SUMMARY
Instrumental digital didactics is based on the use of various digital means of obtaining, processing, and interpreting empirical data in accordance with the logic of scientific method and engineering design. Appropriate teaching techniques reflect the STEM approach to teaching natural science and engineering subjects. The use of the equivalent circuit created on the NI Multisim platform to investigate the characteristics of electric circuits’ components creates favorable didactic conditions. The methodological approaches proposed by the authors are demonstrated by the examples of determining the parameters of technologically advanced devices - photoelectric converter (for example, determining its maximum power point, as well as Fill Factor) and supercapacitor (for example, designating changes in charging and discharging characteristics depending on the type of construction). In such educational projects the parameters of the circuit components obtained by the equivalent circuit method are compared with the specifications of commercial devices available on the market. This approach, on the one hand, demonstrates statistical errors of results to the students, and on the other hand, it is a source of sufficient data for constructing an equivalent circuit of devices without prior experimental research. It is shown that the use of equivalent circuits in a computer simulation environment to replace real electronic and electrical devices, measuring systems and equipment with their virtual counterparts expands the didactic possibilities. Techniques based on the versatile use of digital didactic tools are being actively developed and implemented in the MANLab STEM-laboratory of the National Centre “Junior Academy of Sciences of Ukraine”.