Developers of electrical and electronic devices, in the process of creating them, proceed from the fact that the future device will operate under conditions of a stable supply voltage. This is necessary so that the electrical circuit of the electronic device, firstly, provides stable output parameters in accordance with its intended purpose, and secondly, the stability of the supply voltage protects the device from surges that are fraught with too high current consumption and burnout of the electrical elements of the device. To solve the problem of ensuring the constant supply voltage, some version of a voltage stabilizer is used. Based on the nature of the current consumed by the device, alternating and direct voltage stabilizers are distinguished.

AC voltage stabilizers

AC voltage stabilizers are used if voltage deviations in the electrical network from the nominal value exceed 10%. This standard was chosen based on the fact that AC consumers with such deviations retain their functionality throughout their entire service life. In modern electronic technology, as a rule, to solve the problem of a stable power supply, a switching power supply is used, in which an alternating voltage stabilizer is not needed. But in refrigerators, microwave ovens, air conditioners, pumps, etc. external stabilization of the AC supply voltage is required. In such cases, one of three types of stabilizer is most often used: electromechanical, the main link of which is an adjustable autotransformer with a controlled electric drive, relay-transformer, based on a powerful transformer having several taps in the primary winding, and a switch made of electromagnetic relays, triacs, thyristors or powerful key transistors, as well as purely electronic ones. Ferroresonant stabilizers, widespread in the last century, are now practically not used due to the presence of numerous shortcomings.

To connect consumers to a 50 Hz AC network, a 220 V voltage stabilizer is used. The electrical circuit of a voltage stabilizer of this type is shown in the following figure.

Transformer A1 increases the voltage in the network to a level sufficient to stabilize the output voltage at low input voltage. The regulating element RE changes the output voltage. At the output, the control element UE measures the voltage value across the load and issues a control signal to adjust it, if necessary.

Electromechanical stabilizers

This stabilizer is based on the use of a household adjustable autotransformer or laboratory LATR. The use of an autotransformer provides higher efficiency of the installation. The autotransformer adjustment handle is removed, and instead of it, a small motor with a gearbox is installed coaxially on the body, providing a rotation force sufficient to turn the slider in the autotransformer. The necessary and sufficient rotation speed is about 1 revolution in 10 - 20 seconds. These requirements are met by the RD-09 type engine, which was previously used in recorders. The engine is controlled by an electronic circuit. When the mains voltage changes within +- 10 volts, a command is issued to the motor, which turns the slider until the output voltage reaches 220 V.

Examples of electromechanical stabilizer circuits are given below:

Electrical circuit of a voltage stabilizer using logic chips and relay control of an electric drive

Electromechanical stabilizer based on an operational amplifier.

The advantage of such stabilizers is their ease of implementation and high accuracy of output voltage stabilization. The disadvantages include low reliability due to the presence of mechanical moving elements, relatively low permissible load power (within 250 ... 500 W), and the low prevalence of autotransformers and the necessary electric motors in our time.

Relay transformer stabilizers

The relay-transformer stabilizer is more popular due to the simplicity of the design, the use of common elements and the possibility of obtaining significant output power (up to several kilowatts), significantly exceeding the power of the used power transformer. The choice of its power is influenced by the minimum voltage in a particular AC network. If, for example, it is not less than 180 V, then the transformer will be required to provide a voltage boost of 40 V, which is 5.5 times less than the rated voltage in the network. The output power of the stabilizer will be the same number of times greater than the power of the power transformer (if you do not take into account the efficiency of the transformer and the maximum permissible current through the switching elements). The number of voltage change steps is usually set within 3...6 steps, which in most cases ensures acceptable accuracy of output voltage stabilization. When calculating the number of turns of windings in a transformer for each stage, the voltage in the network is taken to be equal to the operating level of the switching element. As a rule, electromagnetic relays are used as switching elements - the circuit turns out to be quite elementary and does not cause difficulties when repeated. The disadvantage of such a stabilizer is the formation of an arc at the relay contacts during the switching process, which destroys the relay contacts. In more complex versions of the circuits, the relay is switched at the moments when the voltage half-wave passes through the zero value, which prevents the occurrence of a spark, albeit provided that high-speed relays are used or switching occurs at the decline of the previous half-wave. The use of thyristors, triacs or other non-contact elements as switching elements increases the reliability of the circuit sharply, but becomes more complicated due to the need to provide galvanic isolation between the control electrode circuits and the control module. For this purpose, optocoupler elements or isolating pulse transformers are used. Below is a schematic diagram of a relay transformer stabilizer:

Scheme of a digital relay-transformer stabilizer based on electromagnetic relays

Electronic stabilizers

Electronic stabilizers, as a rule, have low power (up to 100 W) and high stability of the output voltage, necessary for the operation of many electronic devices. They are usually built in the form of a simplified low-frequency amplifier, which has a fairly large margin for changing the level of supply voltage and power. A sinusoidal signal with a frequency of 50 Hz from an auxiliary generator is supplied to its input from the electronic voltage regulator. You can use the step-down winding of a power transformer. The amplifier output is connected to a step-up transformer up to 220 V. The circuit has inertial negative feedback on the output voltage value, which guarantees the stability of the output voltage with an undistorted shape. To achieve power levels of several hundred watts, other methods are used. Typically, a powerful DC-AC converter is used based on the use of a new type of semiconductor - the so-called IGBT transistor.

These switching elements in switching mode can pass a current of several hundred amperes at a maximum permissible voltage of more than 1000 V. To control such transistors, special types of microcontrollers with vector control are used. Pulses with a variable width are applied to the gate of a transistor with a frequency of several kilohertz, which changes according to a program entered into the microcontroller. At the output, such a converter is loaded onto the corresponding transformer. The current in the transformer circuit varies according to a sinusoid. At the same time, the voltage retains the shape of the original rectangular pulses with different widths. This circuit is used in powerful guaranteed power supplies used for uninterrupted operation of computers. The electrical circuit of a voltage stabilizer of this type is very complex and practically inaccessible for independent reproduction.

