Exploiting the recent achievements of the information and communication technologies, a new e-learning initiation entitled Yoto project was launched in 2004. On longer run its most important objective is to build up and maintain an electrical engineering knowledge base, on shorter run it helps giving more and more publicity to some relevant fields, especially power electronics, drives and motion control. The multimedia rich content can be utilized in the high level academic education, in the industrial vocational trainings and also in supporting the circuit and system design specialists by fast interactive tools. This paper presents a new e-module attached to the Yoto project about the dynamic operation and modeling of dc-dc converters.