An expert system on transformer design for switched mode power supplies

Switched mode power supplies (SMPS) have become an important subassembly for any type of electronic equipment. Operation in the switched mode decreases the volume of the magnetic core material. The choice of the magnetic components depends on the circuit topology. Given the large number of converter topologies available, the design of the magnetic components constitutes a substantial problem. A wide variety of materials, core geometries, and commercial core products must be considered for an optimal transformer design. An expert system was developed to support this task. It selects the optimum core for a specified SMPS from a given database. Criteria like power rating, DC output voltage, temperature rating, importance of a low-profile core and isolation class can be preselected. A fully interactive graphic interface is realized. The expert system is based on Common-LISP. It is executable on UNIX graphic workstations using the X11R4 window system and the OSF/Motif library