fuse FU1 and thyristor VS1, mounted on a printed circuit board made of foil fiberglass laminate 1.5 mm thick.
The board drawing is presented in radio magazine No. 11 for 2001.

Under normal operating conditions, the vehicle's electrical system is self-sufficient. We are talking about energy supply - a combination of a generator, a voltage regulator, and a battery works synchronously and ensures uninterrupted power supply to all systems.

This is in theory. In practice, car owners make amendments to this harmonious system. Or the equipment refuses to work in accordance with the established parameters.

For example:

Operating a battery that has exhausted its service life. The battery does not hold a charge
Irregular trips. Prolonged downtime of the car (especially during the “ hibernation") leads to battery self-discharge
The car is used for short trips, with frequent stopping and starting of the engine. The battery simply does not have time to recharge
Connection additional equipment increases the load on the battery. Often leads to increased current self-discharge when the engine is off
Extreme low temperature accelerates self-discharge
Faulty fuel system leads to increased load: the car does not start immediately, you have to turn the starter for a long time
A faulty generator or voltage regulator prevents the battery from charging properly. This problem includes worn power wires and poor contact in the charging circuit.
And finally, you forgot to turn off the headlights, lights or music in the car. For full discharge battery overnight in the garage, sometimes it’s enough to close the door loosely. Interior lighting consumes quite a lot of energy.

Any of the following reasons leads to an unpleasant situation: you need to drive, but the battery is unable to crank the starter. The problem is solved by external recharge: that is, a charger.

It is absolutely easy to assemble it with your own hands. An example of a charger made from an uninterruptible power supply.

Any car charger circuit consists of the following components:

Power unit.
Current stabilizer.
Charge current regulator. Can be manual or automatic.
Indicator of current level and (or) charge voltage.
Optional - charge control with automatic shutdown.

Any charger, from the simplest to an intelligent machine, consists of the listed elements or a combination thereof.

Simple diagram for a car battery

Normal charge formula as simple as 5 kopecks - the basic battery capacity divided by 10. The charging voltage should be a little more than 14 volts ( we're talking about about the standard 12 volt starter battery).

Simple principle electrical The car charger circuit consists of three components: power supply, regulator, indicator.

Classic - resistor charger

The power supply is made of two winding “trans” and a diode assembly. The output voltage is selected by the secondary winding. The rectifier is a diode bridge; a stabilizer is not used in this circuit.
The charging current is controlled by a rheostat.

Important! No variable resistors, even those with a ceramic core, will withstand such a load.

Wire rheostat necessary for confrontation main problem such a scheme - excess power is released in the form of heat. And this happens very intensively.

Of course, the efficiency of such a device tends to zero, and the service life of its components is very low (especially the rheostat). Nevertheless, the scheme exists, and it is quite workable. For emergency charging, if you don’t have ready-made equipment at hand, you can literally assemble it “on your knees.” There are also limitations - a current of more than 5 amperes is the limit for such a circuit. Therefore, you can charge a battery with a capacity of no more than 45 Ah.

DIY charger, details, diagrams - video

Quenching capacitor

The operating principle is shown in the diagram.

Thanks to the reactance of the capacitor included in the primary winding circuit, the charging current can be adjusted. The implementation consists of the same three components - power supply, regulator, indicator (if necessary). The circuit can be configured to charge one type of battery, and then the indicator will not be needed.

If we add one more element - automatic charge control, and also assemble a switch from a whole bank of capacitors - you get a professional charger that remains easy to manufacture.

The charge control and automatic shutdown circuit does not need any comments. The technology has been proven, you can see one of the options on general scheme. The response threshold is set by variable resistor R4. When the own voltage at the battery terminals reaches the configured level, relay K2 turns off the load. An ammeter acts as an indicator, which stops showing the charge current.

The highlight of the charger– capacitor battery. The peculiarity of circuits with a quenching capacitor is that by adding or decreasing capacitance (simply connecting or removing additional elements) you can adjust the output current. By selecting 4 capacitors for currents of 1A, 2A, 4A and 8A, and switching them with ordinary switches in various combinations, you can adjust the charge current from 1 to 15 A in 1 A steps.

If you are not afraid to hold a soldering iron in your hands, you can assemble a car accessory with continuously adjustable charge current, but without the disadvantages inherent in the resistor classics.

The regulator is not a heat dissipator in the form of a powerful rheostat, but an electronic switch based on a thyristor. The entire power load passes through this semiconductor. This scheme designed for a current of up to 10 A, that is, it allows you to charge a battery up to 90 Ah without overload.

By adjusting the degree of opening of the junction on transistor VT1 with resistor R5, you ensure smooth and very precise control of the trinistor VS1.

The circuit is reliable, easy to assemble and configure. But there is one condition that prevents such a charger from being included in the list of successful designs. The power of the transformer must provide a threefold reserve of charging current.

That is, for the upper limit of 10 A, the transformer must withstand a continuous load of 450-500 W. Practically implemented scheme will be bulky and heavy. However, if the charger is permanently installed indoors, this is not a problem.

