Analysis of Electronic Circuits Equipped with Free Wheel Diodes

Abstract

This paper addresses the important role of the flyback or freewheel diodes in the protection of electronic circuits as well as their impact on the transient response of these circuits. Sample case studies are presented and analyzed in the time domain using the software Mathematica (Version12.1). Without any loss of generality, a delayed step- voltage source starting at the time point 2 seconds and a single diode are assumed. The transient response of the investigated circuits is mathematically formulated by a set of differential and algebraic equations with zero initial conditions. They follow Kirchhoff’s current and voltage laws. The unit-step function ia approximated within the computer code in terms of the inverse tangent function. The presented results of the program illustrate, among other quantities, the node voltages, the voltage across and the current through the free wheel diode as well as the currents flowing through the other circuit branches. For the sake of clarity, they are also illustrated graphically over the time range between zero and 5 seconds. Their sensitivities to changes in the numerical values of the circuit parameters are demonstrated and discussed. The results are validated through the comparison with the corresponding voltage and current plots published elsewhere in the literature.