Mains voltage, especially in rural areas, often goes beyond the limits allowed for powered equipment, which leads to its failure.

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

The proposed device belongs to very promising designs, in which the load is automatically connected to the corresponding tap of the autotransformer winding, depending on the current value of the mains 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 the instability of the voltage in the network in the suburbs, the 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 acquiring a stabilizer. Acquaintance with the prices for finished products plunged into shock. I began to look for schemes in the literature and the Internet.

An almost suitable microcontroller-controlled stabilizer 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 mains voltage. Therefore, it was decided to create our own stabilizer design that does not have these shortcomings.

The proposed stabilizer does not use a microcontroller, which makes it available for repetition to a wider range of radio amateurs. Insensitivity to the frequency of the mains voltage allows it to be used in the field, 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 (shutdown) time, ms: 10

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

The stabilizer works as follows. After the power is turned on, the capacitor C1 is discharged, the 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 on, all triacs are closed, the load is off. The voltage across the capacitor C1 increases as it is charged from the power supply through the resistor R1. At the end of the three-second delay interval required to complete the transients, the Schmidt trigger on transistors VT1 and VT2 is activated, the transistor VT3 opens and allows the load to be turned on.

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

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

If the mains 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, opto-simistor U1.2 is open, the load is connected to the upper output of the winding of the autotransformer T2 through the open triac VS1.

If the mains 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 output of the autotransformer winding T2 from the top through an open triac VS2.

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

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

If the mains voltage is greater than 270 V, the outputs of all comparators and the output H of the controller are logic high. The rest of the controller outputs are low. Transistor VT12 is open, flashing LED HL9 is on, indicating excessive high voltage network, in which the stabilizer cannot provide power to the load. All other LEDs are off, triacs are closed, the load is off.

The stabilizer withstands indefinitely an emergency increase in mains voltage up to 380 V. The inscriptions indicated by the LEDs are similar to those described in.

Option with one power transformer

Construction and details

The stabilizer is assembled on a printed circuit board 90x115 mm from one-sided foil fiberglass.

The HL1-HL9 LEDs are mounted so that when the printed circuit board is installed in the case, they fall into the corresponding holes on the front panel of the device.

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

Foreign diode bridge DF005M(VD1, VD2) can be replaced by domestic KTS407A or any with a voltage of at least 50V and a current of at least 0.4A. The VD3 zener diode 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 by a domestic analogue K1401CA1. microchip 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 wirewound multi-turn 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 dissipation power not lower than that indicated in the diagram. Oxide capacitors C1-C3, C5 can be any, with a capacity indicated on the diagram, and a voltage not lower than those indicated for them. The remaining capacitors C4, C6-C8 - any film or ceramic.

Imported triac optocouplers MOC3041(U1-U7) are chosen because they contain built-in voltage zero crossing controllers. This is necessary to synchronize turning off one powerful triac and turning on another in order to prevent the autotransformer windings from shorting.

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

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

Transformer T1 is self-made, designed for an overall power of 3 W, having a cross-sectional area of ​​\u200b\u200bthe magnetic circuit 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 contain 522 turns of PEV-2 wire with a diameter of 0.185 mm.

Option with two power transformers

At a nominal mains voltage of 220 V, the voltage of each output winding should be 12 V. Instead of a self-made transformer T1, two transformers can be used 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) was performed using the program Sprint Layout 4.0, which allows you to print a picture in a mirror image and is very convenient for the manufacture of printed circuit boards using laser printer and iron. It can be downloaded here.

Power transformer

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

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

The taps are made from the 203rd, 232nd, 266th, 305th, 348th and 398th turns, counting from the bottom according to the output scheme. The mains voltage is applied to the tap of the 266th turn.

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

The number of turns of the winding should be proportionally increased by 1.3 times. The operating current of the QF1 fuse switch must be reduced to 20 A. It is advisable to put an additional 10A automatic machine before the load

In the manufacture of 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 the taps of an autotransformer according to their overall dimensions of the stator with a known value of the magnetic permeability Vmax of the core.

If the load power does not exceed 3 kW, then the T2 autotransformer 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 operating current of the QF1 fuse switch 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.

Setting

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

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

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

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

Calculate the step of voltage change:

∆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 \u003d U1 / I \u003d 1.6 / 0.1583 \u003d 10.107 kOhm,
R23 \u003d (Upit - U6 - ∆U) / I \u003d (6-3.5-0.3166) / 0.1588 \u003d 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, however, its accuracy is sufficient for practical adjustment of the stabilizer.

