Almost all electronic devices operate on direct current. This approach significantly reduces the number of electronic components used, the size of the circuit and the cost of manufacturing the device.
Rectifiers are used to convert alternating electrical voltage into direct voltage. The article will give a detailed explanation of what full wave rectifiers are. Describes their operating principle, varieties, main advantages and disadvantages.
History of invention
In 1873, the English scientist Frederick Guthrie developed the operating principle of directly heated vacuum tube diodes.
A year later, in Germany, physicist Karl Ferdinand Braun suggested similar properties in solid-state materials and invented a point rectifier. In early 1904, John Fleming created the first complete tube diode. He used copper oxide as the material for its manufacture. Diodes have begun to be widely used in radio frequency detectors. The study of semiconductors led to the invention of the crystal detector in 1906 by Greenleaf Witter Pickard.
In the mid-30s of the 20th century, the main research of physicists was aimed at studying the phenomena occurring at the metal-semiconductor contact boundary. Their result was the production of a silicon ingot with two types of conductivity. While studying it, in 1939, the American scientist Russell Ohl discovered a phenomenon later called the pn transition. He found that depending on the impurities existing at the interface of two semiconductors, the reducibility changes. In the early 50s, Bell Telephone Labs engineers developed planar diodes, and five years later, germanium-based diodes with a transition of less than 3 cm appeared in the USSR.
The inventor of the rectifier bridge circuit is considered to be an electrical engineer from Poland, Karol Pollak. Later, the results of Leo Graetz’s research were published in the journal Elektronische Zeitung, so in the literature one can also find another name for a diode bridge - circuit or Graetz bridge.
Physical properties of pn junction
The main element used to create a rectifier unit is a diode. Its operation is based on the electron-hole transition (pn).
The generally accepted definition says: a pn junction is a region of space located at the boundary of the junction of two semiconductors of different types. In this space, an n-type to p-type transition is formed. The value of conductivity depends on the atomic structure of the material, namely on how tightly the atoms hold electrons. Atoms in semiconductors are arranged in a lattice, and electrons are bound to them by electrochemical forces. This material itself is a dielectric. It either conducts current poorly or does not conduct it at all. But if atoms of certain elements are added to the lattice (doping), the physical properties of such a material change radically.
Mixed atoms begin to form, depending on their nature, free electrons or holes. The resulting excess electrons form a negative charge, and the holes form a positive charge.
An excess charge of one sign causes carriers to repel each other, while an area with an opposite charge tends to attract them towards itself. An electron, moving, occupies a free space, a hole. At the same time, a hole also forms in its old place. As a result, two flows of charge movement are created: one main and the other reverse. A material with a negative charge uses electrons as majority carriers and is called an n-type semiconductor, while a material with a positive charge using holes is called a p-type semiconductor. In both types of semiconductors, minority charges generate a current opposite to the movement of the main charges.
In radio electronics, germanium and silicon are used from materials to create pn junctions. When crystals of these substances are doped, a semiconductor with different conductivity is formed. For example, the introduction of boron leads to the appearance of free holes and the formation of p-type conductivity. Adding phosphorus, on the other hand, will create electrons and the semiconductor will become n-type.
Design and structure of the rectifier
To smooth out the received rectified voltage pulses, a leveling filter consisting of capacitors, chokes and resistances is connected after the output of the rectifier. To equalize and regulate the resulting current and voltage, a stabilizer circuit is connected to the output of the smoothing filter. Such devices are often connected to alternating current at the input of the device.
The operating modes and properties of the individual components of the rectifier, stabilizer, regulator and filter are coordinated with the specific operating conditions of the consumer load. Therefore, the main task when designing rectification devices is to calculate relationships that make it possible to determine the electrical properties and parameters of the stabilizer components and other parts based on the consumer’s operating mode. Next, you need to calculate these elements and select them from the catalog in the retail chain.
