A voltage stabilizer is a device that removes mains power defects by applying a voltage close to sinusoidal to the output. Compensates or eliminates all disadvantages. A state standard has been developed, where requirements are imposed on the parameters of industrial power grids. It is known, for example, that when the amplitude is exceeded by 10%, the service life of the incandescent bulbs decreases fourfold. Think about it, deciding whether to buy a voltage regulator.
Requirements for the parameters of industrial mains supply 220 V AC.The objectives of the
GOST 13109 voltage regulator unambiguously establish the requirements for the voltage quality of general-purpose networks:
- The effective voltage value( 220 V) normally deviates from the value by 5% in both directions. Maximum allowable - by 10%.
- Frequency deviation( 50 Hz), as a rule, not more than 0.2 Hz, the maximum permissible - 0.4.
Separate requirements are imposed on flicker dose - flickering. When the voltage deviates in shape from a sinusoid, the light sources produce visual oscillations that tire vision, leading to negative points. This is especially true of the nervous system. Voltage stabilizers are able to correct the shape, giving the consumer the perfect quality.
power supply stabilizer. Starting from 380 V, an agreement is concluded with the supplier, and GOST 13109 forms the basis. Requirements for electrical parameters are prescribed. According to the norms, the actual value should not go beyond 210 - 230 V( rounded), in practice we see the opposite picture. As a result, other devices refuse to work or fail. The latter is especially relevant for three-phase networks, so voltage regulators monitor the parameters and the availability of power on all channels. If the branch disappears, the power supply is cut off completely. This helps protect equipment and explains why a three-phase voltage regulator cannot be replaced by three single-phase ones.
Resistant network settings reduce, for example, the noise of a personal computer unit. Due to the simple phenomenon - even rotation of the blades of the coolers. Technique, especially electronics, works better when the power supply parameters coincide with the nominal ones. However, in practice, the requirements of GOST 13109 are grossly violated. This is not due to the negligence of the service personnel, but rather because of illiteracy, disregard of attitude and lack of awareness of the population.
There are requirements for power surges, other parameters. It is not difficult to learn from the applications of the standard 13109. The need is negotiated. For example, the incandescent bulbs serve four times less when the voltage rises above 10%, give 40% less light, if the network performance fell by the same value. Both cases are bad. In electronics, the increase in the filament voltage by only 1%( in volts) reduces the service life of a vacuum tube by 15%.Slow changes in the frequency of the supply voltage:
- In cathode-ray tubes disrupt the image building process. The frame is resized, focusing disappears, spontaneously varies brightness.
- The local oscillator frequency is violated in the receiving part. As a result, the quality of the picture or sound is significantly different from the norm.
Rapid changes( voltage surges) in most cases pass directly to the output, detecting a large amplitude. With old TVs, this causes unpleasant image shake. If, after purchasing a motherboard with integrated graphics, it turned out that the store had slipped the marriage, and not the return option, buy a digital monitor. In it, the effect is eliminated automatically, thanks to the principle of action.
So, the voltage regulator in frequent situations qualitatively improves the performance and service life of the equipment. In severe cases - make it work in principle. If the light in the house is constantly flickering, and the refrigerator is intermittent, it's time to think about buying a voltage regulator.
Varieties of voltage regulators
A regulating element is installed inside the voltage regulator. From the control method, the devices are divided into three types:
- Parametric voltage regulators are extremely simple. Affect the input signal to bring it to the desired form. They lack a scheme for estimating the parameters of the output voltage;
- Compensation stabilizer compares the output voltage with the reference, produces a control signal. This type of device is ideal for DC networks. The simplest methods reference voltage is obtained by using any Zener diode.
- Combined stabilizers work on both of these principles at the same time, representing the combination of the best qualities of other models.