Circuit diagram of a pulse charger for a car battery

All the shortcomings The solutions listed above can be changed to one - the complexity of the assembly. This is the essence of pulse chargers. These circuits have enviable power, heat up little, and have high efficiency. In addition, their compact size and light weight allow you to simply carry them with you in the glove compartment of your car.

The circuit design is understandable to any radio amateur who has an idea of what a PWM generator is. It is assembled on the popular (and completely inexpensive) IR2153 controller. This circuit implements a classic semi-bridge inverter.

With existing capacitors output power is 200 W. This is a lot, but the load can be doubled by replacing the capacitors with 470 µF capacitors. Then it will be possible to charge with a capacity of up to 200 Ah.

The assembled board turned out to be compact and fits into a box 150*40*50 mm. No forced cooling required, but ventilation holes must be provided. If you increase the power to 400 W, power switches VT1 and VT2 should be installed on radiators. They must be taken outside the building.

The power supply from the PC system unit can act as a donor.

Important! When using an AT or ATX power supply, there is a desire to convert the finished circuit into a charger. To implement such an idea, you need a factory power supply circuit.

Therefore, we will simply use the element base. A transformer, inductor and diode assembly (Schottky) as a rectifier are ideal. Everything else: transistors, capacitors and other little things are usually available to the radio amateur in all sorts of boxes. So the charger turns out to be conditionally free.

The video shows and explains how to assemble a pulse charger for a car yourself.

The cost of a factory 300-500 W pulse generator is at least $50 (in equivalent).

Conclusion:

Collect and use. Although it is wiser to keep your battery in good shape.

The figure shows a diagram of a thyristor charger, which automatically stops charging a car battery when the battery is fully charged.

Operating principle: the 220V mains voltage arriving at T1 is reduced and supplied to the rectifier diodes D1 D2, then the 12V voltage is supplied in two ways through D3R1R2 and the high power thyristor D4. Through the first circuit, the battery is charged with a current of only 0.1A. The value of this current is close to the self-discharge value of the battery, so even a long charge of the battery will not harm it and will always maintain it in full readiness. The current is set by resistor R2.

The second charging circuit goes through thyristor D4; a current of up to 6A can flow through it. The thyristor is controlled using a zener diode D6 (8V), a thyristor D7 and a voltage divider on R5R6, midpoint which is connected through diode D5 to the control electrode D4. The level of termination of charging with a large current is set using a voltage divider on R3 and variable R4. The constant voltage is removed from the R4 engine and controls the switching on and off of the thyristor D7 through the zener diode D6.

The threshold voltage at which the battery is fully charged and the charging current must be significantly reduced is set using resistor R4 individually for each battery.

When manufacturing a charger, a 100V transformer is required, the secondary winding of which must be designed for a voltage of 45V with a tap from the middle. If you don’t have the required transformer, you can take a power transformer from an old TV, leaving the primary winding unchanged, and wind the secondary winding at 45V. The number of turns should be as follows: the number of turns for heating the cathode of the kinescope multiplied by 7. The winding must be made of PEL, PEV-1, PEV-2 wire with a diameter of 2 mm.

Literature MRB 1018

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Charging device for car batteries.

It’s not new to anyone if I say that any motorist should have a battery charger in their garage. Of course, you can buy it in a store, but when faced with this question, I came to the conclusion that I don’t want to buy an obviously not very good device at an affordable price. There are those in which the charging current is regulated by a powerful switch, which adds or reduces the number of turns in the secondary winding of the transformer, thereby increasing or decreasing the charging current, while in principle there is no current control device. This is probably the most cheap option factory-made charger, but a smart device is not that cheap, the price is really steep, so I decided to find a circuit on the Internet and assemble it myself. The selection criteria were as follows:

A simple scheme, without unnecessary bells and whistles;
- availability of radio components;
- smooth adjustment of charging current from 1 to 10 amperes;
- it is desirable that this is a diagram of a charging and training device;
- easy setup;
- stability of operation (according to reviews of those who have already done this scheme).

After searching on the Internet, I came across an industrial circuit for a charger with regulating thyristors.

Everything is typical: a transformer, a bridge (VD8, VD9, VD13, VD14), a pulse generator with adjustable duty cycle (VT1, VT2), thyristors as switches (VD11, VD12), a charge control unit. Simplifying this design somewhat, we get a simpler diagram:

There is no charge control unit in this diagram, and the rest is almost the same: trans, bridge, generator, one thyristor, measuring heads and fuse. Please note that the circuit contains a KU202 thyristor; it is a little weak, so in order to prevent breakdown by high current pulses, it must be installed on a radiator. The transformer is 150 watt, or you can use a TS-180 from an old tube TV.

Adjustable charger with a charge current of 10A on the KU202 thyristor.

And one more device that does not contain scarce parts, with a charging current of up to 10 amperes. It is a simple thyristor power regulator with phase-pulse control.

The thyristor control unit is assembled on two transistors. The time during which capacitor C1 will charge before switching the transistor is set by variable resistor R7, which, in fact, sets the value of the battery charging current. Diode VD1 serves to protect the thyristor control circuit from reverse voltage. The thyristor, as in the previous schemes, is placed on a good radiator, or on a small one with a cooling fan. The printed circuit board of the control unit looks like this:

The scheme is not bad, but it has some disadvantages:
- fluctuations in supply voltage lead to fluctuations in the charging current;
- no short circuit protection other than a fuse;
- the device interferes with the network (can be treated with an LC filter).

