Many people know what power outages and surges are. It's one thing when the bulbs just blink from this and can burn out. And another thing is when a washing machine or refrigerator burns out from voltage surges. This will significantly hit the family budget. Imported household appliances are not designed for such voltage surges that often occur in domestic networks. To protect yourself from the risk of malfunctions in home household devices, you need to get a voltage stabilizer, which is selected according to the total power of the devices that will work in your home network.

Varieties

Voltage stabilizers are devices that equalize the supply voltage to those parameters that correspond to standard values, and also clean the voltage from high-frequency interference. The type of stabilizer determines the type of main built-in mechanism that acts as a stabilizer.

Voltage stabilizers are divided into two main types:

1. Accumulating.
2. Corrective.

The first type of stabilizers is not currently used, since they are large. Previously, they were used in production, and not in a domestic environment. Cumulative voltage stabilizers function by accumulating electrical energy in a container, and then receive from this container the required electric current with the required parameters. Uninterruptible power supplies work on a similar principle.

Corrective stabilizers voltages most often include a control unit. It reacts to voltage drops in one direction or the other, and at the same time connects the corresponding transformer winding. Corrective stabilizers are widely used in domestic conditions.

They, in turn, are divided into several types:

• Relay.
• Electronic (thyristor).
• Ferroresonant.
• Electromechanical.
• Inverter.
• Linear.

Design features and work

The corrective type of stabilizers has become the most popular in everyday life.

Relay voltage stabilizers

They became the most popular due to their low cost and quality of work. The main advantage of relay stabilizers is their speed. They very quickly respond to voltage changes, and return its value to standard limits, thereby protecting household devices.

Of the shortcomings, it can be noted that when the relay is triggered, a sharp voltage jump of 5-15 volts occurs, depending on the manufacturer. For household appliances, such a leap will not have a negative effect, however, the lighting will flicker noticeably. Therefore, when the relay stabilizer is operating, blinking is sometimes observed, while they do not react to it.

As in other types of stabilizer, the main element of the relay model is the control unit based on semiconductor elements. The electronic block of the stabilizer is made in the form of a powerful microcontroller that analyzes the voltage at the input and output. As a result, it generates control signals for power relays or switches. The microcontroller, when creating a control voltage, takes into account the response time of the power relays and switches. This makes it possible to carry out switching circuits without breaking them. As a result, the shape of the output voltage graph becomes identical to the input voltage shape.

Electronic voltage stabilizers

Thyristor stabilizers work according to the principle, which is based on automatic switching of different transformer windings with power switches in the form. This principle is similar to the operation of relay devices. The difference between relay stabilizers is that they do not have mechanical contacts, there is a greater number of voltage equalization steps and a high operating accuracy of 2-5%.

Electronic appliances do not generate noise in the home as there are no mechanical relays. They are replaced by electronic keys. Thyristor stabilizers work with high efficiency.

In practical application, electronic models have shown themselves to be sensitive devices that are negatively affected by overheating. Domestic manufacturers most often produce just this type of stabilizers.

The most serious disadvantage of thyristor models is their high cost. The warranty period for almost all types of stabilizers is within 1-3 years, depending on the manufacturer.

Ferroresonant

Their action is based on a change in the value of the inductance of coils with a metal core, when the current changes. Capacitance C1 is connected in series with the primary winding of the transformer. Together with the primary winding, it forms a resonant circuit, which is tuned to a network frequency of 50 hertz.

The size of the capacitor depends on the power of the transformer. With a transformer power of up to 60 watts, a capacitor is used with a value of up to 12 μF. A saturation choke is used to create significant stabilizer power.

With a low mains voltage, a small current flows through the choke, and the inductance of the choke is large. The main part of the current flows through the parallel connected capacitor. Moreover, the total resistance of this circuit is of the capacitive type.

The capacitor compensates for some of the inductive reactance of the transformer coil. This increases the coil current. The output voltage of the transformer also increases. This is characteristic of the voltage resonance effect.

As the voltage rises, the inductor current also rises, and its inductance drops. The value of the capacitance is calculated so that a resonance occurs in the inductor-capacitor circuit, at which the resistance of this circuit would be the greatest, and the current coming from the power supply to the transformer would be the smallest.

With an increase in the mains voltage, the resistance of the circuit increases until the moment of resonance. This makes it possible to stabilize the voltage across the transformer with large voltage drops.

The advantages of ferroresonant devices are reliability and simplicity. The disadvantage is the significant dependence of the voltage at the output of the device on the frequency of the current and the distortion of the voltage waveform. Also, stabilizers with saturated coil cores have high magnetic dissipation. This negatively affects the functioning of the surrounding devices and the person.

Electromechanical voltage stabilizers

The principle of operation of such a device is quite simple. When the voltage drops, graphite brushes move along the coil of the transformer, thereby regulating and adjusting the output voltage.

In the first examples of electromechanical stabilizers, the manual method (switch) was used to move the brushes. The user had to constantly monitor the voltage indicator readings.

In new models of devices, this function is performed automatically by a small motor, which, in case of voltage drops, moves the brush along the transformer winding.

