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Adjusting the charging current with a thyristor. Charger with thyristor current regulator. Simple charger. Features of assembly and operation

The described charger was developed for restoring and charging batteries of cars and motorcycles. His main feature- this is a pulsed charging current, which has a positive effect on the time and quality of battery regeneration.
IN new development a circuit based on composite thyristors is used, the control band is expanded, and powerful cooling heat sinks are not required. The circuit not only works out the optimal conditions for charging and restoring the battery, but also protects them when the nominal voltage level at the terminals is reached.
The voltage from the alternating network is supplied to the power transformer T1 through a network filter composed of capacitors C1, C2 and a network choke T2 with back-to-back windings. This filter suppresses the interference that occurs as a result of turning on the thyristors VS1 ... VS3. Network noise after the rectifier bridge VD1 is filtered by capacitor C5. The key thyristor control circuit includes a low-power thyristor VS1 with control circuits on a resistive divider R1-R2-R3 and an indication LED HL1. The lower arm of the divider is formed by resistor R2 and LED HL1, which performs two functions: an indicator of the presence of mains voltage and a control voltage stabilizer. Resistor R3 smoothly regulates the charge current.

Resistor R4 in the anode circuit of thyristor VS1 limits the control current of the key thyristor VS2 to the nominal level. The R5-HL2 chain is the load of VS1, and the glow of HL2 indicates the battery charge.
The control signal from the R3 engine (adjustable constant voltage level) is supplied to the control electrode of the thyristor VS1 and, at a certain voltage at its anode, opens VS1. A voltage appears on the R5-HL2 chain, which is supplied to the control electrode of the power thyristor VS2 and turns it on. The current from the rectifier bridge VD1 through the open thyristor VS2 passes through the measuring device PA1 to the charging battery GB1. Capacitors SZ and C4 reduce noise in the circuits, which eliminates random switching of the control thyristor VS1.

To protect the battery from overcharging, a limiting circuit is used. The switch on thyristor VS3 turns off the power thyristor VS2 when the voltage on the battery increases above a specified limit. When thyristor VS3 opens, the voltage at its anode drops to almost zero, as does the voltage at the control electrode of thyristor VS1, which closes. Power thyristor VS2 also closes and charging of battery GB1 stops. The HL2 LED goes out.
When battery GB1 self-discharges for a long time, the voltage at its terminals decreases and the battery charge is resumed. Diode VD2 prevents the reverse supply of voltage from resistor R9 to the control electrode of thyristor VS1 in the charge current control circuit.
For normal operation protection, the voltage on the battery should not exceed 16.2... 16.8 volts. The protection response voltage is set using resistor R7. Initially, the resistor R7 slider is installed in the upper position according to the diagram. When the protection is triggered, the voltage on the battery is measured, then the engine slowly “lowers” ​​down and the charge switching voltage is monitored.
Basic specifications thyristor charger:
Mains voltage: 190-230 volts
Power: 200 watts
Maximum load current: 20 amperes
Average charge current: 3-5 amperes
Efficiency: more than 80%
Rated battery voltage: 12 volts
Battery capacity: 55-240 Ah
Charging time: 1-3 hours
All radio components of the device, both domestic and foreign:
FU1 - 2 amp fuse
T1 - network transformer for 16-18 volts and 20 amperes
T2 - TLF214
VS1, VS3 - KU101B
VS2 - T122-25-6 - can be replaced with KU202N
VD1 - RS405L
VD2 - D106B - replace with D226B
VD3 - D818G - replace with KS168B
HL1 - AL307B - "Network"
HL2 - AL307V - "Charge"
R1 - 1.5 kOhm
R2, R5 - 2.2 kOhm
R3 - 47 kOhm
R4 - 120 Ohm
R6 - 1.3 kOhm
R7 - 10 kOhm
R8 - 33 kOhm
R9 - 510 Ohm
C1 - 0.33 uF x 275 volts
C2 - 0.1 uF x 450 volts
C3 - 0.1 µF
C4 - 2.2 uF x 16 volts
C5 - 0.33 µF
C6 - 1 uF x 16 volts

A simple thyristor charger.

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 disadvantages of the device include - fluctuations 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 printed circuit board made of foil fiberglass 1.5 mm thick.
The board drawing is presented in radio magazine No. 11 for 2001.

V. VOEVODA, p. Konstantinovka, Amur region.
Currently, the market offers the motorist a wide variety of chargers~ automatic and semi-automatic, including simple ones, but their cost is very high. However, if the car owner is familiar with the basics of electronics, he can easily take on self-production simple charger.

