Types of transformers
The transformer call the static elektromagyonitny device transforming parameters of alternating-current electrical energy and transferring this energy from one chain in druyogy.
By means of transformers it is possible to transform the main payorametra of electrical energy (tension, current, frequency, number of phases and the form of the curve of tension or current) in chains of the variable or changing current.
Transformers use for alternating-current transformation of one tension to alternating current of another (others) of tension without frequency change. Each of transformations is usually carried out together with transmission of energy in the electromagnetic way from one electric circuit to another.
Often the transformer performs function of the electric razyovyazka of chains and is called isolating. Also the komyobinirovanny (electromagnetic and electric) way of transmission of energy when the source and the consumer of electromagnetic energy electrically are connected via the transformer is possible. Such type of the transforyomator is called the autotransformer.
In electrotechnical devices of the radio-electronic apparayotura low-power transformers of different function and devices are widely used.
The different signs determined by their circuit assignment, electric parameters, the design, etc. are the basis for classification of transformers.
On circuit assignment transformers podrazyodelyat on 3 main groups: power, coordinating and imyopulsny.
Power transformers serve for power supply of devices of the radio-electronic equipment (micromotors, windings of the relay, magnetic amplifiers, rectifiers, control units and the indiyokation, lighting and heating instruments, etc.) as the changed current.
Matching transformers are intended for approval of resistance between links (cascades) in the radio-receiving, radio-transmitting, intensifying and other equipment.
These transformers can be subdivided on entrance, intermediate and output. They work at the fixed frequency or in the frequency band.
Impulsnyetransformatora are intended for transfer of imyopuls of tension or current from one electric circuit in another. They are widely used in the pulse equipment and in control units by thyratrons and thyristors.
On circuit execution (number of windings) transformers divide into one - two - and multiwinding.
Odnoobmotochnyytransformator — the autotransformer in which between primary (entrance) and secondary (day off) party there is not only the magnetic, but also direct electric link.
The double-wound transformer has one primary and one secondary electrically not the connected windings. It is very widespread and is base in the theoretical analysis. In such transformers current and aa. of page of primary winding are connected by unambiguous ratios with current and tension of secondary winding. The multi-winding transformer has one primary and several electrically not connected secondary winding. The quantity of windings can be any. Multi-winding transformers most often occur among power.
On operating frequency transformers can conditionally be separated into transformers:
- underfrequency (it is lower than 50 Hz);
- industrial frequency (50 Hz);
- the increased frequency (100 - 10 LLC Gts);
- high frequency (over 10 LLC Gts).
Transformers of the promyshlennoychastota are widely used in the common industrial, radio-electronic, broadcasting and household equipment. Transformers of other types are used generally in the special equipment. On number of phases transformers divide on single-phase and multiphase (three-phase, hexaphase, etc.). The number of phases of primary party of the transformer is defined by number of phases of primary alternating current source, and number of phases of the secondary party, circuit assignment of the transformer.
On tension transformers can be separated on:
- low-voltage (the operating voltage on one of windings does not exceed 1000 - 1500 V);
- high-voltage (operating voltage at least is higher than 1000 - 1500 V of one of windings), high-potential (windings low-voltage, but between them or concerning the body exist high potential differences).
On the transformation ratio of N and п р I е and I transformers divide N on lowering and raising. On the magnetic conductor design - on rod, armored and ring, and on the design of windings - on bobbin, the disk and toroidal. In general on constructive signs transformers are subdivided on opened, closed and pressurized. These signs define ways of cooling, isolation and protection against influence of the external environment.Top