15.5 General information about inverters and converters
Primary sources produce direct current electrical energy of one voltage. For the functioning of electronic devices, DC and AC voltages of different values are required. To obtain it, DC-DC converters are used, which generate either the required AC voltage, or a DC voltage of a given value, or several DC voltages of different values.
Converters that have an alternating voltage output are called inverters. Converters that have a constant output voltage of one or more values are called converters.
The main elements of inverters and converters are transistors and thyristors operating in an open-closed valve mode, which periodically interrupt the current or change its direction. Thanks to this, the efficiency of inverters and converters can reach 99%.
What types of rectifiers are there?
The construction of devices that rectify alternating current is based on the function of the final unit. If it is only necessary to equalize vibrations, assembly on printed circuit boards is carried out using uncontrolled semiconductor elements - diodes. This is how the simplest leveling elements are built.
If it is necessary to change the level of power that is transmitted to the receiving equipment, the device is assembled using controlled valves (thyristors). These rectifiers are required to operate some electrically powered motors. By adjusting the supplied voltage, the rotation speed of the rotor changes.
N-phase rectifiers
Such devices have more than 3 phases for current rectification. Other design features vary. A multiphase rectifier can consist of either a full bridge or a quarter and half bridge. Based on the number of inputs and parallelization, they are divided into separate ones, united by stars or rings. In addition, there are sequential types.
Classification by purpose and device
AC generator
AC rectifiers are divided into several different types, depending on the characteristics, the use of alternating current periods, circuits, the number of phases and the type of transmitting element. In general, the classification is as follows:
- By the number of periods involved in the work (one- and two-half-wave, as well as with full and incomplete use of the wave);
- By type, devices are divided into those that include an electronic bridge, voltage multipliers, with or without transformers;
- Based on the number of phases, they are divided into single-phase, two-phase, three-phase and N-phase;
- According to the type of device that transmits a sine wave, they are divided into semiconductor diode and thyristor, mechanical and vacuum, mercury;
- Based on the type of transmitted waves, they are divided into pulsed, analog and digital.
Bridge device type
A three-phase bridge rectification circuit uses six diodes (or thyristors if control is required). The output voltage is characterized by three values: minimum U, average U and peak voltage.
A full-wave three-phase rectifier is similar to a Heitz bridge.
Diagram of a full-wave three-phase device. A conventional three-phase rectifier does not use a neutral. For 230 V / 400 V network between two rectifier inputs. Indeed, there is always a composite voltage U (= 400 V) between the 2 inputs.
A controlled rectifier allows you to regulate the average output voltage by influencing the response delay of the thyristor (used instead of diodes). This command requires complex electronic circuitry. The diode behaves like a thyristor loaded without delay. The rectified voltage looks like this.
Output U three-phase output voltage. There are 7 curves in total: 6 sinusoids and a red curve connecting the upper part of the sinusoids (“sinusoidal caps”). 6 sinusoids represent 3 voltages that make up U between phases and 3 identical voltages, but with opposite sign:
U31 = -U13U23 = -U32U21 = -U12.
The red curve represents U at the output of the rectifier, that is, at the terminals of the resistive load. This U does not refer to neutral. She swims. This U fluctuates between 1.5 Vmax and 1.732 Vmax (root of 3).
Umax is the peak value of one voltage and is 230 × 1.414 = 325 V.
Operating principle of a half-wave rectifier
In this example, resistance RL represents the load, although in reality the load could be any element or group of elements that could cause a voltage drop.
Half-wave rectifier circuit
During the first half of the AC cycle, diode D1 is in a direct-connected state—a positive electrical potential is applied to its anode and a negative potential is applied to its cathode. When D1 is in the direct-connected state, current flows from the negative side of the transformer secondary, through the load resistance, through the diode, back to the positive side of the secondary. As current flows through the load resistance, a voltage drop occurs across it; The current leaving the rectifier circuit appears as a positive half-wave across the load resistance.