Simplified electronic voltage stabilizers

Such devices are used when the voltage of the household network (especially in rural areas) is often reduced, almost never providing the nominal 220 V.

In such a situation, the refrigerator works intermittently and is at risk of failure, the lighting turns out to be dim, and the water in the electric kettle cannot boil for a long time. The power of an old, Soviet-era voltage stabilizer designed to power a TV is, as a rule, insufficient for all other household electrical consumers, and the voltage in the network often drops below the level acceptable for such a stabilizer.

There is a simple method for increasing the voltage in the network by using a transformer with a power significantly lower than the power of the applied load. The primary winding of the transformer is connected directly to the network, and the load is connected in series to the secondary (step-down) winding of the transformer. With correct phasing, the voltage at the load will be equal to the sum of the voltage taken from the transformer and the mains voltage.

The electrical circuit of a voltage stabilizer operating on this simple principle is shown in the figure below. When the transistor VT2 (field effect) located in the diagonal of the diode bridge VD2 is closed, winding I (which is the primary) of transformer T1 is not connected to the network. The voltage at the switched-on load is almost equal to the mains voltage minus a small voltage at winding II (secondary) of transformer T1. When the field-effect transistor opens, the primary winding of the transformer will be short-circuited, and the sum of the mains voltage and the secondary winding voltage will be applied to the load.

Electronic voltage stabilizer circuit

The voltage from the load, through transformer T2 and diode bridge VD1, is supplied to transistor VT1. The adjuster of the trimming potentiometer R1 must be set to a position that ensures the opening of the transistor VT1 and the closing of VT2 when the load voltage exceeds the nominal (220 V). If the voltage is less than 220 volts, transistor VT1 will close and VT2 will open. The negative feedback obtained in this way keeps the voltage across the load approximately equal to the nominal value.

The rectified voltage from the VD1 bridge is also used to power the VT1 collector circuit (through the DA1 integrated stabilizer circuit). Chain C5R6 dampens unwanted drain-source voltage surges on transistor VT2. Capacitor C1 reduces interference entering the network during operation of the stabilizer. The values ​​of resistors R3 and R5 are selected to obtain the best and most stable voltage stabilization. Switch SA1 provides switching on and off of the stabilizer and load. Closing switch SA2 turns off the automatic system that stabilizes the voltage at the load. In this case, it turns out to be the maximum possible at the current network voltage.

After connecting the assembled stabilizer to the network, trimming resistor R1 sets the load voltage to 220 V. It should be taken into account that the stabilizer described above cannot eliminate changes in the mains voltage that exceed 220 V, or that are below the minimum used in calculating the transformer windings.

Note: In some modes of operation of the stabilizer, the power dissipated by transistor VT2 turns out to be very significant. It is this, and not the power of the transformer, that can limit the permissible load power. Therefore, care should be taken to ensure good heat dissipation from this transistor.

A stabilizer installed in a damp room must be placed in a grounded metal case.

See also diagrams.

The network voltage, especially in rural areas, often exceeds the permissible limits for the powered equipment, which leads to its failure.

It is possible to avoid such unpleasant consequences with the help of a stabilizer, which maintains the output voltage within the required limits for the load, and if this is not possible, turns it off.

The proposed device is a very promising design in which the load is automatically connected to the corresponding tap of the autotransformer winding depending on the current value of the network voltage.

Godin A.V. AC voltage stabilizer

Magazine "RADIO". 2005. No. 08 (p. 33-36)
Magazine "RADIO". 2005. No. 12 (p. 45)
Magazine "RADIO". 2006. No. 04 (p. 33)

Due to instability of the network voltage in the Moscow region, a refrigerator failed. Checking the voltage during the day revealed its changes from 150 to 250 V. As a result, I took up the issue of purchasing a stabilizer. When I looked at the prices for finished products I was shocked. I started looking for diagrams in the literature and the Internet.

A microcontroller-controlled stabilizer with almost suitable parameters is described in. But its output power is not high enough; load switching depends not only on the amplitude, but also on the frequency of the network voltage. Therefore, it was decided to create our own stabilizer design that does not have these disadvantages.

The proposed stabilizer does not use a microcontroller, which makes it accessible to a wider range of radio amateurs. Insensitivity to mains voltage frequency allows it to be used in field conditions when the source of electricity is an autonomous diesel generator.

Main technical characteristics

Input voltage, V: 130…270
Output voltage, V: 205…230
Maximum load power, kW: 6
Load switching (disconnection) time, ms: 10

The device contains the following components: Power supply on elements T1, VD1, DA1, C2, C5. Load turn-on delay unit C1, VT1-VT3, R1-R5. Rectifier for measuring the voltage amplitude of the network VD2, C2 with a divider R13, R14 and a zener diode VD3. Voltage comparator DA2, DA3, R15-R39. Logic controller based on DD1-DD5 chips. Amplifiers based on transistors VT4-VT12 with current-limiting resistors R40-R48. Indicator LEDs HL1-HL9, seven optocoupler switches containing optosimistors U1-U7, resistors R6-R12, triacs VS1-VS7. The mains voltage is connected to the corresponding winding tap of the autotransformer T2 through the automatic fuse switch QF1. The load is connected to autotransformer T2 through an open triac (one of VS1-VS7).

The stabilizer works as follows. After turning on the power, capacitor C1 is discharged, transistor VT1 is closed, and VT2 is open. Transistor VT3 is closed, and since the current through the LEDs, including those included in the triac optocouplers U1-U7, can only flow through this transistor, not a single LED is lit, all triacs are closed, the load is turned off. The voltage across capacitor C1 increases as it is charged from the power supply through resistor R1. At the end of the three-second delay interval required to complete the transient processes, the Schmidt trigger on transistors VT1 and VT2 is triggered, transistor VT3 opens and allows the load to be turned on.

