Research on the flyback switch power supply based on the primary feedback and the valley control

In order to decrease components, cut costs and realize multiple output, combining with the advantages of the traditional flyback switch power supply, a design scheme of the flyback power supply is proposed based on the primary feedback and the valley control. So, many components are omitted based on the primary feedback, such as the optical coupler, the compensation network and the given voltage components. And then, the amplitude of dV/dt from the power switch can be reduced based on the valley control. Firstly, the working principle of flyback converter is described based on the primary feedback and the valley control. Then, the calculation method of transformer and the parameter selection of main components are given. Finally, the principle experiment prototype is developed. The experimental results verify the feasibility and effectiveness of the design, and meet the design requirements.