RL circuits and RC circuits

Papabravo

Joined Feb 24, 2006
22,081
how do i calculate voltage drop and current across the capacitor and inductor?
It is fairly straightforward if you know about, and can solve, 1st order ordinary differential equations. You solve the equation, and that solution is valid for all time. If you don.t know about differential equations you can still treat the problem as a voltage divider if you know the expressions for the impedance of an inductor or a capacitor at some frequency of interest. If you are unfamiliar with either of those methods then I'm afraid that any other explanation I come up with will fly over your head like a basic drone on steroids.
 

MrAl

Joined Jun 17, 2014
13,702
how do i calculate voltage drop and current across the capacitor and inductor?
Hello there,

I am adding a little more information to the already good replies here.

First, you have to specify what type of analysis you want to do. There are basically three types:
[1] DC, usually involves a constant DC voltage and/or current, or dependent sources.
[2] AC, usually involves a constant AC voltage at a single frequency, and/or dependent sources.
[3] Transient., involves finding the time domain solution.

For an example of DC analysis result we might get 12.4 volts DC.
For an example of AC analysis, we might get 12.4volts AC at 50 Hertz, with a phase shift of 20 degrees.
For an example of a transient analysis, we usually get a function of time such as
Vouy=e^(-2*t)*sin(377*t),
and to get a result st a single point in time we substitute the desired time into that formula.

Many DC and AC circuits can be solved using impedances which are very general, although there are a lot of different tricks you can use sometimes to make the analysis simpler. For one example, Thevenin equivalents.
For transient analysis for many circuits one of the simplest methods is to use Laplace Transforms. This allows you to use algebra for the most part of the analysis, then use transform techniques to come up with the final time solution.
 
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