The advantages of such stabilizers are simplicity and reliability of the device, increased efficiency. Among the shortcomings, one can note the low speed of response during voltage drops, as well as the rapid wear of mechanical parts. Therefore, the electromechanical form of the stabilizer requires constant maintenance in the form of control and replacement of brushes.

Inverter voltage stabilizers

They convert direct current into alternating current, and also perform the opposite action, that is, convert alternating current into direct current using a microcontroller and a crystal oscillator.

Among the advantages of inverter stabilizers, one can single out low noise during the operation of the device, compact size and a wide range of input operating voltages, which ranges from 115-290 volts.

The disadvantage of inverter designs is their high cost, unlike many other types of stabilizers.

Linear

Made in the form of a voltage divider. An unstable voltage is applied to the input of such a device, and the equalized voltage comes out from the lower arm of the divider. Alignment is performed by changing the resistance of the voltage divider arm. In this case, the resistance value is maintained such a value at which the output voltage of the device was within certain limits.

With a significant ratio of the values ​​of the output and input voltages, the linear stabilizer has a reduced efficiency, since a significant part of the power is dissipated into heat at the tuning element. Therefore, the voltage regulator is usually mounted on a heat sink to allow heat dissipation.

The advantage of a linear device is the absence of interference, simplicity of design and a small number of parts. The disadvantage is low efficiency, high heat generation.

What to look for when choosing a stabilizer

• Mounting method ... It can be wall-mounted, with horizontal or vertical installation (for stationary appliances). It can be installed next to the device for which it was purchased.
• Accuracy of work,input and output voltage... This characteristic depends mainly on the parameters of the input voltage. It is better to choose the lowest accuracy rate of the device from 1 to 3%, at a voltage of 220 volts.
• Stabilizer power is selected not only by the power of the connected electrical device. A certain power reserve is added to this value. For the entire apartment, this margin should be within 30%.
• Power supply phases (single-phase or three-phase network).

• Performance (response time to voltage drops), in milliseconds.

• Stabilizer protection ... Expensive devices are most often equipped with protective systems that protect the stabilizer from short circuits, sudden voltage changes and other negative phenomena.
• dimensions the device and its noise during operation.
• Price... Professionals do not recommend buying cheap Chinese fakes, since you should not skimp on the quality of the stabilizer. A quality device doesn't have to be cheap. It is better to purchase a domestic model, or a European-made device.
• Guarantee period plays a big role when choosing any device. If the device is Chinese, then it is unlikely that there will be any guarantee for it. Stabilizers purchased from specialized retail outlets can be exchanged free of charge during the warranty period in the event of a malfunction or defect.

The greatest difficulty is usually caused when choosing a device, its power. In addition to the active component of power, which is consumed by household devices, some of them have. It appears if available (if the device has a powerful electric motor). When it is started, the current increases several times. If you choose a stabilizer without taking into account this reactive power component, then it may not cope with a high load when starting a device with an electric motor.

Another factor that greatly influences the choice of a regulator is the transformation ratio, which is zero if the regulator is operating under ideal conditions. That is, exactly 220 volts are supplied to the input, and exactly the same value comes out to the consumer. And if the regulator has to equalize the voltage, then the power decreases.

Voltage regulator

Voltage regulator- a converter of electrical energy, allowing to obtain the output voltage, which is within the specified limits with significantly large fluctuations in the input voltage and load resistance.

By the type of output voltage, stabilizers are divided into DC and AC stabilizers. Typically, the type of power supply (DC or AC) is the same as the output voltage, although exceptions are possible.

DC stabilizers

Linear stabilizer microcircuit KR1170EN8

Linear stabilizer

The linear stabilizer is a voltage divider, the input of which is supplied with an input (unstable) voltage, and the output (stabilized) voltage is removed from the lower arm of the divider. Stabilization is carried out by changing the resistance of one of the divider arms: the resistance is constantly maintained so that the voltage at the output of the stabilizer is within the specified limits. With a large ratio of input / output voltages, the linear stabilizer has a low efficiency, since most of the power P rac = (U in - U out) * I t is dissipated in the form of heat on the regulating element. Therefore, the regulating element must be able to dissipate sufficient power, that is, it must be installed on a radiator of the required area. The advantage of a linear regulator is simplicity, no interference and few parts used.

Depending on the location of the element with variable resistance, linear stabilizers are divided into two types:

• Consistent: the control element is connected in series with the load.
• Parallel: the control element is connected in parallel with the load.

Depending on the stabilization method:

• Parametric: in such a stabilizer, a section of the I - V characteristic of the device is used, which has a large steepness.
• Compensatory: has feedback. In it, the voltage at the output of the stabilizer is compared with the reference one, and a control signal for the regulating element is formed from the difference between them.

Parallel parametric stabilizer on a zener diode

It is used to stabilize the voltage in low-current circuits, since for the normal operation of the circuit, the current through the Zener diode D1 must several times (3-10) exceed the current in the stabilized load R L. Often this linear regulator circuit is used as a voltage reference in more complex regulator circuits. To reduce the instability of the output voltage caused by changes in the input voltage, a resistor R V is used instead of. However, this measure does not reduce the output voltage instability caused by the change in load resistance.