The voltage from winding III of transformer T1 is rectified by elements VD2C2 and supplied to the divider R13, R14. The voltage on the engine of the tuning resistor R14, proportional to the network voltage, is supplied to the non-inverting inputs of eight comparators (chips DA2, DA3). The inverting inputs of these comparators receive constant reference voltages from the resistor divider R15-R23. The signals from the outputs of the comparators are processed by the controller using “exclusive OR” logic elements (chips DD1-DD5). On the group communication line Fig. The outputs of the comparators DA2.1-DA2.4 and DA3.1-DA2.3 are designated by numbers 1-7, and the controller outputs are designated by letters A-H. The output of the comparator DA3.4 is not included in the group communication line.

If the network voltage is less than 130 V, the outputs of all comparators and the controller outputs have a low logic level. Transistor VT4 is open, the blinking LED HL1 is on, indicating an excessively low network voltage, at which the stabilizer cannot supply power to the load. All other LEDs are off, triacs are closed, the load is disconnected.

If the network voltage is less than 150 V, but more than 130 V, the logical level of signals 1 and A is high, the rest are low. Transistor VT5 is open, LEDs HL2 and U1.1 are on, optosimistor U1.2 is open, the load is connected to the upper terminal of the winding of autotransformer T2 through the open triac VS1.

If the network voltage is less than 170 V, but more than 150 V, the logical level of signals 1, 2 and B is high, the rest are low. Transistor VT6 is open, LEDs HL3 and U2.1 are on, optosimistor U1.2 is open, the load is connected to the second from the top terminal of the autotransformer winding T2 through the open triac VS2.

The remaining network voltage levels corresponding to switching the load to another tap of the autotransformer winding T2: 190, 210, 230 and 250 V.

To prevent repeated switching of the load, in the case when the mains voltage fluctuates at a threshold level, a hysteresis of 2-3 V (comparator switching delay) is introduced using positive feedback through R32-R39. The greater the resistance of these resistors, the less hysteresis.

If the network voltage is more than 270 V, the outputs of all comparators and the controller output H are at a high logical level. The remaining controller outputs are low. Transistor VT12 is open, the blinking LED HL9 is turned on, indicating an excessively high network voltage, at which the stabilizer cannot supply power to the load. All other LEDs are off, triacs are closed, the load is disconnected.

The stabilizer can withstand an emergency increase in network voltage up to 380 V for an unlimited time. The inscriptions displayed by LEDs are similar to those described in.

Option with one power transformer

Construction and details

The stabilizer is assembled on a 90x115 mm printed circuit board made of single-sided foil fiberglass.

LEDs HL1-HL9 are mounted so that when installing the printed circuit board into the case, they fit into the corresponding holes on the front panel of the device.

Depending on the housing design, it is possible to mount LEDs on the side of the printed conductors. The values ​​of current-limiting resistors R41-R47 are selected so that the current flowing through the LEDs of triac optocouplers U1.1-U7.1 is within 15-16 mA. It is not necessary to use flashing LEDs HL1 and HL9, but their glow should be clearly visible, so they can be replaced with continuous red LEDs of increased brightness, such as AL307KM or L1543SRC-E.

Foreign diode bridge DF005M(VD1,VD2) can be replaced with domestic KTs407A or any with a voltage of at least 50V and a current of at least 0.4A. Zener diode VD3 can be any low-power one with a stabilization voltage of 4.3...4.7 V.

Voltage regulator KR1158EN6A(DA1) can be replaced by KR1158EN6B. Quad comparator chip LM339N(DA2,DA3), can be replaced with a domestic analogue K1401SA1. Microcircuit KR1554LP5(DD1-DD5), can be replaced with a similar one from the series KR1561 And KR561 or foreign 74AC86PC.

Triac optocouplers MOC3041(U1-U7) can be replaced MOC3061.

Trimmer resistors R14, R15 and R23 multi-turn wirewound SP5-2 or SP5-3. Fixed resistors R16-R22 C2-23 with a tolerance of at least 1%, the rest can be any with a tolerance of 5%, having a power dissipation not lower than that indicated in the diagram. Oxide capacitors C1-C3, C5 can be any, with the capacitance indicated in the diagram and a voltage not lower than those specified for them. The remaining capacitors C4, C6-C8 are any film or ceramic.

Imported triac optocouplers MOC3041(U1-U7) were chosen because they contain built-in voltage zero crossing controllers. This is necessary to synchronize the turn-off of one powerful triac and the turn-on of another, in order to prevent short-circuiting of the autotransformer windings.

Powerful triacs VS1-VS7 are also foreign BTA41-800B, since domestic ones of the same power require too much control current, which exceeds the maximum permissible current of optosimistors 120 mA. All triacs VS1-VS7 are installed on one heat sink with a cooling surface area of ​​at least 1600 cm2.

Stabilizer chip KR1158EN6A(DA1) must be installed on a heat sink made from a piece of aluminum plate or U-shaped profile with a surface area of ​​at least 15 cm2.

The T1 transformer is homemade, designed for an overall power of 3 W, having a cross-sectional area of ​​the magnetic circuit of 1.87 cm2. Its network winding I, designed for a maximum emergency network voltage of 380 V, contains 8669 turns of PEV-2 wire with a diameter of 0.064 mm. Windings II and III each contain 522 turns of PEV-2 wire with a diameter of 0.185 mm.

Option with two power transformers

With a rated network voltage of 220 V, the voltage of each output winding should be 12 V. Instead of a homemade transformer T1, you can use two transformers TPK-2-2×12V, connected in series according to the method described in as shown in Fig.

Device Print File PrintStab-2.lay(option with two transformers TPK-2-2×12V) performed using the program Sprint Layout 4.0, which allows you to print a design in a mirror image and is very convenient for making printed circuit boards using a laser printer and an iron. It can be downloaded here.

Power transformer

Transformer T2 6 kW, also homemade, wound on a toroidal magnetic core with an overall power of 3-4 kW, in the manner described in. Its winding contains 455 turns of PEV-2 wire.