Charging and restoring device for rechargeable batteries.

This pulse device can charge and restore almost any type of battery. The charging time depends on the condition of the battery and ranges from 4 to 6 hours. Due to the pulsed charging current, the battery plates are desulfated. See the diagram below.

In this scheme, the generator is assembled on a microcircuit, which ensures more stable operation. Instead of NE555 can be used Russian analogue- timer 1006VI1. If anyone doesn’t like the KREN142 for powering the timer, it can be replaced with a conventional parametric stabilizer, i.e. resistor and zener diode with the required stabilization voltage, and reduce resistor R5 to 200 Ohm. Transistor VT1- on the radiator in mandatory, gets very hot. The circuit uses a transformer with a 24 volt secondary winding. A diode bridge can be assembled from diodes like D242. For better cooling of the transistor heatsink VT1 You can use a fan from a computer power supply or system unit cooling.

Restoring and charging the battery.

As a result of improper use of car batteries, their plates can become sulfated and the battery fails.
There is a known method for restoring such batteries when charging them with an “asymmetrical” current. In this case, the ratio of charging and discharging current is selected to be 10:1 (optimal mode). This mode allows you not only to restore sulfated batteries, but also to carry out preventive treatment of serviceable ones.

Rice. 1. Electrical circuit of the charger

In Fig. 1 shows a simple charger designed to use the method described above. The circuit provides a pulse charging current of up to 10 A (used for accelerated charging). To restore and train batteries, it is better to set the pulse charging current to 5 A. In this case, the discharge current will be 0.5 A. The discharge current is determined by the value of the resistor R4.
The circuit is designed in such a way that the battery is charged by current pulses during one half of the period of the mains voltage, when the voltage at the output of the circuit exceeds the voltage at the battery. During the second half-cycle, diodes VD1, VD2 are closed and the battery is discharged through load resistance R4.

The charging current value is set by regulator R2 using an ammeter. Considering that when charging the battery, part of the current also flows through resistor R4 (10%), the readings of ammeter PA1 should correspond to 1.8 A (for a pulse charging current of 5 A), since the ammeter shows the average value of the current over a period of time, and the charge produced during half the period.

The circuit provides protection for the battery from uncontrolled discharge in the event of an accidental loss of mains voltage. In this case, relay K1 with its contacts will open the battery connection circuit. Relay K1 is used of the RPU-0 type with an operating winding voltage of 24 V or a lower voltage, but in this case a limiting resistor is connected in series with the winding.

For the device, you can use a transformer with a power of at least 150 W with a voltage in the secondary winding of 22...25 V.
The PA1 measuring device is suitable with a scale of 0...5 A (0...3 A), for example M42100. Transistor VT1 is installed on a radiator with an area of at least 200 square meters. cm, for which it is convenient to use the metal case of the charger design.

The circuit uses a transistor with a high gain (1000...18000), which can be replaced with a KT825 when changing the polarity of the diodes and zener diode, since it has a different conductivity (see Fig. 2). The last letter in the transistor designation can be anything.

Rice. 2. Electrical circuit of the charger

To protect the circuit from accidental short circuit, fuse FU2 is installed at the output.
The resistors used are R1 type C2-23, R2 - PPBE-15, R3 - C5-16MB, R4 - PEV-15, the value of R2 can be from 3.3 to 15 kOhm. Any VD3 zener diode is suitable, with a stabilization voltage from 7.5 to 12 V.
reverse voltage.

Which wire is better to use from the charger to the battery.

Of course, it is better to take flexible copper stranded, but the cross-section needs to be selected based on the maximum current that will flow through these wires, for this we look at the plate:

If you are interested in the circuitry of pulsed charge-recovery devices using the 1006VI1 timer in the master oscillator, read this article:

A device with electronic control of the charging current, made on the basis of a thyristor phase-pulse power regulator.
It does not contain scarce parts; if the parts are known to work, it does not require adjustment.
The charger allows you to charge car batteries with a current of 0 to 10 A, and can also serve as an adjustable power source for a powerful low-voltage soldering iron, vulcanizer, or portable lamp.
The charging current is similar in shape to pulse current, which is believed to help extend battery life.
The device is operational at ambient temperatures from - 35 °C to + 35 °C.
The device diagram is shown in Fig. 2.60.
The charger is a thyristor power regulator with phase-pulse control, powered from winding II of the step-down transformer T1 through the moctVDI + VD4 diode.
The thyristor control unit is made on an analogue of the unijunction transistor VTI, VT2. The time during which capacitor C2 is charged before switching the unijunction transistor can be adjusted with variable resistor R1. When its motor is positioned to the far right in the diagram, the charging current will become maximum, and vice versa.
Diode VD5 protects the control circuit of thyristor VS1 from reverse voltage that appears when the thyristor is turned on.