The current path through the half-wave is in the direct connection state D1
During the second half of the AC cycle, diode D1 is in a reverse-connected state—its anode is exposed to a negative electrical potential and a positive electrical potential is exposed to its cathode. This diode does not conduct, so no voltage is present in the load resistance RL.
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Half-wave rectifier in reverse conduction state D1
As can be seen from the shape of the curve, half-wave rectifiers have only one half-wave of DC output for each full cycle of AC input. For this reason, equipment usually does not use half-wave rectifiers; When used, they are usually installed in equipment or circuits where low voltage current is required and where voltage fluctuations are not a cause for concern.
Full Wave Rectifier Output Waveform
How to organize bipolar power supply
By combining a balanced circuit and a bridge circuit, you can get a converter that will provide bipolar power at the output with a common (zero) point. Moreover, for one it will be negative, and for the other it will be positive. Such devices are widely used in power supplies for digital radio technology.
Diagram: example of a converter with bipolar output
Electrical parameters
Each type of diode has its own operating and maximum permissible parameters, according to which they are selected for operation in a particular circuit:
- Irev – constant reverse current, µA;
- Upr – constant forward voltage, V;
- Ipr max – maximum permissible forward current, A;
- Urev max – maximum permissible reverse voltage, V;
- Р max – maximum permissible power dissipated by the diode;
- Operating frequency, kHz;
- Operating temperature, C.
Not all diode parameters are given here, but, as a rule, if you need to find a replacement, then these parameters are sufficient.
Circuit of a simple AC rectifier using one diode
We will apply AC mains voltage to the input of the rectifier, in which positive half-cycles are highlighted in red and negative half-cycles are highlighted in blue. We will connect a load (Rн) to the output of the rectifier, and a diode (VD) will perform the function of the rectifying element. With positive half-cycles of voltage applied to the anode of the diode, the diode opens.
At these moments of time, a forward diode current Ipr flows through the diode, and therefore through the load (Rн), powered by the rectifier (the half-cycle wave is shown in red in the right graph). With negative half-cycles of voltage supplied to the anode of the diode, the diode closes, and a slight reverse diode current (Irev) will flow throughout the entire circuit. Here, the diode seems to cut off the negative half-wave of the alternating current (in the right graph, such a half-wave is shown by a blue dotted line).
As a result, it turns out that through the load (Rн), connected to the network through a diode (VD), it is no longer alternating current, since this current flows only in positive half-cycles, and the pulsating current is a current of one direction. This is AC rectification. But this voltage can only power a low-power load that is powered by an AC mains and does not have any special power requirements, for example, an incandescent lamp.
Voltage will only pass through the lamp during positive half-waves (pulses), so the lamp will flicker faintly at a frequency of 50 Hz. However, due to thermal inertia, the filament will not have time to cool down in the intervals between pulses, and therefore the flickering will be faintly noticeable. If we power a receiver or power amplifier with this voltage, then in the loudspeaker or speakers we will hear a low-pitched hum with a frequency of 50 Hz, called AC hum. This will happen because the pulsating current, passing through the load, creates a pulsating voltage in it, which is the source of the background.
This drawback can be partially eliminated if a high-capacity filtering electrolytic capacitor (Cf) is connected in parallel with the load. Charging with current pulses during positive half-cycles, the capacitor (Cf) during negative half-cycles is discharged through the load (Rн)
. If the capacitor is of sufficiently large capacity, then during the time between current pulses it will not have time to completely discharge, which means that the load (Rн) will continuously maintain current both during positive and negative half-cycles. The current maintained by charging the capacitor is shown in the right graph as a solid wavy red line.
Power rectifier diode But even with such a somewhat smoothed current, it is also impossible to power a receiver or amplifier because they will “phon”, since the level of pulsation (Upulse) is still very noticeable. In the rectifier, the operation of which we have become acquainted with, the energy of only half of the alternating current waves is usefully used, therefore more than half of the input voltage is lost on it and therefore such rectification of alternating current is called half-wave, and rectifiers are called half-wave rectifiers. These shortcomings are eliminated in rectifiers using a diode bridge.