Program for calculating R8, R16 and boundary stresses switches can be downloaded in attachments.

Next, the device is disconnected from the network and, using a digital voltmeter, set the resistances of resistors R15 and R23 equal to the calculated values ​​and mount them 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-a from the minimum to the maximum and vice versa. The simultaneous glow 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 on the board not the microcircuits themselves, but the panels for them.

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

If the maximum voltage LATR-a less than 270 V, set its output to 250 V, calculate the voltage U7 according to the formula: U7 \u003d U6 + ∆U \u003d 3.82 V. Move the R14 engine up, check that the load is disconnected at voltage U7, and then return the engine R14 down, setting U6 to its previous value of 3.5 V.

It is desirable to complete the adjustment 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 capacities (about six months), there were no failures and failures in their operation. There were no malfunctions of the equipment fed through them due to unstable mains voltage.

Literature

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

Autotransformer calculation

You managed to get the stator out of the engine, but you don't know what material it is made of. In general, when calculating cores with a power higher than 1 kW, problems often arise with the initial data. You can easily avoid problems if you do research on your existing core. It is very easy to do this.

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

N / V \u003d 50 / ((140-140 * 0.25) \u003d 0.48 turns per volt.

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

Tap #1 - 128.5V x 0.48V = 62 Vit
Tap #2 - 147 V x 0.48 V = 71 Vit
Tap #3 - 168 V x 0.48 V = 81 Vit
Tap #4 - 192 V x 0.48 V = 92 Vit
Tap #5 - 220V x 0.48V = 106 Vit(voltage is removed from it to the load)
Tap #6 - 251.5 V x 0.48 V = 121 Vit
Tap #7 - 287.5 V x 0.48 V = 138 Vit(total number of turns of the autotransformer)

That's the whole problem!

Modernization

Liked this.

Often, for safe use, for example, a TV, usually in rural areas, you need a single-phase voltage stabilizer 220V, which, with a strong decrease in voltage in the mains, produces a nominal output voltage of 220 volts at its output.

In addition, when operating most types of consumer electronics, it is desirable to use a voltage regulator that does not create changes in the output voltage sine wave. Schemes of similar stabilizers for 220 volts are given in many electronics magazines.

In this article we will give an example of one of the options for such a device. The stabilizer circuit, depending on the actual voltage in the network, has 4 ranges automatic installation output voltage. This contributed to a significant expansion of the stabilization boundaries of 160 ... 250 volts. And with all this, the output voltage is provided within the normal range (220V +/- 5%).

Description of the operation of a single-phase voltage stabilizer 220 volts

AT wiring diagram devices include 3 threshold blocks, made according to the principle, consisting of a zener diode and resistors (R2-VD1-R1, VD5-R3-R6, R5-VD6-R6). Also in the circuit there are 2 transistor switches VT1 and VT2, which control the electromagnetic relays K1 and K2.

Diodes VD2 and VD3 and filter capacitor C2 form a constant voltage source for the entire circuit. Capacitors C1 and C3 are designed to dampen minor voltage surges in the network. Capacitor C4 and resistance R4 are “spark arresting” elements. To prevent self-induction voltage surges, two diodes VD4 and VD7 are added to the circuit in the relay windings when they are turned off.

With the perfect operation of the transformer and threshold blocks, each of the 4 control ranges would create a voltage range from 198 to 231 volts, and the probable mains voltage could be in the region from 140 ... 260 volts.

However, in reality, it is necessary to take into account the spread of parameters of radio components and the instability of the transformation ratio of the transformer under different loads. In this regard, for all 3 threshold blocks, the output voltage range is reduced in relation to the output voltage: 215 ± 10 volts. Accordingly, the oscillation interval at the input narrowed to 160 ... 250 volts.

Stages of the stabilizer:

1. When the voltage in the mains is less than 185 volts, the voltage at the rectifier output is low enough for one of the threshold blocks to work. At this moment, the contact groups of both relays are located, as indicated on circuit diagram. The voltage at the load is equal to the mains voltage plus the boost voltage taken from the windings II and III of the transformer T1.

