Home appliances require a stable voltage to function properly. As a rule, various failures can occur in the network. The voltage from 220 V may deviate and the device will malfunction. First of all, the lamps get hit. If we consider household appliances in the house, then TVs, audio equipment and other appliances that operate on the mains may suffer.
In this situation, a switching voltage stabilizer comes to the aid of people. He is fully capable of coping with the surges that occur daily. At the same time, many are concerned about the question of how voltage drops appear, and what they are associated with. They depend mainly on the workload of the transformer. Today, the number of electrical appliances in residential buildings is constantly increasing. As a result, demand for electricity is sure to grow.
It should also be taken into account that cables that have long been outdated can be laid to a residential building. In turn, apartment wiring in most cases is not designed for heavy loads. To keep your appliances safe at home,you should familiarize yourself with the device of voltage stabilizers in more detail, as well as the principle of their operation.
What is the function of the stabilizer?
The switching voltage regulator mainly serves as a network controller. All jumps are tracked by him and eliminated. As a result, the equipment receives a stable voltage. Electromagnetic interference is also taken into account by the stabilizer, and they cannot affect the operation of the devices. Thus, the network gets rid of overloads, and cases of short circuits are practically excluded.
A simple stabilizer device
If we consider a standard switching voltage current regulator, then only one transistor is installed in it. As a rule, they are used exclusively of the switching type, since today they are considered more efficient. As a result, the efficiency of the device can be greatly increased.
The second important element of the switching voltage regulator should be called diodes. In the usual scheme, they can be found no more than three units. They are connected to each other with a choke. Filters are important for the normal operation of transistors. They are installed at the beginning, as well as at the end of the chain. In this case, the control unit is responsible for the operation of the capacitor. Its integral part is considered to be a resistor divider.
How does it work?
Depending on the type of device, the principle of operation of the switching voltage regulator may differ. Considering the standardmodel, we can say that first the current is supplied to the transistor. At this stage, it is being transformed. Further, diodes are included in the work, whose duties include signal transmission to the capacitor. With the help of filters, electromagnetic interference is eliminated. The capacitor at this moment smooths out voltage fluctuations and through the inductor the current through the resistive divider again returns to the transistors for conversion.
Homemade Devices
You can make a switching voltage regulator with your own hands, but they will have low power. In this case, the most common resistors are installed. If you use more than one transistor in the device, you can achieve a high efficiency. An important task in this regard is the installation of filters. They affect the sensitivity of the device. In turn, the dimensions of the device are not important at all.
Single Transistor Stabilizers
This type of switching DC voltage stabilizer boasts an efficiency of 80%. As a rule, they function only in one mode and can only cope with small interference in the network.
Feedback in this case is completely absent. The transistor in the standard switching voltage regulator circuit operates without a collector. As a result, a large voltage is immediately applied to the capacitor. Another distinguishing feature of devices of this type can be called a weak signal. Various amplifiers can solve this problem.
As a result, you can achieve better performancetransistors. The resistor of the device in the circuit must be behind the voltage divider. In this case, it will be possible to achieve better performance of the device. As a regulator in the circuit, the switching DC voltage stabilizer has a control unit. This element is able to weaken, as well as increase the power of the transistor. This phenomenon occurs with the help of chokes that are connected to diodes in the system. The load on the regulator is controlled through filters.
Switch Type Voltage Stabilizers
This kind of switching voltage regulator 12V has an efficiency of 60%. The main problem is that it is not able to cope with electromagnetic interference. In this case, devices with a power of more than 10 W are at risk. Modern models of these stabilizers are able to boast a maximum voltage of 12 V. The load on the resistors is significantly weakened. Thus, on the way to the capacitor, the voltage can be completely converted. Directly the current frequency generation occurs at the output. Capacitor wear in this case is minimal.
Another problem is related to the use of simple capacitors. In fact, they performed quite poorly. The whole problem lies precisely in the high-frequency emissions that occur in the network. To solve this problem, manufacturers began to install electrolytic capacitors on a switching voltage regulator (12 volts). As a resultthe quality of work was improved by increasing the capacity of the device.
How do filters work?
The principle of operation of a standard filter is based on generating a signal that is fed to the converter. In this case, the comparison device is additionally activated. In order to cope with large fluctuations in the network, the filter needs control units. In this case, the output voltage can be smoothed.
To solve problems with small fluctuations, the filter has a special difference element. With its help, the voltage passes with a limiting frequency of not more than 5 Hz. In this case, this has a positive effect on the signal that is available at the output in the system.
Modified device models
The maximum load current for this type is perceived up to 4 A. The input voltage of the capacitor can be processed up to a mark of no more than 15 V. The input current parameter they usually do not exceed 5 A. In this case, the ripple is allowed to be minimal with an amplitude in the network of not more than 50 mV. In this case, the frequency can be maintained at the level of 4 Hz. All this will ultimately have a positive effect on the overall efficiency.
Modern models of stabilizers of the above type cope with a load in the region of 3 A. Another distinguishing feature of this modification is the fast conversion process. This is largely due to the use of powerful transistors that work with through current. As a result, it is possible to stabilize the output signal. At the output, a switching diode is additionally activated. It is installed in the system near the voltage node. The heating loss is greatly reduced, and this is a clear advantage of this type of stabilizer.