Full-Wave Rectifier Voltage Filtering
The output we get from the full wave rectifier is a pulsating DC voltage that increases to a maximum and then decreases to zero.
To obtain a ripple-free voltage, we need to filter the output signal. One way to do this is to connect a capacitor, known as a smoothing capacitor, across a load resistor, as shown below:
Initially the capacitor is not charged. During the first quarter of the cycle, diode D1 is forward biased, so the capacitor begins to charge. Charging continues until the voltage reaches its peak value. At this moment, the voltage across the capacitor will be equal to Vp.
After the input voltage reaches its peak, it begins to decrease. As soon as the input voltage becomes less than Vp, the voltage across the capacitor will be higher than the input voltage, which will close the diode.
When the diode is not conducting, the capacitor discharges through the load until the next peak is reached. When the next peak occurs, diode D2 briefly opens and charges the capacitor to the peak value.
Application of diodes
One should not think that diodes are used only as rectifiers and detectors. In addition, you can highlight many more of their professions. The current-voltage characteristics of diodes allow their use where nonlinear processing of analog signals is required. These are frequency converters, logarithmic amplifiers, detectors and other devices. Diodes in such devices are used either directly as a converter or form the characteristics of the device when included in the feedback circuit. Diodes are widely used in stabilized power supplies, as reference voltage sources (zener diodes), or as switching elements of storage inductors (pulse voltage stabilizers).
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Rectifier diodes.
Using diodes it is very easy to create signal limiters: two diodes connected back-to-back - in parallel serve as excellent protection for the input of an amplifier, for example, a microphone, from supplying an increased signal level. In addition to the listed devices, diodes are very often used in signal switches, as well as in logic devices. It is enough to recall the logical operations AND, OR and their combinations. One type of diode is LED. Once upon a time they were used only as indicators in various devices. Now they are everywhere, from the simplest flashlights to TVs with LED backlighting, it is simply impossible not to notice them.
Features of a three-phase bridge and options for its construction
Bridge circuits of three-phase rectifiers have design options that make it possible to improve the parameters of the device. They can be improved by introducing additional valve elements. They are equipped with 6, 9 or even 12 rectifier diodes connected in a star or delta circuit.
The more phases (or pairs of diodes) are used in the rectifier circuit, the lower the level of output voltage ripple.
As an example, consider a device with 12 rectifier diodes. One of the groups of 6 pieces is included in this case according to the “star” circuit with a common zero point, and the second - in a triangle (without ground). Taking into account the fact that the rectifiers are connected in series, the potentials at the system output are summed up, and the ripple frequency in the load turns out to be 12 times greater than the network value (50 Hertz). After filtering, the voltage supplied to the consumer is of higher quality.
Diode bridge circuit
One of the most important parts of electronic devices powered by a 220 volt AC network is the so-called diode bridge. A diode bridge is one of the circuit solutions on the basis of which the AC rectification function is performed.
As you know, most devices require direct current rather than alternating current to operate. Therefore, there is a need for rectification of alternating current.
For example, the power supply, which has already been discussed on the pages of the site, contains a single-phase full-bridge rectifier - a diode bridge. In the circuit diagram, the diode bridge is depicted as follows.
Diode bridge circuit
This is a so-called single-phase bridge rectifier, one of several types of rectifiers that are actively used in electronics. It is used to produce full-wave rectification of alternating current.
In hardware it looks like this.
Diode bridge made of individual diodes S1J37
This circuit was invented by the German physicist Leo Graetz, therefore this circuit solution is sometimes called the “Graetz circuit” or “Graetz bridge”. In electronics, this circuit is currently used everywhere. With the advent of cheap semiconductor diodes, this circuit began to be used more and more often. Now you won’t surprise anyone with it, but in the era of radio tubes the “Graetz bridge” was ignored, since it required the use of as many as 4 tube diodes, which were quite expensive at that time.