The charger can later be supplemented with various automatic components (switching off upon completion of charging, maintaining normal battery voltage during long-term storage, signaling the correct polarity of the battery connection, protection against output short circuits, etc.).
The shortcomings of the device include fluctuations in the charging current when the voltage of the electric lighting network is unstable.
Like all similar thyristor phase-pulse regulators, the device interferes with radio reception. To combat them, it is necessary to provide a network LC- a filter similar to that used in switching power supplies.

The need to charge a car battery appears regularly among our compatriots. Some people do this because the battery is low, others do it as part of maintenance. In any case, the presence of a charger (charger) greatly facilitates this task. Read more about what a thyristor charger for a car battery is and how to make such a device according to the diagram below.

Description of the thyristor memory

A thyristor charger is a device with electronic control of the charging current. Such devices are produced on the basis of a thyristor power regulator, which is phase-pulse. There are no scarce components in a memory device of this type, and if all its parts are intact, then it will not even have to be configured after manufacturing.

Using such a charger, you can charge a vehicle battery with a current from zero to ten amperes. In addition, it can be used as a regulated power source for certain devices, for example, a soldering iron, a portable lamp, etc. In its form, the charging current is very similar to pulsed, and the latter, in turn, allows you to extend the battery life. The use of a thyristor charger is allowed in the temperature range from -35 to +35 degrees.

Scheme

If you decide to build a thyristor charger with your own hands, you can use many different circuits. Let's consider the description using the example of circuit 1. Thyristor memory in in this case It is powered from winding 2 of the transformer unit through a VDI+VD4 diode bridge. The control element is designed as an analogue of a unijunction transistor. In this case, using a variable resistor element, you can regulate the time during which the capacitor component C2 will be charged. If the position of this part is to the far right, then the charging current will be the highest, and vice versa. Thanks to the diode VD5, the control circuit of the thyristor VS1 is protected.

Advantages and disadvantages

The main advantage of such a device is high-quality charging with current, which will not destroy, but increase the service life of the battery as a whole.

If necessary, the memory can be supplemented with all sorts of automatic components designed for the following options:

the device will be able to turn off automatically when charging is complete;
maintaining optimal battery voltage in case of long-term storage without use;
another function that can be regarded as an advantage - the thyristor charger can inform the car owner whether he has connected the battery polarity correctly, and this is very important when charging;
Also, if additional components are added, another advantage can be realized - protecting the node from output short circuits (the author of the video is the Blaze Electronics channel).

As for the shortcomings themselves, these include fluctuations in the charging current if the voltage in the household network is unstable. In addition, like other thyristor regulators, such a charger can create certain interference with signal transmission. To prevent this, it is necessary to additionally install an LC filter during the manufacture of the memory. Such filter elements are, for example, used in network power supplies.

How to make a memory yourself?

If we talk about producing a charger with our own hands, then we will consider this process using the example of circuit 2. In this case, thyristor control is carried out through a phase shift. We will not describe the entire process, since it is individual in each case, depending on the addition of additional components to the design. Below we will consider the main nuances that should be taken into account.

In our case, the device is assembled on ordinary hardboard, including the capacitor:

The diode elements, marked in the diagram as VD1 and VD 2, as well as thyristors VS1 and VS2, should be installed on the heat sink; installation of the latter is allowed on a common heat sink.
Resistance elements R2, as well as R5, should be used at least 2 watts each.
As for the transformer, you can purchase it in a store or take it from soldering station(high-quality transformers can be found in old Soviet soldering irons). You can rewind the secondary wire to a new one with a cross-section of about 1.8 mm at 14 volts. In principle, you can use thinner wires, since this power will be enough.
When you have all the elements in your hands, the entire structure can be installed in one housing. For example, you can take an old oscilloscope for this. In this case, we will not make any recommendations, since the case is a personal matter for everyone.
After the charger is ready, you need to check its functionality. If you have doubts about the build quality, we would recommend diagnosing the device on an older battery, which you wouldn’t mind throwing away if something happens. But if you did everything correctly, in accordance with the diagram, then there should be no problems in terms of operation. Please also keep in mind that the manufactured memory does not need to be configured; it should initially work correctly.

Video “Simple thyristor charger with your own hands”

How to make a simple thyristor charger with your own hands - see the video below (the author of the video is the Blaze Electronics channel).

The device with electronic control of the charging current is made on the basis of a thyristor phase-pulse power regulator. It does not contain scarce parts, and if the elements are known to be good, it does not require adjustment.

The charger allows you to charge car batteries with a current of 0 to 10 A, and can also serve as a regulated power source for a powerful low-voltage soldering iron, vulcanizer, or portable lamp. The charging current is similar in shape to pulse current, which is believed to help extend battery life. The device is operational at ambient temperatures from - 35 °C to + 35 °C.

The device diagram is shown in Fig. 2.60.

The charger is a thyristor power regulator with phase-pulse control, powered from winding II of the step-down transformer T1 through the moctVDI + VD4 diode.

The thyristor control unit is made on an analogue of the unijunction transistor VT1, VT2. The time during which capacitor C2 is charged before switching the unijunction transistor can be adjusted with a variable resistor R1. When the engine is in the extreme right position according to the diagram, the charging current will be maximum, and vice versa.

Diode VD5 protects the control circuit of thyristor VS1 from reverse voltage that occurs when the thyristor is turned on.

