Design Of Switching Power Supply With Multiple Output And Electromagnetic Compatibility

With the development of economy and society, energy use has become more frequent, switching power supply is the power converter which is now widely used, with low cost, reliability, adjustable output and the strong ability to adapt. It is the most common power conversion device. However, by the development of the power system, the electromagnetic environment of space is also exacerbated by a variety of electromagnetic interference, it is a potential threat for electronic devices. The electromagnetic compatibility sometimes directly determines the scope and the life of a product, it is a problem that must be considered for electrical and electronic product design at present.This paper presents multiple output switching power supply design that is resistant to electromagnetic interference, it can work in specific electromagnetic environment. Paper introduces the development of EMC discipline and switching power supply, then introduces the selection and basic topology for switching power supply with detail analysis and detail comparison. The tip is the analysis for the pros and cons of the five main conversion circuit topology, And the paper determines the controller program with PWM anti-single-ended forward converter. In the specific design aspects, according to the information we calculate the approximate capacity and inductance of the main transformer. To determine the data of filter capacitor and inductor turns ratio, circuit simulation is used by the idea that simulation and practice are combined, At last the physical output of power is detected.Switching power supply always works in harsh electromagnetic environment, so the electromagnetic compatibility design is a project that must be carried out, filtering and surge suppression design has been used based on the existing conditions, while the anti-interference measures also used in PCB design. Finally, a simple electromagnetic compatibility test has been carried out for the power board, experimental result shows that the switching power supply can suit the general case.