2. If the voltage in the network is in the range of 185 ... 205 volts, then the VD5 zener diode is in the open state. The current flows through the relay K1, the zener diode VD5 and the resistances R3 and R6. This current is not enough for relay K1 to work. Due to the voltage drop across R6, the transistor VT2 opens. This transistor, in turn, turns on the relay K2 and the contact group K2.1 switches the winding II (voltage boost)

3. If the voltage in the network is in the range of 205 ... 225 volts, then the zener diode VD1 is already in the open state. This leads to the opening of the transistor VT1, because of this, the second threshold block is turned off and, accordingly, the transistor VT2. Relay K2 turns off. At the same time, the relay K1 is turned on by the contact group K1.1. switches to another position, in which the windings II and III are not involved and therefore the output voltage will be the same as at the input.

4. If the voltage in the network is in the range of 225 ... 245 volts, the Zener diode VD6 opens. This contributes to the activation of the third threshold block, which leads to the opening of both transistor switches. Both relays are on. Now winding III of transformer T1 is already connected to the load, but in antiphase with the mains voltage (“negative” voltage boost). The output in this case will also have a voltage in the region of 205 ... 225 volts.

When setting the control range, you need to carefully select the zener diodes, since, as you know, they can differ significantly in the spread of the stabilization voltage.

Instead of KS218Zh (VD5), it is possible to use KS220Zh zener diodes. This zener diode must certainly be with two anodes, since in the mains voltage range of 225 ... 245 volts, when the zener diode VD6 opens, both transistors open, the circuit R3 - VD5 shunts the resistance R6 of the threshold block R5-VD6-R6. To eliminate the shunting effect, the VD5 zener diode must be with two anodes.

Zener diode VD5 for a voltage of not more than 20V. Zener diode VD1 - KS220Zh (22 V); it is possible to assemble a chain of two zener diodes - D811 and D810. Zener diode KS222Zh (VD6) for 24 volts. It can be changed to a chain of zener diodes D813 and D810. Transistors from the series. Relays K1 and K2 - REN34, passport HP4.500.000-01.

The transformer is assembled on an OL50/80-25 magnetic circuit made of steel E360 (or E350). Tape thickness - 0.08 mm. Winding I - 2400 turns wound with wire PETV-2 0.355 (for rated voltage 220V) . Windings II and III are equal, each containing 300 turns of wire PETV-2 0.9 (13.9 V).

It is necessary to adjust the stabilizer with the connected load in order to take into account the load on the transformer T1.

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

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

You can buy a current equalizing device by 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 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 self-repair. If one of the elements of the purchased stabilizer is out of order, you are unlikely to be able to replace it, even if you understand electrical engineering. You simply will not find how to replace a worn part. FROM homemade device everything is simpler: you initially bought all the elements in the store. It remains only 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 action will help you quickly identify the cause of the failure of the stabilizer. Having figured it out, you can easily fix a home-made unit.

The stabilizer of its own production 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 2-5 times larger range, which can be critical for technology that is super sensitive to current changes;
3. Complex setup. If you buy a stabilizer, then the setup step is bypassed, you just have to connect the device and control its operation. If you are the creator of the current equalizer, then you can also configure it. This is difficult, even if you have made the simplest voltage regulator with your own hands.

Homemade current equalizer: characteristics

The stabilizer is characterized by two parameters:

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

This article focuses on the triac current converter because it has high efficiency. For him, Uin is 130-270V, and Uout is 205-230V. If a large input voltage range is an advantage, then for an output voltage it is a disadvantage.

However, for household appliances this range remains valid. This is easy to check, because the allowable voltage fluctuations are jumps and dips of no more than 10%. And this is 22.2 Volts up or down. This means that a change in voltage from 197.8 to 242.2 Volts is acceptable. 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 not more than 6 kW. Its switching is carried out in 0.01 seconds.

The design of the current stabilizing device

A home-made voltage stabilizer 220V, the circuit of which is presented above, includes the following elements:

• Power Supply. It used drives C2 and C5, a voltage transformer T1, as well as a comparator (comparison device) DA1 and LED VD1;
• node, postponing the start of the load. To assemble it, you will need resistances from R1 to R5, transistors from VT1 to VT3, as well as drive C1;
• Rectifier, measuring the value of voltage jumps 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 need resistances from R15 to R39 and comparing devices DA2 with DA3;
• Boolean controller. It needs DD chips from 1 to 5;
• Amplifiers. They will need resistance 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 keys(7) with triacs VS 1 to 7, resistors R 6 to 12, and optocoupler triacs U 1 to 7;
• auto switch with fuse QF1;
• Autotransformer T2.

How will this device work?

After the drive of the node with deferred 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 go 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 drive, which begins to store energy.

