They gave me some kind of incomprehensible block from Soviet times. The schematic resembled some kind of power regulator or something. In itself, it was of no value, but I really wanted to adapt the KU202 it contained somewhere.
I would like to present to your attention a small experiment with phase-pulse charging. The long-known scheme was taken as a basis
The purpose of the experiment is to make the circuit more reliable and practical.
The circuit also fits well with this charger
How many rubles will such a charger cost?
KU202 80*2=160
BD140/139 15*2=26
Diodes D4/5/8 3*5=15
Diodes D1/2 2*100=200
Resistors 9*3=27
Potentiometer 60
Capacitor 20
Textolite 50
And that’s 558R plus a 1500R transformer and, if desired, an ammeter +500R.
It's good when you have something of your own. For this scheme as a whole, I paid 300 RUR, purchasing additional change.
Charging on KU202 is just an experiment. For safe, high-quality and reliable charging of any types of batteries, I recommend this
With uv. Admin check
Many questions are asked about this charger. I’ll put the most interesting ones here. Write comments at the bottom of the page
-Did I understand you correctly that this scheme has some nuances?
-Yes, it has. Every time before connecting to the battery, it is necessary to set the voltage to 14.4 V or 16.5 “for some calcium ones.” The voltage is not stable and depends on the voltage in the primary winding of the transformer. in general, the protection does not have current and voltage stabilization
-How long have you been using it?
— This is the one I used, 2 battery charges 65A
-How did she show herself?
-I charged it, but I have to control the voltage all the time
-I would supplement it with voltage control for automatic shutdown
— It’s easier to put together the diagram that I suggested to you. Supplementing that scheme is simply hemorrhoids
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Don’t want to delve into the routine of radio electronics? I recommend paying attention to the proposals of our Chinese friends. For a very reasonable price you can purchase quite high-quality chargers
A simple charger with an LED charging indicator, green battery is charging, red battery is charged.
There is short circuit protection and reverse polarity protection. Perfect for charging Moto batteries with a capacity of up to 20A/h; a 9A/h battery will charge in 7 hours, 20A/h in 16 hours. The price for this charger is only 403 rubles, free delivery
This type of charger is capable of automatically charging almost any type of 12V car and motorcycle batteries up to 80A/H. It has a unique charging method in three stages: 1. Constant current charging, 2. Constant voltage charging, 3. Drop charging 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.
Quite a high-quality device for home needs, the price is just RUR 781.96, free delivery. At the time of writing these lines number of orders 1392, grade 4.8 out of 5. Eurofork
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 automatically 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
The price for this miracle 1,625 rubles, delivery is free. At the time of writing these lines, the number 23 orders, grade 4.7 out of 5. When ordering, do not forget to indicate Eurofork
If any product has become unavailable, please write in the comment at the bottom of the page.
With uv. Edward
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.
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 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 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 of chargers with a 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 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.
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.
Analysis of more than 11 circuits for making a charger with your own hands at home, new circuits for 2017 and 2018, how to assemble a circuit diagram in an hour.
TEST:
To understand whether you have the necessary information about batteries and chargers for them, you should take a short test:- What are the main reasons why a car battery discharges on the road?
A) The motorist got out of the vehicle and forgot to turn off the headlights.
B) The battery has become too hot due to exposure to sunlight.
- Can the battery fail if the car is not used for a long time (sitting in a garage without starting)?
A) If left idle for a long time, the battery will fail.
B) No, the battery will not deteriorate, it will only need to be charged and it will function again.
- What current source is used to recharge the battery?
A) There is only one option - a network with a voltage of 220 volts.
B) 180 Volt network.
- Is it necessary to remove the battery when connecting a homemade device?
A) It is advisable to remove the battery from its installed location, otherwise there is a risk of damaging the electronics due to high voltage.
B) It is not necessary to remove the battery from its installed location.
- If you confuse “minus” and “plus” when connecting a charger, will the battery fail?
A) Yes, if connected incorrectly, the equipment will burn out.
B) The charger simply will not turn on; you will need to move the necessary contacts to the correct places.
Answers:
- A) Headlights not turned off when stopping and sub-zero temperatures are the most common causes of battery discharge on the road.
- A) The battery fails if it is not recharged for a long time when the car is idle.
- A) For recharging, a mains voltage of 220 V is used.
- A) It is not advisable to charge the battery with a homemade device if it is not removed from the car.
- A) The terminals should not be mixed up, otherwise the homemade device will burn out.
Battery on vehicles require periodic charging. The reasons for the discharge can be different - from headlights that the owner forgot to turn off, to negative temperatures outside in winter. For recharge battery You will need a good charger. This device is available in large varieties in auto parts stores. But if there is no opportunity or desire to purchase, then memory You can do it yourself at home. There are also a large number of schemes - it is advisable to study them all in order to choose the most suitable option.
Definition: A car charger is designed to transmit electric current with a given voltage directly to Battery
Answers to 5 Frequently Asked Questions
- Will I need to take any additional measures before charging the battery in my car?– Yes, you will need to clean the terminals, since acid deposits appear on them during operation. Contacts It needs to be cleaned very well so that current flows to the battery without difficulty. Sometimes motorists use grease to treat terminals; this should also be removed.