Pulse width models
Pulse adjustable voltage stabilizer of this type has an efficiency of 80%. It is able to withstand the rated current at the level of 2 A. The input voltage parameter is on average 15 V. Thus, the output current ripple is quite low. A distinctive feature of these devices can be called the ability to work in the circuit mode. As a result, it is possible to withstand loads up to 4 A. In this case, short circuits are extremely rare.
Among the disadvantages, chokes should be noted, which have to cope with voltage from capacitors. Ultimately, this leads to rapid wear of the resistors. To cope with this problem, scientists propose to use a large number of them. The capacitors in the network are required to control the operating frequency of the device. In this case, it becomes possible to eliminate the oscillatory process, as a result of which the efficiency of the stabilizer is sharply reduced.
Resistance in the circuit must also be taken into account. For this purpose, scientists install special resistors. In turn, diodes can help with sharp transitions in the circuit. The stabilization mode is activated only at the maximum current of the device. To solve the problem with transistors, some use heat sink mechanisms. In this casethe dimensions of the device will increase significantly. Chokes for the system should be used multi-channel. Wires for this purpose are usually taken in the "PEV" series. They are placed initially in a magnetic drive, which is made of a cup type. Additionally, it contains such an element as ferrite. A gap of no more than 0.5 mm should eventually form between them.
Stabilizers for domestic use are most suitable for the "WD4" series. They are able to withstand a significant load current due to a proportional change in resistance. At this time, the resistor will be able to handle the small alternating current. It is advisable to pass the input voltage of the device through filters of the LS series.
How does the stabilizer deal with small ripples?
First of all, the 5V switching voltage regulator activates the start-up unit, which is connected to the capacitor. In this case, the reference current source must send a signal to the comparison device. To solve the problem with the conversion, a DC amplifier is included in the work. Thus, the maximum amplitude of the jumps can be immediately calculated.
Further through the inductive storage current passes to the switching diode. To keep the input voltage stable, there is a filter at the output. In this case, the limiting frequency can change significantly. The maximum transistor load can withstand up to 14 kHz. The inductor is responsible for the voltage in the winding. Thanks to the ferrite, the current can be stabilized at the initialstage.
The difference between step-up stabilizers
The switching boost voltage stabilizer features powerful capacitors. During feedback, they take all the burden on themselves. In this case, a galvanic isolation must be located in the network. She is responsible only for increasing the limiting frequency in the system.
An additional important element is the gate behind the transistor. It receives current from a power source. At the output, the conversion process occurs from the inductor. At this stage, an electromagnetic field is formed in the capacitor. In the transistor, thus, the reference voltage is obtained. The self-induction process starts sequentially.
Diodes are not used at this stage. First of all, the inductor gives voltage to the capacitor, and then the transistor sends it to the filter and also back to the inductor. As a result, feedback is formed. It occurs until the voltage on the control unit stabilizes. The installed diodes will help him in this, which receive a signal from transistors, as well as a stabilizer capacitor.
The principle of operation of inverting devices
The whole process of inverting is connected with the activation of the converter. Switching AC voltage stabilizer transistors has a closed type of the "VT" series. Another element of the system can be called a resistor that monitors the oscillatory process. Directly induction is to reduce the limiting frequency. At the entrance sheavailable at 3 Hz. After the conversion processes, the transistor sends a signal to the capacitor. Ultimately, the limiting frequency can double. In order to make the jumps less noticeable, a powerful converter is needed.
Resistance in the oscillatory process is also taken into account. This parameter maximum is allowed at the level of 10 ohms. Otherwise, the diodes on the transistor will not be able to transmit the signal. Another problem lies in the magnetic interference that is present at the output. In order to install many filters, NM series chokes are used. The load on the transistors directly depends on the load on the capacitor. At the output, a magnetic drive is activated, which helps the stabilizer to lower the resistance to the desired level.
How do buck regulators work?
Switching step-down voltage stabilizer is usually equipped with "KL" series capacitors. In this case, they are able to significantly help with the internal resistance of the device. Power sources are considered to be very diverse. On average, the resistance parameter fluctuates around 2 ohms. The operating frequency indicator is monitored by resistors that are connected to a control unit that sends a signal to the converter.
Partly the load goes away due to the process of self-induction. It occurs initially in the capacitor. Thanks to the feedback process, the limiting frequency in some models is able to reach 3 Hz. In this casethe electromagnetic field has no effect on the electrical circuit.
Power supplies
As a rule, 220 V power supplies are used in the network. In this case, a high efficiency can be expected from a switching voltage regulator. For DC conversion, the number of transistors in the system is taken into account. Mains transformers are rarely used in power supplies. This is largely due to the big jumps. However, rectifiers are often installed instead. In the power supply, it has its own filtering system, which stabilizes the limit voltage.
Why install expansion joints?
Compensators in most cases play a secondary role in the stabilizer. It is connected with the regulation of impulses. Transistors do this for the most part. However, compensators still have their advantages. In this case, a lot depends on which devices are connected to the power source.
If we talk about radio equipment, then a special approach is needed. It is associated with various vibrations that are perceived differently by such a device. In this case, compensators can help the transistors stabilize the voltage. Installing additional filters in the circuit, as a rule, does not improve the situation. However, they greatly affect the efficiency.
Disadvantages of galvanic isolation
Galvanic isolations are installed for signal transmission between important elements of the system. Their main problemcan be called an incorrect estimate of the input voltage. This happens most often with outdated models of stabilizers. The controllers in them are not able to quickly process information and connect capacitors to work. As a result, the diodes suffer first. If the filtering system is installed behind the resistors in the electrical circuit, then they simply burn out.