Bends 1,2,3 are wound with a wire with a diameter of 3 mm. Bends 4,5,6,7 are wound with a bus with a cross-section of 18.0 mm2 (2 mm by 9 mm). This cross-section is necessary so that the autotransformer does not heat up during long-term operation.

The taps are made from the 203, 232, 266, 305, 348 and 398th turns, counting from the bottom one in the output circuit. The mains voltage is supplied to the tap of the 266th turn.

If the load power does not exceed 2.2 kW, then the autotransformer T2 can be wound on the stator of an electric motor with a power of 1.5 kW with PEV-2 wire. Bends 1,2,3 are wound with a wire with a diameter of 2 mm. Bends 4,5,6,7 are wound with a wire with a diameter of 3 mm

The number of winding turns should be proportionally increased by 1.3 times. The operating current of the QF1 fuse switch should be reduced to 20 A. Before the load, it is advisable to install an additional 10 A circuit breaker

When manufacturing an autotransformer, with an unknown value of the magnetic permeability Vmax of the core, in order not to make a mistake in choosing the ratio of turns per volt, it is necessary to conduct a practical study of the stator (see section below).

In the general archive there is a program for calculating autotransformer taps based on the overall dimensions of the stator with a known value of magnetic permeability Vmax of the core.

If the load power does not exceed 3 kW, then the autotransformer T2 can be wound on the stator of a 4 kW electric motor with a PEV-2 wire with a diameter of 2.8 mm (section 6.1 mm2). The number of winding turns should be proportionally increased by 1.2 times. The operation current of the fuse switch QF1 must be reduced to 16 A. Triacs VS1-VS7 BTA140-800 can be used, placed on a heat sink with an area of ​​at least 800 cm2.

Settings

The adjustment is carried out using LATR- and two voltmeters. It is necessary to set the load switching thresholds and make sure that the output voltage of the stabilizer is within acceptable limits for the powered equipment.

Let's denote U1, U2, U3, U4, U5, U6, U7 - the voltage values ​​on the engine of the tuning resistor R14, corresponding to the network voltage 130, 150, 170, 190, 210, 230, 250, 270 V (switching and load disconnection thresholds).

Instead of trimming resistors R15 and R23, permanent resistors with a resistance of 10 kOhm are temporarily installed.

Next, the stabilizer without autotransformer T2 is connected to the network via LATR. At the exit LATR-a increase the voltage to 250 V, then use the trimmer resistor R14 to set the voltage U6 equal to 3.5 V, measuring it with a digital voltmeter. After this, reduce the voltage LATR-a up to 130 V and measure the voltage U1. Let, for example, it be 1.6 V.

Calculate the voltage change step:

∆U=(U6 – U1)/6=(3.5-1.6)/6=0.3166 V ,
current flowing through the divider R15-R23
I=∆U/R16=0.3166/2=0.1583 mA

Calculate the resistance of resistors R15 and R23:

R15= U1/I=1.6/0.1583=10.107 kOhm,
R23= (Upit – U6 –∆U)/I=(6–3.5–0.3166)/0.1588=13.792 kOhm , where Upit is the stabilization voltage of the DA1 microcircuit. The calculation is approximate, since it does not take into account the influence of resistors R32-R39, but its accuracy is sufficient for practical adjustment of the stabilizer.

The program for calculating R8, R16 and switching boundary voltages can be downloaded in the attachments.

Next, the device is disconnected from the network and, using a digital voltmeter, the resistances of resistors R15 and R23 are set equal to the calculated values ​​and mounted on the board instead of the fixed resistors mentioned above. Turn on the stabilizer again and monitor the switching of the LEDs, gradually increasing the voltage LATR-and from minimum to maximum and back. The simultaneous lighting of two or more LEDs indicates a malfunction of one of the microcircuits DA2, DA3, DD1-DD5. A faulty microcircuit must be replaced, so it is more convenient to install panels for them rather than the microcircuits themselves on the board.

After making sure that the microcircuits are in good condition, connect the autotransformer T2 and the load - an incandescent lamp with a power of 100...200 W. The switching thresholds and voltages U1-U7 are measured again. To check the correctness of the calculations, changing LATR-th input on T1, you need to make sure that the HL1 LED blinks at a voltage below 130 V, the sequential activation of the HL2 - HL8 LEDs when crossing the switching thresholds indicated above, and also the HL9 blinks at a voltage above 270 V.

If the maximum voltage LATR-a is less than 270 V, set its output to 250 V, calculate the voltage U7 using the formula: U7 = U6 + ∆U = 3.82 V. Move the R14 slider up, check that at voltage U7 the load is turned off, and then return the R14 slider down, setting U6 to its previous value of 3.5 V.

It is advisable to complete the installation of the stabilizer by connecting it to a voltage of 380 V for several hours.

During the operation of several copies of stabilizers of different power (about six months), there were no failures or failures in their operation. There were no malfunctions of the equipment powered through them due to unstable network voltage.

Literature

1. Koryakov S. Network voltage stabilizer with microcontroller control. - Radio, 2002, No. 8, p. 26-29.
2. Kopanev V. Protection of a transformer from increased network voltage. - Radio, 1997, No. 2 p.46.
3. Andreev V. Manufacturing of transformers. - Radio, 2002, No. 7, p. 58
4. http://rexmill.ucoz.ru/forum/50-152-1

Autotransformer calculation

You managed to remove the stator from the engine, but you do not know what material it is made of. In general, when calculating cores with a power above 1 kW, problems often arise with the initial data. You can easily avoid problems if you conduct research on your existing core. It's very easy to do.

We prepare the core for winding the primary winding: we process the sharp edges, apply insulating pads (in my case, I made cardboard pads on the toroidal core). Now we wind 50 turns of wire with a diameter of 0.5-1 mm. For measurements we will need an ammeter with a measurement limit of approximately 5 amperes, an alternating voltage voltmeter and LATR.MS Excel

N/V= 50/((140-140*0.25) = 0.48 turns per volt.

