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For conversion alternating current In a pre-transformer, its voltage is reduced, and then straightened by selenium valves.
| DC generator device. |
To convert an AC to constant, the collector is used, the principle of operation is as follows. The ends of the turn / (Fig. 133) are attached to two copper semirings (segments), called collector plates. The plates are rigidly strengthened on the shaft of the machine and isolate both from each other and from the shaft. Fixed brushes 2 and 3 are placed on the plates, electrically connected to the energy receiver.
The transformer is built from copper and sheet steel, and these materials are becoming more and more expensive, and it is there that we have just arrived. "We could go upstairs, right?". In London, the bar is filled - we turn back, climb the stairs - and Simon explains how he completely freed from tension.
That we have implemented here: voltage can fluctuate, for example, when the grid is powered sunny batteriesThe voltage of which changes in the daily rhythm when the battery is discharged or the power should pass through long cables. According to Simon Daniel, there is no comparable concept yet.
To convert an AC to a constant along with rectifiers, thermoelectric transducers are used. The thermoelectric converter consists of a conductor heater, which passes the convertible (measured) current, and a miniature thermocouple. The heater uses a thin wire made of a material allowing long heating, for example, from nichrome or constant. The thermocouple electrodes are usually performed from metals and their alloys.
"The system is very compatible with it, you can easily connect it to installed photo galvanic systems, you can even run it with an emergency car batteries." Passing by actors, we make our way along the corridor, heading for one of the four doors, the last stop: the theater offices. Again an important place, because here his system should show that it is also suitable in everyday labor life.
Benn Todd, "Dr. Benn Todd," he says. This is a bold comparison, but. why not? Arkol is a place where we want to promote the border, we are not a hospital here, no one dies, if something does not work, yes, now the light went out, but it doesn't matter, people here say then: someone ever Is there light? - And then someone will fix it.
Semiconductor rectifiers are used to convert alternating current.
To convert an AC to a permanent until 1912, rotating transducers (engine generators) were used, until mercury rectifiers appeared. In 1908, the low-voltage mercury rectifier was invented by Yuitt. Since 1915, mercury rectifiers get widespread.
Only continuous low-voltage electricity is harmless. Only he can flow through the human body, not leaving an inconvenient feeling. On the other hand, if the alternating current passes through any living body, the result is immediate death. Especially compared to traditional energy supply can be significantly saved energy.
Of the three coal shovers, which land in the boiler at the power plant, comes shovel. Two go to the losses on the power plant and the network, and from this one half the shovels is lost in computer sources of power so much energy can be consumed as coal in the bucket, so six of them should be burned on the power plant - this is not a good balance if the solar system can do the same thing.
To convert an AC to the constant, the engine generators, mercury, mechanical, as well as semiconductor rectifiers are used.
To convert an AC to a constant in the modern industry, semiconductors are used, which in contact with metals form electric valves - instruments that have the ability to carry out electrical current in one (direct conductive) direction and badly in the opposite direction. For the manufacture of sufficiently powerful valves, specially cooked semiconductors from Selena, Germany and silicon high purity are suitable.
Later this year he plans to equip a few hundred houses with its system in various experimental programs. On the other hand, the large industry focuses on large projects, and, for example, Johen Cruise is much more careful. So it should be our experience, with the exception of high-voltage transmission of direct current, where only one technical advantage Justifies the system change, more distribution applications, medium voltage applications still need some value added to justify the jump.
To convert an AC to constant on electrical and electric trains, rectifier semiconductor-nut installations are provided.
To convert the AC to constant and reverse, also apply rotating transducers of three types: engine generators, single-locking and cascade converters. The generator engine consists of two separate machines - the engine and the generator sitting on the same shaft and the connected coupling. To convert an AC to constant, an asynchronous or synchronous motor and a direct current generator with an independent excitation or self-excitation are used. The one-stop converter is a direct current generator, which, in addition to the collector, there are contact rings. A variable current is converted to a permanent in one anchor. In the event of a three-way current conversion, the anchor winding on one side of the machine is connected to the collector. Three pointing points of the anchor winding, located at an angle of 120, are attached to the three contact rings, reinforced on the shaft on the other side of the machine. To convert single-phase alternating, the permanent transducers are used, in which two contact rings attached to two diametrically opposite points of the anchor winding are strengthened.
