With the rapid development of power electronics technology, power electronic equipment is increasingly closely related to people's work and life, and electronic equipment is inseparable from reliable power supply. In the 80s, computer power supplies fully realized switching power supply, taking the lead in completing the development of computers. In the 90s, switching power supplies entered various electronic and electrical equipment fields. Program-controlled switches, communications, electronic testing equipment power supplies, control equipment power supplies, etc. have widely used switching power supplies, which has promoted the rapid development of switching power supply technology. . As the core component of power supply, transformer has also followed the development rhythm of power supply, evolving from industrial frequency transformer to high frequency transformer, and developing towards higher frequency technology route. High frequency of transformers is the direction of its development. High frequency makes transformers miniaturized, and the corresponding switching power supply has a smaller appearance. This allows switching power supplies to enter a wider range of application fields, especially in high-tech fields. Application has promoted the miniaturization and portability of high-tech products.
The following table shows the three main stages of modern transformer development:

     From the above three main stages of transformer development, it can be seen that the development of transformers mainly revolves around three directions: 1. The operating frequency is getting higher and higher. The higher the frequency, the higher the power density and the conversion efficiency can also be improved; 2. The size of the product is getting smaller and smaller, and the smaller size can make a smaller power supply, thereby adapting to a wider range of application fields; 3. The production process is getting simpler and simpler, the fewer the process processes, the higher the product consistency, and the cost is also can be significantly reduced; and as far as the current technical level is concerned, the most promising among these three directions is the development of planar transformers.
     Looking to the future, with the continuous advancement of technology and the continuous innovation of materials, it is believed that planar transformers will become the mainstream of the industry and move towards integration and modularization.