Modern electronic and electrical devices have a rather complex structure. Their efficient and trouble-free operation is ensured by a large number of components. One of them is a pulse transformer, the principle of which is based on active conversion of electric current.
Content
- Main function
- Production requirements
- Mechanism of action and types of devices
- Calculation of indicators
Main function
Devices that depend on electric current are often equipped with pulse transformers (IT). This is done in order to provide protection against short circuit, too high voltage coming from the network, and overheating of the housing of electrical appliances. A pulse transformer installed inside the power supply converts the voltage in such a way that the pulse received at the output has a minimum of distortion. The conversion rate of the output pulse depends on the technical characteristics of the IT.
The use of such a transforming device makes it possible to significantly reduce the weight, size and price of the devices in which it is installed.
It is present both in household appliances (color TVs, computer monitors) and in special equipment, which is based on the action of a pulse (gas lasers, magnetrons, triode generators, differentiating transformers).
Production requirements
The process of creating a pulse transformer takes place with strict adherence to certain requirements. Requirements to be met by IT are divided into: Technical and economic. These include weight, dimensions, cost. It is also important that readily available raw materials and manufacturing techniques are used to manufacture the instrument. This category of requirements is very conditional, since the parameters included in it can easily change depending on various factors. For example, conductors, dielectrics of different types can act as starting materials, which in the future can affect the weight in different ways, size or cost of the finished transformer.
- Operational. Determine the degree of reliability of the feedstock, its thermal stability, resistance to climatic factors and mechanical damage. An important operational requirement is the mandatory check of the transformer for the ability to operate in emergency mode.
Key IT performance metrics such as voltage, power and pulse shape are controlled by functional requirements. It depends on how accurately they are observed, how long and with what efficiency the pulse transformer will perform its function.
During the manufacture of the core, different materials can be used. Most often, the raw materials are:
- Electrical steel.
- Ferrite.
- Permalloy.
Alsifer is considered the best raw material for the production of transformer cores. It is a fairly rare material, so alsifer cores are quite rare.
Mechanism of action and types of devices
The operation of a pulse transformer is ensured by a pair of coils connected by a magnetic core and having a winding of various configurations. The number of turns on the winding determines the power of the electrical energy received at the output.
The primary winding circuit receives unipolar pulse signals. It also detects rectangular pulses with a short time interval. Then the same pulses are reflected on the secondary winding. The principle of reflection is fundamental in the work of all IT.
Transformers can have a different design. One of the distinguishing features of the design is the types of windings. Depending on it, the following types of device are distinguished:
- toroidal,
- pivot,
- armored,
- armored rod.
Different windings can be used inside these transformers. The coils can be in the form:
-
Spirals. Foil is used as the main material. Spiral coils are characterized by the minimum leakage inductance and are most often installed in autotransformers. - Cylinder. This coil is simple in shape and low in inductance.
- Cone. This shape is obtained due to the different thickness of the contours, increasing from the beginning to the end.
The types and shapes of windings have a direct impact on the technical and operational parameters of IT, such as voltage, overall power, dimensions and weight.
Each transformer has a special marking containing information about its type and type of installed coil.
Calculation of indicators
A pulse transformer is not only produced in production, but also created independently. In order for a self-made device to perform its functions without errors and failures, you will need to calculate in advance:
- core area (in its cross section),
- minimum number of winding turns,
- cross-sectional diameter of wires for circuits,
Having determined the value of the main parameters, it will not be difficult to find out the overall IT capacity. Correct calculations will help to create a pulse transformer, which, with a relatively low weight, will have a high efficiency, an extended voltage range. At the same time, the costs for the independent manufacture of the device will be very small.
