The static design of AC/DC and DC/DC switching power supplies relies on a simple but repetitive process. Although specific spreadsheets, available in various CAD programs, are widely used, they are difficult to use in educational applications. In this paper a graphic tool programmed in MATLAB is presented to allow students to make a rapid static design. This tool has been successfully employed in the subject ldquoSistemas Electronicos de Alimentacionrdquo in the Telecommunications Engineering degree as part of the project of new education methods (University of Oviedo project PB-08-019). During practical sessions the students have used the tool to design the power supply, achieving better learning results than before it was used. In addition, the tool has been successfully used to improve the students, theoretical knowledge of the subject.