Series Bipolar Transistor Regulator

U out = U z - U be.

In fact, this is a parallel parametric stabilizer on a zener diode discussed above, connected to the input of the emitter follower. It has no feedback circuits to compensate for changes in output voltage.

Its output voltage is less than the stabilization voltage of the zener diode by the value U be, which is practically independent of the amount of current flowing through the p-n junction, and for devices based on silicon is approximately 0.6V. The dependence of U be on the magnitude of the current and temperature worsens the stability of the output voltage, in comparison with a parallel parametric stabilizer based on a zener diode.

The emitter follower (current amplifier) ​​allows you to increase the maximum output current of the stabilizer, in comparison with a parallel parametric stabilizer on a zener diode, by a factor of β (where β is the current gain of this transistor instance). If this is not enough, a composite transistor is used.

In the absence of load resistance (or at load currents of the microampere range), the output voltage of such a stabilizer (open circuit voltage) increases by 0.6V due to the fact that U be in the microcurrent range becomes close to zero. To overcome this feature, a ballast load resistor is connected to the output of the stabilizer, which provides a load current of several mA.

Series compensation stabilizer using an operational amplifier

The part of the output voltage U out taken from the potentiometer R2 is compared with the reference voltage U z at the zener diode D1. The voltage difference is amplified by the operational amplifier U1 and fed to the base of the regulating transistor connected according to the emitter follower circuit. For stable operation of the circuit, the loop phase shift should be close to 180 ° + n * 360 °. Since part of the output voltage U out is fed to the inverting input of the operational amplifier U1, the operational amplifier U1 shifts the phase by 180 °, the regulating transistor is switched on according to the emitter follower circuit, which does not shift the phase. The loop phase shift is 180 °, the phase stability condition is met.

The reference voltage Uz is practically independent of the magnitude of the current flowing through the zener diode, and is equal to the stabilization voltage of the zener diode. To increase its stability with changes in Uin, it is used instead of the resistor R V.

In this stabilizer, the operational amplifier is actually connected in a non-inverting amplifier circuit (with an emitter follower to increase the output current). The ratio of the resistors in the feedback loop sets its gain, which determines how many times the output voltage will be higher than the input voltage (i.e., the reference voltage applied to the non-inverting input of the op-amp). Since the gain of a non-inverting amplifier is always greater than unity, the value of the reference voltage (stabilization voltage of the zener diode) must be selected less than the required minimum output voltage.

The instability of the output voltage of such a stabilizer is almost completely determined by the instability of the reference voltage, due to the large loop gain of modern op amps ( G openloop = 10 5 ÷ 10 6).

To exclude the influence of the instability of the input voltage on the operating mode of the op-amp itself, it can be powered by a stabilized voltage (from additional parametric stabilizers on a zener diode).

Pulse stabilizer

In a switching regulator, the current from an unstabilized external source is supplied to a storage device (usually a capacitor or choke) in short pulses; in this case, energy is stored, which is then released into the load in the form of electrical energy, but, in the case of a choke, already with a different voltage. Stabilization is carried out by controlling the duration of pulses and pauses between them - pulse-width modulation. A switching regulator, in comparison with a linear one, has a significantly higher efficiency. The disadvantage of a switching regulator is the presence of impulse noise in the output voltage.

Unlike a linear regulator, a switching regulator can convert the input voltage in an arbitrary way (depending on the regulator circuit):

• Downward below
• Raising stabilizer: output stabilized voltage always above input and has the same polarity.
• Buck-Buck stabilizer: the output voltage is stabilized, can be as above and below input and has the same polarity. Such a stabilizer is used in cases where the input voltage is slightly different from the required one and can vary, taking a value both higher and lower than the required one.
• Inverting stabilizer: the output stabilized voltage has reverse polarity relative to the input, the absolute value of the output voltage can be any.

AC voltage stabilizers

Ferroresonant stabilizers

During the Soviet era, household ferroresonant voltage stabilizers became widespread. Usually, TVs were connected through them. In TVs of the first generations, network power supplies with linear voltage stabilizers were used (and in some circuits they were completely powered by unregulated voltage), which did not always cope with voltage fluctuations in the network, especially in rural areas, which required preliminary voltage stabilization. With the advent of 4UPITST and USTsT TVs, which had switching power supplies, the need for additional stabilization of the mains voltage has disappeared.

The ferroresonant stabilizer consists of two chokes: with an unsaturated core (having a magnetic gap) and a saturated one, as well as a capacitor. The peculiarity of the I - V characteristic of a saturated inductor is that the voltage across it changes little when the current through it changes. By selecting the parameters of the chokes and capacitors, it is possible to ensure voltage stabilization when the input voltage changes within a fairly wide range, but a slight deviation in the frequency of the supply network greatly influenced the characteristics of the stabilizer.