The number of turns in the taps is calculated based on the average voltages of each of the input ranges of the controller and will be:

Tap No. 1 – 128.5 V x 0.48 V = 62 Vit
Tap No. 2 – 147 V x 0.48 V = 71 Vit
Tap No. 3 – 168 V x 0.48 V = 81 Vit
Tap No. 4 – 192 V x 0.48 V = 92 Vit
Tap No. 5 – 220 V x 0.48 V = 106 Vit(the voltage on the load is also removed from it)
Tap No. 6 – 251.5 V x 0.48 V = 121 Vit
Tap No. 7 – 287.5 V x 0.48 V = 138 Vit(total number of autotransformer turns)

That's the whole problem!

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Content:

In electrical circuits, there is a constant need to stabilize certain parameters. For this purpose, special control and monitoring schemes are used. The accuracy of the stabilizing actions depends on the so-called standard, with which a specific parameter, for example, voltage, is compared. That is, when the parameter value is below the standard, the voltage stabilizer circuit will turn on the control and give a command to increase it. If necessary, the opposite action is performed - to reduce.

This operating principle underlies the automatic control of all known devices and systems. Voltage stabilizers operate in the same way, despite the variety of circuits and elements used to create them.

DIY 220V voltage stabilizer circuit

With ideal operation of electrical networks, the voltage value should change by no more than 10% of the nominal value, up or down. However, in practice, voltage drops reach much higher values, which has an extremely negative effect on electrical equipment, even to the point of failure.

Special stabilizing equipment will help protect against such troubles. However, due to its high cost, its use in domestic conditions is in many cases economically unprofitable. The best way out of the situation is a homemade 220V voltage stabilizer, the circuit of which is quite simple and inexpensive.

You can take an industrial design as a basis to find out what parts it consists of. Each stabilizer includes a transformer, resistors, capacitors, connecting and connecting cables. The simplest is considered an alternating voltage stabilizer, the circuit of which operates on the principle of a rheostat, increasing or decreasing the resistance in accordance with the current strength. Modern models additionally contain many other functions that protect household appliances from power surges.

Among homemade designs, triac devices are considered the most effective, so this model will be considered as an example. Current equalization with this device will be possible with an input voltage in the range of 130-270 volts. Before starting assembly, you must purchase a certain set of elements and components. It consists of a power supply, rectifier, controller, comparator, amplifiers, LEDs, autotransformer, load turn-on delay unit, optocoupler switches, fuse switch. The main working tools are tweezers and a soldering iron.

To assemble a 220 volt stabilizer First of all, you will need a printed circuit board measuring 11.5x9.0 cm, which must be prepared in advance. It is recommended to use foil fiberglass as a material. The layout of the parts is printed on a printer and transferred to the board using an iron.

Transformers for the circuit can be taken ready-made or assembled yourself. Finished transformers must be brand TPK-2-2 12V and connected in series to each other. To create your first transformer with your own hands, you will need a magnetic core with a cross-section of 1.87 cm2 and 3 PEV-2 cables. The first cable is used in one winding. Its diameter will be 0.064 mm, and the number of turns will be 8669. The remaining wires are used in other windings. Their diameter will be already 0.185 mm, and the number of turns will be 522.

The second transformer is made on the basis of a toroidal magnetic core. Its winding is made of the same wire as in the first case, but the number of turns will be different and will be 455. In the second device, seven taps are made. The first three are made from wire with a diameter of 3 mm, and the rest from tires with a cross-section of 18 mm2. This prevents the transformer from heating up during operation.

It is recommended to purchase all other components ready-made in specialized stores. The basis of the assembly is the circuit diagram of a factory-made voltage stabilizer. First, a microcircuit is installed that acts as a controller for the heat sink. For its manufacture, an aluminum plate with an area of ​​over 15 cm2 is used. Triacs are installed on the same board. The heat sink intended for installation must have a cooling surface. After this, LEDs are installed here in accordance with the circuit or on the side of the printed conductors. The structure assembled in this way cannot be compared with factory models either in terms of reliability or quality of work. Such stabilizers are used with household appliances that do not require precise current and voltage parameters.

Transistor voltage stabilizer circuits

High-quality transformers used in the electrical circuit effectively cope even with large interference. They reliably protect household appliances and equipment installed in the house. A customized filtration system allows you to deal with any power surges. By controlling the voltage, current changes occur. The limiting frequency at the input increases, and at the output it decreases. Thus, the current in the circuit is converted in two stages.

First, a transistor with a filter is used at the input. Next comes the start of work. To complete the current conversion, the circuit uses an amplifier, most often installed between resistors. Due to this, the required temperature level is maintained in the device.

The rectification circuit operates as follows. Rectification of alternating voltage from the secondary winding of the transformer occurs using a diode bridge (VD1-VD4). Voltage smoothing is performed by capacitor C1, after which it enters the compensation stabilizer system. The action of resistor R1 sets the stabilizing current on the zener diode VD5. Resistor R2 is a load resistor. With the participation of capacitors C2 and C3, the supply voltage is filtered.

The value of the output voltage of the stabilizer will depend on the elements VD5 and R1, for the selection of which there is a special table. VT1 is installed on a radiator whose cooling surface area must be at least 50 cm2. The domestic transistor KT829A can be replaced with a foreign analogue BDX53 from Motorola. The remaining elements are marked: capacitors - K50-35, resistors - MLT-0.5.

12V linear voltage regulator circuit

Linear stabilizers use KREN chips, as well as LM7805, LM1117 and LM350. It should be noted that the KREN symbol is not an abbreviation. This is an abbreviation of the full name of the stabilizer chip, designated as KR142EN5A. Other microcircuits of this type are designated in the same way. After the abbreviation, this name looks different - KREN142.

Linear stabilizers or DC voltage regulators are the most common. Their only drawback is the inability to operate at a voltage lower than the declared output voltage.

