Transformers are usually power transformers and signal transformers.
Magnetic components are essential components in power switching converters and signal transformers.
Due to the nonlinear characteristics of magnetic materials and their dependence on temperature, frequency and air gap, it is difficult to measure the parameters of magnetic materials. Therefore, when designing magnetic elements, it is necessary to have a certain understanding of the parameters, general characteristics and design methods of magnetic elements.
First of all, the main part of this paper describes the basic theory of transformer magnetism and magnetic theorem, the meaning and interpretation of parameters. Secondly, the performance model and equivalent circuit of the transformer are described, and various parameters and terms of the transformer are explained.
The paper also introduces the high frequency current effect in the design of high frequency switching power supply, and describes the measurement method of transformer equivalent circuit parameters used in transformer testing.
In order to understand the performance of the transformer in application, a general equivalent circuit model is derived based on the response characteristics of the broadband signal of the transformer in frequency domain under the condition of pure resistive load.
The time-domain response characteristic curve best describes the effect of equivalent circuit parameters on the rising, peak and falling edges of the pulse waveform applied to it. For LAN and long distance communication using high repetition rate digital pulse signal, the transformer should pay special attention to this pulse signal response.