Modern stabilizers

Currently, the main types of stabilizers are:

• electrodynamic servo (mechanical)
• static (electronic switchable)
• relay
• compensation (electronic smooth)

The models are produced in both single-phase (220/230 V) and three-phase (380/400 V) versions, their power ranges from several hundred watts to several megawatts. Three-phase models are produced in two modifications: with independent adjustment for each phase or with adjustment for the average-phase voltage at the input of the stabilizer.

The produced models also differ in the allowable input voltage range, which can be, for example, the following: ± 15%, ± 20%, ± 25%, ± 30%, -25% / + 15%, -35% / + 15% or -45% / + 15%. The wider the range (especially in the negative direction), the larger the dimensions of the stabilizer and the higher its cost at the same output power.

An important characteristic of a voltage regulator is its speed, that is, the higher the speed, the faster the regulator will react to changes in the input voltage. Speed ​​is a period of time (milliseconds) during which the regulator is able to change the voltage by one volt. Different types of stabilizers have different speed of response, for example, for electrodynamic ones, the speed is 12 ... 18 ms / V, static stabilizers will provide 2 ms / V, but for electronic, compensation type, this parameter is 0.75 ms / V.

Another important parameter is the accuracy of the output voltage stabilization. According to GOST 13109-97, the maximum permissible deviation of the supply voltage is ± 10% of the nominal. The accuracy of modern voltage regulators ranges from 1% to 8%. An accuracy of 8% is quite enough to ensure the correct operation of the vast majority of household and industrial electrical appliances. More stringent requirements (1%) are usually imposed on the power supply of complex equipment (medical, high-tech, and the like). An important consumer parameter is the ability of the stabilizer to operate at the declared power in the entire input voltage range, but not all stabilizers correspond to this parameter. Some stabilizers can withstand tenfold overloads; when purchasing such a stabilizer, a power reserve is not required.

see also

• Microcircuits of the 78xx series - a series of common linear stabilizers

Literature

• Veresov G.P. Power supply for household electronic equipment. - M .: Radio and communication, 1983 .-- 128 p.
• V.V. Kitaev and others Power supply for communication devices. - M .: Communication, 1975 .-- 328 p. - 24,000 copies
• V.G. Kostikov Parfenov E.M. Shakhnov V.A. Sources of power supply for electronic devices. Circuitry and design: Textbook for universities. - 2. - M .: Hotline - Telecom, 2001. - 344 p. - 3000 copies. - ISBN 5-93517-052-3
• Shtilman V.I. Microelectronic voltage stabilizers. - Kiev: Technika, 1976.

Links

• Stabilizers. Manufacturers. Description. (How to keep your home and appliances from power surges and how to choose the right stabilizer that will help you with this)
• Voltage stabilizer for home (Why do you need a voltage stabilizer for home, how to choose it, types of stabilizers)
• GOST R 52907-2008 "Power sources for radio electronic equipment. Terms and Definitions"

A voltage stabilizer is a device to the input of which voltage is supplied with unstable or unsuitable parameters for the consumer of electricity. At the output of the stabilizer, the voltage already has the necessary (stable) parameters that make it possible to supply electricity to consumers susceptible to voltage changes. How does a voltage regulator work, and what is it for?

DC voltage stabilization is required if the incoming voltage is too low or high for the consumer. When passing through the supporting device, it becomes larger or smaller to the desired value. If necessary, the regulator circuit can be designed so that the output voltage has the opposite polarity to the input voltage.

Linear

A linear regulator is a divider that is supplied with an unstable voltage. It turns out it is already leveled, with stable characteristics. The principle of operation is to constantly change the resistance to maintain a constant voltage at the output.

Advantages:

• Simple design with few details;
• No interference is observed in operation.

Disadvantages:

• With a large difference between the input and output voltages, the linear current converter gives poor efficiency, since most of the generated power is converted into heat and dissipated in the resistance regulator. Therefore, it becomes necessary to install a control device on a radiator of sufficient size.

Parametric with zener diode, parallel

Gas-discharge and semiconductor zener diodes are suitable for the circuit of a current-stabilizing device in which the control element is located parallel to the loaded branch.

A current that is 3 to 10 times the current in R L must pass through the zener diode. Therefore, the mechanism is suitable for voltage equalization only in low current mechanisms. It is usually used as a component of current converters with a more complex filling.

Series with bipolar transistor

The principle of operation of the voltage stabilizer can be seen using the device diagram.

It can be seen that it combines two elements:

1. The already known parallel parametric stabilizer on a zener diode;
2. A bipolar transistor that increases current by a constant rate. It is also called an emitter follower.

The output voltage is determined by the formula: Uout = Uz - Ube. Uz is the voltage supported by the zener diode. It is almost independent of the current flowing through the zener diode. Ube - the difference between the output voltage and the voltage stabilized by the Zener diode. It is almost independent of the current supplied to the pn junction. However, the difference depends on the nature of the substance (for silicon Ube - 0.6 V, for germanium - 0.25 V). It is because of the comparative independence of these values ​​that the output voltage is stable.

When passing through a three-layer transistor, the voltage at the output of the stabilizer increases. If the use of one transistor does not meet the needs of the energy consumer, then a design of several transistors is taken to increase the current to the desired value.

