Development of a Virtual Laboratory in Logic Design

In this study is presented the development of a virtual laboratory for the "Logic design" course, using the Engine for Virtual Electrical Engineering Equipment (EVEEE). The basic logic gates (AND, OR, NAND, NOR, NOT) and combinational logic (decoder and multiplexer) are modeled as analog devices, with inputs and outputs. Each input is represented with a 1 MΩ resistor, and each output is a nonlinear dependent source, both connected to ground. The logic of the dependent source is implemented using SPICE’ conditional logic. To improve the traceability of the logic circuit, each input/output socket has a corresponding virtual light emitting diode, which visualizes its state – digital one or digital zero.