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 range
- 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.
Over time, I tried a modified scheme with automatic battery shutdown, I recommend reading it
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 - 0.25 W
R3 = 3.3k - 0.25W
R4 = 110 - 0.25 W
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
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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
We have repeatedly talked about all kinds of chargers for car batteries on a pulse basis, and today is no exception. And we will consider the design of an SMPS, which can have an output power of 350-600 watts, but this is not the limit, since the power, if desired, can be increased to 1300-1500 watts, therefore, on such a basis it is possible to build a starting-charger device, because at a voltage of 12 -14 Volts from a 1500 watt unit can draw up to 120 Amperes of current! well of course
The design attracted my attention a month ago, when an article caught my eye on one of the sites. The power regulator circuit seemed quite simple, so I decided to use this circuit for my design, which is very simple and does not require any adjustment. The circuit is designed for charging powerful acid batteries with a capacity of 40-100A/h, implemented on a pulse basis. The main power part of our charger is a mains switching power supply with power
Just recently I decided to make several chargers for car batteries, which I was going to sell on the local market. There were quite beautiful industrial buildings available; all you had to do was make a good filling and that was it. But then I encountered a number of problems, starting from the power supply and ending with the output voltage control unit. I went and bought a good old electronic transformer like Tashibra (Chinese brand) for 105 watts and started reworking it.
A fairly simple automatic charger can be implemented on the LM317 chip, which is a linear voltage regulator with an adjustable output voltage. The microcircuit can also work as a current stabilizer.
A high-quality charger for a car battery can be purchased on the market for $50, and today I will tell you the easiest way to make such a charger with minimal expenditure of money; it is simple and even a novice radio amateur can make it.
The design of a simple charger for car batteries can be implemented in half an hour at minimal cost; the process of assembling such a charger will be described below.
The article discusses a charger (charger) with a simple circuit design for batteries of various classes intended to power the electrical networks of cars, motorcycles, flashlights, etc. The charger is easy to use, does not require adjustments while charging the battery, is not afraid of short circuits, and is simple and cheap to manufacture.
Recently, I came across a diagram of a powerful charger for car batteries with a current of up to 20A on the Internet. In fact, this is a powerful regulated power supply assembled with just two transistors. The main advantage of the circuit is the minimum number of components used, but the components themselves are quite expensive, we are talking about transistors.
Naturally, everyone in the car has cigarette lighter chargers for all kinds of devices: navigator, phone, etc. The cigarette lighter is naturally not without dimensions, and especially since there is only one (or rather, a cigarette lighter socket), and if there is also a person who smokes, then the cigarette lighter itself must be taken out somewhere and put somewhere, and if you really need to connect something to the charger, then using the cigarette lighter for its intended purpose is simply impossible , you can solve the connection of all kinds of tees with a socket like a cigarette lighter, but it’s like that
Recently I came up with the idea of assembling a car charger based on cheap Chinese power supplies with a price of $5-10. In electronics stores you can now find units that are designed to power LED strips. Since such tapes are powered by 12 Volts, therefore the output voltage of the power supply is also within 12 Volts
I present the design of a simple DC-DC converter that will allow you to charge a mobile phone, tablet computer or any other portable device from a 12-volt car on-board network. The heart of the circuit is a specialized 34063api chip designed specifically for such purposes.
After the article charger from an electronic transformer, many letters were sent to my email address asking me to explain and tell how to power up the circuit of an electronic transformer, and in order not to write to each user separately, I decided to print this article, where I will talk about the main components that need will be modified to increase the output power of the electronic transformer.
I made this charger to charge car batteries, the output voltage is 14.5 volts, the maximum charge current is 6 A. But it can also charge other batteries, for example lithium-ion ones, since the output voltage and output current can be adjusted within a wide range. The main components of the charger were purchased on the AliExpress website.
These are the components:
You will also need an electrolytic capacitor 2200 uF at 50 V, a transformer for the TS-180-2 charger (see how to solder the TS-180-2 transformer), wires, a power plug, fuses, a radiator for the diode bridge, crocodiles. You can use another transformer with a power of at least 150 W (for a charging current of 6 A), the secondary winding must be designed for a current of 10 A and produce a voltage of 15 - 20 volts. The diode bridge can be assembled from individual diodes designed for a current of at least 10A, for example D242A.
The wires in the charger should be thick and short. The diode bridge must be mounted on a large radiator. It is necessary to increase the radiators of the DC-DC converter, or use a fan for cooling.
Charger assembly
Connect a cord with a power plug and a fuse to the primary winding of the TS-180-2 transformer, install the diode bridge on the radiator, connect the diode bridge and the secondary winding of the transformer. Solder the capacitor to the positive and negative terminals of the diode bridge.
Connect the transformer to a 220 volt network and measure the voltages with a multimeter. I got the following results:
- The alternating voltage at the terminals of the secondary winding is 14.3 volts (mains voltage 228 volts).
- The constant voltage after the diode bridge and capacitor is 18.4 volts (no load).