First, this distribution of the network is performed in very high currents, so that effectiveness is significant, and secondly, they receive space, because the technology is easier, less components of the conversion and less space in cities - if you have a center Data processing, because it just stands something.
Rick de Donker, in turn, says that he sees the greatest potential in the wind energy on the shelf. If the power generated by wind turbines in the open sea is directed to the south using the usual AC technology, 13 percent of the generated power is lost. On the other hand, the transition to permanent current will give two advantages.
| DC generator. |
To convert an AC to constant, the collector is used, the principle of operation is as follows. The plates are rigidly strengthened on the shaft of the machine and isolate both one from the other and from the shaft. Fixed brushes 2 and 3 are placed on the plates, electrically connected to the energy receiver.
To convert an AC to constant and revolt, rotating transducers of three types are also used: engine generators, single-locking and cascade transducers. The generator engine consists of two separate machines - the engine and the generator sitting on the same shaft and the connected coupling. To convert an AC to constant, an asynchronous or synchronous motor and a direct current generator with an independent excitation or self-excitation are used. The same converter is a direct current generator, which, in addition to the collector, there are contact rings. A variable current is converted to a permanent in one anchor. In the case of a three-phase current conversion, the anchor winding on one side of the machine is connected to the collector. Three pointing points of the anchor winding, located at an angle of 120, are attached to the three contact rings, reinforced on the shaft on the other side of the machine. To convert single-phase alternating current to constant, converters are used, in which two contact rings attached to two diametrically opposite points of the anchor winding are strengthened.
The transfer of direct current in the open sea would also be less complex, the conversion stations would be eliminated, the nodes would be less, the necessary islands are much cheaper - therefore several advantages would be gathered here. Another niche that appears at the international level is office buildings.
Their goal: General standards for DC systems with a voltage of 380 volts, intended for lighting and operation computer Systems. Rick de Donker also wants to try it - and turn one floor of his institute to Colombia District. He thinks more about his own decisions and its own standards for Europe.
To convert an AC to constant, one - and multipostable welding transducers serve. Single-bed transducers (Table 3) that feed on the electrical network are machines consisting of an electric motor included in the electrical circuit and an electric welding generator that feeds the welding arc of a direct current. Typically, the engine rotor and an anchor of the generator are placed on the total shaft, sometimes on separate shafts that are connected by couplings. The electric motor and the generator are placed in a common case.
Why don't we do it? In addition, more and more high-voltage direct current lines come, and Rick de Donker wants to submit five years of solutions for entire DC collection networks for renewable energy sources. How far will the development will advance, until it is foreseen. However, experience shows that methods with semiconductors often underestimate the dynamics. It is possible that our grandchildren will consider a white output with two holes as curiosity.
Again and again the same problem arises: one has a voltage source, but it requires a smaller or more DC voltage. Should I now install a separate power supply for each required voltage? The project quickly exceeds any restrictions on the area and cost. There are many practical and solid solutions for voltage transformers. Here are some tensile converters. Because in order to buy the correct voltage converter, you need many considerations.
One of the important advantages of AC before constant is that the AC voltage is relatively easy to change using electromagnetic induction, and the methods of conversion of DC are complex.
The device for converting voltage and the forces of the AC at a constant frequency is called a transformer (Fig. 26.7, a). It was invented by P. N. Apple to the transformer consists of a closed core made of soft steel or ferrite, on which there are two isolated coils from each other (they are called windings) with different numbers of turns. The primary winding is included in the AC network, and the secondary one is connected to the consumer.
To convert a DC voltage exist different opportunities. Linear voltage regulators or linear converters constant voltage Very inexpensive, compact and therefore can be purchased very inexpensively. These small voltage transformers typically reach currents up to 2 amps. Some options can also process currents up to 10 amps. However, the productivity of losses from heat loss sometimes increases sharply. In the end, in adverse cases, 50% efficiency or less is not a problem.