The process described above takes 3 seconds, after which the Schmitt trigger, based on transistors VT 1 and 2, fires, after which transistor 3 turns 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 sent to R13, passes through R14. On the this moment voltage is proportional to the voltage in the network. Then the current is supplied to the non-inverting comparators. Immediately, an already equalized current enters the inverting comparing devices, which is applied to resistances from 15 to 23. Then a controller is connected that processes the input signals on the devices for comparison.

The nuances of stabilization depending on the voltage applied to the input

If a voltage of up to 130 Volts is entered, then the logic level (LU) of low voltage is indicated on the terminals of the comparators. 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 give out the voltage of the desired value. Therefore, all triacs are closed, and there is no load.

If the input voltage 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 output of the winding of the second autotransformer from above.

With an input voltage of 150-170 Volts, a high LU is observed on 1, 2 and V signals, 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 you count from above) output of the winding of the second autotransformer.

Similarly, the operation of the stabilizer is described for voltage ranges of 170-190V, 190-210V, 210-230V, 230-250V.

PCB manufacturing

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

The board can be printed on a laser-type printer, after which the iron will be used. It is convenient to make a board yourself using the Sprint Loyout program. And the layout of the 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 circuit with a cross-sectional area (CPS) of 187 sq. mm. And three wires PEV-2:

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

If there is no desire to wind the wire, then you can purchase two transformers TPK-2-2 × 12V 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 circuit and a PEV-2 wire, from which a twist of 455 turns will be made. And here we need taps (7 pieces):

• Winding 1-3 branches from a wire with PPS 7 sq. mm;
• Winding 4-7 branches from wire with PPS 254 sq. mm.

What to buy?

In an electrical and radio engineering store, buy (in brackets the designation on the diagram):

• 7 optocoupler triacs MOC3041 or 3061 (U from 1 to 7);
• 7 simple triacs BTA41-800B (VS 1 to 7);
• 2 LEDs DF005M or KTS407A (VD 1 and 2);
• 3 resistors SP5-2, maybe 5-3 (R 13, 14, 25);
• Equalizing current element KR1158EN6A or B (DA1);
• 2 comparison devices LM339N or K1401CA1 (DA 1 and 2);
• Safety switch;
• 4 film or ceramic capacitors (C 4, 6, 7, 8);
• 4 oxide capacitors (C 1, 2, 3, 5);
• 7 resistances to limit the current, on their terminals it must 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).

Features of the assembly of the device for equalizing voltage

The microcircuit of the current-stabilizing device is mounted 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 manufactured by us to work, you need a microcontroller. The KR1554LP5 chip does an excellent job with its role.

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

Non-flashing LEDs may be used instead of flashing LEDs. But in this case, you need to take diodes with a bright red glow. Suitable elements of brands: AL307KM and L1543SRC-E.

Now you know how to make a voltage regulator for 220 volts. 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.

Compilation amateur radio circuits and designs of voltage stabilizers assembled by hand. Some circuits consider a stabilizer without protection against short circuit in the load, others have the possibility of smooth voltage regulation from 0 to 20 Volts. Well, a distinctive feature of individual circuits is the ability to protect against short circuits in the load.

5 very simple circuits mainly assembled on transistors, one of them, with short circuit protection

It often happens when, to feed your newborn electronic homemade a stable voltage is required that does not change with the load, for example, 5 volts or 12 volts to power the car radio. And in order not to bother much with the design homemade block power supply on transistors, so-called voltage stabilizer microcircuits are used. At the output of such an element, we will get the voltage for which this device is designed

Many radio amateurs have repeatedly assembled voltage stabilizer circuits on specialized microcircuits of the 78xx, 78Mxx, 78Lxx series. For example, on a KIA7805 chip, you can assemble homemade scheme designed for an output voltage of +5 V and a maximum load current of 1 A. But few people know that there are highly specialized microcircuits of the 78Rxx series, which combine voltage regulators of positive polarity with a low saturation voltage that does not exceed 0.5 V at load current 1 A. We will consider one of these schemes in more detail.

The LM317 adjustable 3-terminal positive voltage regulator provides a load current of 100mA over an output voltage range of 1.2V to 37V. The regulator is very easy to use and requires only two external resistors to provide the output voltage. In addition, the voltage and current instability of the LM317L stabilizer has better performance than traditional stabilizers with a fixed output voltage value.

For voltage stabilization direct current of sufficiently high power, among others, continuous compensation stabilizers are used. The principle of operation of such a stabilizer is to maintain the output voltage at a given level by changing the voltage drop across the regulating element. In this case, the magnitude of the control signal supplied to the regulating element depends on the difference between the given and output voltages of the stabilizer.