Serial compensation on the operational amplifier

Compensatory means with feedback. In this stabilizer, the output voltage is always compared with what is taken as a standard. The difference between them is necessary for the formation and transmission of a signal to the mechanism that controls voltage.

A part of the output voltage Uout is removed from the resistor R2, which is compared with Uz (reference voltage) on the zener diode, indicated in the diagram as D1. The resulting difference passes through an operational amplifier (in the diagram U1) and is transmitted to the control transistor.

Stable operation is ensured with a loop phase shift that approaches 180 ° + n * 360 °. Since part of the output voltage is supplied to the amplifier, the latter shifts the phase by a swept angle. A transistor connected according to the current amplifier circuit does not cause a phase shift. In this case, the loop shift remains equal to 180 °.

Pulse

An electric current with unstable parameters is supplied by means of short pulses to the storage device of the stabilizer (an inductive coil or capacitor plays its role). The stored electricity subsequently goes into the load with different parameters. There are two options for stabilization:

1. By controlling the duration of the pulses and the pauses between them ( pulse width modulation principle);
2. By comparing the output voltage with the minimum and maximum allowable values. If it is higher than the maximum, then the drive stops storing energy and discharges. Then the voltage at the output becomes less than the minimum. In this case, the drive starts working again ( two-position control principle).

Depending on the circuit, the pulse current equalizer can convert the voltage to achieve different results. Therefore, its varieties are distinguished:

• Downward(the voltage at the output is less than at the input, but with the same polarity);
• Raising(the voltage at the output is greater than at the input, but with the same polarity);
• Buck-boost(the voltage at the pin can be higher or lower than at the input, but the polarity is the same). The device is used when U at the input and output are very different, but at the input unwanted deviations up or down are possible;
• Inverting(the voltage at the output is greater or less than that at the input, the polarity is opposite).

Advantages:

• Low energy loss.

Disadvantages:

• Pulse noise at the output.

AC voltage stabilizers

An AC voltage stabilizer is designed to maintain a constant current at the output, regardless of what parameters it has at the input. The output voltage should be described by an ideal sinusoid even with sharp jumps, drops, or even a break at the input. There are accumulative and corrective stabilizing devices.

Stabilizers-accumulators

These are devices that first store electricity from an incoming current source. Then the energy is generated anew, but with constant characteristics, the current is directed to the output.

Engine-generator system

The principle of operation is to convert electrical energy into kinetic energy using an electric motor. Then the generator converts it back from kinetic to electric, but the current already has specific and constant characteristics.

The key element of the system is the flywheel, which stores kinetic energy and stabilizes the output voltage. The flywheel is rigidly connected to the moving parts of the engine and generator. It is very massive and has a high inertia keeping speed, which depends only on the phase frequency. Since the speed of the flywheel is relatively constant, the voltage remains constant even with significant dips and surges in the input.

The motor-generator system is suitable for three-phase voltages. Today it is used only at strategic sites. Previously used to power high-speed electronic computers.

Ferroresonant

The device includes:

• Saturated core inductive coil;
• An inductor with an unsaturated core (there is a magnetic gap inside);
• Capacitor.

Since a coil with a saturated core has a constant voltage, regardless of the current that flows through it, by selecting the characteristics of the second coil and the capacitor, it is possible to achieve voltage stabilization within the required limits.

The principle of operation of the resulting mechanism can be compared to a swing, which is difficult to stop abruptly or make it swing at a higher speed. There is even no need to push the swing every time, because the oscillatory motion is an inertial process. Therefore, strong voltage dips and interruptions are permissible. The oscillation frequency is also difficult to change, since the system has its own steady-state frequency.

Ferroresonant stabilizers were popular in Soviet times. They were used to supply electricity to televisions.

Inverter

The inverter stabilizer circuit includes:

• Input filters;
• Rectifier with a device that changes the power factor;
• Capacitors;
• Microcontroller;
• Voltage converter (DC to AC).

The principle of operation is based on two processes:

1. The incoming alternating current is first converted to direct current as it passes through the corrector and rectifier. Energy is stored in capacitors;
2. The DC current is then converted to AC output. From the capacitor, the current goes to the inverter, which transforms the current into alternating current, but with unchanged parameters.

Example (the principle of operation of a voltage stabilizer 220V): the input voltage is less or more than 220V, its shape does not correspond to a sinusoid. After passing through the rectifier and corrector, the current becomes constant, the voltage waveform is an ideal sinusoid. After passing through the inverter, an alternating sinusoidal current with a frequency of 50 Hz and a voltage of 220V rushes to the output.

Due to the high efficiency of the mechanism (the efficiency is close to 100%), such a stabilizer is used for expensive medical and sports equipment.

UPS

Uninterruptible power supplies are similar in design and principle to inverter converting devices. The similarity ends with the fact that the accumulation of electricity does not occur in the capacitor, but in the battery, from which the current comes out with the parameters necessary for the consumer.

UPSs are necessary to power computing equipment, since they not only stabilize the voltage, but also exclude the failure of programs during an emergency shutdown. Example: if there is a break in voltage, then the accumulated energy in the battery is enough to properly shutdown the computer. All data will be saved, and the computer "stuffing" will remain intact.