Calculation of a bridge rectification circuit
The specified or known values are the voltage at the load (Uav.set, current through the load Iav, ripple factor of the rectified voltage Kp.set at the output, voltage and frequency of the supply network.
The calculated values are determined by the formulas:
A valve with permissible reverse voltage is selected from the directory
Urev ≥ 1.6 Uav.r
and current through the valve
I'avg ≥ 0.6Iavg
Next, the electrical quantities characterizing the secondary winding of the transformer are calculated:
UII=(1.1÷1.3)Uav.r III = 0.8Iav; PII=UIIII
In order to obtain a flat external characteristic, it is advisable to choose a filter starting with inductance.
Voltage ripple coefficient at the filter input
Kp.in = 0.67.
Smoothing factor
At a load current of up to 200 mA, the capacitance value of the filter link does not exceed 8–12 μF. Having specified the filter link capacitance Cf, we can determine the inductance of the filter choke
(208)
The capacitance of capacitor C1 shunting the inductor is calculated by the formula
(209)
Capacitor C1 must be designed for operating voltage
Uwork = 4πƒLдрIср
In conclusion, you need to determine the calculated (overall) power of the power transformer using the formula
Using Op Amps
As is known, the current-voltage characteristic of diodes is nonlinear; by creating a single-phase precision (high-precision) full-wave rectifier on an op-amp chip, the error can be significantly reduced. In addition, it is possible to create a converter that allows you to stabilize the current on the load. An example diagram of such a device is shown below.
Circuit: a simple op-amp stabilizer
The figure shows a simple current stabilizer. The op amp used in it is a voltage controlled source. This implementation makes it possible to ensure that the current at the output of the converter does not depend on the voltage loss across the load Rн and the diode bridge D1-D4.
If voltage stabilization is required, the converter circuit can be slightly complicated by adding a zener diode to it. It is connected in parallel to the smoothing capacitance.
Bridge Circuit Operation
Understanding electrical measuring instruments
The device consists of four semiconductor gates combined into a bridge. In this case, the secondary winding of the transforming device is combined with the opposite arms of the diode bridge. The load resistors will be connected via other shoulders. In this case, the output characteristics are significantly higher than those of two-period ones, due to the flow of the entire wave of alternating current voltages through the device.
During the positive half-wave, the signal moves from the negative part of the secondary winding of the transforming device through the valves and load resistor to the positive part of the set of turns of the transforming device. With a negative half-wave, the process occurs in the reverse order.
How to implement voltage doubling
Below is a circuit that allows you to obtain a voltage at the output of the device that is twice as high as the original one.
Voltage doubling circuit
It is typical for such a device that two capacitors are charged in different half-cycles, and since they are located in series, then, as a result, the total voltage at “Rn” will be twice as high as at the input.
In a converter with such a multiplier, transformers with a lower secondary winding voltage can be used.
Simple rectifier circuit
Sinusoidal voltage is a periodic signal that varies over time. From a mathematical point of view, it is described by a function in which the origin corresponds to time equal to zero. The signal consists of two half-waves. The half-wave located in the upper part of the coordinates relative to zero is called a positive half-cycle, and in the lower part - negative.
When an alternating voltage is applied to the diode through a load connected to its terminals, current begins to flow. This current is due to the fact that at the moment the positive half-cycle of the input signal arrives, the diode opens. In this case, a positive potential is applied to the anode and a negative potential to the cathode. When the wave changes to a negative half-cycle, the diode is turned off, as the polarity of the signal at its terminals changes.
Thus, it turns out that the diode, as it were, cuts off the negative half-wave, without passing it to the load, and a pulsating current of only one polarity appears on it. Depending on the frequency of the applied voltage, and for industrial networks it is 50 Hz, the distance between the pulses also changes. This type of current is called rectified, and the process itself is called half-wave rectification.