For example, if you need to get a voltage of 5 volts at the output of the LM7805, then the input voltage must be at least 6.5 volts. When less than 6.5V is applied to the input, a so-called voltage drop will occur, and the output will no longer have the declared 5 volts. In addition, linear stabilizers get very hot under load. This property underlies the principle of their operation. That is, voltage higher than stabilized is converted into heat. For example, when a voltage of 12V is applied to the input of the LM7805 microcircuit, then 7 of them will be used to heat the case, and only the necessary 5V will go to the consumer. During the transformation process, such strong heating occurs that this microcircuit will simply burn out in the absence of a cooling radiator.

Adjustable voltage stabilizer circuit

Situations often arise when the voltage supplied by the stabilizer needs to be adjusted. The figure shows a simple circuit of an adjustable voltage and current stabilizer, which allows not only to stabilize, but also to regulate the voltage. It can be easily assembled even with only basic knowledge of electronics. For example, the input voltage is 50V, and the output is any value within 27 volts.

The main part of the stabilizer is the IRLZ24/32/44 field-effect transistor and other similar models. These transistors are equipped with three terminals - drain, source and gate. The structure of each of them consists of a dielectric metal (silicon dioxide) - a semiconductor. The housing contains a TL431 stabilizer chip, with the help of which the output electrical voltage is adjusted. The transistor itself can remain on the heatsink and be connected to the board by conductors.

This circuit can operate with input voltage in the range from 6 to 50V. The output voltage ranges from 3 to 27V and can be adjusted using a trimmer resistor. Depending on the design of the radiator, the output current reaches 10A. The capacity of smoothing capacitors C1 and C2 is 10-22 μF, and C3 is 4.7 μF. The circuit can work without them, but the quality of stabilization will be reduced. The electrolytic capacitors at the input and output are rated at approximately 50V. The power dissipated by such a stabilizer does not exceed 50 W.

Triac voltage stabilizer circuit 220V

Triac stabilizers work in a similar way to relay devices. A significant difference is the presence of a unit that switches the transformer windings. Instead of relays, powerful triacs are used, operating under the control of controllers.

Control of the windings using triacs is non-contact, so there are no characteristic clicks when switching. Copper wire is used to wind the autotransformer. Triac stabilizers can operate at low voltage from 90 volts and high voltage up to 300 volts. Voltage regulation is carried out with an accuracy of up to 2%, which is why the lamps do not blink at all. However, during switching, a self-induced emf occurs, as in relay devices.

Triac switches are highly sensitive to overloads, and therefore they must have a power reserve. This type of stabilizer has a very complex temperature regime. Therefore, triacs are installed on radiators with forced fan cooling. The DIY 220V thyristor voltage stabilizer circuit works in exactly the same way.

There are devices with increased accuracy that operate on a two-stage system. The first stage performs a rough adjustment of the output voltage, while the second stage carries out this process much more precisely. Thus, control of two stages is performed using one controller, which actually means the presence of two stabilizers in a single housing. Both stages have windings wound in a common transformer. With 12 switches, these two stages allow you to adjust the output voltage in 36 levels, which ensures its high accuracy.

Voltage stabilizer with current protection circuit

These devices provide power primarily for low-voltage devices. This current and voltage stabilizer circuit is distinguished by its simple design, accessible element base, and the ability to smoothly adjust not only the output voltage, but also the current at which the protection is triggered.
The basis of the circuit is a parallel regulator or an adjustable zener diode, also with high power. Using a so-called measuring resistor, the current consumed by the load is monitored.

Sometimes a short circuit occurs at the output of the stabilizer or the load current exceeds the set value. In this case, the voltage across resistor R2 drops, and transistor VT2 opens. There is also a simultaneous opening of transistor VT3, which shunts the reference voltage source. As a result, the output voltage is reduced to almost zero level, and the control transistor is protected from current overloads. In order to set the exact threshold for current protection, a trimming resistor R3 is used, connected in parallel with resistor R2. The red color of LED1 indicates the protection has tripped, and the green LED2 indicates the output voltage.

After correctly assembled, the circuits of powerful voltage stabilizers are immediately put into operation; you just need to set the required output voltage value. After loading the device, the rheostat sets the current at which the protection is triggered. If the protection should operate at a lower current, for this it is necessary to increase the value of resistor R2. For example, with R2 equal to 0.1 Ohm, the minimum protection current will be about 8A. If, on the contrary, you need to increase the load current, you should connect two or more transistors in parallel, the emitters of which have equalizing resistors.

Relay voltage stabilizer circuit 220

Using a relay stabilizer, reliable protection of instruments and other electronic devices is provided, for which the standard voltage level is 220V. This voltage stabilizer is 220V, the circuit of which is known to everyone. It is widely popular due to the simplicity of its design.

In order to properly operate this device, it is necessary to study its design and operating principle. Each relay stabilizer consists of an automatic transformer and an electronic circuit that controls its operation. In addition, there is a relay housed in a durable housing. This device belongs to the voltage booster category, that is, it only adds current in the event of low voltage.

Adding the required number of volts is done by connecting the transformer winding. Usually 4 windings are used for operation. If the current in the electrical network is too high, the transformer automatically reduces the voltage to the desired value. The design can be supplemented with other elements, for example, a display.

Thus, the relay voltage stabilizer has a very simple operating principle. The current is measured by an electronic circuit, then, after receiving the results, it is compared with the output current. The resulting voltage difference is regulated independently by selecting the required winding. Next, the relay is connected and the voltage reaches the required level.

Voltage and current stabilizer on LM2576

Household appliances are susceptible to voltage surges: they wear out faster and fail. And in the network, the voltage often jumps, falls, or even breaks off: this is due to the distance from the source and the imperfection of power lines.

To power devices with current with stable characteristics, voltage stabilizers are used in apartments. Regardless of the parameters of the current introduced into the device at its output, it will have almost unchanged parameters.

A current equalizing device can be purchased, choosing from a wide range (differences in power, principle of operation, control and output voltage parameter). But our article is devoted to how to make a voltage stabilizer with your own hands. Is homemade work justified in this case?