Corrective

Corrective stabilizers include voltage converters, which change it due to the additional potential, which was not enough to obtain the value required for the consumer.

Electromagnetic

Another name is ferromagnetic. It differs from ferroresonant in the absence of a capacitor, lower power and larger dimensions.

If the linear reactor (in the diagram L1) is connected in series with the resistor Rh, and the nonlinear reactor L2 is connected in parallel with Rh, then no matter how the input voltage changes, the output will be constant. This is due to the operation of the second reactor in the saturation mode, which is why the voltage across it does not change with a varying current. Therefore, changing input voltage does not affect the output value. It is only redistributed between L1 and L2. The increment from the input value goes completely to L1.

Electromechanical and electrodynamic

These are two types of stabilizers, similar in design, representing a booster transformer. In them, the voltage is converted by moving the node that takes the current at the input along the transformer winding. As a result, the stabilization coefficient changes gently to the value that is needed for the output voltage.

In an electromechanical leveler, the control is realized by brushes, which wear out quickly, since they are moving elements. It is possible to reduce wear in the electrodynamic analogue, in which the brushes are replaced by a roller.

These are the only current converters that not only ensure its smooth transformation, but also form a sinusoid from it. At the conclusion, the value is relatively constant, the maximum deviation from the nominal value does not exceed 3%. This energy supply is optimal for household and industrial appliances.

Advantages:

• Wide range of input voltage (130-260V);
• No interference on the output;
• Overload capability up to 200% for half a second;
• Quiet operation (if there is no overload);
• Excellent noise immunity.

Disadvantages:

• Cannot be used in cold weather (the design can only work with short light frosts and up to 40 degrees Celsius);
• Low stabilization speed (the problem is solved by adding the number of brushes).

The advantages of the electrodynamic analogue include its ability to work at negative temperatures (no more than 15 degrees below zero). Another plus: the design can withstand overloads by 200% for up to 120 seconds.

Relay

The principle of operation of a relay voltage stabilizer is similar to the operation of other autotransformer converters with step adjustment by turning on / off individual windings of a power automatic transformer using electromechanical relays. Therefore, raising and lowering the output voltage is a parallel process of raising and lowering at the input of the supporting device.

A special feature of the relay converter is that the displayed value always changes within a step. For example, the range of acceptable values ​​is set from 215 to 220 volts. This means that the voltage will constantly change within these limits, while at the input this range can be 200-230 Volts. The step swing depends on the number of windings: the more there are, the smaller the range, and the more even the voltage at the output will be.

From this we can conclude that a high-quality stabilizer cannot show only 220 volts on the screen. If the value does not change, we can conclude that the LEDs are located exactly in the form of the number "220" and they cannot show any other number. This is done by unscrupulous manufacturers to reduce the cost of AC converters.

Advantages:

• High speed stabilization;
• Small size;
• Large input voltage range (from 140 to 270 Volts);
• Low susceptibility to input voltage changes;
• Overload 110% for 4 seconds;
• Quiet work;
• Ability to work from -20 to +40 degrees Celsius.

Disadvantages:

• Stepped (not smooth) stabilization (light blinks with a large step range);
• The stabilization speed depends on the accuracy of the output voltage: the more accurate the voltage, the lower the speed.

Electronic

If you need to convert a current with unstable parameters, then pay attention to an electronic stabilizer. The electronic device of a voltage stabilizer of 220 volts is an analogue of a relay converter. The difference between them lies only in the method of changing the transformer windings included in the loaded circuit.

In this design, switching occurs not due to the presence of a relay, but due to triacs or thyristors. Since there are no mechanical parts, the service life of the device is dramatically increased. In combination with an acceptable cost, this option is optimal for household appliances. Otherwise, the advantages and disadvantages are the same as those indicated for the relay converter.

Hybrid

In 2012, a new type of stabilizer appeared on sale - a hybrid. It is an electromechanical device, the design of which additionally includes two relay converters.

The main element is electromechanical. Relay elements are included in the work only when the latter can no longer issue 220 volts at the output. This happens if the incoming voltage is either too low or too high. So, an electromechanical converter operates at 144-256V. And the relay turns on when the value falls below 144V or rises above 256V. The maximum range is 105-280 Volts.

Hybrid converters are suitable for uninterrupted power supply to electricity consumers in a private house, apartment, office or even a store.

The quality and service life of electrical appliances depends on the parameters of the supplied energy. With sharp surges, breaks or voltage dips, the equipment fails. This can only be resisted by an uninterrupted power supply with a voltage of the agreed value. It is this that allows you to get voltage stabilizers, without which modern life is impossible.

The most important parameters of the stabilizer are the stabilization coefficient K st, the output resistance R out and the efficiency η.

Stabilization factor determined from the expression K st = [∆u in / u in] / [∆u out / u out]

where u in, u out- constants, respectively, at the input and output of the stabilizer; ∆u in- the change u in; ∆u out- the change u out corresponding to the change in ∆u in.