By rectifying the signal using a single diode, you can power a load that does not have special requirements for voltage quality. For example, a filament. But if you power up, for example, a receiver, a low-frequency hum will appear, the source of which will be the gap that occurs between the pulses. To some extent, to get rid of the disadvantages of half-wave rectification, a capacitor connected in parallel with the load is used together with a diode. This capacitor will charge when pulses arrive and discharge when there are no pulses to the load. This means that the larger the capacitance value of the capacitor, the smoother the current across the load will be.
But the highest signal quality can be achieved if two half-waves are used simultaneously for rectification. The device that allows this to be realized is called a diode bridge, or in other words, a rectifier bridge.
Specifications
When choosing a specific diode bridge to replace in a rectifier block or for any other circuit, it is important to have a good understanding of the basic technical parameters.
Among these characteristics, the most significant for a diode bridge are:
- The maximum amplitude voltage of reverse polarity is a threshold value beyond which an irreversible process will already occur and the semiconductor will fail. Designated as UAobr in domestic models or Vrpm for foreign ones.
- Average reverse voltage - represents the nominal value of an electrical quantity that can be applied during operation. It is designated Uobr in domestic samples or Vr(rms) for foreign diode bridges.
- Average rectified current - indicates the effective value of the electric current at the output of the diode bridge. On devices it is indicated as Ipr or Io for models of domestic or foreign production, respectively.
- The peak-to-peak rectified current is the maximum current at the output of the rectifier, determined by the half-wave peak on the curve, denoted as Ifsm for the pulsating current at the positive and negative terminals.
- Voltage drop in direct polarity - determines the voltage loss from the diode bridge’s own resistance. On the device it is designated as Vfm.
If you want to choose a replacement model, let’s say in a 220 V network, then the main parameter for the diode bridge is reverse current and voltage. The performance characteristics must significantly exceed the network rating, for example, at a voltage of 220 V - the diode bridge must withstand about 400 V. In terms of current, a smaller reserve is suitable, but it should also be provided for.
Purpose and practical use
The scope of use of a bridge made of diodes is quite wide. These can be power supplies and control units. It is installed in all devices powered by a 220 volt industrial network. For example, TVs, receivers, chargers, dishwashers, LED lamps.
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Cars cannot do without it either. After starting the engine, the generator starts working, producing alternating current. Since the on-board network is all powered by constant voltage, a rectifier bridge is installed through which rectified voltage is supplied. The same constant signal also recharges the battery.
The rectifier device is used to operate the welding machine. True, it uses powerful devices that can withstand currents of more than 200 amperes. The use of diode assembly in devices provides a number of advantages compared to a simple diode. This straightening allows you to:
- increase the ripple frequency, which can then simply be smoothed out using an electrolytic capacitor;
- when working together with a transformer, get rid of the bias current, which makes it possible to more efficiently use the overall power of the converter;
- pass more power with less heat, thereby increasing efficiency.
But it is also worth noting the drawback due to which in some cases the bridge is not used. First of all, this is a double voltage drop, which is especially sensitive in low-voltage circuits. And also, when some of the diodes burn out, the device begins to operate in half-wave mode, which is why parasitic harmonics penetrate into the circuit, which can damage sensitive radioelements.
power unit
Not a single modern power supply can do without a rectifier. High-quality sources are manufactured using bridge rectifiers. The classic scheme consists of only three parts:
- A step-down transformer.
- Rectifier bridge.
- Filter.
A sinusoidal signal with an amplitude of 220 volts is supplied to the primary winding of the transformer. Due to the phenomenon of electromagnetic induction, an electromotive force is induced in its secondary winding and current begins to flow. Depending on the type of transformer, the voltage value is reduced by a certain value due to the transformation ratio.