In the simplest case, the excess voltage decreases through the resistor. However, due to current flow through the resistor and voltage drops, there is a lot of power scattering. Thus, the linear voltage regulator has the advantage of a cheap price. But the price is bought with significant energy losses.
The current in the primary winding creates an alternating magnetic flux in the core (Fig. 26.7, b), which leads the same e. d. s. Induction in every turn of both windings. If the primary winding has turns, and secondary to ", then e. d. s. Inductions in the windings are directly proportional to the number of turns in them:
In the simplest case, small switching regulators have the same body as linear voltage transformers. Although the components are slightly thicker than their ordinary relatives. Due to higher efficiency, much space can be saved with smaller radiators. The efficiency of more than 70% can be easily implemented using small switching regulators as voltage transformers.
Such as this high-performance module, as in the figure above. In version 5, a similar voltage converter 400 V DC can provide output current 200a. Because these voltage transformers begin where small solutions stop. Voltage solid transformers for greater power Begin at a speed of about 5 W and reach power up to 000 W. The less losses, the less heat allocated. The radiator and fan blocks can be compact accordingly.
With the opening chain of the secondary winding (idle transformer), the voltage on its clips is equal. In the primary winding, there is a weak current which is called idling current. Since the voltage drop on the resistance of the winding is very small, then the voltage is slightly more er. d. s. , but practically
Imagine you have a gazebo. This gazebo has a sunny element that supplies the battery. Or you switch the voltage converter 12 V between them. The only error in this: the voltage converter ruthlessly empty your battery. In this case, please consider protection against the deep discharge of the battery.
And finally, to industrial technology, where voltage transformers can be found in almost all areas. No matter, conveyor technology, automation, avionics or event and fair. For photo galleries, special charge regulators are required, which take into account the specific characteristics of the solar cell. But in fact it is quite simple: if you connect the voltage transformer 12 in directly to halogen lamps, then your voltage converter 12 will turn off or dies.
Thus, when idling The voltage transformer on the Wheel is directly proportional to the number of turns of the windings:
If the number of turns in the secondary winding is greater than in the primary, the transformer is called boosting, and if less than - downward. The ratio of the number of turns of the primary winding to the number of turns of the secondary winding is called
The reason is that cold halogen lamp It has a much larger starting current than the rated current is assumed, namely from three to four times the starting current. In the hobby, laboratory and typical structures, low-cost linear voltage regulators are still used. However, as soon as efficiency and compactness play a role, modern modern DC converters are used in switching technology.
Even industrial enterprises often use these components. This is necessary because most of the respective devices functions only under the DC voltage. On the other hand, the devices adapt the voltage. This step is necessary because most electronic products work with very low voltage. In addition, in this category there is special devicesthat perform additional tasks. These include, for example, buffer modules. This can lead to a short-term interruption of energy supply and, thus, prevent violation of production processes.
the transformation coefficient
So, at a lowering transformer, more than a unit, and at an increase - less than one.
When the secondary winding circuit closes (the load is connected to the transformer), the current of the secondary winding 12 creates a magnetic stream in the core, aimed towards the flow of the primary winding. Weakening flow in the core reduces e. d. s. In the primary winding. Therefore, the current in it increases to such a value at which its magnetic flux compensates the oncoming stream of the secondary coil and the resulting flow in the core will remain the same.
In the field of power, you can choose one of two options. First, there are products for a linear DC power source. They are pretty simple and therefore relatively inexpensive. On the other hand, you can use pulse power sources. They are equipped with a more complex technology that uses much smaller transformers. This facilitates their management and relief. In addition, they require less energy during operation. The online store provides products of leading world manufacturers - for example.
This movement of electrons along the conductor. Types electric current AC: This changes the direction of electrons at a certain frequency. Electrical generator machine that allows you to maintain the potential difference between two points. A device that allows you to change the tension using a magnetic field.