During stationary operation of equipment, CDs and audio players, problems arise with the power supply unit. Most mass-produced power supplies domestic manufacturer, (to be precise) almost all cannot satisfy the consumer, as they contain simplified circuits. If we talk about imported Chinese and similar power supplies, then they generally represent an interesting set of "buy and throw" parts. These and many other problems force amateur radio to manufacture power supplies. But even at this stage, amateurs are faced with the problem of choice: many designs have been published, but not all work well. This amateur radio development is presented as a variant of the non-traditional inclusion of an operational amplifier, previously published and soon forgotten

Almost all amateur radio homemade and designs incorporate a stabilized power supply. And if your design operates on a voltage of five volts, then the best option would be to use a three-terminal integral stabilizer 78L05

Voltage stabilizer for 220 volts

The stabilizer is a network autotransformer, the winding taps of which are switched automatically depending on the voltage in the mains.

The stabilizer allows you to maintain the output voltage at the level of 220V when the input voltage changes from 180 to 270 V. The stabilization accuracy is 10V.

The circuit diagram can be divided into low current circuit (or control circuit) and high current circuit (or autotransformer circuit).

The control circuit is shown in Figure 1. The role of the voltage meter is assigned to a polycomparator microcircuit with a linear voltage indication, - A1 (LM3914).

Mains voltage is supplied to primary winding low-power transformer T1. This transformer has two secondary windings, 12V each, with one common terminal (or one 24V winding with a tap from the middle).

The rectifier on the diode VD1 is used to obtain the supply voltage. The voltage from the capacitor C1 is supplied to the power supply circuit of the A1 chip and the LEDs of the H1.1-H9.1 optocouplers. And also, it serves to obtain exemplary stable voltages of the minimum and maximum scale marks. To obtain them, a parametric stabilizer on US and P1 is used. The measurement limits are set by trimmer resistors R2 and R3 (resistor R2 - upper value, resistor RЗ -lower).

The measured voltage is taken from the other secondary winding of the transformer T1. It is rectified by the VD2 diode and fed to the resistor R5. It is by the level of constant voltage across the resistor R5 that the degree of deviation of the mains voltage from the nominal value is assessed. During the adjustment process, the resistor R5 is preliminarily set to the middle position, and the resistor R3 to the lower position according to the scheme.

Then, an increased voltage (about 270V) is applied to the primary winding T1 from an autotransformer of the LATR type and resistor R2 sets the microcircuit scale to the value at which the LED connected to pin 11 lights up (temporarily instead of optocoupler LEDs you can connect ordinary light diodes). Then the input alternating voltage is reduced to 190V and the scale is brought to the value by the resistor R3 when the LED connected to pin 18 A1 is on.

If the above settings fail, you need to adjust a little R5 and repeat them again. So, by successive approximations, a result is achieved when a change in the input voltage by 10V corresponds to switching the outputs of the A1 chip.

In total, nine threshold values ​​are obtained - 270V, 260V, 250V, 240V, 230V, 220V, 210V, 200V, 190V.

The schematic diagram of the autotransformer is shown in Figure 2. It is based on a converted transformer of the LATR type. The transformer housing is disassembled and the slider contact, which serves to switch taps, is removed. Then, based on the results of preliminary measurements of the voltages from the taps, conclusions are drawn (from 180 to 260V in 10V steps), which are subsequently switched using triac switches VS1-VS9, controlled by the control system via optocouplers H1-H9. The optocouplers are connected in such a way that when the reading of the A1 microcircuit decreases by one division (by 10V), it switches to a step-up (by the next 10V) tap of the autotransformer. And vice versa - an increase in the readings of the A1 microcircuit leads to switching to a step-down tap of the autotransformer. By selecting the resistance of the resistor R4 (Fig. 1), the current through the LEDs of the optocouplers is set, at which the triac switches switch confidently. The circuit on transistors VT1 and VT2 (Fig. 1) serves to delay the switching on of the autotransformer load for the time required to complete the transients in the circuit after switching on. This circuit delays the connection of the optocoupler LEDs to power.

Instead of the LM3914 chip, you cannot use similar LM3915 or LM3916 chips, due to the fact that they work according to the logarithmic law, but here you need a linear one, like the LM3914. Transformer T1 - small Chinese transformer type TLG, for primary voltage 220V and two secondary 12V each (12-0-12V) and current 300mA. You can use another similar transformer.

The T2 transformer can be made from LATR, as described above, or you can wind it yourself.