- How to wipe charger terminals?— You can buy a specialized product in a store or prepare it yourself. Water and soda are used as a self-made solution. The components are mixed and stirred. This is an excellent option for treating all surfaces. When the acid comes into contact with soda, a reaction will occur and the motorist will definitely notice it. This area will need to be thoroughly wiped to get rid of all acids. If the terminals were previously treated with grease, it can be removed with any clean rag.
- If there are covers on the battery, do they need to be opened before charging?— If there are covers on the body, they must be removed.
- Why is it necessary to unscrew the battery caps?— This is necessary so that the gases formed during the charging process can freely exit the case.
- Is there a need to pay attention to the electrolyte level in the battery?- This is done without fail. If the level is lower than required, then you need to add distilled water inside the battery. Determining the level is not difficult - the plates must be completely covered with liquid.
It’s also important to know: 3 nuances about operation
The homemade product differs somewhat in its method of operation from the factory version. This is explained by the fact that the purchased unit has built-in functions, helping in work. They are difficult to install on a device assembled at home, and therefore you will have to adhere to several rules when operation.
- A self-assembled charger will not turn off when the battery is fully charged. That is why it is necessary to periodically monitor the equipment and connect it to multimeter– for charge control.
- You need to be very careful not to confuse “plus” and “minus”, otherwise Charger will burn.
- The equipment must be turned off when connecting to charger.
By following these simple rules, you will be able to recharge correctly battery and avoid unpleasant consequences.
Top 3 charger manufacturers
If you don’t have the desire or ability to assemble it yourself memory, then pay attention to the following manufacturers:
- Stack.
- Sonar.
- Hyundai.
How to avoid 2 mistakes when charging a battery
It is necessary to follow the basic rules in order to properly nourish battery by car.
- Direct to mains battery connection is prohibited. Chargers are intended for this purpose.
- Even device it is made with high quality and from good materials, you will still need to periodically monitor the process charging, so that troubles don't happen.
Following simple rules will ensure reliable operation of self-made equipment. It is much easier to monitor the unit than to spend money on components for repairs.
The simplest battery charger
Scheme of a 100% working 12 volt charger
Look at the picture for the diagram memory at 12 V. The equipment is intended for charging car batteries with a voltage of 14.5 Volts. The maximum current received during charging is 6 A. But the device is also suitable for other batteries - lithium-ion, since the voltage and output current can be adjusted. All the main components for assembling the device can be found on the Aliexpress website.
Required components:
- dc-dc buck converter.
- Ammeter.
- Diode bridge KVRS 5010.
- Hubs 2200 uF at 50 volts.
- transformer TS 180-2.
- Circuit breakers.
- Plug for connecting to the network.
- "Crocodiles" for connecting terminals.
- Radiator for diode bridge.
Transformer any one can be used at your own discretion. The main thing is that its power is not lower than 150 W (with a charging current of 6 A). It is necessary to install thick and short wires on the equipment. The diode bridge is fixed on a large radiator.
Look at the picture of the charger circuit Dawn 2. It is compiled according to the original Memory If you master this scheme, you will be able to independently create a high-quality copy that is no different from the original sample. Structurally, the device is a separate unit, closed with a housing to protect the electronics from moisture and exposure to bad weather conditions. It is necessary to connect a transformer and thyristors on the radiators to the base of the case. You will need a board that will stabilize the current charge and control the thyristors and terminals.
1 smart memory circuit
Look at the picture for a circuit diagram of a smart charger. The device is necessary for connection to lead-acid batteries with a capacity of 45 amperes per hour or more. This type of device is connected not only to batteries that are used daily, but also to those on duty or in reserve. This is a fairly budget version of the equipment. It does not provide indicator, and you can buy the cheapest microcontroller.
If you have the necessary experience, then you can assemble the transformer yourself. There is also no need to install audible warning signals - if battery connects incorrectly, the discharge lamp will light up to indicate an error. The equipment must be equipped with a switching power supply of 12 volts - 10 amperes.
1 industrial memory circuit
Look at the industrial diagram charger from Bars 8A equipment. Transformers are used with one 16-volt power winding, several vd-7 and vd-8 diodes are added. This is necessary in order to provide a bridge rectifier circuit from one winding.
1 inverter device diagram
Look at the picture for a diagram of an inverter charger. This device discharges the battery to 10.5 Volts before charging. The current is used with a value of C/20: “C” indicates the capacity of the installed battery. After that process the voltage rises to 14.5 Volts using a discharge-charge cycle. The ratio of charge and discharge is ten to one.
1 electrical circuit charger electronics
1 powerful memory circuit
Look at the picture at the diagram of a powerful charger for a car battery. The device is used for acidic battery, having high capacity. The device easily charges a car battery with a capacity of 120 A. The output voltage of the device is self-regulated. It ranges from 0 to 24 volts. Scheme It is notable for the fact that it has few components installed, but it does not require additional settings during operation.
