104 IEEE TRANSACTIONS ON EDUCATION, VOL. 54, NO. 1, FEBRUARY 2011 A Switching-Mode Power Supply Design Tool to Improve Learning in a Power Electronics Course Pablo F. Miaja, Student Member, IEEE, Diego G. Lamar, Member, IEEE, Manuel Arias Pérez de Azpeitia, Student Member, IEEE, Alberto Rodríguez, Student Member, IEEE, Miguel Rodríguez, Student Member, IEEE, and Marta M. Hernando, Member, IEEE Abstract—The static design of ac/dc and dc/dc switching-mode power supplies (SMPS) relies on a simple but repetitive process. Al- though specific spreadsheets, available in various computer-aided design (CAD) programs, are widely used, they are difficult to use in educational applications. In this paper, a graphic tool programmed in MATLAB is presented, which allows students to apply and to reflect upon the knowledge acquired in theoretical classes. This tool has been successfully employed in the course “Sistemas Elec- trónicos de Alimentación” in the Telecommunications Engineering degree as part of a project in new education methods (University of Oviedo project PB-08–019). During practical sessions, the stu- dents used the tool to design a SMPS, achieving better learning results than was the case without the tool. In addition, the tool was successfully used to improve the students’ theoretical knowledge of the subject. Index Terms—Computer-aided engineering, education, edu- cational technology, learning, project-based learning, switching power supplies teaching. I. INTRODUCTION T ELECOMMUNICATIONS engineering is a five-year de- gree program in the University of Oviedo (Gijón, Spain). The courses that make up this degree cover topics that range from the mathematical background of telecommunications to electronic design with special emphasis given to radio and to high-frequency designs. Computer networks and computer science also feature prominently. During their last year, the students have to choose between various elective courses in order to specialize. The course ”Sistemas Electrónicos de Alimentación” (”Electronic Power Systems”) [1] is one of these elective courses offered. Its main topics are the typical topologies of ac/dc and dc/dc switching-mode power supplies (SMPS), magnetic design, and power devices. Only these types of conversions are covered in this power electronics course because they are the most common in telecommunication equipment. Manuscript received May 21, 2009; revised November 17, 2009; accepted March 11, 2010. Date of publication April 15, 2010; date of current version February 02, 2011. This work was supported by the University of Oviedo under the project in new educational methods: PB-08–019. The authors are with the Power Supply Systems Group, Department of Electrical and Electronic Engineering, University of Oviedo, Gijón 33204, Spain (e-mail: fernandezpablo.uo@uniovi.es; gonzalezdiego@uniovi.es; ariasmanuel@uniovi.es; rodriguezalberto@uniovi.es; rodriguezmiguel. uo@uniovi.es; mmhernando@uniovi.es). Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/TE.2010.2046490 From their courses, students can learn a great deal of telecom- munications theory, but they are rarely offered the opportunity to work on the development of a real product, either software or hardware. However, the ability to apply their knowledge in a real situation is one of the most necessary skills that an engi- neer must have. A training in the development of a real product gives the students the opportunity to face some of the real prob- lems they will encounter in their future careers. One of the better ways to learn something is by the methodology often known as learning by doing: To learn something properly, you must actu- ally do it yourself. That is the reason why the teachers giving the course offer the students the opportunity to build a full SMPS so they can apply the knowledge acquired in theoretical classes. In order to accomplish these objectives, a lot of preliminary work has to be done: Students should learn all the theory behind the development of ac/dc and dc/dc power converters before working on a real one. This is explained in theoretical classes that cover all the aspects involved in the design: the specifica- tions of the semiconductor devices, the design of magnetic com- ponents, the static and dynamic models of the converters, and so on. The students have to pass an exam on those theoretical con- cepts and must demonstrate that they have understood all the concepts taught by developing a simple spreadsheet to analyze a converter not covered in class. This spreadsheet is often done in MATLAB. The last, but not the least significant, part of the course is the design and construction of the power supply, where they have to apply all the theoretical concepts they have learned. This paper is focused on this point: the proper design and con- struction of an SMPS during the practical sessions of a course. One of the main problems of making real power supplies in power electronics courses is the time that must be spent on the laborious calculations needed. These are based on static models of power supply topologies, widely known and refer- enced in [2]–[5]. These models are fundamental for correctly comprehending how switching power supplies work, and they are explained in the theoretical classes of power electronic courses. However, these models imply numerous calculations that take a lot of time. This makes it very difficult to complete a power supply design during the theoretical sessions of the course. Thus, design time must be optimized. This could be achieved by using computer programs. Traditionally, designers have written specific spreadsheets for every task needed in the design process. Some of these are used for the static de- sign, others for the estimation of efficiency, and others for the magnetic components needed. These spreadsheets were not designed for educational purposes and are lacking in usability, so a lot of time is spent getting used to the tool. This work 0018-9359/$26.00 © 2010 IEEE