The charger can later be supplemented with various automatic components (switching off at the end of charging, maintaining normal battery voltage during long-term storage, signaling the correct polarity of the battery connection, protection against output short circuits, etc.).

The disadvantages of the device include fluctuations in the charging current when the voltage of the electric lighting network is unstable.

Like all similar thyristor phase-pulse regulators, the device interferes with radio reception. To combat them, you should provide an LC network filter, similar to that used in switching network power supplies.

Capacitor C2 - K73-11, with a capacity of 0.47 to 1 µF, or. K73-16, K73-17, K42U-2, MBGP.

We will replace the KT361A transistor with KT361B - KT361Ё, KT3107L, KT502V, KT502G, KT501Zh - KT50IK, and KT315L with KT315B + KT315D KT312B, KT3102L, KT503V + KT503G, P307 Instead of KD10 5B suitable diodes KD105V, KD105G or. D226 with any letter index.

Variable resistor R1 - SP-1, SPZ-30a or SPO-1.

Ammeter PA1 - any direct current with a 10 A scale. You can make it yourself from any milliammeter by selecting a shunt based on a standard ammeter.

Fuse F1 is a fuse, but it is convenient to use a 10 A circuit breaker or a car bimetallic fuse for the same current.

Diodes VD1 + VP4 can be any for a forward current of 10 A and a reverse voltage of at least 50 V (series D242, D243, D245, KD203, KD210, KD213).

The rectifier diodes and thyristor are installed on heat sinks, each with a useful area of about 100 cm2. To improve the thermal contact of devices with heat sinks, it is advisable to use thermally conductive pastes.

Instead of a thyristor. KU202V will fit KU202G - KU202E; It has been verified in practice that the device works normally with more powerful thyristors T-160, T-250.

It should be noted that it is permissible to use the metal casing wall directly as a heat sink for the thyristor. Then, however, there will be a negative terminal of the device on the case, which is generally undesirable due to the danger of accidental short circuits of the positive output wire to the case. If you mount the thyristor through a mica gasket, there will be no danger of a short circuit, but the heat transfer from it will worsen.

The device can use a ready-made network step-down transformer of the required power with a secondary winding voltage of 18 to 22 V.

If the transformer has a voltage on the secondary winding of more than 18 V, resistor R5 should be replaced with another one of higher resistance (for example, at 24...26 V, the resistor resistance should be increased to 200 Ohms).

In the case when the secondary winding of the transformer is tapped from the middle, or there are two identical windings and the voltage of each is within the specified limits, then it is better to make the rectifier according to a standard full-wave circuit using two diodes.

When the secondary winding voltage is 28...36 V, you can completely abandon the rectifier - its role will simultaneously be played by the thyristor VS1 (rectification is half-wave). For this version of the power supply, it is necessary to connect a separating diode KD105B or D226 with any letter index (cathode to resistor R5) between resistor R5 and the positive wire. The choice of thyristor in such a circuit will be limited - only those that allow operation under reverse voltage (for example, KU202E) are suitable.

This is in theory. In practice, car owners make amendments to this harmonious system. Or the equipment refuses to work in accordance with the established parameters.

For example:

Operating a battery that has exhausted its service life. The battery does not hold a charge
Irregular trips. Prolonged downtime of the car (especially during hibernation) leads to self-discharge of the battery
The car is used for short trips, with frequent stopping and starting of the engine. The battery simply does not have time to recharge
Connecting additional equipment increases the load on the battery. Often leads to increased self-discharge current when the engine is turned off
Extremely low temperature accelerates self-discharge
A faulty fuel system leads to increased load: the car does not start immediately, you have to turn the starter for a long time
A faulty generator or voltage regulator prevents the battery from charging properly. This problem includes worn power wires and poor contact in the charging circuit.
And finally, you forgot to turn off the headlights, lights or music in the car. To completely discharge the battery overnight in the garage, sometimes it is enough to close the door loosely. Interior lighting consumes quite a lot of energy.

Any of the following reasons leads to an unpleasant situation: you need to drive, but the battery is unable to crank the starter. The problem is solved by external recharge: that is, a charger.

It is absolutely easy to assemble it with your own hands. An example of a charger made from an uninterruptible power supply.

Any car charger circuit consists of the following components:

Power unit.
Current stabilizer.
Charge current regulator. Can be manual or automatic.
Indicator of current level and (or) charge voltage.
Optional - charge control with automatic shutdown.

Any charger, from the simplest to an intelligent machine, consists of the listed elements or a combination thereof.

Simple diagram for a car battery

Normal charge formula as simple as 5 kopecks - the basic battery capacity divided by 10. The charging voltage should be a little more than 14 volts (we are talking about a standard 12 volt starter battery).

Simple principle electrical The car charger circuit consists of three components: power supply, regulator, indicator.

Classic - resistor charger

Important! No variable resistors, even those with a ceramic core, will withstand such a load.

Wire rheostat is necessary to counter the main problem with such a scheme - excess power is released in the form of heat. And this happens very intensively.

DIY charger, details, diagrams - video

Quenching capacitor

The operating principle is shown in the diagram.