Thus, stabilization factor is the ratio of the relative change at the input to the corresponding relative change at the output of the stabilizer.

The larger the stabilization factor, the less the output changes when the input changes. For the simplest stabilizers, the value of K st is unity, and for more complex ones, hundreds and thousands.

Output impedance of the stabilizer defined by the expression R out = | ∆u out / ∆i out |

where ∆u out - change of constant at the output of the stabilizer; ∆i out - the change in the constant output current of the stabilizer, which caused the change in the output voltage.

The output impedance of the stabilizer is the same as the output impedance of a rectifier with a filter. The lower the output resistance, the less the output changes when the load current changes. In the simplest stabilizers, the value of R out is units of Ohm, and in more advanced ones - hundredths and thousandths of Ohms. It should be noted that the regulator usually drastically reduces the voltage ripple.

The efficiency of the stabilizer η st is the ratio of the power supplied to the load P n to the power consumed from the input source P in: η st = P n / R in

Traditionally, stabilizers are divided into parametric and compensation.

Interesting video about voltage stabilizers:

Parametric stabilizers

They are the simplest devices in which small changes in the output are achieved through the use of electronic devices with two terminals, characterized by a pronounced nonlinearity of the current-voltage characteristic. Consider a diagram of a parametric stabilizer based on a zener diode (Fig. 2.82).

Let's analyze this circuit (Fig. 2.82, a), for which we first transform it using the equivalent generator theorem (Fig. 2.82, b). Let's analyze graphically the operation of the circuit, building on the current-voltage characteristic of the zener diode load lines for different values ​​of the equivalent voltage corresponding to different values ​​of the input (Fig. 2.82, c).
From the graphical constructions, it is obvious that with a significant change in the equivalent u e (by ∆u e), and hence the input u in, the output changes by an insignificant amount ∆u out.

Moreover, the less the differential resistance of the zener diode (that is, the more horizontally the characteristic of the zener diode goes), the less ∆u out.

We will determine the main parameters of such a stabilizer, for which in the original circuit we will replace the Zener diode with an equivalent circuit and introduce into the input circuit (Fig. 2.82, d) a voltage source corresponding to the change in the input ∆u in (dotted line on the diagram): R out = r d || R 0 ≈ r d, since R 0 >> r d η st = (u out · I n) / (u in · I in) = (u out · I n) / [u in (I n + I in)].

K st = (∆u in / u in): (∆u out / u out) Since usually R n >> r d Consequently, K st ≈ u out / u in · [(r d + R 0) / r d]

Typically, parametric stabilizers are used for loads from several units to tens of milliamps. Most often they are used as a reference source in compensation voltage stabilizers.

Compensation stabilizers

They are closed-loop automatic control systems. The characteristic elements of the compensation stabilizer are a reference (reference) source (ION), a comparing and amplifying element (MSE) and a regulating element (RE).

It is useful to note that OOS covers two stages - an operational amplifier and a transistor. The considered scheme is a convincing example demonstrating the advantage of general negative feedback over local one.

The main disadvantage of stabilizers with continuous regulation is a low efficiency, since a significant power consumption takes place in the regulating element, since the entire load passes through it, and the drop across it is equal to the difference between the input and output voltages of the stabilizer.

At the end of the 60s, they began to produce integrated circuits of compensation stabilizers with continuous regulation (K142EN series). This series includes stabilizers with fixed output voltage, adjustable output voltage and bipolar and input and output voltages. In cases where it is necessary to pass a current through the load that exceeds the maximum permissible values ​​of integral stabilizers, the microcircuit is supplemented with external regulating transistors.

Some parameters of integral stabilizers are given in table. 2.1, and the option of connecting external elements to the K142EN1 stabilizer is shown in Fig. 2.85.


Resistor R is designed to operate the current protection, and R 1 is used to regulate the output voltage. Microcircuits K142UN5, EH6, EH8 are functionally complete stabilizers with a fixed output voltage, but do not require the connection of external elements.

Impulse stabilizers are now widespread no less than continuous stabilizers.

Due to the use of the key mode of operation of the power elements of such stabilizers, even with a significant difference in the levels of input and output voltages you can get an efficiency equal to 70 - 80%, while for continuous stabilizers it is 30 - 50%.

In a power element operating in a key mode, the average power dissipated in it over the switching period is much less than in a continuous stabilizer, since although in a closed state the current flowing through the power element is maximum, the drop across it is close to zero, and in the open state, the current flowing through it is equal to zero, although it is maximum. Thus, in both cases, the power dissipation is negligible and close to zero.

Small losses in the power elements lead to a decrease or even elimination of cooling radiators, which significantly reduces the weight and dimensions. In addition, the use of a switching regulator makes it possible in some cases to exclude a power transformer operating at a frequency of 50 Hz from the circuit, which also improves the performance of the stabilizers.

The disadvantages of switching power supplies include the presence of output voltage ripple.

Consider a switching serial regulator

Key S is periodically turned on and off by the control circuit (CS) depending on the value on the load. the output is adjusted by changing the ratio t on / t off, where t on, t off are the duration of the time intervals on which the switch is in the on and off states, respectively. The greater this ratio, the more output.