Using the diagram as a guide, connect a step-down converter and a voltammeter to the DC-DC diode bridge.
Setting the output voltage and charging current
There are two trimming resistors installed on the DC-DC converter board, one allows you to set the maximum output voltage, the other allows you to set the maximum charging current.
Plug in the charger (nothing is connected to the output wires), the indicator will show the voltage at the device output and the current is zero. Use the voltage potentiometer to set the output to 5 volts. Close the output wires together, use the current potentiometer to set the short circuit current to 6 A. Then eliminate the short circuit by disconnecting the output wires and use the voltage potentiometer to set the output to 14.5 volts.
This charger is not afraid of a short circuit at the output, but if the polarity is reversed, it may fail. To protect against polarity reversal, a powerful Schottky diode can be installed in the gap in the positive wire going to the battery. Such diodes have a low voltage drop when connected directly. With such protection, if the polarity is reversed when connecting the battery, no current will flow. True, this diode will need to be installed on a radiator, since a large current will flow through it during charging.
Suitable diode assemblies are used in computer power supplies. This assembly contains two Schottky diodes with a common cathode; they will need to be parallelized. For our charger, diodes with a current of at least 15 A are suitable.
It must be taken into account that in such assemblies the cathode is connected to the housing, so these diodes must be installed on the radiator through an insulating gasket.
It is necessary to adjust the upper voltage limit again, taking into account the voltage drop across the protection diodes. To do this, use the voltage potentiometer on the DC-DC converter board to set 14.5 volts measured with a multimeter directly at the output terminals of the charger.
How to charge the battery
Wipe the battery with a cloth soaked in soda solution, then dry. Remove the plugs and check the electrolyte level; if necessary, add distilled water. The plugs must be turned out during charging. No debris or dirt should get inside the battery. The room in which the battery is charged must be well ventilated.
Connect the battery to the charger and plug in the device. During charging, the voltage will gradually increase to 14.5 volts, the current will decrease over time. The battery can be conditionally considered charged when the charging current drops to 0.6 - 0.7 A.
There are times, especially in winter, when car owners need to recharge their car battery from an external power source. Of course, people who do not have good electrical skills will It is advisable to buy a factory battery charger, it’s even better to purchase a starting-charger to start the engine with a discharged battery without wasting time on external recharging.
But if you have a little knowledge in the field of electronics, you can assemble a simple charger with your own hands.
general characteristics
To properly maintain the battery and extend its service life, recharging is required when the voltage at the terminals drops below 11.2 V. At this voltage, the engine will most likely start, but if parked for a long time in winter, this will lead to sulfation of the plates and, as a result, a decrease in capacity batteries. When parked for a long time in winter, it is necessary to regularly monitor the voltage at the battery terminals. It should be 12 V. It is best to remove the battery and take it to a warm place, not forgetting monitor the charge level.
The battery is charged using constant or pulsed current. When using a constant voltage power supply, the current for proper charging should be one tenth of the battery capacity. If the battery capacity is 50 Ah, then a current of 5 amperes is required for charging.
To extend the battery life, battery plate desulfation techniques are used. The battery is discharged to a voltage of less than five volts by repeated consumption of a large current of short duration. An example of such consumption is starting the starter. After this, a slow full charge is carried out with a small current within one ampere. Repeat the process 8-9 times. The desulfation method takes a long time, but according to all studies it gives good results.
It must be remembered that when charging, it is important not to overcharge the battery. The charge is carried out to a voltage of 12.7-13.3 volts and depends on the battery model. Maximum charge indicated in the documentation for the battery, which can always be found on the Internet.
Overcharging causes boiling, increases the density of the electrolyte and, as a result, the destruction of the plates. Factory charging devices have charge monitoring and subsequent shutdown systems. Assemble such systems yourself, without having sufficient knowledge in electronics, it is quite difficult.
DIY assembly diagrams
It is worth talking about simple charging devices that can be assembled with minimal knowledge in electronics, and the charge capacity can be monitored by connecting a voltmeter or an ordinary tester.
Charging circuit for emergencies
There are times when a car that has been parked overnight near the house cannot be started in the morning due to a discharged battery. There can be many reasons for this unpleasant circumstance.
If the battery was in good condition and slightly discharged, the following will help solve the problem:
Ideal as a power source laptop charger. It has an output voltage of 19 volts and a current of within two amperes, which is quite enough to complete the task. On the output connector, as a rule, the internal input is positive, the external circuit of the plug is negative.
As a limiting resistance, which is mandatory, you can use a cabin light bulb. More can be used powerful lamps, for example, from the dimensions, but this will create an extra load on the power supply, which is very undesirable.
An elementary circuit is assembled: the negative of the power supply is connected to the light bulb, the light bulb to the negative of the battery. Plus goes directly from the battery to the power supply. Within two hours the battery will receive a charge to start the engine.