A homemade stabilizer has three advantages:

1. Cheapness. All parts are purchased separately, and this is cost-effective compared to the same parts, but already assembled into a single device - a current equalizer;
2. Possibility of DIY repair. If one of the elements of the purchased stabilizer fails, you are unlikely to be able to replace it, even if you understand electrical engineering. You simply won’t find anything to replace a worn-out part with. With a homemade device, everything is simpler: you initially bought all the elements in the store. All that remains is to go there again and buy what is broken;
3. Easy repair. If you have assembled a voltage converter yourself, then you know it 100%. And understanding the device and operation will help you quickly identify the cause of stabilizer failure. Once you figure it out, you can easily repair your homemade unit.

A self-produced stabilizer has three serious disadvantages:

1. Low reliability. At specialized enterprises, devices are more reliable, since their development is based on the readings of high-precision instrumentation, which cannot be found in everyday life;
2. Wide output voltage range. If industrial stabilizers can produce a relatively constant voltage (for example, 215-220V), then home-made analogues can have a range 2-5 times larger, which can be critical for equipment that is hypersensitive to changes in current;
3. Complex setup. If you buy a stabilizer, then the setup stage is bypassed; all you have to do is connect the device and control its operation. If you are the creator of the current equalizer, then you should configure it too. This is difficult, even if you have made the simplest voltage stabilizer yourself.

Homemade current equalizer: characteristics

The stabilizer is characterized by two parameters:

• Permissible range of input voltage (Uin);
• Permissible range of output voltage (Uout).

This article discusses the triac current converter because it is highly efficient. For it, Uin is 130-270V, and Uout is 205-230V. If a large input voltage range is an advantage, then for the output it is a disadvantage.

However, for household appliances this range remains acceptable. This is easy to check, because the permissible voltage fluctuations are surges and dips of no more than 10%. And this is 22.2 Volts up or down. This means that it is permissible to change the voltage from 197.8 to 242.2 Volts. Compared to this range, the current on our triac stabilizer is even smoother.

The device is suitable for connecting to a line with a load of no more than 6 kW. It switches in 0.01 seconds.

Design of a current stabilizing device

A homemade 220V voltage stabilizer, the diagram of which is presented above, includes the following elements:

• power unit. It uses storage devices C2 and C5, voltage transformer T1, as well as a comparator (comparing device) DA1 and LED VD1;
• Knot, delaying the start of the load. To assemble it you will need resistances from R1 to R5, transistors from VT1 to VT3, as well as storage C1;
• Rectifier, measuring the value of voltage surges and dips. Its design includes a VD2 LED with a zener diode of the same name, a C2 drive, a resistor R14 and R13;
• Comparator. It will require resistances from R15 to R39 and comparing devices DA2 with DA3;
• Logic type controller. It requires DD chips from 1 to 5;
• Amplifiers. They will require resistances to limit the current R40-R48, as well as transistors from VT4 to VT12;
• LEDs, playing the role of an indicator - HL from 1 to 9;
• Optocoupler switches(7) with triacs VS from 1 to 7, resistors R from 6 to 12 and optocoupler triacs U from 1 to 7;
• Auto switch with fuse QF1;
• Autotransformer T2.

How will this device work?

After the drive of the node with the pending load (C1) is connected to the network, it is still discharged. Transistor VT1 turns on, and 2 and 3 close. Through the latter, current will subsequently flow to the LEDs and optocoupler triacs. But while the transistor is closed, the diodes do not give a signal, and the triacs are still closed: there is no load. But the current is already flowing through the first resistor to the storage device, which begins to accumulate energy.

The process described above takes 3 seconds, after which the Schmitt trigger, based on transistors VT 1 and 2, is triggered, after which transistor 3 is turned on. Now the load can be considered open.

The output voltage from the third winding of the transformer on the power supply is equalized by the second diode and capacitor. Then the current is directed to R13, passes through R14. At the moment, the voltage is proportional to the voltage in the network. Then the current is supplied to non-inverting comparators. Immediately, the inverting comparing devices receive an already equalized current, which is supplied to resistances from 15 to 23. Then a controller is connected to process the input signals on the comparison devices.

Nuances of stabilization depending on the voltage supplied to the input

If a voltage of up to 130 Volts is introduced, then a low voltage logical level (LU) is indicated at the comparator terminals. The fourth transistor is open, and LED 1 blinks and indicates that there is a strong dip in the line. You must understand that the stabilizer is not able to produce the required voltage. Therefore, all triacs are closed and there is no load.

If the voltage at the input is 130-150 Volts, then a high LU is observed on signals 1 and A, but for other signals it is still low. The fifth transistor turns on, the second diode lights up. Optocoupler triac U1.2 and triac VS2 open. The load will go along the latter and reach the winding terminal of the second autotransformer from above.

With an input voltage of 150-170 Volts, a high LU is observed on signals 1, 2 and V; on the rest it is still low. Then the sixth transistor turns on and the third diode turns on, VS2 turns on and the current is supplied to the second (if counted from above) winding terminal of the second autotransformer.

The operation of the stabilizer is described similarly in the voltage ranges of 170-190V, 190-210V, 210-230V, 230-250V.

PCB manufacturing

For a triac current converter, you need a printed circuit board on which all the elements will be placed. Its size: 11.5 by 9 cm. To make it you will need fiberglass, covered with foil on one side.

The board can be printed on a laser printer, after which an iron will be used. It is convenient to make a board yourself using the Sprint Loyout program. A diagram of the placement of elements on it is shown below.

How to make transformers T1 and T2?

The first transformer T1 with a power of 3 kW is manufactured using a magnetic core with a cross-sectional area (CSA) of 187 sq. mm. And three wires PEV-2:

• For the first wrapping, the PPS is only 0.003 square meters. mm. Number of turns – 8669;
• For the second and third windings, the PPS is only 0.027 sq. mm. The number of turns is 522 on each.