An alternating signal with reduced amplitude appears between the terminals of the secondary winding. In accordance with the diode bridge connection diagram, this voltage is supplied to its input. Passing through the diode assembly, the alternating signal is converted into a pulsating one.
This form is often considered unacceptable, for example, for sound equipment or lighting sources. Therefore, a capacitor connected in parallel with the output of the rectifier is used for smoothing.
Three-phase rectifier
In production and in places where a three-phase network is used, a three-phase rectifier is used. It consists of six diodes, one pair for each phase. Using this type of device allows you to obtain a higher current value with low ripple. This, in turn, reduces the requirements for the output filter.
The most popular options for connecting three-phase rectifiers are the Mitkevich and Larionov circuits. In this case, not only six diodes can be used simultaneously, but also 12 or even 24. Three-phase bridges are used in diesel locomotives, electric vehicles, on drilling rigs, and in industrial gas and water purification plants.
Thus, the use of bridge rectifiers makes it possible to convert alternating current into direct current, which powers all electronic equipment. Making a diode bridge yourself is not difficult. At the same time, its use allows you to obtain not only a high-quality signal, but also increase the reliability of the device as a whole.
Advantages and disadvantages
In addition to the diode bridge, there are other ways to convert alternating current to direct current. Compared to half-wave rectification, full-wave rectification has a number of advantages:
- Both the negative and positive half-waves of the sine wave are converted into output voltage, so that the entire power of the transformer is used to the most optimal extent.
- Due to the higher pulsation frequency, the voltage received from the diode rectifier is much easier to smooth out using filters.
- The use of electricity under load reduces power losses due to core magnetization reversal, which occurs due to mutual induction processes in the windings of the supply transformer.
- Harmonious redistribution of the curve of electric current and voltage at the output - due to the transmission of each half-cycle by two diodes in the bridge at once, the output parameter is much more uniform.
The disadvantages of a diode bridge include a larger voltage drop compared to a half-wave circuit or a midpoint-tapped rectifier. This is due to the fact that current flows through two semiconductor elements at once and encounters ohmic resistance from each of them. Such a disadvantage can have a significant impact in low-current circuits, where fractions of an ampere can determine the value of signals, operating modes of units, etc. As a solution, diode bridges with Schottky diodes, which have a relatively lower forward voltage drop, can be used.
Another disadvantage is the difficulty of identifying a burnt-out link, since if at least one diode fails, the entire circuit will continue to work. It is possible to understand that one of the semiconductor elements has fallen out of the circuit only through measurements; it is not always the case that a device or circuit will react with a visible malfunction when it fails.
Transformer circuit with double winding and common terminal
The principle of operation is that during the positive half-wave the same voltage is generated. At this time, the lower valve remains closed under the influence of a negative signal, while the upper valve opens. Thus, electric current flows from it.
During the negative part of the half-wave, the upper gate diode is in the closed state due to the voltage flowing to the cathode from the lower valve, which is open due to the positive signal arriving at the anode. In this case, both half-waves work.
Rectified voltage smoothing
The quality level of the rectified signal is assessed according to the ripple factor. To reduce the indicator, semiconductor smoothing filters, both inductive and capacitive, are used.
Sources
- https://tpspribor.ru/interesnoe/diodnyy-most.html
- https://electrosam.ru/glavnaja/jelektrooborudovanie/jelektropitanie/vypriamiteli/
- https://amperof.ru/elektropribory/vypryamitel-toka.html
- https://www.kipiavp.ru/pribori/odnopoluperiodniy-vipryamitel.html
- https://ElectroInfo.net/poluprovodniki/dlja-chego-nuzhny-vyprjamitelnye-diody.html
- https://www.elel.ru/shemavip3.html
- https://amperof.ru/elektropribory/dvuxpoluperiodnyj-vypryamitel.html
- https://tokar.guru/hochu-vse-znat/vypryamitel-shema-diodnogo-mosta.html
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