From a power supply from a desktop computer
Such a device is more difficult to manufacture, but it can be assembled with minimal knowledge of electronics. The basis will be an unnecessary block from the computer system unit. The output voltages of such units are +5 and +12 volts with an output current of about two amperes. These parameters allow you to assemble a low-power charger, which, if assembled correctly will serve the owner for a long time and reliably. Fully charging the battery will take a long time and will depend on the battery capacity, but will not create the effect of desulfation of the plates. So, step-by-step assembly of the device:
- Disassemble the power supply and unsolder all wires except the green one. Remember or mark the input locations of black (GND) and yellow +12 V.
- Solder the green wire to the place where the black one was located (this is necessary to start the unit without a PC motherboard). In place of the black wire, solder a lead, which will be negative for charging the battery. In place of the yellow wire, solder the positive lead for charging the battery.
- You need to find a TL 494 chip or its equivalent. A list of analogs is easy to find on the Internet; one of them will definitely be found in the circuit. With all the variety of blocks, they are not produced without these microcircuits.
- From the first leg of this microcircuit - it is the lower left one, find the resistor that goes to the +12 volt output (yellow wire). This can be done visually along the tracks in the diagram, or using a tester by connecting the power and measuring the voltage at the input of the resistors going to the first leg. Do not forget that the primary winding of the transformer carries a voltage of 220 volts, so you need to take safety precautions when starting the unit without a housing.
- Unsolder the found resistor and measure its resistance with a tester. Select a variable resistor that is close in value. Set it to the desired resistance value and solder it in place of the removed circuit element with flexible wires.
- By starting the power supply by adjusting the variable resistor, get a voltage of 14 V, ideally 14.3 V. The main thing is not to overdo it, remembering that 15 V is usually the limit for working out the protection and, as a result, shutting down.
- Unsolder the variable resistor without changing its setting, and measure the resulting resistance. Select the required or closest resistance value from several resistors and solder it into the circuit.
- Check the unit, the output should have the required voltage. If desired, you can connect a voltmeter to the outputs on the plus and minus circuit, placing it on the case for clarity. Subsequent assembly occurs in reverse order. The device is ready for use.
The unit will perfectly replace an inexpensive factory charger and is quite reliable. But you MUST remember that the device has overload protection, but this will not save you from polarity errors. Simply put, if you confuse the plus and minus when connecting to the battery, The charger will instantly fail.
Charger circuit from an old transformer
If you don’t have an old computer power supply at hand, and your radio engineering experience allows you to install simple circuits yourself, then you can use the following rather interesting battery charging circuit with control and regulation of the supplied voltage.
To assemble the device, you can use transformers from old uninterruptible power supplies or Soviet-made TVs. Any powerful step-down transformer with a total voltage set on the secondary windings of approximately 25 volts will do.
The diode rectifier is assembled on two KD 213A diodes (VD 1, VD 2), which must be installed on the radiator and can be replaced with any imported analogues. There are many analogues, and they can be easily selected from reference books on the Internet. Surely the necessary diodes can be found at home in old unnecessary equipment.
The same method can be used to replace the control transistor KT 827A (VT 1) and zener diode D 814 A (VD 3). The transistor is installed on the radiator.
The supply voltage is adjusted by variable resistor R2. The scheme is simple and obviously working. It can be assembled by a person with minimal knowledge of electronics.
Pulse charging for batteries
The circuit is difficult to assemble, but this is the only drawback. It is unlikely that you will be able to find a simple circuit for a pulse charging unit. This is compensated by the advantages: such blocks hardly heat up, at the same time they have serious power and high efficiency, and are compact in size. The proposed circuit, mounted on a board, fits into a container measuring 160*50*40 mm. To assemble the device, you need to understand the operating principle of the PWM (Pulse Width Modulation) generator. In the proposed version, it is implemented using the common and inexpensive IR 2153 controller.
With capacitors used, the power of the device is 190 watts. This is enough to charge any light car battery with a capacity of up to 100 Ah. By installing 470 µF capacitors, the power will double. It will be possible to charge batteries with a capacity of up to two hundred amperes/hours.
When using devices without automatic battery charge control, you can use the simplest network, daily relay made in China. This will eliminate the need to monitor the time the unit is disconnected from the network.
The cost of such a device is about 200 rubles. Knowing the approximate charging time of your battery, you can set the desired shutdown time. This ensures that the electricity supply is cut off in a timely manner. You can get distracted by business and forget about the battery, which can lead to boiling, destruction of the plates and failure of the battery. A new battery will cost much more
Precautionary measures
When using self-assembled devices, the following safety precautions should be observed:
- All devices, including the battery, must be on a fire-resistant surface.
- When using the manufactured device for the first time, it is necessary to ensure full control of all charging parameters. It is imperative to control the heating temperature of all charging elements and the battery; the electrolyte should not be allowed to boil. The voltage and current parameters are controlled by a tester. Primary monitoring will help determine the time it takes to fully charge the battery, which will be useful in the future.
Assembling a battery charger is easy even for a beginner. The main thing is to do everything carefully and follow safety measures, because you will have to deal with an open voltage of 220 volts.