Many could already see the Soviet Charger. It looks like a small metal box and may seem quite unreliable. But this is not true at all. The main difference between the Soviet model and modern models is reliability. The equipment has structural capacity. In the event that to the old device connect the electronic controller, then charger it will be possible to revive. But if you no longer have one at hand, but there is a desire to assemble it, you need to study the diagram.
To the features their equipment includes a powerful transformer and rectifier, with the help of which it is possible to quickly charge even a very discharged battery. Many modern devices will not be able to reproduce this effect.
Electron 3M
In an hour: 2 DIY charging concepts
Simple circuits
1 the simplest scheme for an automatic charger for a car battery
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.
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 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 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 of chargers with a 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 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.
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 housing.
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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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.
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 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
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 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.
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 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 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 regulate 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 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.
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. 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
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 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 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.
It is known that during the operation of batteries, their plates can become sulfated, which leads to battery failure. If you charge with a pulsed asymmetric current, then it is possible to restore such batteries and extend their service life, while the charge and discharge currents should be set to 10: 1. I have made a charger that can operate in 2 modes. The first mode provides normal charging of batteries with a direct current of up to 10 A. The amount of charging current is set by thyristor regulators. The second mode (Vk 1 is off, Vk 2 is on) provides a pulsed charge current of 5A and a discharge current of 0.5A.Let's consider the operation of the circuit (Fig. 1) in the first mode. An alternating voltage of 220 V is supplied to the step-down transformer Tr1. In the secondary winding, two voltages of 24 V are generated relative to the midpoint. We managed to find a transformer with a midpoint in the secondary winding, which makes it possible to reduce the number of diodes in the rectifiers, create a power reserve and ease the thermal regime. The alternating voltage from the secondary winding of the transformer is supplied to a rectifier using diodes D6, D7. The plus from the middle point of the transformer goes to resistor R8, which limits the current of the zener diode D1. Zener diode D1 determines the operating voltage of the circuit. A thyristor control generator is assembled on transistors T1 and T2. Capacitor C1 is infected through the circuit: power supply plus, variable resistor R3, R1, C1, minus. The charging rate of capacitor C1 is controlled by variable resistor R3. Capacitor C1 is discharged along the circuit: emitter - collector T1, base - emitter T2, R4 capacitor mine. Transistors T1 and T2 open and a positive pulse from the emitter T2 through the limiting resistor R7 and decoupling diodes D4 - D5 arrives at the control electrodes of the thyristors. In this case, switch Vk 1 is turned on, Vk 2 is turned off. The thyristors, depending on the minus phase of the alternating voltage, open one by one, and the minus of each half-cycle goes to the minus of the battery. Plus from the midpoint of the transformer through the ammeter to the plus of the battery. Resistors R5 and R6 determine the operating mode of transistors T1-2. R4 is the load of the T2 emitter on which a positive control pulse is released. R2 - for more stable operation of the circuit (in some cases it can be neglected).
Operation of the memory circuit in the second mode (Vk1 – off; Vk2 – on). When Vk1 is turned off, the control circuit of thyristor D3 is interrupted, while it remains permanently closed. One thyristor D2 remains in operation, which rectifies only one half-cycle and produces a charge pulse during one half-cycle. During the idle second half-cycle, the battery is discharged through the switched on Vk2. The load is an incandescent light bulb 24V x 24 W or 26V x 24 W (when the voltage on it is 12V, it consumes a current of 0.5 A). The light bulb is placed outside the housing so as not to heat the structure. The charging current value is set by regulator R3 using an ammeter. Considering that when charging the battery, part of the current flows through load L1 (10%). Then the ammeter reading should correspond to 1.8A (for a pulse charging current of 5A). since the ammeter has an inertia and shows the average value of the current over a period of time, and the charge is made during half the period.
Details and design of the charger. Any transformer with a power of at least 150 W and a voltage in the secondary winding of 22 - 25 V is suitable. If you use a transformer without a midpoint in the secondary winding, then all elements of the second half-cycle must be excluded from the circuit. (Bk1, D5, D3). The circuit will be fully operational in both modes, only in the first it will work on one half-cycle. Thyristors can be used KU202 for a voltage of at least 60V. They can be installed on a radiator without isolation from each other. Any D4-7 diodes for an operating voltage of at least 60V. Transistors can be replaced with germanium low-frequency transistors with appropriate conductivity. works on any pairs of transistors: P40 – P9; MP39 – MP38; KT814 – KT815, etc. Zener diode D1 is any 12–14V. You can connect two in series to set the desired voltage. As an ammeter, I used the head of a 10 mA, 10 division miliammeter. The shunt was selected experimentally, wound with 1.2 mm wire without a frame to a diameter of 8 mm, 36 turns.
Setting up the charger. If assembled correctly, it works immediately. Sometimes it is necessary to set the Min - Max regulation limits. selection of C1, usually in the direction of increase. If there are regulation failures, select R3. Usually I connected a powerful light bulb from an overhead projector 24V x 300W as a load for adjustment. It is advisable to install a 10A fuse in the open circuit of the battery charge.
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