If you don’t want to wind the wire, then you can purchase two TPK-2-2×12V transformers and connect them in series, as in the figure below.

To make an autotransformer with a second power of 6 kW, you will need a toroidal magnetic core and PEV-2 wire, from which a wrap of 455 turns will be made. And here we need bends (7 pieces):

• Wrapping 1-3 bends from wire with PPS 7 sq. mm;
• Wrapping 4-7 bends from wire with PPS 254 sq. mm.

What to buy?

Buy in an electrical and radio equipment store (designation in brackets in the diagram):

• 7 optocoupler triacs MOC3041 or 3061 (U from 1 to 7);
• 7 simple triacs BTA41-800B (VS from 1 to 7);
• 2 LEDs DF005M or KTs407A (VD 1 and 2);
• 3 resistors SP5-2, 5-3 possible (R 13, 14, 25);
• Current equalizing element KR1158EN6A or B (DA1);
• 2 comparing devices LM339N or K1401CA1 (DA 1 and 2);
• Switch with fuse;
• 4 film or ceramic capacitors (C 4, 6, 7, 8);
• 4 oxide capacitors (C 1, 2, 3, 5);
• 7 resistances to limit the current, at their terminals it should be equal to 16 mA (R from 41 to 47);
• 30 resistances (any) with a tolerance of 5%;
• 7 resistances C2-23 with a tolerance of 1% (R from 16 to 22).

Assembly features of the device for voltage equalization

The current stabilizing device microcircuit is installed on a heat sink, for which an aluminum plate is suitable. Its area should not be less than 15 square meters. cm.

A heat sink with a cooling surface is also necessary for triacs. For all 7 elements, one heat sink with an area of ​​at least 16 square meters is sufficient. dm.

In order for the AC voltage converter we manufacture to work, you will need a microcontroller. The KR1554LP5 microcircuit copes with its role perfectly.

You already know that you can find 9 flashing diodes in the circuit. All of them are located on it so that they fit into the holes that are on the front panel of the device. And if the stabilizer body does not allow their location, as in the diagram, then you can modify it so that the LEDs come out on the side that is convenient for you.

Instead of flashing LEDs, non-blinking LEDs can be used. But in this case, you need to take diodes with a bright red glow. Elements of the following brands are suitable: AL307KM and L1543SRC-E.

Now you know how to make a 220 volt voltage stabilizer. And if you have already had to do something similar before, then this work will not be difficult for you. As a result, you can save several thousand rubles on the purchase of an industrial stabilizer.

The optimal way to operate electrical networks is to change the current functions, as well as the required voltage, by 10% from 220V. However, since the surges change quite often, electrical devices that are directly connected to the network are at risk of breakdown.

To eliminate such troubles, it is necessary to install certain equipment. And since the magazine device has a fairly high cost, naturally many people assemble the stabilizer with their own hands.

Is such a decision justified and what is required to make it a reality?

The principle of operation of the stabilizer

Having decided to create a homemade stabilizer, as in the photo, you need to look at the inside of the case, which consists of certain parts. The operating principle of a conventional device is based directly on the functioning of a rheostat, which increases or decreases resistance.

In addition, the proposed models have a variety of functions, and can also fully protect equipment from unwanted surge voltage surges in the network.

Equipment is classified depending on the methods used to regulate the current. Since the value is the directional movement of particles, it can be influenced accordingly by a mechanical or pulse method.

The first one works according to Ohm's law. Devices whose operation is based on it are called linear. They include several bends, combined by means of a rheostat.

The voltage that is supplied to one part passes through a rheostat, ending up in a similar way to another, from which it is transmitted to the consumer.

This type of device makes it possible to set the required current parameters as accurately as possible and can easily be upgraded with special components.

However, it is unacceptable to use such stabilizers in networks where there is a large difference between the currents, since they will not fully protect equipment from short circuits during overloads.

Pulse options operate using the amplitude current modulation method. The circuit uses a switch that breaks it after the required period of time. This approach makes it possible to accumulate the required current in the capacitor as evenly as possible, and after charging is completed, and then to the devices.

Let's start assembly

Since the most effective device is a triac device, let’s talk about how to make a similar stabilizer with your own hands.

It is important to emphasize that this type of model will be able to equalize the supplied current under the condition that the voltage is in the range of 130-270 V. Components will also be required. The tools you need are tweezers and a soldering iron.

Stages of production

According to the detailed instructions on how to mount the stabilizer, first of all, you should prepare a printed circuit board of the required size. It is created from special foil-coated fiberglass. The microcircuit for the arrangement of elements can be in a printed format, or transferred to the board using an iron.

Then, the scheme for creating a simple stabilizer provides for the direct assembly of the device. For this element you will need a magnetic circuit and several cables. One wire with a diameter of 0.064 mm is used to make the winding. The number of required turns reaches 8669.

The remaining two wires are used to create the remaining windings, which, in comparison with the first option, have a diameter of 0.185 mm. The number of turns arranged for these windings is at least 522.

If it is necessary to simplify the task, it is preferable to use series-connected transformers of the TPK-2-2 12V brand.

When producing these parts independently, after completing the creation of one of them, they proceed to the production of another. For these purposes, a troidal magnetic circuit will be required. PEV-2 with a number of turns of 455 is also suitable as a winding.

In addition, by step-by-step manual production of the stabilizer in the second device, 7 bends should be made. In this case, for several three, a wire of 3 mm in diameter is used, for others, buses with a cross-section of 18 mm2 are used. This will make it possible to eliminate unwanted heating of the device during the working process.

The remaining items should be purchased at a specialized retail outlet. Once everything you need has been purchased, you should assemble the device.

Work should begin with the installation of the necessary microcircuit, which acts as a controller on the heat sink made from platinum. In addition, triacs are installed on it. Then flashing LEDs are mounted on the board.

If creating triac devices is a difficult task for you, then it is recommended to choose a linear version, characterized by similar properties.

Photos of do-it-yourself stabilizers