[en] The Bipolar Junction Transistor (BJT) study is a regular subject on analog electronic subjects taught in the initial phase of electronic engineering courses. This electronic component, often considered elementary, is far from being simple to explain because it covers several concepts, such as three Regions of Operation, two Working Regimes, and two Region of Operation Boundaries. It is not surprising then that students often find it difficult to understand the functioning of this component. The present article describes partially the work developed by a team with a number of students in order to understand the difficulties of teaching/learning the BJT. We present the students’ perceptions from the analysis of several traditional and modern means to support the learning of the BJT. Interestingly, the learning BJT model considered simpler for beginner students corresponds to the model that originally gave it the name i.e. Trans-Resistor (Transistor). (Author)