Transformers-terms and definitions

The system of uniform terms and definitions is based on the current departmental and state standards, which include low-power transformers, mains power transformers, current and voltage transformers, electrical products, as well as means of secondary power supply of CEA.The following terms and basic definitions are used.

Aautotransformer - a transformer, the windings of which are galvanically interconnected so that they have a common part

Input matching signal transformer - matching signal transformer for matching the total internal electrical resistance of the signal source with the total input resistance of the functional unit of the electronic equipment.

Output matching signal transformer - a matching signal transformer for matching the output impedance of the electronic equipment stage with the impedance of the load.

Low power transformer output - the sum of the powers of all secondary windings of the transformer.

High potential electronic power transformer - a power transformer for electronic equipment, having at least one of the points of its electrical circuit a maximum potential exceeding 1,500 V of the peak value.

Durability - the property of an object to maintain an operable state until the onset of a limiting state with an installed maintenance and repair system

Frequency range - the frequency band, which is assigned a code name

Double winding transformer - a transformer having two, galvanically not coupled, windings

Ghermetic transformer - a transformer made in such a way that the possibility of communication between its internalrented space and environment.

Pulse signal transformer is a signal transformer designed to transmit, form, convert and store pulse signals.

Low-power transformer magnetizing inductance - inductance of the primary 'winding of a low-power transformer in no-load mode when a symmetrical voltage is applied to the transformer

Transformation ratio - the ratio of voltages at the terminals of two windings in idle mode

Low power transformer ratio - the ratio of the number of turns of the secondary winding to the number of turns of the primary winding

Magnetic induction Is a vector quantity that characterizes the magnetic field and determines the force acting on a moving charged particle from the side of the magnetic field

Magnetic flux - flux of magnetic induction

Microminiature transformer - a low-power transformer with a distance between the terminals of not more than 2.5 mm.

Micromodular transformer - a transformer with dimensions not exceeding 11.5 x 11.5 x 23 mm, the manufacturing technology of which allows its modular installation

Open circuit voltage of power transformer - voltage across the open secondary winding at rated frequency andrated voltage on the primary winding

Hfailover - the time of uninterrupted operation of the facility from the beginning of its operation to the occurrence of the first failure

Single phase transformer - a transformer, in the magnetic system of which a single-phase magnetic field is created.

Step-up transformer - a transformer with a low voltage on the primary winding

Adjustable transformer - a transformer that allows voltage regulation on one or more windings using special devices built into the transformer structure.

Signal decoupling transformer - signal transformer designed for galvanic isolation of electrical circuits

Mains power transformer - a power transformer for electronic equipment, designed to operate from an alternating current network.

Signal transformer - a low-power transformer designed for transmission, conversion, storage of electrical signals.

Signal matching transformer - a signal transformer designed to match various impedances of electrical circuits when converting and transmitting electrical signals.

Low power transformer - a transformer with an output power of 4 kV ■ A and below for single-phase transformers, 5 kV ■ A and below - for three-phase.

Electronic power transformer - a low-power transformer designed to convert the voltage of electrical networks into voltages required to power electronic equipment.

1.2. Classification of transformers

Small-sized transformers used in household and office electronic equipment.

They are classified according to the following main features:

  • according to the conditions of use and operation, taking into account the requirements for resistance to external influencing factors;
  • by functional purpose, which is determined by the types of electronic equipment;
  • according to the parameters of the input electrical energy (operating voltage and frequency);
  • by design and technological parameters and characteristics, the main of which are the design varieties of magnetic circuits.

Terms of use

Transformers for household and office electronic equipment are subdivided into performance groups and climatic performance categories based on resistance to mechanical factors. Execution groups are selected based on the conditions of use of transformers and the required level of resistance in terms of mechanical and climatic influences. When choosing performance groups, the maximum degree of unification and the minimum possible number of performance groups of transformers of each class must be ensured.

Transformers whose performance group meets the most stringent requirements are preferred, all other things being equal.

The specific group of climatic and other versions is indicated in the technical specifications of the transformers

When using transformers with rigid characteristics in terms of resistance to external influencing factors (VVF), and transformers with less stringent requirements, individual or general protection is used as part of the equipment: depreciation, thermostatting, sealing, etc., while measures of individual protection of products in as part of the electronic equipment should ensure the possibility of using products manufactured according to reduced operational requirements.

For sources and converters, it is allowed to use an adjustable voltage setting, selected from the following range: 0.5; 1.0; 2.0; 3.0; 5.0; 10 and 15% from the nominal values. Permissible deviations from the nominal voltage values can be double-sided symmetrical and asymmetrical, as well as one-sided. When operating ACC and telecommunication equipment, single-phase alternating voltage and phase voltages of three-phase current are used, which must correspond to the following values: rated voltage - 220 V; operating voltage - 187 ... 242 V inclusive for power supply from a general-purpose power grid; 213. .227 V inclusive for power supply of the equipment from the mains power supply through the regulation devices; voltage frequency - 50 Hz; frequency variation limits - 47.5 ... 52.5 Hz inclusive; permissible coefficient of nonlinear distortion - no more than 10%.

The nominal values of alternating voltages at the output of devices and power supplies and input supply voltages of functional units, PPPs, microcircuits and electronic equipment units containing transformers and drawn up by the main set of design documentation are selected from the range: 1,2; 2.4; 3.15; 5.0; 6.0 (6.3); 12.0 (12.6); 15.0; 24.0; 27.0; 36.0; 40.0; 60.0; 80.0; (110); 115; 127; 200; 220 and 380 V.

 Source: reference book MRB, issue 1270

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