If we add one more element - automatic charge control, and also assemble a switch from a whole bank of capacitors - you get a professional charger that remains easy to manufacture.

The charge control and automatic shutdown circuit does not need any comments. The technology has been proven, you can see one of the options in the general diagram. The response threshold is set by variable resistor R4. When the own voltage at the battery terminals reaches the configured level, relay K2 turns off the load. An ammeter acts as an indicator, which stops showing the charge current.

The regulator is not a heat dissipator in the form of a powerful rheostat, but an electronic switch based on a thyristor. The entire power load passes through this semiconductor. This circuit is designed for a current of up to 10 A, that is, it allows you to charge a battery up to 90 Ah without overload.

By adjusting the degree of opening of the junction on transistor VT1 with resistor R5, you ensure smooth and very precise control of the trinistor VS1.

That is, for the upper limit of 10 A, the transformer must withstand a continuous load of 450-500 W. A practically implemented scheme will be bulky and heavy. However, if the charger is permanently installed indoors, this is not a problem.

Circuit diagram of a pulse charger for a car battery

With the existing capacitors, the output power is 200 W. This is a lot, but the load can be doubled by replacing the capacitors with 470 µF capacitors. Then it will be possible to charge with a capacity of up to 200 Ah.

The power supply from the PC system unit can act as a donor.

Important! When using an AT or ATX power supply, there is a desire to convert the finished circuit into a charger. To implement such an idea, you need a factory power supply circuit.

The video shows and explains how to assemble a pulse charger for a car yourself.

The cost of a factory 300-500 W pulse generator is at least $50 (in equivalent).

Conclusion:

Collect and use. Although it is wiser to keep your battery in good shape.

Compliance with the operating mode of rechargeable batteries, and in particular the charging mode, guarantees their trouble-free operation throughout their entire service life. Batteries are charged with a current, the value of which can be determined by the formula

where I is the average charging current, A., and Q is the nameplate electric capacity of the battery, Ah.

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

To regulate the charging current, you can use a store of capacitors connected in series with the primary (mains) winding of the transformer and acting as reactances that dampen excess network voltage. A simplified version of such a device is shown in Fig. 2.

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

The disadvantage in Fig. 2 is the need to provide a voltage on the secondary winding of the transformer one and a half times greater than the load (~ 18÷20V).

The charger circuit, which provides charging of 12-volt batteries with a current of up to 15 A, and the charging current can be changed from 1 to 15 A in steps of 1 A, is 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 circuit and breaks in it.

Switches Q1 - Q4 can be used to connect various combinations of capacitors and thereby regulate the charging current.

The variable resistor R4 sets the response threshold of K2, which should operate when the voltage at the battery terminals is equal to the voltage of a fully charged battery.

In Fig. Figure 4 shows another charger in which the charging current is smoothly regulated from zero to the maximum value.

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

This circumstance is a significant drawback of chargers with a current regulator thyristor (thyristor).

Note:

The rectifier bridge diodes VD1-VD4 and the thyristor VS1 must be installed on radiators.

In the diagram in Fig. 5 control unit is similar to that used in the previous version of the device. SCR VS1 is included in the diagonal of the rectifier bridge VD1 - VD4. Since the current of the primary winding of the transformer is approximately 10 times less than the charging current, relatively little thermal power is released on the diodes VD1-VD4 and the thyristor VS1 and they do not require installation on radiators. In addition, the use of an SCR in the primary winding circuit of the transformer made it possible to slightly improve the shape of the charging current curve and reduce the value of the current curve shape coefficient (which also leads to an increase in the efficiency of the charger). The disadvantage of this charger is the galvanic connection with the network of elements of the control unit, which must be taken into account when developing a design (for example, use a variable resistor with a plastic axis).

A version of the printed circuit board of the charger in Figure 5, measuring 60x75 mm, is shown in the figure below:

Note:

The rectifier bridge diodes VD5-VD8 must be installed on radiators.

Thyristor regulator in the charger.

For a more complete overview of the following material, review the previous articles: And.

♣ These articles say that there are 2 half-wave rectification circuits with two secondary windings, each of which is designed for the full output voltage. The windings operate alternately: one on the positive half-wave, the other on the negative.
Two semiconductor rectifier diodes are used.

♣ Preference for this scheme:

- the current load on each winding and each diode is two times less than on a circuit with one winding;
- the cross-section of the wire of the two secondary windings can be half as large;
- rectifier diodes can be selected for a lower maximum permissible current;
- the wires of the windings best cover the magnetic circuit, the magnetic stray field is minimal;
- complete symmetry - identity of the secondary windings;

♣ We use such a rectification circuit on a U-shaped core to make an adjustable charger using thyristors.
The two-frame design of the transformer allows this to be done in the best possible way.
In addition, the two half-windings turn out to be exactly the same.

♣ And so, ours exercise: build a device to charge a battery with voltage 6 – 12 volts and smooth regulation of charging current 0 to 5 amperes .
I have already proposed it for production, but the charging current in it is adjusted in stages.
Look in this article at how the transformer was calculated on the Ш - shaped core. These calculated data are also suitable for U-shaped transformer of the same power.

