ECE 345 Lecture Notes - Lecture 17: Rl Circuit, Rc Circuit, Telecommunication Circuit
9 Nov 2017
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Document Summary
First-order transient response: the element constraints of capacitors and inductors, introduce differential components into the circuit equations (kcl and kvl equations) as demonstrated for the switched circuit shown in figure 1 below. The switch acts like an open circuit when it is open, and a short circuit when it is closed. i (t)s. For the circuit in figure 1, kirchhoff"s current law gives: t i. Ohm"s law can be used to find is(t) such that: v. This first order differential equation can be solved as: dv t. 1cr where rth is the thevenin equivalent resistance as seen by the capacitor. Kx ln where k is a constant, ln tv. Doing a change of variables to set t1 = t gives tv. We also notice that after the switch has been closed for a long period of time, as t , the capacitor acts like an open circuit and tv. 1 and the voltage across the capacitor reaches its final value.