A bipolar or field-effect transistor is often used as the S key.

The diode ensures the flow of the inductor current when the switch is turned off and, therefore, excludes the appearance of dangerous surges on the switch at the moment of switching. LC filter reduces output ripple.

Another interesting video about stabilizers:

Many people have experienced sudden power surges, as a result of which all household appliances in the house fail. Is it possible to somehow prevent them and protect expensive devices from breakdown? In this article, we will analyze, what they are and how they work.

Modern electrical networks, unfortunately, do not provide a constant voltage to the outlet. Depending on the place of residence, the number of subscribers and the power of devices on one line, the voltage can vary greatly from 180 to 240 volts.

A modern stabilizer looks like this

But most of today's electronics are extremely negative about such experiments, since the limit for it jumps to + -10 volts. For example, a TV or computer may simply turn off if the voltage drops to 210, which happens quite often, especially in the evening.

It is not necessary to count on the fact that the power grids will be modernized in the coming years. Therefore, citizens need to independently take care of the "equalization" of voltage and protection of power grids. All you need to do is purchase a stabilizer.

What it is

A stabilizer is a device that equalizes the voltage in the network by supplying the required 220 volts to the device. Most modern low-cost stabilizers operate in the range of + -10% of the desired indicator, that is, “leveling” surges in the range from 200 to 240 volts. If you are experiencing more serious subsidence, then you need to select a more expensive device - some models are capable of "pulling" the line from 180 volts.

Modern voltage stabilizers these are small devices that work completely silently and do not hum like their “ancestors” from the USSR. They can operate on 220 and 380 volts (must be selected when purchasing).

In addition to the voltage drop, high-quality stabilizers "clean" the line from garbage impulses, interference and overloads. We recommend that you definitely use such devices in everyday life, installing them at the entrance to the apartment or, at least, on every important household appliance (boiler, work computer, etc.). But it is still better not to risk expensive equipment, but to purchase a normal leveling device.

Now that you knowthink about how much money it can save you. At the same time, a large number of equipment is working in the apartment - a washing machine, a computer, a TV, a dishwasher, a phone is charging, etc. If there is a leap, then all this can fail, and the damage will be tens, or even hundreds of thousands of rubles. It is almost impossible to prove in court that the reason for the breakdown of equipment was a power surge, therefore, you will have to pay for repairs and purchase a new one with your own money.

The principle of operation of the stabilizer

Types of stabilizers

At the moment there are three types of stabilizers, which differ from each other according to the principle of alignment:

1. Digital.
2. Relay.
3. Servo drives.

The most practical, convenient and reliable are digital or electronic devices. They work due to the presence of thyristor switches. The main advantage of such systems is the minimum response time, absolute noiselessness, and small size. The disadvantage is the price, they are usually 30-50% more expensive than other devices.

Relay systems belong to the middle price segment. They work by switching power relays, turning on and off the corresponding windings on the transformer. Relay voltage stabilizers for home are considered optimal. The main advantages of the device are affordable prices, fast response speed. Minus - short service life. A conventional relay can withstand about 40-50 thousand switchings, after which the contacts wear out and begin to stick. If you have a fairly stable network, then the relay system will work for you for several years. But if failures happen several times a day, then it can fail in one and a half to two years.

Servo-type devices have a low cost and work by changing the number of turns involved by the transformer. Their switching occurs due to the movement of the servo, which switches the contact, as on a rheostat. The main advantage of these systems is their affordable price. The downside is low reliability and long response time.

How to choose the right one

Now you know,for home. Let's consider how to choose the right devices.

First of all, you need to determine how many devices will work at the same time. For example, if you are in the kitchen, turn on the electric kettle, microwave and dishwasher. In the hall there is a TV and a computer, in the bathroom there is a washing machine. At the same time, a refrigerator and an individual heating boiler work in the apartment without switching off - these devices also consume 200-300 watts.

You can find out the power of the devices according to the passport. But be sure to keep in mind that manufacturers indicate active power, not real.

Method of mounting the stabilizer after the meter

Attention:for a correct calculation, it is necessary to know the total capacity of the installation, and not its operating mode. The refrigerator consumes 100 watts per hour during operation, but when starting the engine requires 300-500 watts of reactive energy. Therefore, always take the device with a margin.

For example, the consumption of your apartment is 2000 watts. This is a very real figure for a classic "kopeck piece" with modern technology, and not equipped with powerful consumers such as a boiler, electric oven and hob. To account for full power, add 20%. Also, you should understand that if the network sags by 20 volts, then the transformer loses 20% of its power. As a result, the total stock will reach 30-40%, and you will need to purchase a stabilizer with a capacity of 2000 * 0.4 + 2000 = 2800-watt device.

This is all the information you need to know about voltage regulator: what is it and you now know how it works. It remains to figure out how to connect it correctly. It is recommended to install it immediately behind the meter, before the electrical panel, although it can also be hooked separately to the required lines. The device must be grounded so that in case of problems it will drain the current and protect your equipment. It is better to invite an experienced electrician to connect.