The calculated data from the article is as follows:

- transformer power – 100 watt ;
- core section – 12 cm square;
- rectified voltage - 18 volts;
- current - up to 5 amps;
- number of turns per 1 volt – 4,2 .

Primary winding:

- number of turns – 924 ;
- current – 0,45 ampere;
- wire diameter – 0,54 mm.

Secondary winding:

- number of turns – 72 ;
- current – 5 ampere;
- wire diameter – 1,8 mm.

♣ We will take these calculated data as the basis for constructing a transformer based on P- shaped core.
Taking into account the recommendations of the above mentioned articles on the manufacture of a transformer using P- shaped core, we will build a rectifier for charging the battery with smoothly adjustable charging current .

The rectifier circuit is shown in the figure. It consists of a transformer TR, thyristors T1 and T2, charging current control circuits, ammeter on 5 - 8 ampere, diode bridge D4 - D7.
Thyristors T1 and T2 simultaneously fulfill the role rectifier diodes and the role of charge current regulators.

♣ Transformer Tr consists of a magnetic core and two frames with windings.
The magnetic core can be assembled from either steel P– shaped plates, and from cut ABOUT– a shaped core made of wound steel tape.
Primary winding (220 volt network - 924 turns) divided in half - 462 turns (a – a1) on one frame, 462 turns (b – b1) on another frame.
Secondary winding (at 17 volts) consists of two half-windings (72 turns each) dangles on the first (A - B) and on the second (A1 – B1) frame 72 turns each. Total 144 turn.

Third winding (c - c1 = 36 turns) + (d - d1 = 36 turns) in total 8.5 V +8.5 V = 17 volts serves to power the control circuit and consists of 72 turns of wire. There are 36 turns on one frame (c - c1) and 36 turns on the other frame (d - d1).
The primary winding is wound with a wire with a diameter of - 0.54 mm.
Each secondary half-winding is wound with a wire with a diameter 1.3 mm. rated for current 2,5 ampere
The third winding is wound with a wire diameter 0.1 - 0.3 mm, whatever happens, the current consumption here is small.

♣ Smooth adjustment The charging current of the rectifier is based on the property of the thyristor to go into the open state upon a pulse arriving at the control electrode. By adjusting the arrival time of the control pulse, it is possible to control the average power passing through the thyristor for each period of alternating electric current.

♣ The given thyristor control circuit works on the principle phase-pulse method.
The control circuit consists of an analogue of a thyristor assembled using transistors Tr1 and Tr2, a temporary chain consisting of a capacitor WITH and resistors R2 and Ry, zener diode D 7 and isolation diodes D1 and D2. The charging current is adjusted using a variable resistor Ry.

AC voltage 17 volts removed from the third winding, straightened by a diode bridge D3 – D6 and has the shape (point No. 1) (in circle No. 1). This is a pulsating voltage of positive polarity with a frequency 100 hertz, changing its value from 0 to 17 volts. Through a resistor R5 voltage is supplied to the zener diode D7 (D814A, D814B or any other on 8 – 12 volts). At the zener diode the voltage is limited to 10 volts and has the form ( point No. 2). Next comes the charge-discharge chain (Ry, R2, C). As the voltage increases from 0, the capacitor begins to charge WITH, through resistors Ry, and R2.
♣ Resistor resistance and capacitor capacity (Ry, R2, C) selected in such a way that the capacitor is charged during one half-cycle of the pulsating voltage. When the voltage across the capacitor reaches its maximum value (point No. 3), from resistors R3 and R4 to the control electrode of a thyristor analogue (transistors Tr1 and Tr2) voltage to open will be supplied. The thyristor analogue will open and the charge of electricity accumulated in the capacitor will be released on the resistor R1. Pulse shape across a resistor R1 shown in circle №4 .
Via isolation diodes D1 and D2 the trigger pulse is applied simultaneously to both control electrodes of the thyristors T1 and T2. The thyristor to which the this moment a positive half-wave of alternating voltage arrived from the secondary windings of the rectifier (point No. 5).
Changing the resistance of the resistor Ry, we change the time during which the capacitor is fully charged WITH, that is, we change the turn-on time of the thyristors during the action of a half-voltage wave. IN point No. 6 shows the voltage waveform at the rectifier output.
The resistance Ry changes, the time at which the thyristors begin to open changes, and the shape of filling the half-cycle with the current changes (Figure No. 6). The half-cycle fill can be adjusted from 0 to maximum. The entire process of voltage regulation over time is shown in the figure.
♣ All voltage waveform measurements shown in points No. 1 - No. 6 carried out relative to the positive terminal of the rectifier.

Rectifier parts:
- thyristors T1 and T2 - KU 202I-N for 10 amperes. Install each thyristor on a radiator with an area 35 – 40 cm2;
- diodes D1 – D6 D226 or any on current 0.3 ampere and the voltage is higher 50 volts;
- zener diode D7 - D814A - D814G or any other on 8 – 12 volts;
- transistors Tr1 and Tr2 any low-power voltages above 50 volts.
It is necessary to select a pair of transistors with the same power, different conductivities and with equal gain factors (at least 35 - 50 ).
I tested different pairs of transistors: KT814 – KT815, KT816 – KT817; MP26 – KT308, MP113 – MP114.
All options worked well.
- Capacitor 0.15 microfarads;
- Resistor R5 set the power to 1 watt. Other power resistors 0.5 watt.
- The ammeter is designed for current 5 – 8 amperes

♣ Care must be taken when installing the transformer. I advise you to re-read the article. Especially the place where recommendations are given on the phasing of the primary and secondary windings.