I bring to the attention of readers a simple device with electronic control of the charging current, made on the basis of a thyristor phase-pulse power regulator. It allows you to charge car batteries with a current from 0 to 10 A, and can also serve as an adjustable power source for a powerful low-voltage soldering iron, vulcanizer, and portable lamp.
The device is operational at ambient temperatures from -35 to +35 °C. It does not contain scarce parts, and if the elements are known to be good, it does not require adjustment. For it, a ready-made network step-down transformer of the required power with a secondary winding voltage of 18 to 22 V can be used. A transformer with windings without leads is also suitable. The charging current is close in shape to pulse current, which, according to some radio amateurs, helps extend the battery life.
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 disadvantage of the device is fluctuations in the charging current when the voltage of the electric lighting network is unstable. Like all similar SCR 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.
The device diagram is shown in Fig. 1. It is a traditional thyristor power regulator with phase-pulse control, powered from winding II of the step-down transformer T1 through the diode bridge VD1-VD4. The thyristor control unit is made on an analogue of the unijunction transistor VT1VT2. The time during which capacitor C2 charges before switching the unijunction transistor can be adjusted by 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 the thyristor from reverse voltage that occurs when the thyristor VS1 is turned on.
All parts of the device, except for transformer T1, rectifier diodes VD1 -VD4, variable resistor R1, fuse FU1 and SCR VS1, are mounted on a printed circuit board made of foil fiberglass laminate 1.5 mm thick. The board drawing is shown in Fig. 2.
Capacitor S2-K73-11, with a capacity of 0.47 to 1 μF, or K73-16, K73-17, K42U-2, MBGP. Diodes VD1-VD4 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). Instead of the KU202V trinistor, KU202G-KU202E are suitable; It has been verified in practice that the device works normally with more powerful thyristors T-160, T-250.
We will replace the KT361A transistor with KT361B-KT361E, KT3107A, KT502V, KT502G, KT501Zh-KT501K, and KT315A with KT315B-KT315D, KT312B, KT3102A, KT503V-KT503G, P307. Instead of KD105B, diodes KD105V, KD105G or D226 with any letter index are suitable.
Variable resistor R1 - SP-1, SPZ-Z0a or SPO-1. Ammeter PA1 - any direct current with a 10A scale. It can be made independently from any milliammeter by selecting a shunt based on a standard ammeter.
Fuse FU1 is a fuse, but it is convenient to use a 10A network breaker or a car bimetallic fuse for the same current.
The charger is mounted in a durable metal or plastic casing of suitable dimensions. The rectifier diodes and the 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.
It should be noted that it is permissible to use the metal casing wall directly as a heat sink for the SCR. 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 attach the thyristor through a mica gasket, there will be no danger of a short circuit, but the heat transfer from it will worsen.
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 (at 24...26 V up 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 make the rectifier using 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 the board) between pin 2 of the board and the positive wire. In addition, the choice of thyristor here is limited - only those that allow operation under reverse voltage (for example, KU202E) are suitable.
From the editor. For the described device, a unified transformer TN-61 is suitable. Its three secondary windings must be connected in series; they are capable of delivering current up to 8 A.
Radio 2001 No. 11

A little aside:
1. Transformer TS-250-2P from a tube TV, remove all secondary windings. Wind 40 turns into two PEV-1.2mm wires (approximately 25-27V).
2. Diode bridge from KD213. Transistors can be used KT814 and KT815. Thyristor KU202N. R5-180 Om. Instead of C1, use a surge protector from a computer power supply or UPS, C2 - 0.5 µFx250V
3. Can be supplemented with short circuit protection. R1 needs to be removed. You can hang an LED on the disconnecting contacts; it will light up during a short circuit. If you use this circuit, then the battery must be charged at least 70%, otherwise the relay will not work and charging will not start. For discharged batteries, this protection will not work, or contacts K1.1 must be short-circuited.

4. ...and protection against polarity reversal

For charging car batteries, you must select a relay for Rated voltage 12 B with a permissible current through the contacts of at least 20 A. These conditions are met by the REN-34 KhP4.500.030-01 relay, the contacts of which should be connected in parallel.

6. The fuse can be made based on:

7. Indicator - the simplest voltmeter

ZY The charger is simple, it’s done in 3-4 days leisurely after work, the parts used are not in short supply, in general I’m happy. Written.

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CAR CHARGER

The topic of chargers for car batteries is very popular, so we bring to your attention another proven and proven charging scheme. The transformer in this device was used at a factory, 36 volts, in control circuits. On its secondary there are two 18 volt windings connected to midpoint. Diodes with a current of 30 A, obtained from a car generator (those that were on hand), are installed on a common radiator with a thyristor.

The thyristor itself is isolated from the radiator body by a mica gasket, and the radiator, in turn, is isolated from the body. It turned out simple and compact, and even at maximum load the radiator temperature did not rise above 40-45 degrees.

We tried different thyristors, the entire KU202 series, but in the end T25-xxx was installed, the inscription is hard to see, but I know for sure that this is a 25 A thyristor.
The control is assembled on a separate board,ammeter used on alternating current, with a total deviation of 5 A, therefore included before the diodes.

Naturally, you can put it in this car charger pointer indicator and for direct current, and not necessarily an ammeter, but even a voltmeter - with a shunt made of a low-resistance resistor.

The charging current adjustment limits are 0.7-5 A; if the current is too low, the generation may fail (all the subtleties of setting up the generator circuits and selecting a thyristor) - who wants to have a charging current from scratch.

On the front panel of the case there is a power switch, a charging current regulator and an ammeter for monitoring the battery charging process.At the back, wire terminals for connecting the battery are mounted on a textolite strip. The entire box is painted black.

Under normal operating conditions, the vehicle's electrical system is self-sufficient. It's about about energy supply - a combination of a generator, a voltage regulator, and 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:

  1. Operating a battery that has exhausted its service life. The battery does not hold a charge
  2. Irregular trips. Prolonged downtime of the car (especially during the “ hibernation") leads to battery self-discharge
  3. The car is used for short trips, with frequent stopping and starting of the engine. The battery simply does not have time to recharge
  4. Connection additional equipment increases the load on the battery. Often leads to increased current self-discharge when the engine is off
  5. Extreme low temperature accelerates self-discharge
  6. Faulty fuel system leads to increased load: the car does not start immediately, you have to turn the starter for a long time
  7. 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.
  8. 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.

The tab contains four proven and reliable car charger circuits from simple to the most complex. Choose any one and it will work.

A simple 12V charger circuit.

Charger with adjustable charging current.

Adjustment from 0 to 10A is carried out by changing the opening delay of the SCR.

Circuit diagram of a battery charger with self-shutdown after charging.

For charging batteries with a capacity of 45 amps.

Scheme of a smart charger that will warn about incorrect connection.

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