Seeing Is Believing: Demonstrating the RC Time Constant Visually

摘要

RC circuits are ubiquitous. They are the most common entities in modern electronics; introductory physics courses typically include a chapter and a lab on RC circuits. Several papers dealing with many aspects of RC circuits have been published in The Physics Teacher and other educational journals. An RC circuit contains a series combination of a resistor and a capacitor (with resistance and capacitance R and C, respectively). In this circuit the capacitor stores electric charge, and the resistor controls the rate of charging or discharging. The potential difference (Delta V) across a discharging capacitor is given by the following exponential function of time (t)