Abstract:

In the paper, we present a new approach to a design of the circuit laboratory, which serves the students of the Faculty of Electronics and Information Technology of the Warsaw University of Technology at the second semester since 2011.

The four cornerstones of this approach are as follows:
• Focusing on fundamental concepts. Introductory exercises are designed to present to the students that for the real circuits, some basic physical laws (like the Ohm's law, the Kirchhoff's laws, the equivalent sources theorems, or the superposition principle) are satisfied with a good accuracy.
• Doing holistic, multi-concept exercises. Such approach allows presenting the intrinsic relations between different concepts covered by the laboratory, leading the students to a deeper review of their conceptual understanding by anchoring learning tasks in authentic situations. The examples include the analysis of a diode bridge followed by a low-pass filter or building the simplistic FM radio receiver.
• Stimulating multiple senses. To actively involve the students in the exercises, a big effort was made to change all potentially tedious experiments and measurements into a real adventure. The exercises have been devised to actively stimulate all the senses of the student: touch, sight, hearing, smell (of overheated resistors) and taste (actually, the taste of success).
• Working with real circuits. It has been decided that students should work with circuits consisting of real electronic elements that form the appropriately simplified (to be easily understood even by untrained students) fragments of real circuits. Such an approach emphasizes the close relationship between the laboratory and the real world.

The hardware base of the laboratory has been obtained by adopting and modifying the existing system of toy electronic "bricks" (invented and patented by a third party). The individual electronic elements are placed on the small printed boards with conductive (neodymium) magnetic terminals that can be connected via small metal balls. In such a way simple circuits can be set up in just a couple of seconds and are easily modifiable. Moreover, the number of possible combinations of element connections is virtually unlimited, and the layout of the connected elements very closely resembles the schematics. To assure the reliability of connections and to facilitate housekeeping of all those elements, a specialized tray is used.

The hardware is accompanied by PC-based software, realizing some virtual measurement instruments, such as four-channel oscilloscope, a couple of synchronized generators, wobbuloscopes, AC vector voltmeters, spectrum analyzers and power meters. These instruments utilize the multi-channel analog-to-digital and digital-to-analog converters card.

The laboratory exercises are supported by a comprehensive textbook containing both the theoretical background and the detailed executive guidelines for each exercise. The textbook is published as a PDF document, accessible to the students via the intranet.

In our personal opinion, the proposed approach to the circuit laboratory successfully reinforces the learning outcomes by revisiting the most fundamental concepts. The presentation of close connections between the theory and the practice, achieved by a thorough selection of the topics of the experiments, familiarizes students with real circuits and their components, motivating them for further studies in the field.

Keywords:

Electronics engineering education, educational technology, circuit theory laboratory.