You can use the primary winding phasing diagram shown below, as in the figure.

♣ An electric light bulb is connected in series to the primary winding circuit for voltage 220 volt and power 60 watt. this light bulb will serve instead of a fuse.
If the windings are phased wrong, bulb will light up.
If connections are made Right, when the transformer is connected to the network 220 volt the light bulb should flare up and go out.
There must be two voltages at the terminals of the secondary windings 17 volts, together (between A and B) 34 volts.
All installation work must be carried out in compliance with ELECTRICAL SAFETY RULES!

The device diagram is shown in Fig. 2.60.

The charger is a thyristor power regulator with phase-pulse control, powered from winding II of the step-down transformer T1 through the moctVDI + VD4 diode.

Diode VD5 protects the control circuit of thyristor VS1 from reverse voltage that occurs when the thyristor is turned on.

The disadvantages of the device include fluctuations in the charging current when the voltage of the electric lighting network is unstable.

Capacitor C2 - K73-11, with a capacity of 0.47 to 1 µF, or. K73-16, K73-17, K42U-2, MBGP.

Variable resistor R1 - SP-1, SPZ-30a or SPO-1.

A thyristor battery charger has a number of advantages. This circuit allows you to safely charge any 12 V car battery, without the risk of boiling.

Additional devices of this type Suitable for reconditioning lead-acid batteries. This is achieved by monitoring charging parameters, which means the ability to simulate recovery modes.

A common, simple, but very effective thyristor phase-pulse power regulator circuit has long been used to charge lead-acid batteries.

Find out the charging time of your battery

Charging on KU202N allows:

achieve charging current up to 10A;
produce a pulse current that has a beneficial effect on the life expectancy of the battery;
assemble the device yourself from inexpensive parts available at any radio electronics store;
repeat the circuit diagram even for a beginner who is superficially familiar with the theory.

Conventionally, the presented scheme can be divided into:

A step-down device is a transformer with two windings that converts 220V from the network into 18-22V, which is necessary for the operation of the device.
Rectifier unit converting impulse voltage c is constantly assembled from 4 diodes or implemented using a diode bridge.
Filters – electrolytic capacitors, cutting off the alternating components of the output current.
Stabilization is carried out using zener diodes.
The current regulator is produced by a component built on transistors, thyristors and variable resistance.
Monitoring of output parameters is realized using an ammeter and a voltmeter.

Principle of operation

A circuit of transistors VT1 and VT2 controls the thyristor electrode. The current passes through VD2, which protects against return pulses. The optimal charging current is controlled by component R5. In our case, it should be equal to 10% of the battery capacity. To monitor the current regulator, this parameter must be installed in front of the connection terminals with an ammeter.

This circuit is powered by a transformer with an output voltage of 18 to 22 V. It is imperative to place the diode bridge, as well as the control thyristor, on the radiators to remove excess heat. The optimal radiator size should exceed 100cm2. When using diodes D242-D245, KD203, be sure to isolate them from the device body.

This thyristor charger circuit must be equipped with a fuse for the output voltage. Its parameters are selected according to your own needs. If you do not intend to use currents greater than 7 A, then a 7.3 A fuse will be sufficient.

Features of assembly and operation

Theristor testing circuit

The charger assembled according to the presented diagram can later be supplemented with automatic protective systems (against polarity reversal, short circuit, etc.). Particularly useful, in our case, will be the installation of a system for cutting off the current supply when charging the battery, which will protect it from overcharging and overheating.

It is advisable to complete other protective systems LED indicators, signaling short circuits and other problems.

Monitor the output current carefully as it may vary due to line fluctuations.

Like similar thyristor phase-pulse regulators, a charger assembled according to the presented circuit interferes with radio reception, so it is advisable to provide an LC filter for the network.

Thyristor KU202N can be replaced with similar ones KU202V, KU 202G or KU202E. You can also use the more productive T-160 or T-250.

DIY thyristor charger

To assemble the presented circuit yourself, you will need a minimum of time and effort, along with low costs for components. Most components can be easily replaced with analogues. Some parts can be borrowed from failed electrical equipment. Before use, the components should be checked, thanks to this, a charger assembled even from used parts will work immediately after assembly.

Unlike models on the market, the performance of a self-assembled charger is maintained over a larger range. You can charge a car battery from -350C to 350C. This and the ability to regulate the output current, giving the battery a large amperage, allows for a short time compensate the battery with a charge sufficient to turn the engine with the starter.

Thyristor chargers have a place in car enthusiasts' garages due to their ability to safely charge a car battery. Schematic diagram of this device allows you to assemble it yourself using products from the radio market. If knowledge is not enough, you can use the services of radio amateurs who, for a fee that is several times less than the cost of a store-bought charger, will be able to assemble the device for you according to the diagram provided to them.