Voltage stabilizers are distinguished according to the method of connection to the circuit:
- Serial type. Regulatory element included in the load circuit. These devices show low no-load current. All power passes through the regulating element. Voltage stabilizers of this type are characterized by the following features:
- High efficiency, economy in idle mode( when the load is disconnected or not working), a stunning range of regulation. If the zener diode is easily able to fail, the transistor switch withstands harsh conditions.
- The main disadvantage arises from the scheme: when a short circuit or overload reliability decreases sharply, a high current passes through the regulating element, which causes an increase in power dissipation. Additional protection systems increase the cost of the device.
- Parallel type stabilizer wiring. The regulating element is connected in parallel with the load. Formed adjustable resistive divider. Minus - part of the power immediately be lost. However, not as large as the total consumed, which to a certain extent reduces the requirements for the element base of the voltage regulator. Key features:
- Parametric stabilizer of parallel type seen each. This is a zener diode, which is used starting from pulse power supplies of cell phone adapters and ending with the automatic control circuit of a spacecraft. Here the current of the stabilizer is higher than the load current to ensure proper stability. To meet the requirements, sometimes it is necessary to combine parallel stabilizers in a cascade, greatly reducing efficiency.
- By design, the zener( the only element) is much simpler than the transistor switch. This becomes the main reason for using parallel stabilizers in practice. And the second is noncriticality to overloads: in fact, the zener diode does not care how much the useful part of the circuit consumes. But the stability of this decreases. For a voltage of 220 V the device is difficult to find.
Parametric voltage regulators - parallel type, compensation - are different. Other devices are able to take into account temperature fluctuations or current consumption. The principle of division according to the design of the regulating element prevails:
- Electronic is now recognized as a curious option. Able to build on the basis of inverters to ensure the stability of the frequency. The structure used transistors, thyristors and integrated circuits. More often the voltage is limited by the control signal. In this case, the current is controlled, due to the relatively low resistance of the pn-junction in the open state, the output power is not so great. The advantages of the design include low weight and the presence of many settings, but the highest switching speed and accuracy are still in the electromechanical varieties.
- Electromechanical voltage regulators in the composition contain a motor that switches the windings of the autotransformer( or transformer) in order to compensate for jumps at the input. Sometimes the difference between neighboring states is reduced to a single coil of thick copper wire. Hence the great accuracy, and the speed often depends on the characteristics of the engine. You will need to monitor and timely maintain. Otherwise, a number of negative effects are possible on contactors and in the mechanical part, up to sparking due to induced emf.
- Relay voltage regulators control the windings not so accurately. The increase in the number of switches reduces the reliability of the device as a whole. It is supposed to carefully extinguish the spark, the disturbance harmful to the load. But relay stabilizers, despite the relatively low accuracy, are relatively silent. Permissible to put in the home. Only occasionally heard clicks relay.
Characteristics of Voltage Regulators
- The instability when the input voltage changes indicates what percentage of the jump will pass into the load. Parameter tend to reduce.
- Instability with a change in load shows how a voltage regulator fulfills the need of devices for electric current. In reality, the possibilities are limited. The output current cannot be infinite, otherwise the stabilizer itself will burn.
- The input voltage range shows the limits of the equipment operability regarding the network parameters, and the output - the maximum deviations from the norm( ideally, at the current voltage value no more than 5% each way).
- The voltage difference between the input and the output is the maximum value within which the specified parameters are ensured. If the network falls below or, on the contrary, it grows, the mode of functioning of the load is broken.
- Noise Voltage - Self Interference Made by a Voltage Stabilizer. For modern complex models irrelevant.
- Sensitivity shows which changes in input voltage the device responds to. Anything less will be ignored and passed to the output.
- The rate of mining is considered an important parameter. The leader in this regard are electromechanical stabilizers.
It is difficult to advise a particular manufacturer. Let's say with a bit of confidence: construction equipment, electrical tools, which include stabilizers in the first approximation, are able to do in Russia. There is no danger of buying nonsense at an outrageous price.